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[v6,05/42] powerpc/powernv: Track IO/M32/M64 segments from PE

Message ID 1438834307-26960-6-git-send-email-gwshan@linux.vnet.ibm.com
State Not Applicable
Headers show

Commit Message

Gavin Shan Aug. 6, 2015, 4:11 a.m. UTC
The patch is adding 6 bitmaps, three to PE and three to PHB, to track
the consumed by one particular PE, which can be released once the PE
is destroyed during PCI unplugging time. Also, we're using fixed
quantity of bits to trace the used IO, M32 and M64 segments by PEs
in one particular PHB.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
---
 arch/powerpc/platforms/powernv/pci-ioda.c | 29 +++++++++++++++--------------
 arch/powerpc/platforms/powernv/pci.h      | 18 ++++++++++++++----
 2 files changed, 29 insertions(+), 18 deletions(-)

Comments

Alexey Kardashevskiy Aug. 10, 2015, 7:16 a.m. UTC | #1
On 08/06/2015 02:11 PM, Gavin Shan wrote:
> The patch is adding 6 bitmaps, three to PE and three to PHB, to track

The patch is also removing 2 arrays (io_segmap and m32_segmap), what is 
that all about? Also, there was no m64_segmap, now there is, needs an 
explanation may be.


> the consumed by one particular PE, which can be released once the PE
> is destroyed during PCI unplugging time. Also, we're using fixed
> quantity of bits to trace the used IO, M32 and M64 segments by PEs
> in one particular PHB.
>

Out of curiosity - have you considered having just 3 arrays, in PHB, 
storing PE numbers, and ditching PE's arrays? Does PE itself need to know 
what PEs it is using? Not sure about this master/slave PEs though.

It would be easier to read patches if this one was right before
[PATCH v6 23/42] powerpc/powernv: Release PEs dynamically



> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
> ---
>   arch/powerpc/platforms/powernv/pci-ioda.c | 29 +++++++++++++++--------------
>   arch/powerpc/platforms/powernv/pci.h      | 18 ++++++++++++++----
>   2 files changed, 29 insertions(+), 18 deletions(-)
>
> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
> index e4ac703..78b49a1 100644
> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
> @@ -388,6 +388,12 @@ static int pnv_ioda_pick_m64_pe(struct pci_bus *bus, bool all)
>   			list_add_tail(&pe->list, &master_pe->slaves);
>   		}
>
> +		/* M64 segments consumed by slave PEs are tracked
> +		 * by master PE
> +		 */
> +		set_bit(pe->pe_number, master_pe->m64_segmap);
> +		set_bit(pe->pe_number, phb->ioda.m64_segmap);
> +
>   		/* P7IOC supports M64DT, which helps mapping M64 segment
>   		 * to one particular PE#. However, PHB3 has fixed mapping
>   		 * between M64 segment and PE#. In order to have same logic
> @@ -2871,9 +2877,11 @@ static void pnv_ioda_setup_pe_seg(struct pci_controller *hose,
>
>   			while (index < phb->ioda.total_pe &&
>   			       region.start <= region.end) {
> -				phb->ioda.io_segmap[index] = pe->pe_number;
> +				set_bit(index, pe->io_segmap);
> +				set_bit(index, phb->ioda.io_segmap);
>   				rc = opal_pci_map_pe_mmio_window(phb->opal_id,
> -					pe->pe_number, OPAL_IO_WINDOW_TYPE, 0, index);
> +					pe->pe_number, OPAL_IO_WINDOW_TYPE,
> +					0, index);

Unrelated change.


>   				if (rc != OPAL_SUCCESS) {
>   					pr_err("%s: OPAL error %d when mapping IO "
>   					       "segment #%d to PE#%d\n",
> @@ -2896,9 +2904,11 @@ static void pnv_ioda_setup_pe_seg(struct pci_controller *hose,
>
>   			while (index < phb->ioda.total_pe &&
>   			       region.start <= region.end) {
> -				phb->ioda.m32_segmap[index] = pe->pe_number;
> +				set_bit(index, pe->m32_segmap);
> +				set_bit(index, phb->ioda.m32_segmap);
>   				rc = opal_pci_map_pe_mmio_window(phb->opal_id,
> -					pe->pe_number, OPAL_M32_WINDOW_TYPE, 0, index);
> +					pe->pe_number, OPAL_M32_WINDOW_TYPE,
> +					0, index);

Unrelated change.


>   				if (rc != OPAL_SUCCESS) {
>   					pr_err("%s: OPAL error %d when mapping M32 "
>   					       "segment#%d to PE#%d",
> @@ -3090,7 +3100,7 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
>   {
>   	struct pci_controller *hose;
>   	struct pnv_phb *phb;
> -	unsigned long size, m32map_off, pemap_off, iomap_off = 0;
> +	unsigned long size, pemap_off;
>   	const __be64 *prop64;
>   	const __be32 *prop32;
>   	int len;
> @@ -3175,19 +3185,10 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
>
>   	/* Allocate aux data & arrays. We don't have IO ports on PHB3 */


This comment came with if(IODA1) below, since you are removing the 
condition below, makes sense to remove the comment as well or move it where 
people will look for it (arch/powerpc/platforms/powernv/pci.h ?)


>   	size = _ALIGN_UP(phb->ioda.total_pe / 8, sizeof(unsigned long));
> -	m32map_off = size;
> -	size += phb->ioda.total_pe * sizeof(phb->ioda.m32_segmap[0]);
> -	if (phb->type == PNV_PHB_IODA1) {
> -		iomap_off = size;
> -		size += phb->ioda.total_pe * sizeof(phb->ioda.io_segmap[0]);
> -	}
>   	pemap_off = size;
>   	size += phb->ioda.total_pe * sizeof(struct pnv_ioda_pe);
>   	aux = memblock_virt_alloc(size, 0);


After adding static arrays to PE and PHB, do you still need this "aux"?


>   	phb->ioda.pe_alloc = aux;
> -	phb->ioda.m32_segmap = aux + m32map_off;
> -	if (phb->type == PNV_PHB_IODA1)
> -		phb->ioda.io_segmap = aux + iomap_off;
>   	phb->ioda.pe_array = aux + pemap_off;
>   	set_bit(phb->ioda.reserved_pe, phb->ioda.pe_alloc);
>
> diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
> index 62239b1..08a4e57 100644
> --- a/arch/powerpc/platforms/powernv/pci.h
> +++ b/arch/powerpc/platforms/powernv/pci.h
> @@ -49,6 +49,15 @@ struct pnv_ioda_pe {
>   	/* PE number */
>   	unsigned int		pe_number;
>
> +	/* IO/M32/M64 segments consumed by the PE. Each PE can
> +	 * have one M64 segment at most, but M64 segments consumed
> +	 * by slave PEs will be contributed to the master PE. One
> +	 * PE can own multiple IO and M32 segments.


A PE can have multiple IO and M32 segments but just one M64 segment? Is 
this correct for IODA1 or IODA2 or both? Is this a limitation of this 
implementation or it comes from P7IOC/PHB3 hardware?


> +	 */
> +	unsigned long		io_segmap[8];
> +	unsigned long		m32_segmap[8];
> +	unsigned long		m64_segmap[8];

Magic constant "8", 64bit*8 = 512 PEs - where did this come from?

Anyway,

#define PNV_IODA_MAX_PE_NUM	512

unsigned long io_segmap[PNV_IODA_MAX_PE_NUM/BITS_PER_LONG]




> +
>   	/* "Weight" assigned to the PE for the sake of DMA resource
>   	 * allocations
>   	 */
> @@ -145,15 +154,16 @@ struct pnv_phb {
>   			unsigned int		io_segsize;
>   			unsigned int		io_pci_base;
>
> +			/* IO, M32, M64 segment maps */
> +			unsigned long		io_segmap[8];
> +			unsigned long		m32_segmap[8];
> +			unsigned long		m64_segmap[8];
> +
>   			/* PE allocation */
>   			struct mutex		pe_alloc_mutex;
>   			unsigned long		*pe_alloc;
>   			struct pnv_ioda_pe	*pe_array;
>
> -			/* M32 & IO segment maps */
> -			unsigned int		*m32_segmap;
> -			unsigned int		*io_segmap;
> -
>   			/* IRQ chip */
>   			int			irq_chip_init;
>   			struct irq_chip		irq_chip;
>
Gavin Shan Aug. 11, 2015, 12:03 a.m. UTC | #2
On Mon, Aug 10, 2015 at 05:16:40PM +1000, Alexey Kardashevskiy wrote:
>On 08/06/2015 02:11 PM, Gavin Shan wrote:
>>The patch is adding 6 bitmaps, three to PE and three to PHB, to track
>
>The patch is also removing 2 arrays (io_segmap and m32_segmap), what is that
>all about? Also, there was no m64_segmap, now there is, needs an explanation
>may be.
>

Originally, the bitmaps (io_segmap and m32_segmap) are allocated dynamically.
Now, they have fixed sizes - 512 bits.

The subject "powerpc/powernv: Track IO/M32/M64 segments from PE" indicates
why m64_segmap is added.

>
>>the consumed by one particular PE, which can be released once the PE
>>is destroyed during PCI unplugging time. Also, we're using fixed
>>quantity of bits to trace the used IO, M32 and M64 segments by PEs
>>in one particular PHB.
>>
>
>Out of curiosity - have you considered having just 3 arrays, in PHB, storing
>PE numbers, and ditching PE's arrays? Does PE itself need to know what PEs it
>is using? Not sure about this master/slave PEs though.
>

I don't follow your suggestion. Can you rephrase and explain it a bit more?

>It would be easier to read patches if this one was right before
>[PATCH v6 23/42] powerpc/powernv: Release PEs dynamically
>

I'll try to reoder the patch, but not expect too much...

>
>
>>Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
>>---
>>  arch/powerpc/platforms/powernv/pci-ioda.c | 29 +++++++++++++++--------------
>>  arch/powerpc/platforms/powernv/pci.h      | 18 ++++++++++++++----
>>  2 files changed, 29 insertions(+), 18 deletions(-)
>>
>>diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>>index e4ac703..78b49a1 100644
>>--- a/arch/powerpc/platforms/powernv/pci-ioda.c
>>+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>>@@ -388,6 +388,12 @@ static int pnv_ioda_pick_m64_pe(struct pci_bus *bus, bool all)
>>  			list_add_tail(&pe->list, &master_pe->slaves);
>>  		}
>>
>>+		/* M64 segments consumed by slave PEs are tracked
>>+		 * by master PE
>>+		 */
>>+		set_bit(pe->pe_number, master_pe->m64_segmap);
>>+		set_bit(pe->pe_number, phb->ioda.m64_segmap);
>>+
>>  		/* P7IOC supports M64DT, which helps mapping M64 segment
>>  		 * to one particular PE#. However, PHB3 has fixed mapping
>>  		 * between M64 segment and PE#. In order to have same logic
>>@@ -2871,9 +2877,11 @@ static void pnv_ioda_setup_pe_seg(struct pci_controller *hose,
>>
>>  			while (index < phb->ioda.total_pe &&
>>  			       region.start <= region.end) {
>>-				phb->ioda.io_segmap[index] = pe->pe_number;
>>+				set_bit(index, pe->io_segmap);
>>+				set_bit(index, phb->ioda.io_segmap);
>>  				rc = opal_pci_map_pe_mmio_window(phb->opal_id,
>>-					pe->pe_number, OPAL_IO_WINDOW_TYPE, 0, index);
>>+					pe->pe_number, OPAL_IO_WINDOW_TYPE,
>>+					0, index);
>
>Unrelated change.
>

True, will drop. However, checkpatch.pl will complain wtih:
exceeding 80 characters.

>>  				if (rc != OPAL_SUCCESS) {
>>  					pr_err("%s: OPAL error %d when mapping IO "
>>  					       "segment #%d to PE#%d\n",
>>@@ -2896,9 +2904,11 @@ static void pnv_ioda_setup_pe_seg(struct pci_controller *hose,
>>
>>  			while (index < phb->ioda.total_pe &&
>>  			       region.start <= region.end) {
>>-				phb->ioda.m32_segmap[index] = pe->pe_number;
>>+				set_bit(index, pe->m32_segmap);
>>+				set_bit(index, phb->ioda.m32_segmap);
>>  				rc = opal_pci_map_pe_mmio_window(phb->opal_id,
>>-					pe->pe_number, OPAL_M32_WINDOW_TYPE, 0, index);
>>+					pe->pe_number, OPAL_M32_WINDOW_TYPE,
>>+					0, index);
>
>Unrelated change.
>

same as above.

>>  				if (rc != OPAL_SUCCESS) {
>>  					pr_err("%s: OPAL error %d when mapping M32 "
>>  					       "segment#%d to PE#%d",
>>@@ -3090,7 +3100,7 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
>>  {
>>  	struct pci_controller *hose;
>>  	struct pnv_phb *phb;
>>-	unsigned long size, m32map_off, pemap_off, iomap_off = 0;
>>+	unsigned long size, pemap_off;
>>  	const __be64 *prop64;
>>  	const __be32 *prop32;
>>  	int len;
>>@@ -3175,19 +3185,10 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
>>
>>  	/* Allocate aux data & arrays. We don't have IO ports on PHB3 */
>
>
>This comment came with if(IODA1) below, since you are removing the condition
>below, makes sense to remove the comment as well or move it where people will
>look for it (arch/powerpc/platforms/powernv/pci.h ?)
>

Yes, will do.

>
>>  	size = _ALIGN_UP(phb->ioda.total_pe / 8, sizeof(unsigned long));
>>-	m32map_off = size;
>>-	size += phb->ioda.total_pe * sizeof(phb->ioda.m32_segmap[0]);
>>-	if (phb->type == PNV_PHB_IODA1) {
>>-		iomap_off = size;
>>-		size += phb->ioda.total_pe * sizeof(phb->ioda.io_segmap[0]);
>>-	}
>>  	pemap_off = size;
>>  	size += phb->ioda.total_pe * sizeof(struct pnv_ioda_pe);
>>  	aux = memblock_virt_alloc(size, 0);
>
>
>After adding static arrays to PE and PHB, do you still need this "aux"?
>

"aux" is still needed to tell the boundary of pe_alloc_bitmap and pe_array.

>
>>  	phb->ioda.pe_alloc = aux;
>>-	phb->ioda.m32_segmap = aux + m32map_off;
>>-	if (phb->type == PNV_PHB_IODA1)
>>-		phb->ioda.io_segmap = aux + iomap_off;
>>  	phb->ioda.pe_array = aux + pemap_off;
>>  	set_bit(phb->ioda.reserved_pe, phb->ioda.pe_alloc);
>>
>>diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
>>index 62239b1..08a4e57 100644
>>--- a/arch/powerpc/platforms/powernv/pci.h
>>+++ b/arch/powerpc/platforms/powernv/pci.h
>>@@ -49,6 +49,15 @@ struct pnv_ioda_pe {
>>  	/* PE number */
>>  	unsigned int		pe_number;
>>
>>+	/* IO/M32/M64 segments consumed by the PE. Each PE can
>>+	 * have one M64 segment at most, but M64 segments consumed
>>+	 * by slave PEs will be contributed to the master PE. One
>>+	 * PE can own multiple IO and M32 segments.
>
>
>A PE can have multiple IO and M32 segments but just one M64 segment? Is this
>correct for IODA1 or IODA2 or both? Is this a limitation of this
>implementation or it comes from P7IOC/PHB3 hardware?
>

It's correct for IO and M32. However, on IODA1 or IODA2, one PE can have
multiple M64 segments as well.

>>+	 */
>>+	unsigned long		io_segmap[8];
>>+	unsigned long		m32_segmap[8];
>>+	unsigned long		m64_segmap[8];
>
>Magic constant "8", 64bit*8 = 512 PEs - where did this come from?
>
>Anyway,
>
>#define PNV_IODA_MAX_PE_NUM	512
>
>unsigned long io_segmap[PNV_IODA_MAX_PE_NUM/BITS_PER_LONG]
>

I prefer "8", not macro for 3 reasons:
- The macro won't be used in the code.
- The total segment number of specific resource is variable
  on IODA1 and IODA2. I just choosed the max value with margin.
- PNV_IODA_MAX_PE_NUM, indicating max PE number, isn't 512 on
  IODA1 or IODA2.

>>+
>>  	/* "Weight" assigned to the PE for the sake of DMA resource
>>  	 * allocations
>>  	 */
>>@@ -145,15 +154,16 @@ struct pnv_phb {
>>  			unsigned int		io_segsize;
>>  			unsigned int		io_pci_base;
>>
>>+			/* IO, M32, M64 segment maps */
>>+			unsigned long		io_segmap[8];
>>+			unsigned long		m32_segmap[8];
>>+			unsigned long		m64_segmap[8];
>>+
>>  			/* PE allocation */
>>  			struct mutex		pe_alloc_mutex;
>>  			unsigned long		*pe_alloc;
>>  			struct pnv_ioda_pe	*pe_array;
>>
>>-			/* M32 & IO segment maps */
>>-			unsigned int		*m32_segmap;
>>-			unsigned int		*io_segmap;
>>-
>>  			/* IRQ chip */
>>  			int			irq_chip_init;
>>  			struct irq_chip		irq_chip;
>>

Thanks,
Gavin

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Alexey Kardashevskiy Aug. 11, 2015, 2:23 a.m. UTC | #3
On 08/11/2015 10:03 AM, Gavin Shan wrote:
> On Mon, Aug 10, 2015 at 05:16:40PM +1000, Alexey Kardashevskiy wrote:
>> On 08/06/2015 02:11 PM, Gavin Shan wrote:
>>> The patch is adding 6 bitmaps, three to PE and three to PHB, to track
>>
>> The patch is also removing 2 arrays (io_segmap and m32_segmap), what is that
>> all about? Also, there was no m64_segmap, now there is, needs an explanation
>> may be.
>>
>
> Originally, the bitmaps (io_segmap and m32_segmap) are allocated dynamically.
> Now, they have fixed sizes - 512 bits.
>
> The subject "powerpc/powernv: Track IO/M32/M64 segments from PE" indicates
> why m64_segmap is added.


But before this patch, you somehow managed to keep it working without a map 
for M64, by the same time you needed map for IO and M32. It seems you are 
making things consistent in this patch but it also feels like you do not 
have to do so as M64 did not need a map before and I cannot see why it 
needs one now.


>>
>>> the consumed by one particular PE, which can be released once the PE
>>> is destroyed during PCI unplugging time. Also, we're using fixed
>>> quantity of bits to trace the used IO, M32 and M64 segments by PEs
>>> in one particular PHB.
>>>
>>
>> Out of curiosity - have you considered having just 3 arrays, in PHB, storing
>> PE numbers, and ditching PE's arrays? Does PE itself need to know what PEs it
>> is using? Not sure about this master/slave PEs though.
>>
>
> I don't follow your suggestion. Can you rephrase and explain it a bit more?


Please explains in what situations you need same map in both PHB and PE and 
how you are going to use them. For example, pe::m64_segmap and phb::m64_segmap.

I believe you need to know what segment is used by what PE and that's it 
and having 2 bitmaps is overcomplicated hard to follow. Is there anything 
else what I am missing?



>> It would be easier to read patches if this one was right before
>> [PATCH v6 23/42] powerpc/powernv: Release PEs dynamically
>>
>
> I'll try to reoder the patch, but not expect too much...
>
>>
>>
>>> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
>>> ---
>>>   arch/powerpc/platforms/powernv/pci-ioda.c | 29 +++++++++++++++--------------
>>>   arch/powerpc/platforms/powernv/pci.h      | 18 ++++++++++++++----
>>>   2 files changed, 29 insertions(+), 18 deletions(-)
>>>
>>> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>>> index e4ac703..78b49a1 100644
>>> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
>>> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>>> @@ -388,6 +388,12 @@ static int pnv_ioda_pick_m64_pe(struct pci_bus *bus, bool all)
>>>   			list_add_tail(&pe->list, &master_pe->slaves);
>>>   		}
>>>
>>> +		/* M64 segments consumed by slave PEs are tracked
>>> +		 * by master PE
>>> +		 */
>>> +		set_bit(pe->pe_number, master_pe->m64_segmap);
>>> +		set_bit(pe->pe_number, phb->ioda.m64_segmap);
>>> +
>>>   		/* P7IOC supports M64DT, which helps mapping M64 segment
>>>   		 * to one particular PE#. However, PHB3 has fixed mapping
>>>   		 * between M64 segment and PE#. In order to have same logic
>>> @@ -2871,9 +2877,11 @@ static void pnv_ioda_setup_pe_seg(struct pci_controller *hose,
>>>
>>>   			while (index < phb->ioda.total_pe &&
>>>   			       region.start <= region.end) {
>>> -				phb->ioda.io_segmap[index] = pe->pe_number;
>>> +				set_bit(index, pe->io_segmap);
>>> +				set_bit(index, phb->ioda.io_segmap);
>>>   				rc = opal_pci_map_pe_mmio_window(phb->opal_id,
>>> -					pe->pe_number, OPAL_IO_WINDOW_TYPE, 0, index);
>>> +					pe->pe_number, OPAL_IO_WINDOW_TYPE,
>>> +					0, index);
>>
>> Unrelated change.
>>
>
> True, will drop. However, checkpatch.pl will complain wtih:
> exceeding 80 characters.

It will not as you are not changing these lines, it only complains on changes.



>
>>>   				if (rc != OPAL_SUCCESS) {
>>>   					pr_err("%s: OPAL error %d when mapping IO "
>>>   					       "segment #%d to PE#%d\n",
>>> @@ -2896,9 +2904,11 @@ static void pnv_ioda_setup_pe_seg(struct pci_controller *hose,
>>>
>>>   			while (index < phb->ioda.total_pe &&
>>>   			       region.start <= region.end) {
>>> -				phb->ioda.m32_segmap[index] = pe->pe_number;
>>> +				set_bit(index, pe->m32_segmap);
>>> +				set_bit(index, phb->ioda.m32_segmap);
>>>   				rc = opal_pci_map_pe_mmio_window(phb->opal_id,
>>> -					pe->pe_number, OPAL_M32_WINDOW_TYPE, 0, index);
>>> +					pe->pe_number, OPAL_M32_WINDOW_TYPE,
>>> +					0, index);
>>
>> Unrelated change.
>>
>
> same as above.
>
>>>   				if (rc != OPAL_SUCCESS) {
>>>   					pr_err("%s: OPAL error %d when mapping M32 "
>>>   					       "segment#%d to PE#%d",
>>> @@ -3090,7 +3100,7 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
>>>   {
>>>   	struct pci_controller *hose;
>>>   	struct pnv_phb *phb;
>>> -	unsigned long size, m32map_off, pemap_off, iomap_off = 0;
>>> +	unsigned long size, pemap_off;
>>>   	const __be64 *prop64;
>>>   	const __be32 *prop32;
>>>   	int len;
>>> @@ -3175,19 +3185,10 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
>>>
>>>   	/* Allocate aux data & arrays. We don't have IO ports on PHB3 */
>>
>>
>> This comment came with if(IODA1) below, since you are removing the condition
>> below, makes sense to remove the comment as well or move it where people will
>> look for it (arch/powerpc/platforms/powernv/pci.h ?)
>>
>
> Yes, will do.
>
>>
>>>   	size = _ALIGN_UP(phb->ioda.total_pe / 8, sizeof(unsigned long));
>>> -	m32map_off = size;
>>> -	size += phb->ioda.total_pe * sizeof(phb->ioda.m32_segmap[0]);
>>> -	if (phb->type == PNV_PHB_IODA1) {
>>> -		iomap_off = size;
>>> -		size += phb->ioda.total_pe * sizeof(phb->ioda.io_segmap[0]);
>>> -	}
>>>   	pemap_off = size;
>>>   	size += phb->ioda.total_pe * sizeof(struct pnv_ioda_pe);
>>>   	aux = memblock_virt_alloc(size, 0);
>>
>>
>> After adding static arrays to PE and PHB, do you still need this "aux"?
>>
>
> "aux" is still needed to tell the boundary of pe_alloc_bitmap and pe_array.
>>
>>>   	phb->ioda.pe_alloc = aux;
>>> -	phb->ioda.m32_segmap = aux + m32map_off;
>>> -	if (phb->type == PNV_PHB_IODA1)
>>> -		phb->ioda.io_segmap = aux + iomap_off;
>>>   	phb->ioda.pe_array = aux + pemap_off;
>>>   	set_bit(phb->ioda.reserved_pe, phb->ioda.pe_alloc);
>>>
>>> diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
>>> index 62239b1..08a4e57 100644
>>> --- a/arch/powerpc/platforms/powernv/pci.h
>>> +++ b/arch/powerpc/platforms/powernv/pci.h
>>> @@ -49,6 +49,15 @@ struct pnv_ioda_pe {
>>>   	/* PE number */
>>>   	unsigned int		pe_number;
>>>
>>> +	/* IO/M32/M64 segments consumed by the PE. Each PE can
>>> +	 * have one M64 segment at most, but M64 segments consumed
>>> +	 * by slave PEs will be contributed to the master PE. One
>>> +	 * PE can own multiple IO and M32 segments.
>>
>>
>> A PE can have multiple IO and M32 segments but just one M64 segment? Is this
>> correct for IODA1 or IODA2 or both? Is this a limitation of this
>> implementation or it comes from P7IOC/PHB3 hardware?
>>
>
> It's correct for IO and M32. However, on IODA1 or IODA2, one PE can have
> multiple M64 segments as well.


But the comment says "Each PE can have one M64 segment at most". Which 
statement is correct?


>>> +	 */
>>> +	unsigned long		io_segmap[8];
>>> +	unsigned long		m32_segmap[8];
>>> +	unsigned long		m64_segmap[8];
>>
>> Magic constant "8", 64bit*8 = 512 PEs - where did this come from?
>>
>> Anyway,
>>
>> #define PNV_IODA_MAX_PE_NUM	512
>>
>> unsigned long io_segmap[PNV_IODA_MAX_PE_NUM/BITS_PER_LONG]
>>
>
> I prefer "8", not macro for 3 reasons:
> - The macro won't be used in the code.

You will use it 6 times in the header, if you give it a good name, people 
won't have to guess if the meaning of all these "8"s is the same and you 
won't have to comment every use of it in this header file (now you have).

Also, using BITS_PER_LONG tells the reader that this is a bitmask for sure.


> - The total segment number of specific resource is variable
>    on IODA1 and IODA2. I just choosed the max value with margin.
> - PNV_IODA_MAX_PE_NUM, indicating max PE number, isn't 512 on
>    IODA1 or IODA2.

Give it a better name.


>
>>> +
>>>   	/* "Weight" assigned to the PE for the sake of DMA resource
>>>   	 * allocations
>>>   	 */
>>> @@ -145,15 +154,16 @@ struct pnv_phb {
>>>   			unsigned int		io_segsize;
>>>   			unsigned int		io_pci_base;
>>>
>>> +			/* IO, M32, M64 segment maps */
>>> +			unsigned long		io_segmap[8];
>>> +			unsigned long		m32_segmap[8];
>>> +			unsigned long		m64_segmap[8];
>>> +
>>>   			/* PE allocation */
>>>   			struct mutex		pe_alloc_mutex;
>>>   			unsigned long		*pe_alloc;
>>>   			struct pnv_ioda_pe	*pe_array;
>>>
>>> -			/* M32 & IO segment maps */
>>> -			unsigned int		*m32_segmap;
>>> -			unsigned int		*io_segmap;
>>> -
>>>   			/* IRQ chip */
>>>   			int			irq_chip_init;
>>>   			struct irq_chip		irq_chip;
>>>
>
> Thanks,
> Gavin
>
Gavin Shan Aug. 12, 2015, 10:45 a.m. UTC | #4
On Tue, Aug 11, 2015 at 12:23:42PM +1000, Alexey Kardashevskiy wrote:
>On 08/11/2015 10:03 AM, Gavin Shan wrote:
>>On Mon, Aug 10, 2015 at 05:16:40PM +1000, Alexey Kardashevskiy wrote:
>>>On 08/06/2015 02:11 PM, Gavin Shan wrote:
>>>>The patch is adding 6 bitmaps, three to PE and three to PHB, to track
>>>
>>>The patch is also removing 2 arrays (io_segmap and m32_segmap), what is that
>>>all about? Also, there was no m64_segmap, now there is, needs an explanation
>>>may be.
>>>
>>
>>Originally, the bitmaps (io_segmap and m32_segmap) are allocated dynamically.
>>Now, they have fixed sizes - 512 bits.
>>
>>The subject "powerpc/powernv: Track IO/M32/M64 segments from PE" indicates
>>why m64_segmap is added.
>
>
>But before this patch, you somehow managed to keep it working without a map
>for M64, by the same time you needed map for IO and M32. It seems you are
>making things consistent in this patch but it also feels like you do not have
>to do so as M64 did not need a map before and I cannot see why it needs one
>now.
>

The M64 map is used by [PATCH v6 23/42] powerpc/powernv: Release PEs dynamically
where the M64 segments consumed by one particular PE will be released.

>>>
>>>>the consumed by one particular PE, which can be released once the PE
>>>>is destroyed during PCI unplugging time. Also, we're using fixed
>>>>quantity of bits to trace the used IO, M32 and M64 segments by PEs
>>>>in one particular PHB.
>>>>
>>>
>>>Out of curiosity - have you considered having just 3 arrays, in PHB, storing
>>>PE numbers, and ditching PE's arrays? Does PE itself need to know what PEs it
>>>is using? Not sure about this master/slave PEs though.
>>>
>>
>>I don't follow your suggestion. Can you rephrase and explain it a bit more?
>
>
>Please explains in what situations you need same map in both PHB and PE and
>how you are going to use them. For example, pe::m64_segmap and
>phb::m64_segmap.
>
>I believe you need to know what segment is used by what PE and that's it and
>having 2 bitmaps is overcomplicated hard to follow. Is there anything else
>what I am missing?
>

The situation is same to all (IO, M32 and M64) segment maps. Taking m64_segmap
as an example, it will be used when creating or destroying the PE who consumes
M64 segments. phb::m64_segmap is recording the M64 segment usage in PHB's domain.
It's used to check same M64 segment won't be used for towice. pe::m64_segmap tracks
the M64 segments consumed by the PE.

>>>It would be easier to read patches if this one was right before
>>>[PATCH v6 23/42] powerpc/powernv: Release PEs dynamically
>>>
>>
>>I'll try to reoder the patch, but not expect too much...
>>
>>>
>>>
>>>>Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
>>>>---
>>>>  arch/powerpc/platforms/powernv/pci-ioda.c | 29 +++++++++++++++--------------
>>>>  arch/powerpc/platforms/powernv/pci.h      | 18 ++++++++++++++----
>>>>  2 files changed, 29 insertions(+), 18 deletions(-)
>>>>
>>>>diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>>>>index e4ac703..78b49a1 100644
>>>>--- a/arch/powerpc/platforms/powernv/pci-ioda.c
>>>>+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>>>>@@ -388,6 +388,12 @@ static int pnv_ioda_pick_m64_pe(struct pci_bus *bus, bool all)
>>>>  			list_add_tail(&pe->list, &master_pe->slaves);
>>>>  		}
>>>>
>>>>+		/* M64 segments consumed by slave PEs are tracked
>>>>+		 * by master PE
>>>>+		 */
>>>>+		set_bit(pe->pe_number, master_pe->m64_segmap);
>>>>+		set_bit(pe->pe_number, phb->ioda.m64_segmap);
>>>>+
>>>>  		/* P7IOC supports M64DT, which helps mapping M64 segment
>>>>  		 * to one particular PE#. However, PHB3 has fixed mapping
>>>>  		 * between M64 segment and PE#. In order to have same logic
>>>>@@ -2871,9 +2877,11 @@ static void pnv_ioda_setup_pe_seg(struct pci_controller *hose,
>>>>
>>>>  			while (index < phb->ioda.total_pe &&
>>>>  			       region.start <= region.end) {
>>>>-				phb->ioda.io_segmap[index] = pe->pe_number;
>>>>+				set_bit(index, pe->io_segmap);
>>>>+				set_bit(index, phb->ioda.io_segmap);
>>>>  				rc = opal_pci_map_pe_mmio_window(phb->opal_id,
>>>>-					pe->pe_number, OPAL_IO_WINDOW_TYPE, 0, index);
>>>>+					pe->pe_number, OPAL_IO_WINDOW_TYPE,
>>>>+					0, index);
>>>
>>>Unrelated change.
>>>
>>
>>True, will drop. However, checkpatch.pl will complain wtih:
>>exceeding 80 characters.
>
>It will not as you are not changing these lines, it only complains on changes.
>
>
>
>>
>>>>  				if (rc != OPAL_SUCCESS) {
>>>>  					pr_err("%s: OPAL error %d when mapping IO "
>>>>  					       "segment #%d to PE#%d\n",
>>>>@@ -2896,9 +2904,11 @@ static void pnv_ioda_setup_pe_seg(struct pci_controller *hose,
>>>>
>>>>  			while (index < phb->ioda.total_pe &&
>>>>  			       region.start <= region.end) {
>>>>-				phb->ioda.m32_segmap[index] = pe->pe_number;
>>>>+				set_bit(index, pe->m32_segmap);
>>>>+				set_bit(index, phb->ioda.m32_segmap);
>>>>  				rc = opal_pci_map_pe_mmio_window(phb->opal_id,
>>>>-					pe->pe_number, OPAL_M32_WINDOW_TYPE, 0, index);
>>>>+					pe->pe_number, OPAL_M32_WINDOW_TYPE,
>>>>+					0, index);
>>>
>>>Unrelated change.
>>>
>>
>>same as above.
>>
>>>>  				if (rc != OPAL_SUCCESS) {
>>>>  					pr_err("%s: OPAL error %d when mapping M32 "
>>>>  					       "segment#%d to PE#%d",
>>>>@@ -3090,7 +3100,7 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
>>>>  {
>>>>  	struct pci_controller *hose;
>>>>  	struct pnv_phb *phb;
>>>>-	unsigned long size, m32map_off, pemap_off, iomap_off = 0;
>>>>+	unsigned long size, pemap_off;
>>>>  	const __be64 *prop64;
>>>>  	const __be32 *prop32;
>>>>  	int len;
>>>>@@ -3175,19 +3185,10 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
>>>>
>>>>  	/* Allocate aux data & arrays. We don't have IO ports on PHB3 */
>>>
>>>
>>>This comment came with if(IODA1) below, since you are removing the condition
>>>below, makes sense to remove the comment as well or move it where people will
>>>look for it (arch/powerpc/platforms/powernv/pci.h ?)
>>>
>>
>>Yes, will do.
>>
>>>
>>>>  	size = _ALIGN_UP(phb->ioda.total_pe / 8, sizeof(unsigned long));
>>>>-	m32map_off = size;
>>>>-	size += phb->ioda.total_pe * sizeof(phb->ioda.m32_segmap[0]);
>>>>-	if (phb->type == PNV_PHB_IODA1) {
>>>>-		iomap_off = size;
>>>>-		size += phb->ioda.total_pe * sizeof(phb->ioda.io_segmap[0]);
>>>>-	}
>>>>  	pemap_off = size;
>>>>  	size += phb->ioda.total_pe * sizeof(struct pnv_ioda_pe);
>>>>  	aux = memblock_virt_alloc(size, 0);
>>>
>>>
>>>After adding static arrays to PE and PHB, do you still need this "aux"?
>>>
>>
>>"aux" is still needed to tell the boundary of pe_alloc_bitmap and pe_array.
>>>
>>>>  	phb->ioda.pe_alloc = aux;
>>>>-	phb->ioda.m32_segmap = aux + m32map_off;
>>>>-	if (phb->type == PNV_PHB_IODA1)
>>>>-		phb->ioda.io_segmap = aux + iomap_off;
>>>>  	phb->ioda.pe_array = aux + pemap_off;
>>>>  	set_bit(phb->ioda.reserved_pe, phb->ioda.pe_alloc);
>>>>
>>>>diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
>>>>index 62239b1..08a4e57 100644
>>>>--- a/arch/powerpc/platforms/powernv/pci.h
>>>>+++ b/arch/powerpc/platforms/powernv/pci.h
>>>>@@ -49,6 +49,15 @@ struct pnv_ioda_pe {
>>>>  	/* PE number */
>>>>  	unsigned int		pe_number;
>>>>
>>>>+	/* IO/M32/M64 segments consumed by the PE. Each PE can
>>>>+	 * have one M64 segment at most, but M64 segments consumed
>>>>+	 * by slave PEs will be contributed to the master PE. One
>>>>+	 * PE can own multiple IO and M32 segments.
>>>
>>>
>>>A PE can have multiple IO and M32 segments but just one M64 segment? Is this
>>>correct for IODA1 or IODA2 or both? Is this a limitation of this
>>>implementation or it comes from P7IOC/PHB3 hardware?
>>>
>>
>>It's correct for IO and M32. However, on IODA1 or IODA2, one PE can have
>>multiple M64 segments as well.
>
>
>But the comment says "Each PE can have one M64 segment at most". Which
>statement is correct?
>

The comment is correct regarding PHB's 15th M64 BAR: Each PE can have one
M64 segment at post. It's from hardware limitation. However, once one PE
consumes multiple M64 segments. all those M64 segments will be tracked in
"master" PE and it's determined by software implementation.

>>>>+	 */
>>>>+	unsigned long		io_segmap[8];
>>>>+	unsigned long		m32_segmap[8];
>>>>+	unsigned long		m64_segmap[8];
>>>
>>>Magic constant "8", 64bit*8 = 512 PEs - where did this come from?
>>>
>>>Anyway,
>>>
>>>#define PNV_IODA_MAX_PE_NUM	512
>>>
>>>unsigned long io_segmap[PNV_IODA_MAX_PE_NUM/BITS_PER_LONG]
>>>
>>
>>I prefer "8", not macro for 3 reasons:
>>- The macro won't be used in the code.
>
>You will use it 6 times in the header, if you give it a good name, people
>won't have to guess if the meaning of all these "8"s is the same and you
>won't have to comment every use of it in this header file (now you have).
>
>Also, using BITS_PER_LONG tells the reader that this is a bitmask for sure.
>
>
>>- The total segment number of specific resource is variable
>>   on IODA1 and IODA2. I just choosed the max value with margin.
>>- PNV_IODA_MAX_PE_NUM, indicating max PE number, isn't 512 on
>>   IODA1 or IODA2.
>
>Give it a better name.
>

Ok. It it has to be a macro, then it's as below:

#define PNV_IODA_MAX_SEG_NUM	512

>
>>
>>>>+
>>>>  	/* "Weight" assigned to the PE for the sake of DMA resource
>>>>  	 * allocations
>>>>  	 */
>>>>@@ -145,15 +154,16 @@ struct pnv_phb {
>>>>  			unsigned int		io_segsize;
>>>>  			unsigned int		io_pci_base;
>>>>
>>>>+			/* IO, M32, M64 segment maps */
>>>>+			unsigned long		io_segmap[8];
>>>>+			unsigned long		m32_segmap[8];
>>>>+			unsigned long		m64_segmap[8];
>>>>+
>>>>  			/* PE allocation */
>>>>  			struct mutex		pe_alloc_mutex;
>>>>  			unsigned long		*pe_alloc;
>>>>  			struct pnv_ioda_pe	*pe_array;
>>>>
>>>>-			/* M32 & IO segment maps */
>>>>-			unsigned int		*m32_segmap;
>>>>-			unsigned int		*io_segmap;
>>>>-
>>>>  			/* IRQ chip */
>>>>  			int			irq_chip_init;
>>>>  			struct irq_chip		irq_chip;
>>>>

Thanks,
Gavin

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Alexey Kardashevskiy Aug. 12, 2015, 11:05 a.m. UTC | #5
On 08/12/2015 08:45 PM, Gavin Shan wrote:
> On Tue, Aug 11, 2015 at 12:23:42PM +1000, Alexey Kardashevskiy wrote:
>> On 08/11/2015 10:03 AM, Gavin Shan wrote:
>>> On Mon, Aug 10, 2015 at 05:16:40PM +1000, Alexey Kardashevskiy wrote:
>>>> On 08/06/2015 02:11 PM, Gavin Shan wrote:
>>>>> The patch is adding 6 bitmaps, three to PE and three to PHB, to track
>>>>
>>>> The patch is also removing 2 arrays (io_segmap and m32_segmap), what is that
>>>> all about? Also, there was no m64_segmap, now there is, needs an explanation
>>>> may be.
>>>>
>>>
>>> Originally, the bitmaps (io_segmap and m32_segmap) are allocated dynamically.
>>> Now, they have fixed sizes - 512 bits.
>>>
>>> The subject "powerpc/powernv: Track IO/M32/M64 segments from PE" indicates
>>> why m64_segmap is added.
>>
>>
>> But before this patch, you somehow managed to keep it working without a map
>> for M64, by the same time you needed map for IO and M32. It seems you are
>> making things consistent in this patch but it also feels like you do not have
>> to do so as M64 did not need a map before and I cannot see why it needs one
>> now.
>>
>
> The M64 map is used by [PATCH v6 23/42] powerpc/powernv: Release PEs dynamically
> where the M64 segments consumed by one particular PE will be released.


Then add it where it is really started being used. It is really hard to 
review a patch which is actually spread between patches. Do not count that 
reviewers will just trust you.


>>>>
>>>>> the consumed by one particular PE, which can be released once the PE
>>>>> is destroyed during PCI unplugging time. Also, we're using fixed
>>>>> quantity of bits to trace the used IO, M32 and M64 segments by PEs
>>>>> in one particular PHB.
>>>>>
>>>>
>>>> Out of curiosity - have you considered having just 3 arrays, in PHB, storing
>>>> PE numbers, and ditching PE's arrays? Does PE itself need to know what PEs it
>>>> is using? Not sure about this master/slave PEs though.
>>>>
>>>
>>> I don't follow your suggestion. Can you rephrase and explain it a bit more?
>>
>>
>> Please explains in what situations you need same map in both PHB and PE and
>> how you are going to use them. For example, pe::m64_segmap and
>> phb::m64_segmap.
>>
>> I believe you need to know what segment is used by what PE and that's it and
>> having 2 bitmaps is overcomplicated hard to follow. Is there anything else
>> what I am missing?
>>
>
> The situation is same to all (IO, M32 and M64) segment maps. Taking m64_segmap
> as an example, it will be used when creating or destroying the PE who consumes
> M64 segments. phb::m64_segmap is recording the M64 segment usage in PHB's domain.
> It's used to check same M64 segment won't be used for towice. pe::m64_segmap tracks
> the M64 segments consumed by the PE.


You could have a single map in PHB, key would be a segment number and value 
would be PE number. No need to have a map in PE. At all. No need to 
initialize bitmaps, etc.



>>>> It would be easier to read patches if this one was right before
>>>> [PATCH v6 23/42] powerpc/powernv: Release PEs dynamically
>>>>
>>>
>>> I'll try to reoder the patch, but not expect too much...
>>>
>>>>
>>>>
>>>>> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
>>>>> ---
>>>>>   arch/powerpc/platforms/powernv/pci-ioda.c | 29 +++++++++++++++--------------
>>>>>   arch/powerpc/platforms/powernv/pci.h      | 18 ++++++++++++++----
>>>>>   2 files changed, 29 insertions(+), 18 deletions(-)
>>>>>
>>>>> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>>>>> index e4ac703..78b49a1 100644
>>>>> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
>>>>> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>>>>> @@ -388,6 +388,12 @@ static int pnv_ioda_pick_m64_pe(struct pci_bus *bus, bool all)
>>>>>   			list_add_tail(&pe->list, &master_pe->slaves);
>>>>>   		}
>>>>>
>>>>> +		/* M64 segments consumed by slave PEs are tracked
>>>>> +		 * by master PE
>>>>> +		 */
>>>>> +		set_bit(pe->pe_number, master_pe->m64_segmap);
>>>>> +		set_bit(pe->pe_number, phb->ioda.m64_segmap);
>>>>> +
>>>>>   		/* P7IOC supports M64DT, which helps mapping M64 segment
>>>>>   		 * to one particular PE#. However, PHB3 has fixed mapping
>>>>>   		 * between M64 segment and PE#. In order to have same logic
>>>>> @@ -2871,9 +2877,11 @@ static void pnv_ioda_setup_pe_seg(struct pci_controller *hose,
>>>>>
>>>>>   			while (index < phb->ioda.total_pe &&
>>>>>   			       region.start <= region.end) {
>>>>> -				phb->ioda.io_segmap[index] = pe->pe_number;
>>>>> +				set_bit(index, pe->io_segmap);
>>>>> +				set_bit(index, phb->ioda.io_segmap);
>>>>>   				rc = opal_pci_map_pe_mmio_window(phb->opal_id,
>>>>> -					pe->pe_number, OPAL_IO_WINDOW_TYPE, 0, index);
>>>>> +					pe->pe_number, OPAL_IO_WINDOW_TYPE,
>>>>> +					0, index);
>>>>
>>>> Unrelated change.
>>>>
>>>
>>> True, will drop. However, checkpatch.pl will complain wtih:
>>> exceeding 80 characters.
>>
>> It will not as you are not changing these lines, it only complains on changes.
>>
>>
>>
>>>
>>>>>   				if (rc != OPAL_SUCCESS) {
>>>>>   					pr_err("%s: OPAL error %d when mapping IO "
>>>>>   					       "segment #%d to PE#%d\n",
>>>>> @@ -2896,9 +2904,11 @@ static void pnv_ioda_setup_pe_seg(struct pci_controller *hose,
>>>>>
>>>>>   			while (index < phb->ioda.total_pe &&
>>>>>   			       region.start <= region.end) {
>>>>> -				phb->ioda.m32_segmap[index] = pe->pe_number;
>>>>> +				set_bit(index, pe->m32_segmap);
>>>>> +				set_bit(index, phb->ioda.m32_segmap);
>>>>>   				rc = opal_pci_map_pe_mmio_window(phb->opal_id,
>>>>> -					pe->pe_number, OPAL_M32_WINDOW_TYPE, 0, index);
>>>>> +					pe->pe_number, OPAL_M32_WINDOW_TYPE,
>>>>> +					0, index);
>>>>
>>>> Unrelated change.
>>>>
>>>
>>> same as above.
>>>
>>>>>   				if (rc != OPAL_SUCCESS) {
>>>>>   					pr_err("%s: OPAL error %d when mapping M32 "
>>>>>   					       "segment#%d to PE#%d",
>>>>> @@ -3090,7 +3100,7 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
>>>>>   {
>>>>>   	struct pci_controller *hose;
>>>>>   	struct pnv_phb *phb;
>>>>> -	unsigned long size, m32map_off, pemap_off, iomap_off = 0;
>>>>> +	unsigned long size, pemap_off;
>>>>>   	const __be64 *prop64;
>>>>>   	const __be32 *prop32;
>>>>>   	int len;
>>>>> @@ -3175,19 +3185,10 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
>>>>>
>>>>>   	/* Allocate aux data & arrays. We don't have IO ports on PHB3 */
>>>>
>>>>
>>>> This comment came with if(IODA1) below, since you are removing the condition
>>>> below, makes sense to remove the comment as well or move it where people will
>>>> look for it (arch/powerpc/platforms/powernv/pci.h ?)
>>>>
>>>
>>> Yes, will do.
>>>
>>>>
>>>>>   	size = _ALIGN_UP(phb->ioda.total_pe / 8, sizeof(unsigned long));
>>>>> -	m32map_off = size;
>>>>> -	size += phb->ioda.total_pe * sizeof(phb->ioda.m32_segmap[0]);
>>>>> -	if (phb->type == PNV_PHB_IODA1) {
>>>>> -		iomap_off = size;
>>>>> -		size += phb->ioda.total_pe * sizeof(phb->ioda.io_segmap[0]);
>>>>> -	}
>>>>>   	pemap_off = size;
>>>>>   	size += phb->ioda.total_pe * sizeof(struct pnv_ioda_pe);
>>>>>   	aux = memblock_virt_alloc(size, 0);
>>>>
>>>>
>>>> After adding static arrays to PE and PHB, do you still need this "aux"?
>>>>
>>>
>>> "aux" is still needed to tell the boundary of pe_alloc_bitmap and pe_array.
>>>>
>>>>>   	phb->ioda.pe_alloc = aux;
>>>>> -	phb->ioda.m32_segmap = aux + m32map_off;
>>>>> -	if (phb->type == PNV_PHB_IODA1)
>>>>> -		phb->ioda.io_segmap = aux + iomap_off;
>>>>>   	phb->ioda.pe_array = aux + pemap_off;
>>>>>   	set_bit(phb->ioda.reserved_pe, phb->ioda.pe_alloc);
>>>>>
>>>>> diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
>>>>> index 62239b1..08a4e57 100644
>>>>> --- a/arch/powerpc/platforms/powernv/pci.h
>>>>> +++ b/arch/powerpc/platforms/powernv/pci.h
>>>>> @@ -49,6 +49,15 @@ struct pnv_ioda_pe {
>>>>>   	/* PE number */
>>>>>   	unsigned int		pe_number;
>>>>>
>>>>> +	/* IO/M32/M64 segments consumed by the PE. Each PE can
>>>>> +	 * have one M64 segment at most, but M64 segments consumed
>>>>> +	 * by slave PEs will be contributed to the master PE. One
>>>>> +	 * PE can own multiple IO and M32 segments.
>>>>
>>>>
>>>> A PE can have multiple IO and M32 segments but just one M64 segment? Is this
>>>> correct for IODA1 or IODA2 or both? Is this a limitation of this
>>>> implementation or it comes from P7IOC/PHB3 hardware?
>>>>
>>>
>>> It's correct for IO and M32. However, on IODA1 or IODA2, one PE can have
>>> multiple M64 segments as well.
>>
>>
>> But the comment says "Each PE can have one M64 segment at most". Which
>> statement is correct?
>>
>
> The comment is correct regarding PHB's 15th M64 BAR: Each PE can have one
> M64 segment at post. It's from hardware limitation. However, once one PE
> consumes multiple M64 segments. all those M64 segments will be tracked in
> "master" PE and it's determined by software implementation.
>
>>>>> +	 */
>>>>> +	unsigned long		io_segmap[8];
>>>>> +	unsigned long		m32_segmap[8];
>>>>> +	unsigned long		m64_segmap[8];
>>>>
>>>> Magic constant "8", 64bit*8 = 512 PEs - where did this come from?
>>>>
>>>> Anyway,
>>>>
>>>> #define PNV_IODA_MAX_PE_NUM	512
>>>>
>>>> unsigned long io_segmap[PNV_IODA_MAX_PE_NUM/BITS_PER_LONG]
>>>>
>>>
>>> I prefer "8", not macro for 3 reasons:
>>> - The macro won't be used in the code.
>>
>> You will use it 6 times in the header, if you give it a good name, people
>> won't have to guess if the meaning of all these "8"s is the same and you
>> won't have to comment every use of it in this header file (now you have).
>>
>> Also, using BITS_PER_LONG tells the reader that this is a bitmask for sure.
>>
>>
>>> - The total segment number of specific resource is variable
>>>    on IODA1 and IODA2. I just choosed the max value with margin.
>>> - PNV_IODA_MAX_PE_NUM, indicating max PE number, isn't 512 on
>>>    IODA1 or IODA2.
>>
>> Give it a better name.
>>
>
> Ok. It it has to be a macro, then it's as below:
>
> #define PNV_IODA_MAX_SEG_NUM	512


Thanks mate :)


>>
>>>
>>>>> +
>>>>>   	/* "Weight" assigned to the PE for the sake of DMA resource
>>>>>   	 * allocations
>>>>>   	 */
>>>>> @@ -145,15 +154,16 @@ struct pnv_phb {
>>>>>   			unsigned int		io_segsize;
>>>>>   			unsigned int		io_pci_base;
>>>>>
>>>>> +			/* IO, M32, M64 segment maps */
>>>>> +			unsigned long		io_segmap[8];
>>>>> +			unsigned long		m32_segmap[8];
>>>>> +			unsigned long		m64_segmap[8];
>>>>> +
>>>>>   			/* PE allocation */
>>>>>   			struct mutex		pe_alloc_mutex;
>>>>>   			unsigned long		*pe_alloc;
>>>>>   			struct pnv_ioda_pe	*pe_array;
>>>>>
>>>>> -			/* M32 & IO segment maps */
>>>>> -			unsigned int		*m32_segmap;
>>>>> -			unsigned int		*io_segmap;
>>>>> -
>>>>>   			/* IRQ chip */
>>>>>   			int			irq_chip_init;
>>>>>   			struct irq_chip		irq_chip;
>>>>>
>
> Thanks,
> Gavin
>
Gavin Shan Aug. 12, 2015, 11:20 a.m. UTC | #6
On Wed, Aug 12, 2015 at 09:05:09PM +1000, Alexey Kardashevskiy wrote:
>On 08/12/2015 08:45 PM, Gavin Shan wrote:
>>On Tue, Aug 11, 2015 at 12:23:42PM +1000, Alexey Kardashevskiy wrote:
>>>On 08/11/2015 10:03 AM, Gavin Shan wrote:
>>>>On Mon, Aug 10, 2015 at 05:16:40PM +1000, Alexey Kardashevskiy wrote:
>>>>>On 08/06/2015 02:11 PM, Gavin Shan wrote:
>>>>>>The patch is adding 6 bitmaps, three to PE and three to PHB, to track
>>>>>
>>>>>The patch is also removing 2 arrays (io_segmap and m32_segmap), what is that
>>>>>all about? Also, there was no m64_segmap, now there is, needs an explanation
>>>>>may be.
>>>>>
>>>>
>>>>Originally, the bitmaps (io_segmap and m32_segmap) are allocated dynamically.
>>>>Now, they have fixed sizes - 512 bits.
>>>>
>>>>The subject "powerpc/powernv: Track IO/M32/M64 segments from PE" indicates
>>>>why m64_segmap is added.
>>>
>>>
>>>But before this patch, you somehow managed to keep it working without a map
>>>for M64, by the same time you needed map for IO and M32. It seems you are
>>>making things consistent in this patch but it also feels like you do not have
>>>to do so as M64 did not need a map before and I cannot see why it needs one
>>>now.
>>>
>>
>>The M64 map is used by [PATCH v6 23/42] powerpc/powernv: Release PEs dynamically
>>where the M64 segments consumed by one particular PE will be released.
>
>
>Then add it where it is really started being used. It is really hard to
>review a patch which is actually spread between patches. Do not count that
>reviewers will just trust you.
>

Ok. I'll try. 

>
>>>>>
>>>>>>the consumed by one particular PE, which can be released once the PE
>>>>>>is destroyed during PCI unplugging time. Also, we're using fixed
>>>>>>quantity of bits to trace the used IO, M32 and M64 segments by PEs
>>>>>>in one particular PHB.
>>>>>>
>>>>>
>>>>>Out of curiosity - have you considered having just 3 arrays, in PHB, storing
>>>>>PE numbers, and ditching PE's arrays? Does PE itself need to know what PEs it
>>>>>is using? Not sure about this master/slave PEs though.
>>>>>
>>>>
>>>>I don't follow your suggestion. Can you rephrase and explain it a bit more?
>>>
>>>
>>>Please explains in what situations you need same map in both PHB and PE and
>>>how you are going to use them. For example, pe::m64_segmap and
>>>phb::m64_segmap.
>>>
>>>I believe you need to know what segment is used by what PE and that's it and
>>>having 2 bitmaps is overcomplicated hard to follow. Is there anything else
>>>what I am missing?
>>>
>>
>>The situation is same to all (IO, M32 and M64) segment maps. Taking m64_segmap
>>as an example, it will be used when creating or destroying the PE who consumes
>>M64 segments. phb::m64_segmap is recording the M64 segment usage in PHB's domain.
>>It's used to check same M64 segment won't be used for towice. pe::m64_segmap tracks
>>the M64 segments consumed by the PE.
>
>
>You could have a single map in PHB, key would be a segment number and value
>would be PE number. No need to have a map in PE. At all. No need to
>initialize bitmaps, etc.
>

So it would be arrays for various segmant maps if I understood your suggestion
as below. Please confirm:

#define PNV_IODA_MAX_SEG_NUM	512

	int struct pnv_phb::io_segmap[PNV_IODA_MAX_SEG_NUM];
			    m32_segmap[PNV_IODA_MAX_SEG_NUM];
			    m64_segmap[PNV_IODA_MAX_SEG_NUM];
- Initially, they are initialize to IODA_INVALID_PE;
- When one segment is assigned to one PE, the corresponding entry
  of the array is set to PE number.
- When one segment is relased, the corresponding entry of the array
  is set to IODA_INVALID_PE;
 

>>>>>It would be easier to read patches if this one was right before
>>>>>[PATCH v6 23/42] powerpc/powernv: Release PEs dynamically
>>>>>
>>>>
>>>>I'll try to reoder the patch, but not expect too much...
>>>>
>>>>>
>>>>>
>>>>>>Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
>>>>>>---
>>>>>>  arch/powerpc/platforms/powernv/pci-ioda.c | 29 +++++++++++++++--------------
>>>>>>  arch/powerpc/platforms/powernv/pci.h      | 18 ++++++++++++++----
>>>>>>  2 files changed, 29 insertions(+), 18 deletions(-)
>>>>>>
>>>>>>diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>>>>>>index e4ac703..78b49a1 100644
>>>>>>--- a/arch/powerpc/platforms/powernv/pci-ioda.c
>>>>>>+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>>>>>>@@ -388,6 +388,12 @@ static int pnv_ioda_pick_m64_pe(struct pci_bus *bus, bool all)
>>>>>>  			list_add_tail(&pe->list, &master_pe->slaves);
>>>>>>  		}
>>>>>>
>>>>>>+		/* M64 segments consumed by slave PEs are tracked
>>>>>>+		 * by master PE
>>>>>>+		 */
>>>>>>+		set_bit(pe->pe_number, master_pe->m64_segmap);
>>>>>>+		set_bit(pe->pe_number, phb->ioda.m64_segmap);
>>>>>>+
>>>>>>  		/* P7IOC supports M64DT, which helps mapping M64 segment
>>>>>>  		 * to one particular PE#. However, PHB3 has fixed mapping
>>>>>>  		 * between M64 segment and PE#. In order to have same logic
>>>>>>@@ -2871,9 +2877,11 @@ static void pnv_ioda_setup_pe_seg(struct pci_controller *hose,
>>>>>>
>>>>>>  			while (index < phb->ioda.total_pe &&
>>>>>>  			       region.start <= region.end) {
>>>>>>-				phb->ioda.io_segmap[index] = pe->pe_number;
>>>>>>+				set_bit(index, pe->io_segmap);
>>>>>>+				set_bit(index, phb->ioda.io_segmap);
>>>>>>  				rc = opal_pci_map_pe_mmio_window(phb->opal_id,
>>>>>>-					pe->pe_number, OPAL_IO_WINDOW_TYPE, 0, index);
>>>>>>+					pe->pe_number, OPAL_IO_WINDOW_TYPE,
>>>>>>+					0, index);
>>>>>
>>>>>Unrelated change.
>>>>>
>>>>
>>>>True, will drop. However, checkpatch.pl will complain wtih:
>>>>exceeding 80 characters.
>>>
>>>It will not as you are not changing these lines, it only complains on changes.
>>>
>>>
>>>
>>>>
>>>>>>  				if (rc != OPAL_SUCCESS) {
>>>>>>  					pr_err("%s: OPAL error %d when mapping IO "
>>>>>>  					       "segment #%d to PE#%d\n",
>>>>>>@@ -2896,9 +2904,11 @@ static void pnv_ioda_setup_pe_seg(struct pci_controller *hose,
>>>>>>
>>>>>>  			while (index < phb->ioda.total_pe &&
>>>>>>  			       region.start <= region.end) {
>>>>>>-				phb->ioda.m32_segmap[index] = pe->pe_number;
>>>>>>+				set_bit(index, pe->m32_segmap);
>>>>>>+				set_bit(index, phb->ioda.m32_segmap);
>>>>>>  				rc = opal_pci_map_pe_mmio_window(phb->opal_id,
>>>>>>-					pe->pe_number, OPAL_M32_WINDOW_TYPE, 0, index);
>>>>>>+					pe->pe_number, OPAL_M32_WINDOW_TYPE,
>>>>>>+					0, index);
>>>>>
>>>>>Unrelated change.
>>>>>
>>>>
>>>>same as above.
>>>>
>>>>>>  				if (rc != OPAL_SUCCESS) {
>>>>>>  					pr_err("%s: OPAL error %d when mapping M32 "
>>>>>>  					       "segment#%d to PE#%d",
>>>>>>@@ -3090,7 +3100,7 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
>>>>>>  {
>>>>>>  	struct pci_controller *hose;
>>>>>>  	struct pnv_phb *phb;
>>>>>>-	unsigned long size, m32map_off, pemap_off, iomap_off = 0;
>>>>>>+	unsigned long size, pemap_off;
>>>>>>  	const __be64 *prop64;
>>>>>>  	const __be32 *prop32;
>>>>>>  	int len;
>>>>>>@@ -3175,19 +3185,10 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
>>>>>>
>>>>>>  	/* Allocate aux data & arrays. We don't have IO ports on PHB3 */
>>>>>
>>>>>
>>>>>This comment came with if(IODA1) below, since you are removing the condition
>>>>>below, makes sense to remove the comment as well or move it where people will
>>>>>look for it (arch/powerpc/platforms/powernv/pci.h ?)
>>>>>
>>>>
>>>>Yes, will do.
>>>>
>>>>>
>>>>>>  	size = _ALIGN_UP(phb->ioda.total_pe / 8, sizeof(unsigned long));
>>>>>>-	m32map_off = size;
>>>>>>-	size += phb->ioda.total_pe * sizeof(phb->ioda.m32_segmap[0]);
>>>>>>-	if (phb->type == PNV_PHB_IODA1) {
>>>>>>-		iomap_off = size;
>>>>>>-		size += phb->ioda.total_pe * sizeof(phb->ioda.io_segmap[0]);
>>>>>>-	}
>>>>>>  	pemap_off = size;
>>>>>>  	size += phb->ioda.total_pe * sizeof(struct pnv_ioda_pe);
>>>>>>  	aux = memblock_virt_alloc(size, 0);
>>>>>
>>>>>
>>>>>After adding static arrays to PE and PHB, do you still need this "aux"?
>>>>>
>>>>
>>>>"aux" is still needed to tell the boundary of pe_alloc_bitmap and pe_array.
>>>>>
>>>>>>  	phb->ioda.pe_alloc = aux;
>>>>>>-	phb->ioda.m32_segmap = aux + m32map_off;
>>>>>>-	if (phb->type == PNV_PHB_IODA1)
>>>>>>-		phb->ioda.io_segmap = aux + iomap_off;
>>>>>>  	phb->ioda.pe_array = aux + pemap_off;
>>>>>>  	set_bit(phb->ioda.reserved_pe, phb->ioda.pe_alloc);
>>>>>>
>>>>>>diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
>>>>>>index 62239b1..08a4e57 100644
>>>>>>--- a/arch/powerpc/platforms/powernv/pci.h
>>>>>>+++ b/arch/powerpc/platforms/powernv/pci.h
>>>>>>@@ -49,6 +49,15 @@ struct pnv_ioda_pe {
>>>>>>  	/* PE number */
>>>>>>  	unsigned int		pe_number;
>>>>>>
>>>>>>+	/* IO/M32/M64 segments consumed by the PE. Each PE can
>>>>>>+	 * have one M64 segment at most, but M64 segments consumed
>>>>>>+	 * by slave PEs will be contributed to the master PE. One
>>>>>>+	 * PE can own multiple IO and M32 segments.
>>>>>
>>>>>
>>>>>A PE can have multiple IO and M32 segments but just one M64 segment? Is this
>>>>>correct for IODA1 or IODA2 or both? Is this a limitation of this
>>>>>implementation or it comes from P7IOC/PHB3 hardware?
>>>>>
>>>>
>>>>It's correct for IO and M32. However, on IODA1 or IODA2, one PE can have
>>>>multiple M64 segments as well.
>>>
>>>
>>>But the comment says "Each PE can have one M64 segment at most". Which
>>>statement is correct?
>>>
>>
>>The comment is correct regarding PHB's 15th M64 BAR: Each PE can have one
>>M64 segment at post. It's from hardware limitation. However, once one PE
>>consumes multiple M64 segments. all those M64 segments will be tracked in
>>"master" PE and it's determined by software implementation.
>>
>>>>>>+	 */
>>>>>>+	unsigned long		io_segmap[8];
>>>>>>+	unsigned long		m32_segmap[8];
>>>>>>+	unsigned long		m64_segmap[8];
>>>>>
>>>>>Magic constant "8", 64bit*8 = 512 PEs - where did this come from?
>>>>>
>>>>>Anyway,
>>>>>
>>>>>#define PNV_IODA_MAX_PE_NUM	512
>>>>>
>>>>>unsigned long io_segmap[PNV_IODA_MAX_PE_NUM/BITS_PER_LONG]
>>>>>
>>>>
>>>>I prefer "8", not macro for 3 reasons:
>>>>- The macro won't be used in the code.
>>>
>>>You will use it 6 times in the header, if you give it a good name, people
>>>won't have to guess if the meaning of all these "8"s is the same and you
>>>won't have to comment every use of it in this header file (now you have).
>>>
>>>Also, using BITS_PER_LONG tells the reader that this is a bitmask for sure.
>>>
>>>
>>>>- The total segment number of specific resource is variable
>>>>   on IODA1 and IODA2. I just choosed the max value with margin.
>>>>- PNV_IODA_MAX_PE_NUM, indicating max PE number, isn't 512 on
>>>>   IODA1 or IODA2.
>>>
>>>Give it a better name.
>>>
>>
>>Ok. It it has to be a macro, then it's as below:
>>
>>#define PNV_IODA_MAX_SEG_NUM	512
>
>
>Thanks mate :)
>
>
>>>
>>>>
>>>>>>+
>>>>>>  	/* "Weight" assigned to the PE for the sake of DMA resource
>>>>>>  	 * allocations
>>>>>>  	 */
>>>>>>@@ -145,15 +154,16 @@ struct pnv_phb {
>>>>>>  			unsigned int		io_segsize;
>>>>>>  			unsigned int		io_pci_base;
>>>>>>
>>>>>>+			/* IO, M32, M64 segment maps */
>>>>>>+			unsigned long		io_segmap[8];
>>>>>>+			unsigned long		m32_segmap[8];
>>>>>>+			unsigned long		m64_segmap[8];
>>>>>>+
>>>>>>  			/* PE allocation */
>>>>>>  			struct mutex		pe_alloc_mutex;
>>>>>>  			unsigned long		*pe_alloc;
>>>>>>  			struct pnv_ioda_pe	*pe_array;
>>>>>>
>>>>>>-			/* M32 & IO segment maps */
>>>>>>-			unsigned int		*m32_segmap;
>>>>>>-			unsigned int		*io_segmap;
>>>>>>-
>>>>>>  			/* IRQ chip */
>>>>>>  			int			irq_chip_init;
>>>>>>  			struct irq_chip		irq_chip;
>>>>>>

Thanks,
Gavin

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Alexey Kardashevskiy Aug. 12, 2015, 12:57 p.m. UTC | #7
On 08/12/2015 09:20 PM, Gavin Shan wrote:
> On Wed, Aug 12, 2015 at 09:05:09PM +1000, Alexey Kardashevskiy wrote:
>> On 08/12/2015 08:45 PM, Gavin Shan wrote:
>>> On Tue, Aug 11, 2015 at 12:23:42PM +1000, Alexey Kardashevskiy wrote:
>>>> On 08/11/2015 10:03 AM, Gavin Shan wrote:
>>>>> On Mon, Aug 10, 2015 at 05:16:40PM +1000, Alexey Kardashevskiy wrote:
>>>>>> On 08/06/2015 02:11 PM, Gavin Shan wrote:
>>>>>>> The patch is adding 6 bitmaps, three to PE and three to PHB, to track
>>>>>>
>>>>>> The patch is also removing 2 arrays (io_segmap and m32_segmap), what is that
>>>>>> all about? Also, there was no m64_segmap, now there is, needs an explanation
>>>>>> may be.
>>>>>>
>>>>>
>>>>> Originally, the bitmaps (io_segmap and m32_segmap) are allocated dynamically.
>>>>> Now, they have fixed sizes - 512 bits.
>>>>>
>>>>> The subject "powerpc/powernv: Track IO/M32/M64 segments from PE" indicates
>>>>> why m64_segmap is added.
>>>>
>>>>
>>>> But before this patch, you somehow managed to keep it working without a map
>>>> for M64, by the same time you needed map for IO and M32. It seems you are
>>>> making things consistent in this patch but it also feels like you do not have
>>>> to do so as M64 did not need a map before and I cannot see why it needs one
>>>> now.
>>>>
>>>
>>> The M64 map is used by [PATCH v6 23/42] powerpc/powernv: Release PEs dynamically
>>> where the M64 segments consumed by one particular PE will be released.
>>
>>
>> Then add it where it is really started being used. It is really hard to
>> review a patch which is actually spread between patches. Do not count that
>> reviewers will just trust you.
>>
>
> Ok. I'll try.
>
>>
>>>>>>
>>>>>>> the consumed by one particular PE, which can be released once the PE
>>>>>>> is destroyed during PCI unplugging time. Also, we're using fixed
>>>>>>> quantity of bits to trace the used IO, M32 and M64 segments by PEs
>>>>>>> in one particular PHB.
>>>>>>>
>>>>>>
>>>>>> Out of curiosity - have you considered having just 3 arrays, in PHB, storing
>>>>>> PE numbers, and ditching PE's arrays? Does PE itself need to know what PEs it
>>>>>> is using? Not sure about this master/slave PEs though.
>>>>>>
>>>>>
>>>>> I don't follow your suggestion. Can you rephrase and explain it a bit more?
>>>>
>>>>
>>>> Please explains in what situations you need same map in both PHB and PE and
>>>> how you are going to use them. For example, pe::m64_segmap and
>>>> phb::m64_segmap.
>>>>
>>>> I believe you need to know what segment is used by what PE and that's it and
>>>> having 2 bitmaps is overcomplicated hard to follow. Is there anything else
>>>> what I am missing?
>>>>
>>>
>>> The situation is same to all (IO, M32 and M64) segment maps. Taking m64_segmap
>>> as an example, it will be used when creating or destroying the PE who consumes
>>> M64 segments. phb::m64_segmap is recording the M64 segment usage in PHB's domain.
>>> It's used to check same M64 segment won't be used for towice. pe::m64_segmap tracks
>>> the M64 segments consumed by the PE.
>>
>>
>> You could have a single map in PHB, key would be a segment number and value
>> would be PE number. No need to have a map in PE. At all. No need to
>> initialize bitmaps, etc.
>>
>
> So it would be arrays for various segmant maps if I understood your suggestion
> as below. Please confirm:
>
> #define PNV_IODA_MAX_SEG_NUM	512
>
> 	int struct pnv_phb::io_segmap[PNV_IODA_MAX_SEG_NUM];
> 			    m32_segmap[PNV_IODA_MAX_SEG_NUM];
> 			    m64_segmap[PNV_IODA_MAX_SEG_NUM];
> - Initially, they are initialize to IODA_INVALID_PE;
> - When one segment is assigned to one PE, the corresponding entry
>    of the array is set to PE number.
> - When one segment is relased, the corresponding entry of the array
>    is set to IODA_INVALID_PE;


No, not arrays, I meant DEFINE_HASHTABLE(), hash_add(), etc from 
include/linux/hashtable.h.

http://kernelnewbies.org/FAQ/Hashtables is a good place to start :)
Gavin Shan Aug. 12, 2015, 11:34 p.m. UTC | #8
On Wed, Aug 12, 2015 at 10:57:33PM +1000, Alexey Kardashevskiy wrote:
>On 08/12/2015 09:20 PM, Gavin Shan wrote:
>>On Wed, Aug 12, 2015 at 09:05:09PM +1000, Alexey Kardashevskiy wrote:
>>>On 08/12/2015 08:45 PM, Gavin Shan wrote:
>>>>On Tue, Aug 11, 2015 at 12:23:42PM +1000, Alexey Kardashevskiy wrote:
>>>>>On 08/11/2015 10:03 AM, Gavin Shan wrote:
>>>>>>On Mon, Aug 10, 2015 at 05:16:40PM +1000, Alexey Kardashevskiy wrote:
>>>>>>>On 08/06/2015 02:11 PM, Gavin Shan wrote:
>>>>>>>>The patch is adding 6 bitmaps, three to PE and three to PHB, to track
>>>>>>>
>>>>>>>The patch is also removing 2 arrays (io_segmap and m32_segmap), what is that
>>>>>>>all about? Also, there was no m64_segmap, now there is, needs an explanation
>>>>>>>may be.
>>>>>>>
>>>>>>
>>>>>>Originally, the bitmaps (io_segmap and m32_segmap) are allocated dynamically.
>>>>>>Now, they have fixed sizes - 512 bits.
>>>>>>
>>>>>>The subject "powerpc/powernv: Track IO/M32/M64 segments from PE" indicates
>>>>>>why m64_segmap is added.
>>>>>
>>>>>
>>>>>But before this patch, you somehow managed to keep it working without a map
>>>>>for M64, by the same time you needed map for IO and M32. It seems you are
>>>>>making things consistent in this patch but it also feels like you do not have
>>>>>to do so as M64 did not need a map before and I cannot see why it needs one
>>>>>now.
>>>>>
>>>>
>>>>The M64 map is used by [PATCH v6 23/42] powerpc/powernv: Release PEs dynamically
>>>>where the M64 segments consumed by one particular PE will be released.
>>>
>>>
>>>Then add it where it is really started being used. It is really hard to
>>>review a patch which is actually spread between patches. Do not count that
>>>reviewers will just trust you.
>>>
>>
>>Ok. I'll try.
>>
>>>
>>>>>>>
>>>>>>>>the consumed by one particular PE, which can be released once the PE
>>>>>>>>is destroyed during PCI unplugging time. Also, we're using fixed
>>>>>>>>quantity of bits to trace the used IO, M32 and M64 segments by PEs
>>>>>>>>in one particular PHB.
>>>>>>>>
>>>>>>>
>>>>>>>Out of curiosity - have you considered having just 3 arrays, in PHB, storing
>>>>>>>PE numbers, and ditching PE's arrays? Does PE itself need to know what PEs it
>>>>>>>is using? Not sure about this master/slave PEs though.
>>>>>>>
>>>>>>
>>>>>>I don't follow your suggestion. Can you rephrase and explain it a bit more?
>>>>>
>>>>>
>>>>>Please explains in what situations you need same map in both PHB and PE and
>>>>>how you are going to use them. For example, pe::m64_segmap and
>>>>>phb::m64_segmap.
>>>>>
>>>>>I believe you need to know what segment is used by what PE and that's it and
>>>>>having 2 bitmaps is overcomplicated hard to follow. Is there anything else
>>>>>what I am missing?
>>>>>
>>>>
>>>>The situation is same to all (IO, M32 and M64) segment maps. Taking m64_segmap
>>>>as an example, it will be used when creating or destroying the PE who consumes
>>>>M64 segments. phb::m64_segmap is recording the M64 segment usage in PHB's domain.
>>>>It's used to check same M64 segment won't be used for towice. pe::m64_segmap tracks
>>>>the M64 segments consumed by the PE.
>>>
>>>
>>>You could have a single map in PHB, key would be a segment number and value
>>>would be PE number. No need to have a map in PE. At all. No need to
>>>initialize bitmaps, etc.
>>>
>>
>>So it would be arrays for various segmant maps if I understood your suggestion
>>as below. Please confirm:
>>
>>#define PNV_IODA_MAX_SEG_NUM	512
>>
>>	int struct pnv_phb::io_segmap[PNV_IODA_MAX_SEG_NUM];
>>			    m32_segmap[PNV_IODA_MAX_SEG_NUM];
>>			    m64_segmap[PNV_IODA_MAX_SEG_NUM];
>>- Initially, they are initialize to IODA_INVALID_PE;
>>- When one segment is assigned to one PE, the corresponding entry
>>   of the array is set to PE number.
>>- When one segment is relased, the corresponding entry of the array
>>   is set to IODA_INVALID_PE;
>
>
>No, not arrays, I meant DEFINE_HASHTABLE(), hash_add(), etc from
>include/linux/hashtable.h.
>
>http://kernelnewbies.org/FAQ/Hashtables is a good place to start :)
>

Are you sure it needs hashtable to represent the simple data struct?
I really don't understand the benefits, could you provide more details
about the benefits?

With hashtable, every bucket will include multiple items with conflicting
hash key, each of which would be represented by data struct as below. The
data struct uses 24 bytes memory and not efficient enough from this aspect.
When one more segment consued, instance of "struct pnv_ioda_segment" is
allocated and put into the conflicting list of the target bucket. At later
point, the instance is removed from the list and released when the segment
is detached from the PE. It's more complex than it should be.

struct pnv_ioda_segment {
	int               pe_number;
	int               seg_number;
	struct hlist_node node;
};

Thanks,
Gavin

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diff mbox

Patch

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index e4ac703..78b49a1 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -388,6 +388,12 @@  static int pnv_ioda_pick_m64_pe(struct pci_bus *bus, bool all)
 			list_add_tail(&pe->list, &master_pe->slaves);
 		}
 
+		/* M64 segments consumed by slave PEs are tracked
+		 * by master PE
+		 */
+		set_bit(pe->pe_number, master_pe->m64_segmap);
+		set_bit(pe->pe_number, phb->ioda.m64_segmap);
+
 		/* P7IOC supports M64DT, which helps mapping M64 segment
 		 * to one particular PE#. However, PHB3 has fixed mapping
 		 * between M64 segment and PE#. In order to have same logic
@@ -2871,9 +2877,11 @@  static void pnv_ioda_setup_pe_seg(struct pci_controller *hose,
 
 			while (index < phb->ioda.total_pe &&
 			       region.start <= region.end) {
-				phb->ioda.io_segmap[index] = pe->pe_number;
+				set_bit(index, pe->io_segmap);
+				set_bit(index, phb->ioda.io_segmap);
 				rc = opal_pci_map_pe_mmio_window(phb->opal_id,
-					pe->pe_number, OPAL_IO_WINDOW_TYPE, 0, index);
+					pe->pe_number, OPAL_IO_WINDOW_TYPE,
+					0, index);
 				if (rc != OPAL_SUCCESS) {
 					pr_err("%s: OPAL error %d when mapping IO "
 					       "segment #%d to PE#%d\n",
@@ -2896,9 +2904,11 @@  static void pnv_ioda_setup_pe_seg(struct pci_controller *hose,
 
 			while (index < phb->ioda.total_pe &&
 			       region.start <= region.end) {
-				phb->ioda.m32_segmap[index] = pe->pe_number;
+				set_bit(index, pe->m32_segmap);
+				set_bit(index, phb->ioda.m32_segmap);
 				rc = opal_pci_map_pe_mmio_window(phb->opal_id,
-					pe->pe_number, OPAL_M32_WINDOW_TYPE, 0, index);
+					pe->pe_number, OPAL_M32_WINDOW_TYPE,
+					0, index);
 				if (rc != OPAL_SUCCESS) {
 					pr_err("%s: OPAL error %d when mapping M32 "
 					       "segment#%d to PE#%d",
@@ -3090,7 +3100,7 @@  static void __init pnv_pci_init_ioda_phb(struct device_node *np,
 {
 	struct pci_controller *hose;
 	struct pnv_phb *phb;
-	unsigned long size, m32map_off, pemap_off, iomap_off = 0;
+	unsigned long size, pemap_off;
 	const __be64 *prop64;
 	const __be32 *prop32;
 	int len;
@@ -3175,19 +3185,10 @@  static void __init pnv_pci_init_ioda_phb(struct device_node *np,
 
 	/* Allocate aux data & arrays. We don't have IO ports on PHB3 */
 	size = _ALIGN_UP(phb->ioda.total_pe / 8, sizeof(unsigned long));
-	m32map_off = size;
-	size += phb->ioda.total_pe * sizeof(phb->ioda.m32_segmap[0]);
-	if (phb->type == PNV_PHB_IODA1) {
-		iomap_off = size;
-		size += phb->ioda.total_pe * sizeof(phb->ioda.io_segmap[0]);
-	}
 	pemap_off = size;
 	size += phb->ioda.total_pe * sizeof(struct pnv_ioda_pe);
 	aux = memblock_virt_alloc(size, 0);
 	phb->ioda.pe_alloc = aux;
-	phb->ioda.m32_segmap = aux + m32map_off;
-	if (phb->type == PNV_PHB_IODA1)
-		phb->ioda.io_segmap = aux + iomap_off;
 	phb->ioda.pe_array = aux + pemap_off;
 	set_bit(phb->ioda.reserved_pe, phb->ioda.pe_alloc);
 
diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
index 62239b1..08a4e57 100644
--- a/arch/powerpc/platforms/powernv/pci.h
+++ b/arch/powerpc/platforms/powernv/pci.h
@@ -49,6 +49,15 @@  struct pnv_ioda_pe {
 	/* PE number */
 	unsigned int		pe_number;
 
+	/* IO/M32/M64 segments consumed by the PE. Each PE can
+	 * have one M64 segment at most, but M64 segments consumed
+	 * by slave PEs will be contributed to the master PE. One
+	 * PE can own multiple IO and M32 segments.
+	 */
+	unsigned long		io_segmap[8];
+	unsigned long		m32_segmap[8];
+	unsigned long		m64_segmap[8];
+
 	/* "Weight" assigned to the PE for the sake of DMA resource
 	 * allocations
 	 */
@@ -145,15 +154,16 @@  struct pnv_phb {
 			unsigned int		io_segsize;
 			unsigned int		io_pci_base;
 
+			/* IO, M32, M64 segment maps */
+			unsigned long		io_segmap[8];
+			unsigned long		m32_segmap[8];
+			unsigned long		m64_segmap[8];
+
 			/* PE allocation */
 			struct mutex		pe_alloc_mutex;
 			unsigned long		*pe_alloc;
 			struct pnv_ioda_pe	*pe_array;
 
-			/* M32 & IO segment maps */
-			unsigned int		*m32_segmap;
-			unsigned int		*io_segmap;
-
 			/* IRQ chip */
 			int			irq_chip_init;
 			struct irq_chip		irq_chip;