diff mbox

Support huge alignment in pbus_size_mem()

Message ID CAE9FiQXmWG2RNP-t=U06JUsqkmDm2My5762za8QuwUMZsG+yNg@mail.gmail.com
State Changes Requested
Headers show

Commit Message

Yinghai Lu Feb. 17, 2014, 7:28 p.m. UTC
On Sun, Feb 16, 2014 at 8:50 PM, Guo Chao <yan@linux.vnet.ibm.com> wrote:
> pbus_size_mem() limits resource alignment within 2G. We want to extend
> this limit to support a 16G BAR. I found similar effort was tried before:
>
>         https://lkml.org/lkml/2012/6/21/411
>
> What's the result? Does anyone come up with an adaptive algorithm?

I suggest following changes:

From: Nikhil P Rao <nikhil.rao@intel.com>
Subject: [PATCH] PCI: Fix bus align checking to support more than 2G

current 2G is out of date.

-v3: We only need to extend that when 64bit mmio is supported.
     So extract mmio64 mask checking, and still keep old 2G checking
     for other path.  --- Yinghai

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
 drivers/pci/setup-bus.c |   42 ++++++++++++++++++++++++++++++++++++++----
 1 file changed, 38 insertions(+), 4 deletions(-)

Comments

Yinghai Lu Feb. 17, 2014, 9:15 p.m. UTC | #1
On Mon, Feb 17, 2014 at 11:28 AM, Yinghai Lu <yinghai@kernel.org> wrote:
> On Sun, Feb 16, 2014 at 8:50 PM, Guo Chao <yan@linux.vnet.ibm.com> wrote:
>> pbus_size_mem() limits resource alignment within 2G. We want to extend
>> this limit to support a 16G BAR. I found similar effort was tried before:
>>
>>         https://lkml.org/lkml/2012/6/21/411
>>
>> What's the result? Does anyone come up with an adaptive algorithm?
>
> I suggest following changes:
>
> From: Nikhil P Rao <nikhil.rao@intel.com>
> Subject: [PATCH] PCI: Fix bus align checking to support more than 2G
>
> current 2G is out of date.
>
> -v3: We only need to extend that when 64bit mmio is supported.
>      So extract mmio64 mask checking, and still keep old 2G checking
>      for other path.  --- Yinghai
>
> Signed-off-by: Yinghai Lu <yinghai@kernel.org>
>
> ---
>  drivers/pci/setup-bus.c |   42 ++++++++++++++++++++++++++++++++++++++----
>  1 file changed, 38 insertions(+), 4 deletions(-)
>
> Index: linux-2.6/drivers/pci/setup-bus.c
> ===================================================================
> --- linux-2.6.orig/drivers/pci/setup-bus.c
> +++ linux-2.6/drivers/pci/setup-bus.c
> @@ -921,7 +921,7 @@ static int pbus_size_mem(struct pci_bus
>  {
>      struct pci_dev *dev;
>      resource_size_t min_align, align, size, size0, size1;
> -    resource_size_t aligns[12];    /* Alignments from 1Mb to 2Gb */
> +    resource_size_t aligns[44];    /* Alignments from 1Mb to 2^63 */
>      int order, max_order;
>      struct resource *b_res = find_free_bus_resource(bus, type);
>      unsigned int mem64_mask = 0;
> @@ -937,6 +937,40 @@ static int pbus_size_mem(struct pci_bus
>      mem64_mask = b_res->flags & IORESOURCE_MEM_64;
>      b_res->flags &= ~IORESOURCE_MEM_64;
>
> +    /* kernel does not support 64bit */
> +    if (sizeof(resource_size_t) == 4)
> +        mem64_mask &=  ~IORESOURCE_MEM_64;
> +
> +    if (!(mem64_mask & IORESOURCE_MEM_64))
> +        goto mem64_mask_check_done;
> +
> +    /* check if mem64 support is supported and needed at first */
> +    list_for_each_entry(dev, &bus->devices, bus_list) {
> +        int i;
> +
> +        for (i = 0; i < PCI_NUM_RESOURCES; i++) {
> +            struct resource *r = &dev->resource[i];
> +            resource_size_t r_size;
> +
> +            if (r->parent || (r->flags & mask) != type)
> +                continue;
> +            r_size = resource_size(r);
> +#ifdef CONFIG_PCI_IOV
> +            /* put SRIOV requested res to the optional list */
> +            if (realloc_head && i >= PCI_IOV_RESOURCES &&
> +                    i <= PCI_IOV_RESOURCE_END)
> +                continue;
> +#endif
> +            mem64_mask &= r->flags & IORESOURCE_MEM_64;
> +
> +            if (!(mem64_mask & IORESOURCE_MEM_64))
> +                goto mem64_mask_check_done;
> +
> +        }
> +    }
> +
> +mem64_mask_check_done:
> +
>      list_for_each_entry(dev, &bus->devices, bus_list) {
>          int i;
>
> @@ -959,8 +993,9 @@ static int pbus_size_mem(struct pci_bus
>  #endif
>              /* For bridges size != alignment */
>              align = pci_resource_alignment(dev, r);
> -            order = __ffs(align) - 20;
> -            if (order > 11) {
> +            order = __ffs64(align) - 20;
> +            if (order > ARRAY_SIZE(aligns) ||
> +                (!(mem64_mask & IORESOURCE_MEM_64) && order > 11) ) {

...
> For 64bit systems, we want to ensure that the align < 1^63, so shouldn't
> order be checked against 43, instead of ARRAY_SIZE(aligns) ?

yes, should change to 43.

Thanks

Yinghai
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Bjorn Helgaas Feb. 19, 2014, 12:52 a.m. UTC | #2
On Mon, Feb 17, 2014 at 01:15:15PM -0800, Yinghai Lu wrote:
> On Mon, Feb 17, 2014 at 11:28 AM, Yinghai Lu <yinghai@kernel.org> wrote:
> > On Sun, Feb 16, 2014 at 8:50 PM, Guo Chao <yan@linux.vnet.ibm.com> wrote:
> >> pbus_size_mem() limits resource alignment within 2G. We want to extend
> >> this limit to support a 16G BAR. I found similar effort was tried before:
> >>
> >>         https://lkml.org/lkml/2012/6/21/411
> >>
> >> What's the result? Does anyone come up with an adaptive algorithm?
> >
> > I suggest following changes:
> >
> > From: Nikhil P Rao <nikhil.rao@intel.com>
> > Subject: [PATCH] PCI: Fix bus align checking to support more than 2G
> >
> > current 2G is out of date.
> >
> > -v3: We only need to extend that when 64bit mmio is supported.
> >      So extract mmio64 mask checking, and still keep old 2G checking
> >      for other path.  --- Yinghai
> >
> > Signed-off-by: Yinghai Lu <yinghai@kernel.org>
> >
> > ---
> >  drivers/pci/setup-bus.c |   42 ++++++++++++++++++++++++++++++++++++++----
> >  1 file changed, 38 insertions(+), 4 deletions(-)
> >
> > Index: linux-2.6/drivers/pci/setup-bus.c
> > ===================================================================
> > --- linux-2.6.orig/drivers/pci/setup-bus.c
> > +++ linux-2.6/drivers/pci/setup-bus.c
> > @@ -921,7 +921,7 @@ static int pbus_size_mem(struct pci_bus
> >  {
> >      struct pci_dev *dev;
> >      resource_size_t min_align, align, size, size0, size1;
> > -    resource_size_t aligns[12];    /* Alignments from 1Mb to 2Gb */
> > +    resource_size_t aligns[44];    /* Alignments from 1Mb to 2^63 */
> >      int order, max_order;
> >      struct resource *b_res = find_free_bus_resource(bus, type);
> >      unsigned int mem64_mask = 0;
> > @@ -937,6 +937,40 @@ static int pbus_size_mem(struct pci_bus
> >      mem64_mask = b_res->flags & IORESOURCE_MEM_64;
> >      b_res->flags &= ~IORESOURCE_MEM_64;
> >
> > +    /* kernel does not support 64bit */
> > +    if (sizeof(resource_size_t) == 4)
> > +        mem64_mask &=  ~IORESOURCE_MEM_64;
> > +
> > +    if (!(mem64_mask & IORESOURCE_MEM_64))
> > +        goto mem64_mask_check_done;
> > +
> > +    /* check if mem64 support is supported and needed at first */
> > +    list_for_each_entry(dev, &bus->devices, bus_list) {
> > +        int i;
> > +
> > +        for (i = 0; i < PCI_NUM_RESOURCES; i++) {
> > +            struct resource *r = &dev->resource[i];
> > +            resource_size_t r_size;
> > +
> > +            if (r->parent || (r->flags & mask) != type)
> > +                continue;
> > +            r_size = resource_size(r);
> > +#ifdef CONFIG_PCI_IOV
> > +            /* put SRIOV requested res to the optional list */
> > +            if (realloc_head && i >= PCI_IOV_RESOURCES &&
> > +                    i <= PCI_IOV_RESOURCE_END)
> > +                continue;
> > +#endif
> > +            mem64_mask &= r->flags & IORESOURCE_MEM_64;
> > +
> > +            if (!(mem64_mask & IORESOURCE_MEM_64))
> > +                goto mem64_mask_check_done;
> > +
> > +        }
> > +    }

Why did you add the loop above?  Didn't the original loop compute the same
value of mem64_mask as your new loop?

> > +mem64_mask_check_done:
> > +
> >      list_for_each_entry(dev, &bus->devices, bus_list) {
> >          int i;
> >
> > @@ -959,8 +993,9 @@ static int pbus_size_mem(struct pci_bus
> >  #endif
> >              /* For bridges size != alignment */
> >              align = pci_resource_alignment(dev, r);
> > -            order = __ffs(align) - 20;
> > -            if (order > 11) {
> > +            order = __ffs64(align) - 20;
> > +            if (order > ARRAY_SIZE(aligns) ||
> > +                (!(mem64_mask & IORESOURCE_MEM_64) && order > 11) ) {
> 
> ...
> > For 64bit systems, we want to ensure that the align < 1^63, so shouldn't
> > order be checked against 43, instead of ARRAY_SIZE(aligns) ?
> 
> yes, should change to 43.

Can you post an updated patch with this change, please?
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Yinghai Lu Feb. 21, 2014, 6:31 p.m. UTC | #3
On Tue, Feb 18, 2014 at 4:52 PM, Bjorn Helgaas <bhelgaas@google.com> wrote:
>
> Why did you add the loop above?  Didn't the original loop compute the same
> value of mem64_mask as your new loop?

it is the same at last. but that could be different in the middle.
like several resources, but only last one can not use 64bit resource.

Thanks

Yinghai
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diff mbox

Patch

From: Nikhil P Rao <nikhil.rao@intel.com>
Subject: [PATCH] PCI: Fix bus align checking to support more than 2G

current 2G is out of date.

-v3: We only need to extend that when 64bit mmio is supported.
     So extract mmio64 mask checking, and still keep old 2G checking
     for other path.  --- Yinghai

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
 drivers/pci/setup-bus.c |   42 ++++++++++++++++++++++++++++++++++++++----
 1 file changed, 38 insertions(+), 4 deletions(-)

Index: linux-2.6/drivers/pci/setup-bus.c
===================================================================
--- linux-2.6.orig/drivers/pci/setup-bus.c
+++ linux-2.6/drivers/pci/setup-bus.c
@@ -921,7 +921,7 @@  static int pbus_size_mem(struct pci_bus
 {
 	struct pci_dev *dev;
 	resource_size_t min_align, align, size, size0, size1;
-	resource_size_t aligns[12];	/* Alignments from 1Mb to 2Gb */
+	resource_size_t aligns[44];	/* Alignments from 1Mb to 2^63 */
 	int order, max_order;
 	struct resource *b_res = find_free_bus_resource(bus, type);
 	unsigned int mem64_mask = 0;
@@ -937,6 +937,40 @@  static int pbus_size_mem(struct pci_bus
 	mem64_mask = b_res->flags & IORESOURCE_MEM_64;
 	b_res->flags &= ~IORESOURCE_MEM_64;
 
+	/* kernel does not support 64bit */
+	if (sizeof(resource_size_t) == 4)
+		mem64_mask &=  ~IORESOURCE_MEM_64;
+
+	if (!(mem64_mask & IORESOURCE_MEM_64))
+		goto mem64_mask_check_done;
+
+	/* check if mem64 support is supported and needed at first */
+	list_for_each_entry(dev, &bus->devices, bus_list) {
+		int i;
+
+		for (i = 0; i < PCI_NUM_RESOURCES; i++) {
+			struct resource *r = &dev->resource[i];
+			resource_size_t r_size;
+
+			if (r->parent || (r->flags & mask) != type)
+				continue;
+			r_size = resource_size(r);
+#ifdef CONFIG_PCI_IOV
+			/* put SRIOV requested res to the optional list */
+			if (realloc_head && i >= PCI_IOV_RESOURCES &&
+					i <= PCI_IOV_RESOURCE_END)
+				continue;
+#endif
+			mem64_mask &= r->flags & IORESOURCE_MEM_64;
+
+			if (!(mem64_mask & IORESOURCE_MEM_64))
+				goto mem64_mask_check_done;
+
+		}
+	}
+
+mem64_mask_check_done:
+
 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		int i;
 
@@ -959,8 +993,9 @@  static int pbus_size_mem(struct pci_bus
 #endif
 			/* For bridges size != alignment */
 			align = pci_resource_alignment(dev, r);
-			order = __ffs(align) - 20;
-			if (order > 11) {
+			order = __ffs64(align) - 20;
+			if (order > ARRAY_SIZE(aligns) ||
+			    (!(mem64_mask & IORESOURCE_MEM_64) && order > 11) ) {
 				dev_warn(&dev->dev, "disabling BAR %d: %pR "
 					 "(bad alignment %#llx)\n", i, r,
 					 (unsigned long long) align);
@@ -976,7 +1011,6 @@  static int pbus_size_mem(struct pci_bus
 				aligns[order] += align;
 			if (order > max_order)
 				max_order = order;
-			mem64_mask &= r->flags & IORESOURCE_MEM_64;
 
 			if (realloc_head)
 				children_add_size += get_res_add_size(realloc_head, r);