diff mbox

[1/3] RFC: AHCI: libahci is missing DMA

Message ID 1386159055-10264-2-git-send-email-oliver@schinagl.nl
State Not Applicable
Delegated to: David Miller
Headers show

Commit Message

Olliver Schinagl Dec. 4, 2013, 12:10 p.m. UTC 
From: Oliver Schinagl <oliver@schinagl.nl>

The Allwinner sunxi platforms have patched in the following to enable
DMA. This patch enables DMA controllers for the SUNXI Architecture.

Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>
---
 drivers/ata/ahci.h    | 6 ++++++
 drivers/ata/libahci.c | 8 ++++++++
 2 files changed, 14 insertions(+)

Comments

Tejun Heo Dec. 4, 2013, 12:32 p.m. UTC | #1 
On Wed, Dec 04, 2013 at 01:10:53PM +0100, oliver@schinagl.nl wrote:
> From: Oliver Schinagl <oliver@schinagl.nl>
> 
> The Allwinner sunxi platforms have patched in the following to enable
> DMA. This patch enables DMA controllers for the SUNXI Architecture.
> 
> Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>
> ---
>  drivers/ata/ahci.h    | 6 ++++++
>  drivers/ata/libahci.c | 8 ++++++++
>  2 files changed, 14 insertions(+)
> 
> diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
> index 2289efdf..2bf2423 100644
> --- a/drivers/ata/ahci.h
> +++ b/drivers/ata/ahci.h
> @@ -138,6 +138,7 @@ enum {
>  	PORT_SCR_NTF		= 0x3c, /* SATA phy register: SNotification */
>  	PORT_FBS		= 0x40, /* FIS-based Switching */
>  	PORT_DEVSLP		= 0x44, /* device sleep */
> +	PORT_DMA		= 0x70, /* direct memory access */
>  
>  	/* PORT_IRQ_{STAT,MASK} bits */
>  	PORT_IRQ_COLD_PRES	= (1 << 31), /* cold presence detect */
> @@ -209,6 +210,11 @@ enum {
>  	PORT_DEVSLP_DSP		= (1 << 1),       /* DevSlp present */
>  	PORT_DEVSLP_ADSE	= (1 << 0),       /* Aggressive DevSlp enable */
>  
> +	/* PORT_DMA bits */
> +	PORT_DMA_SETUP_OFFSET	= 8, /* dma setup offset */
> +	PORT_DMA_SETUP_MASK	= (0xff << PORT_DMA_SETUP_OFFSET),/* dma mask */
> +	PORT_DMA_SETUP_INIT	= (0x44 << 0),

Ummm... this doesn't belong to ahci proper, right?

> +
>  	/* hpriv->flags bits */
>  
>  #define AHCI_HFLAGS(flags)		.private_data	= (void *)(flags)
> diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
> index c482f8c..d697a74 100644
> --- a/drivers/ata/libahci.c
> +++ b/drivers/ata/libahci.c
> @@ -570,6 +570,14 @@ void ahci_start_engine(struct ata_port *ap)
>  	void __iomem *port_mmio = ahci_port_base(ap);
>  	u32 tmp;
>  
> +#ifdef CONFIG_ARCH_SUNXI
> +	/* Setup DMA before DMA start */
> +	tmp = readl(port_mmio + PORT_DMA);
> +	tmp &= ~PORT_DMA_SETUP_MASK;
> +	tmp |= PORT_DMA_SETUP_INIT << PORT_DMA_SETUP_OFFSET;
> +	writel(tmp, port_mmio + PORT_DMA);
> +#endif

If this is something platform device specific, wouldn't overriding
->port_start() which wraps around ahci_port_start() make more sense?

Thanks.
Olliver Schinagl Dec. 4, 2013, 12:36 p.m. UTC | #2 
Hey Tejun Heo,

On 04-12-13 13:32, Tejun Heo wrote:
> On Wed, Dec 04, 2013 at 01:10:53PM +0100, oliver@schinagl.nl wrote:
>> From: Oliver Schinagl <oliver@schinagl.nl>
>>
>> The Allwinner sunxi platforms have patched in the following to enable
>> DMA. This patch enables DMA controllers for the SUNXI Architecture.
>>
>> Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>
>> ---
>>   drivers/ata/ahci.h    | 6 ++++++
>>   drivers/ata/libahci.c | 8 ++++++++
>>   2 files changed, 14 insertions(+)
>>
>> diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
>> index 2289efdf..2bf2423 100644
>> --- a/drivers/ata/ahci.h
>> +++ b/drivers/ata/ahci.h
>> @@ -138,6 +138,7 @@ enum {
>>   	PORT_SCR_NTF		= 0x3c, /* SATA phy register: SNotification */
>>   	PORT_FBS		= 0x40, /* FIS-based Switching */
>>   	PORT_DEVSLP		= 0x44, /* device sleep */
>> +	PORT_DMA		= 0x70, /* direct memory access */
>>   
>>   	/* PORT_IRQ_{STAT,MASK} bits */
>>   	PORT_IRQ_COLD_PRES	= (1 << 31), /* cold presence detect */
>> @@ -209,6 +210,11 @@ enum {
>>   	PORT_DEVSLP_DSP		= (1 << 1),       /* DevSlp present */
>>   	PORT_DEVSLP_ADSE	= (1 << 0),       /* Aggressive DevSlp enable */
>>   
>> +	/* PORT_DMA bits */
>> +	PORT_DMA_SETUP_OFFSET	= 8, /* dma setup offset */
>> +	PORT_DMA_SETUP_MASK	= (0xff << PORT_DMA_SETUP_OFFSET),/* dma mask */
>> +	PORT_DMA_SETUP_INIT	= (0x44 << 0),
> Ummm... this doesn't belong to ahci proper, right?
I have no idea why Allwinner added that and what it really does. We have 
no documentation, only code drops.

I had high hopes someone around here knows what it could mean and where 
it does belong.
>
>> +
>>   	/* hpriv->flags bits */
>>   
>>   #define AHCI_HFLAGS(flags)		.private_data	= (void *)(flags)
>> diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
>> index c482f8c..d697a74 100644
>> --- a/drivers/ata/libahci.c
>> +++ b/drivers/ata/libahci.c
>> @@ -570,6 +570,14 @@ void ahci_start_engine(struct ata_port *ap)
>>   	void __iomem *port_mmio = ahci_port_base(ap);
>>   	u32 tmp;
>>   
>> +#ifdef CONFIG_ARCH_SUNXI
>> +	/* Setup DMA before DMA start */
>> +	tmp = readl(port_mmio + PORT_DMA);
>> +	tmp &= ~PORT_DMA_SETUP_MASK;
>> +	tmp |= PORT_DMA_SETUP_INIT << PORT_DMA_SETUP_OFFSET;
>> +	writel(tmp, port_mmio + PORT_DMA);
>> +#endif
> If this is something platform device specific, wouldn't overriding
> ->port_start() which wraps around ahci_port_start() make more sense?
Again, I don't know, this is where Allwinner had put it. We don't even 
know who's IP they use. I'm happy to start experimenting moving this 
around a bit and will take your clue to figure out what you mean and if 
it could work.

Oliver
>
> Thanks.
>

--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Sergei Shtylyov Dec. 4, 2013, 12:47 p.m. UTC | #3 
Hello.

On 04-12-2013 16:10, oliver@schinagl.nl wrote:

> From: Oliver Schinagl <oliver@schinagl.nl>

> The Allwinner sunxi platforms have patched in the following to enable
> DMA. This patch enables DMA controllers for the SUNXI Architecture.

> Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>
> ---
>   drivers/ata/ahci.h    | 6 ++++++
>   drivers/ata/libahci.c | 8 ++++++++
>   2 files changed, 14 insertions(+)

> diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
> index 2289efdf..2bf2423 100644
> --- a/drivers/ata/ahci.h
> +++ b/drivers/ata/ahci.h
[...]
> @@ -209,6 +210,11 @@ enum {
>   	PORT_DEVSLP_DSP		= (1 << 1),       /* DevSlp present */
>   	PORT_DEVSLP_ADSE	= (1 << 0),       /* Aggressive DevSlp enable */
>
> +	/* PORT_DMA bits */
> +	PORT_DMA_SETUP_OFFSET	= 8, /* dma setup offset */
> +	PORT_DMA_SETUP_MASK	= (0xff << PORT_DMA_SETUP_OFFSET),/* dma mask */
> +	PORT_DMA_SETUP_INIT	= (0x44 << 0),

    Why not shift it right by PORT_DMA_SETUP_OFFSET if you do it in the next 
file anyway?

[...]
> diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
> index c482f8c..d697a74 100644
> --- a/drivers/ata/libahci.c
> +++ b/drivers/ata/libahci.c
> @@ -570,6 +570,14 @@ void ahci_start_engine(struct ata_port *ap)
>   	void __iomem *port_mmio = ahci_port_base(ap);
>   	u32 tmp;
>
> +#ifdef CONFIG_ARCH_SUNXI
> +	/* Setup DMA before DMA start */
> +	tmp = readl(port_mmio + PORT_DMA);
> +	tmp &= ~PORT_DMA_SETUP_MASK;
> +	tmp |= PORT_DMA_SETUP_INIT << PORT_DMA_SETUP_OFFSET;
> +	writel(tmp, port_mmio + PORT_DMA);
> +#endif
> +

    I don't think #ifdef is appropriate here.

WBR, Sergei

--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Olliver Schinagl Dec. 4, 2013, 1:09 p.m. UTC | #4 
On 04-12-13 13:47, Sergei Shtylyov wrote:
> Hello.
>
> On 04-12-2013 16:10, oliver@schinagl.nl wrote:
>
>> From: Oliver Schinagl <oliver@schinagl.nl>
>
>> The Allwinner sunxi platforms have patched in the following to enable
>> DMA. This patch enables DMA controllers for the SUNXI Architecture.
>
>> Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>
>> ---
>>   drivers/ata/ahci.h    | 6 ++++++
>>   drivers/ata/libahci.c | 8 ++++++++
>>   2 files changed, 14 insertions(+)
>
>> diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
>> index 2289efdf..2bf2423 100644
>> --- a/drivers/ata/ahci.h
>> +++ b/drivers/ata/ahci.h
> [...]
>> @@ -209,6 +210,11 @@ enum {
>>       PORT_DEVSLP_DSP        = (1 << 1),       /* DevSlp present */
>>       PORT_DEVSLP_ADSE    = (1 << 0),       /* Aggressive DevSlp 
>> enable */
>>
>> +    /* PORT_DMA bits */
>> +    PORT_DMA_SETUP_OFFSET    = 8, /* dma setup offset */
>> +    PORT_DMA_SETUP_MASK    = (0xff << PORT_DMA_SETUP_OFFSET),/* dma 
>> mask */
>> +    PORT_DMA_SETUP_INIT    = (0x44 << 0),
>
>    Why not shift it right by PORT_DMA_SETUP_OFFSET if you do it in the 
> next file anyway?
Verbosity and clarity I suppose, try to reduce the number of magic 
values. I don't know what the preferred way is as we know so little 
about the IP.
>
> [...]
>> diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
>> index c482f8c..d697a74 100644
>> --- a/drivers/ata/libahci.c
>> +++ b/drivers/ata/libahci.c
>> @@ -570,6 +570,14 @@ void ahci_start_engine(struct ata_port *ap)
>>       void __iomem *port_mmio = ahci_port_base(ap);
>>       u32 tmp;
>>
>> +#ifdef CONFIG_ARCH_SUNXI
>> +    /* Setup DMA before DMA start */
>> +    tmp = readl(port_mmio + PORT_DMA);
>> +    tmp &= ~PORT_DMA_SETUP_MASK;
>> +    tmp |= PORT_DMA_SETUP_INIT << PORT_DMA_SETUP_OFFSET;
>> +    writel(tmp, port_mmio + PORT_DMA);
>> +#endif
>> +
>
>    I don't think #ifdef is appropriate here.
It's not, but I was hoping Smarter devs then me would point me the right 
way ;)

Oliver
>
> WBR, Sergei
>

--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index 2289efdf..2bf2423 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -138,6 +138,7 @@  enum {
 	PORT_SCR_NTF		= 0x3c, /* SATA phy register: SNotification */
 	PORT_FBS		= 0x40, /* FIS-based Switching */
 	PORT_DEVSLP		= 0x44, /* device sleep */
+	PORT_DMA		= 0x70, /* direct memory access */
 
 	/* PORT_IRQ_{STAT,MASK} bits */
 	PORT_IRQ_COLD_PRES	= (1 << 31), /* cold presence detect */
@@ -209,6 +210,11 @@  enum {
 	PORT_DEVSLP_DSP		= (1 << 1),       /* DevSlp present */
 	PORT_DEVSLP_ADSE	= (1 << 0),       /* Aggressive DevSlp enable */
 
+	/* PORT_DMA bits */
+	PORT_DMA_SETUP_OFFSET	= 8, /* dma setup offset */
+	PORT_DMA_SETUP_MASK	= (0xff << PORT_DMA_SETUP_OFFSET),/* dma mask */
+	PORT_DMA_SETUP_INIT	= (0x44 << 0),
+
 	/* hpriv->flags bits */
 
 #define AHCI_HFLAGS(flags)		.private_data	= (void *)(flags)
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index c482f8c..d697a74 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -570,6 +570,14 @@  void ahci_start_engine(struct ata_port *ap)
 	void __iomem *port_mmio = ahci_port_base(ap);
 	u32 tmp;
 
+#ifdef CONFIG_ARCH_SUNXI
+	/* Setup DMA before DMA start */
+	tmp = readl(port_mmio + PORT_DMA);
+	tmp &= ~PORT_DMA_SETUP_MASK;
+	tmp |= PORT_DMA_SETUP_INIT << PORT_DMA_SETUP_OFFSET;
+	writel(tmp, port_mmio + PORT_DMA);
+#endif
+
 	/* start DMA */
 	tmp = readl(port_mmio + PORT_CMD);
 	tmp |= PORT_CMD_START;