diff mbox

[6/7] drm/i915: Add support to parse DMI table and get platform memory info

Message ID 1452772968-24772-7-git-send-email-shobhit.kumar@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Kumar, Shobhit Jan. 14, 2016, 12:02 p.m. UTC
This is needed for WM computation workaround for arbitrated display
bandwidth.

Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
---
 drivers/gpu/drm/i915/i915_dma.c | 19 +++++++++++++++++++
 drivers/gpu/drm/i915/i915_drv.h |  6 ++++++
 2 files changed, 25 insertions(+)

Comments

Matt Roper Jan. 15, 2016, 1:44 a.m. UTC | #1
On Thu, Jan 14, 2016 at 05:32:47PM +0530, Shobhit Kumar wrote:
> This is needed for WM computation workaround for arbitrated display
> bandwidth.
> 
> Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
> ---
>  drivers/gpu/drm/i915/i915_dma.c | 19 +++++++++++++++++++
>  drivers/gpu/drm/i915/i915_drv.h |  6 ++++++
>  2 files changed, 25 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
> index a0f5659..03c3131 100644
> --- a/drivers/gpu/drm/i915/i915_dma.c
> +++ b/drivers/gpu/drm/i915/i915_dma.c
> @@ -49,6 +49,7 @@
>  #include <linux/pm.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/oom.h>
> +#include <linux/dmi.h>
>  
>  
>  static int i915_getparam(struct drm_device *dev, void *data,
> @@ -855,6 +856,21 @@ static void intel_init_dpio(struct drm_i915_private *dev_priv)
>  	}
>  }
>  
> +static void dmi_decode_memory_info(const struct dmi_header *hdr, void *priv)
> +{
> +	struct drm_i915_private *dev_priv = (struct drm_i915_private *) priv;
> +	const u8 *data = (const u8 *) hdr;
> +
> +	if (hdr->type == 17 && hdr->length > 0x17) {

I think there are some constants in include/linux/dmi.h that we can use
instead of magic numbers.  DMI_ENTRY_MEM_DEVICE.

I'm not familiar with any of this DMI stuff; it seems like there are
functions elsewhere in the kernel (e.g., decode_dclk() in
drivers/edac/i7core_edac.c) that decode this into a memdev_dmi_entry and
then do some more robust/paranoid checking to determine the actual
speed.  Unfortunately it's static to that file and not directly callable
by us.

I wonder if it would make sense to refactor that structure and decoding
out into the general DMI files and export them for module use so that we
could just call those functions.


Matt

> +
> +		/* Found a memory channel */
> +		dev_priv->dmi.mem_channel++;
> +
> +		/* Get the speed */
> +		dev_priv->dmi.mem_speed = (uint16_t) (*((uint16_t *)(data + 0x15)));
> +	}
> +}
> +
>  /**
>   * i915_driver_load - setup chip and create an initial config
>   * @dev: DRM device
> @@ -882,6 +898,9 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
>  	dev->dev_private = dev_priv;
>  	dev_priv->dev = dev;
>  
> +	/* walk the dmi device table for getting platform memory information */
> +	dmi_walk(dmi_decode_memory_info, (void *) dev_priv);
> +
>  	/* Setup the write-once "constant" device info */
>  	device_info = (struct intel_device_info *)&dev_priv->info;
>  	memcpy(device_info, info, sizeof(dev_priv->info));
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 104bd18..f588993 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1962,6 +1962,12 @@ struct drm_i915_private {
>  	 * NOTE: This is the dri1/ums dungeon, don't add stuff here. Your patch
>  	 * will be rejected. Instead look for a better place.
>  	 */
> +
> +	/* DMI data for memory bandwidth calculation */
> +	struct {
> +		uint16_t mem_channel;
> +		uint16_t mem_speed;
> +	} dmi;
>  };
>  
>  static inline struct drm_i915_private *to_i915(const struct drm_device *dev)
> -- 
> 2.4.3
>
Shobhit Kumar Jan. 27, 2016, 4:04 p.m. UTC | #2
On 01/15/2016 07:14 AM, Matt Roper wrote:
> On Thu, Jan 14, 2016 at 05:32:47PM +0530, Shobhit Kumar wrote:
>> This is needed for WM computation workaround for arbitrated display
>> bandwidth.
>>
>> Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
>> ---
>>   drivers/gpu/drm/i915/i915_dma.c | 19 +++++++++++++++++++
>>   drivers/gpu/drm/i915/i915_drv.h |  6 ++++++
>>   2 files changed, 25 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
>> index a0f5659..03c3131 100644
>> --- a/drivers/gpu/drm/i915/i915_dma.c
>> +++ b/drivers/gpu/drm/i915/i915_dma.c
>> @@ -49,6 +49,7 @@
>>   #include <linux/pm.h>
>>   #include <linux/pm_runtime.h>
>>   #include <linux/oom.h>
>> +#include <linux/dmi.h>
>>
>>
>>   static int i915_getparam(struct drm_device *dev, void *data,
>> @@ -855,6 +856,21 @@ static void intel_init_dpio(struct drm_i915_private *dev_priv)
>>   	}
>>   }
>>
>> +static void dmi_decode_memory_info(const struct dmi_header *hdr, void *priv)
>> +{
>> +	struct drm_i915_private *dev_priv = (struct drm_i915_private *) priv;
>> +	const u8 *data = (const u8 *) hdr;
>> +
>> +	if (hdr->type == 17 && hdr->length > 0x17) {
>
> I think there are some constants in include/linux/dmi.h that we can use
> instead of magic numbers.  DMI_ENTRY_MEM_DEVICE.
>

Yeah will do that.

> I'm not familiar with any of this DMI stuff; it seems like there are
> functions elsewhere in the kernel (e.g., decode_dclk() in
> drivers/edac/i7core_edac.c) that decode this into a memdev_dmi_entry and
> then do some more robust/paranoid checking to determine the actual
> speed.  Unfortunately it's static to that file and not directly callable
> by us.
>
> I wonder if it would make sense to refactor that structure and decoding
> out into the general DMI files and export them for module use so that we
> could just call those functions.
>

Perhaps we can but that will take some time. I will add paranoid parsing 
as done in edac with minimal #defined offsets for now. Think that should 
suffice. At next level we can work on exporting new functionality from 
the DMI files.

Regards
Shobhit

>
> Matt
>
>> +
>> +		/* Found a memory channel */
>> +		dev_priv->dmi.mem_channel++;
>> +
>> +		/* Get the speed */
>> +		dev_priv->dmi.mem_speed = (uint16_t) (*((uint16_t *)(data + 0x15)));
>> +	}
>> +}
>> +
>>   /**
>>    * i915_driver_load - setup chip and create an initial config
>>    * @dev: DRM device
>> @@ -882,6 +898,9 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
>>   	dev->dev_private = dev_priv;
>>   	dev_priv->dev = dev;
>>
>> +	/* walk the dmi device table for getting platform memory information */
>> +	dmi_walk(dmi_decode_memory_info, (void *) dev_priv);
>> +
>>   	/* Setup the write-once "constant" device info */
>>   	device_info = (struct intel_device_info *)&dev_priv->info;
>>   	memcpy(device_info, info, sizeof(dev_priv->info));
>> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>> index 104bd18..f588993 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.h
>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>> @@ -1962,6 +1962,12 @@ struct drm_i915_private {
>>   	 * NOTE: This is the dri1/ums dungeon, don't add stuff here. Your patch
>>   	 * will be rejected. Instead look for a better place.
>>   	 */
>> +
>> +	/* DMI data for memory bandwidth calculation */
>> +	struct {
>> +		uint16_t mem_channel;
>> +		uint16_t mem_speed;
>> +	} dmi;
>>   };
>>
>>   static inline struct drm_i915_private *to_i915(const struct drm_device *dev)
>> --
>> 2.4.3
>>
>
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index a0f5659..03c3131 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -49,6 +49,7 @@ 
 #include <linux/pm.h>
 #include <linux/pm_runtime.h>
 #include <linux/oom.h>
+#include <linux/dmi.h>
 
 
 static int i915_getparam(struct drm_device *dev, void *data,
@@ -855,6 +856,21 @@  static void intel_init_dpio(struct drm_i915_private *dev_priv)
 	}
 }
 
+static void dmi_decode_memory_info(const struct dmi_header *hdr, void *priv)
+{
+	struct drm_i915_private *dev_priv = (struct drm_i915_private *) priv;
+	const u8 *data = (const u8 *) hdr;
+
+	if (hdr->type == 17 && hdr->length > 0x17) {
+
+		/* Found a memory channel */
+		dev_priv->dmi.mem_channel++;
+
+		/* Get the speed */
+		dev_priv->dmi.mem_speed = (uint16_t) (*((uint16_t *)(data + 0x15)));
+	}
+}
+
 /**
  * i915_driver_load - setup chip and create an initial config
  * @dev: DRM device
@@ -882,6 +898,9 @@  int i915_driver_load(struct drm_device *dev, unsigned long flags)
 	dev->dev_private = dev_priv;
 	dev_priv->dev = dev;
 
+	/* walk the dmi device table for getting platform memory information */
+	dmi_walk(dmi_decode_memory_info, (void *) dev_priv);
+
 	/* Setup the write-once "constant" device info */
 	device_info = (struct intel_device_info *)&dev_priv->info;
 	memcpy(device_info, info, sizeof(dev_priv->info));
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 104bd18..f588993 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1962,6 +1962,12 @@  struct drm_i915_private {
 	 * NOTE: This is the dri1/ums dungeon, don't add stuff here. Your patch
 	 * will be rejected. Instead look for a better place.
 	 */
+
+	/* DMI data for memory bandwidth calculation */
+	struct {
+		uint16_t mem_channel;
+		uint16_t mem_speed;
+	} dmi;
 };
 
 static inline struct drm_i915_private *to_i915(const struct drm_device *dev)