From: Shobhit Kumar <shobhit.kumar@xxxxxxxxx>
This is needed for WM computation workaround for arbitrated display
bandwidth.
v2: Address Matt's review comments
- Be more paranoid while dmi decoding
- Also add support for decoding speed from configured memory speed
if availble in DMI memory entry
v3 (by Matt):
- Use memdev_dmi_entry from dmi.h
- Don't try to use/compare negative numbers in unsigned types
Cc: matthew.d.roper@xxxxxxxxx
Signed-off-by: Shobhit Kumar <shobhit.kumar@xxxxxxxxx>
Signed-off-by: Matt Roper <matthew.d.roper@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_dma.c | 34 ++++++++++++++++++++++++++++++++++
drivers/gpu/drm/i915/i915_drv.h | 7 +++++++
2 files changed, 41 insertions(+)
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 4aa3db6..4259afe 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,
@@ -973,6 +974,33 @@ static void i915_mmio_cleanup(struct drm_device *dev)
pci_iounmap(dev->pdev, dev_priv->regs);
}
+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 struct memdev_dmi_entry *memdev =
+ (const struct memdev_dmi_entry *)hdr;
+ uint16_t mem_speed = 0;
+
+ if (hdr->type != DMI_ENTRY_MEM_DEVICE)
+ return;
+
+ /* Get the speed */
+ if (hdr->length > offsetof(struct memdev_dmi_entry, conf_mem_clk_speed))
+ mem_speed = memdev->conf_mem_clk_speed;
+ else if (hdr->length > offsetof(struct memdev_dmi_entry, speed))
+ mem_speed = memdev->speed;
+ else
+ return;
+
+ dev_priv->dmi.mem_channel++;
+
+ /* All channels are expected to have same the speed */
+ if (dev_priv->dmi.mem_speed == 0)
+ dev_priv->dmi.mem_speed = mem_speed;
+ else if (mem_speed != dev_priv->dmi.mem_speed)
+ dev_priv->dmi.valid = false;
+}
+
/**
* i915_driver_load - setup chip and create an initial config
* @dev: DRM device
@@ -1000,6 +1028,12 @@ 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 */
+ dev_priv->dmi.valid = true;
+ dmi_walk(dmi_decode_memory_info, dev_priv);
+ if (!dev_priv->dmi.mem_speed)
+ dev_priv->dmi.valid = false;
+
/* 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 f37ac12..a2a7d8d 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2022,6 +2022,13 @@ 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 {
+ bool valid;
+ uint16_t mem_channel;
+ int16_t mem_speed;
+ } dmi;
};
static inline struct drm_i915_private *to_i915(const struct drm_device *dev)
--
2.1.4
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