drm/xe/pm: Toggle d3cold_allowed using vram_usages

Adding support to control d3cold by using vram_usages metric from
ttm resource manager.
When root port  is capable of d3cold but xe has disallowed d3cold
due to vram_usages above vram_d3ccold_threshol. It is required to
disable d3cold to avoid any resume failure because root port can
still transition to d3cold when all of pcie endpoints and
{upstream, virtual} switch ports will transition to d3hot.
Also cleaning up the TODO code comment.

v2:
- Modify d3cold.allowed in xe_pm_d3cold_allowed_toggle. [Riana]
- Cond changed (total_vram_used_mb < xe->d3cold.vram_threshold)
  according to doc comment.
v3:
- Added enum instead of true/false argument in
  d3cold_toggle(). [Rodrigo]
- Removed TODO comment. [Rodrigo]

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
Reviewed-by: Badal Nilawar <badal.nilawar@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230718080703.239343-5-anshuman.gupta@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

diff --git a/drivers/gpu/drm/xe/xe_pci.c b/drivers/gpu/drm/xe/xe_pci.c
index 74aba4f09f7daa93c9a0fb1d2fc37c47b81885e4..6d04e570735af0410bb1168bcb366b189ecff385 100644 (file)
--- a/drivers/gpu/drm/xe/xe_pci.c
+++ b/drivers/gpu/drm/xe/xe_pci.c
@@ -25,6 +25,11 @@
 #include "xe_pm.h"
 #include "xe_step.h"
 
+enum toggle_d3cold {
+       D3COLD_DISABLE,
+       D3COLD_ENABLE,
+};
+
 struct xe_subplatform_desc {
        enum xe_subplatform subplatform;
        const char *name;
@@ -726,6 +731,28 @@ static int xe_pci_resume(struct device *dev)
        return 0;
 }
 
+static void d3cold_toggle(struct pci_dev *pdev, enum toggle_d3cold toggle)
+{
+       struct xe_device *xe = pdev_to_xe_device(pdev);
+       struct pci_dev *root_pdev;
+
+       if (!xe->d3cold.capable)
+               return;
+
+       root_pdev = pcie_find_root_port(pdev);
+       if (!root_pdev)
+               return;
+
+       switch (toggle) {
+       case D3COLD_DISABLE:
+               pci_d3cold_disable(root_pdev);
+               break;
+       case D3COLD_ENABLE:
+               pci_d3cold_enable(root_pdev);
+               break;
+       }
+}
+
 static int xe_pci_runtime_suspend(struct device *dev)
 {
        struct pci_dev *pdev = to_pci_dev(dev);
@@ -743,6 +770,7 @@ static int xe_pci_runtime_suspend(struct device *dev)
                pci_ignore_hotplug(pdev);
                pci_set_power_state(pdev, PCI_D3cold);
        } else {
+               d3cold_toggle(pdev, D3COLD_DISABLE);
                pci_set_power_state(pdev, PCI_D3hot);
        }
 
@@ -767,6 +795,8 @@ static int xe_pci_runtime_resume(struct device *dev)
                        return err;
 
                pci_set_master(pdev);
+       } else {
+               d3cold_toggle(pdev, D3COLD_ENABLE);
        }
 
        return xe_pm_runtime_resume(xe);
@@ -780,15 +810,15 @@ static int xe_pci_runtime_idle(struct device *dev)
        if (!xe->d3cold.capable) {
                xe->d3cold.allowed = false;
        } else {
+               xe_pm_d3cold_allowed_toggle(xe);
+
                /*
                 * TODO: d3cold should be allowed (true) if
                 * (IS_DGFX(xe) && !xe_device_mem_access_ongoing(xe))
                 * but maybe include some other conditions. So, before
                 * we can re-enable the D3cold, we need to:
                 * 1. rewrite the VRAM save / restore to avoid buffer object locks
-                * 2. block D3cold if we have a big amount of device memory in use
-                *    in order to reduce the latency.
-                * 3. at resume, detect if we really lost power and avoid memory
+                * 2. at resume, detect if we really lost power and avoid memory
                 *    restoration if we were only up to d3cold
                 */
                xe->d3cold.allowed = false;

diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
index 261c0ad57b634b252a81bb46056d126f76fd6625..21964e4d09f87c724e23eca4a0413709a8392e32 100644 (file)
--- a/drivers/gpu/drm/xe/xe_pm.c
+++ b/drivers/gpu/drm/xe/xe_pm.c
@@ -280,3 +280,28 @@ int xe_pm_set_vram_threshold(struct xe_device *xe, u32 threshold)
 
        return 0;
 }
+
+void xe_pm_d3cold_allowed_toggle(struct xe_device *xe)
+{
+       struct ttm_resource_manager *man;
+       u32 total_vram_used_mb = 0;
+       u64 vram_used;
+       int i;
+
+       for (i = XE_PL_VRAM0; i <= XE_PL_VRAM1; ++i) {
+               man = ttm_manager_type(&xe->ttm, i);
+               if (man) {
+                       vram_used = ttm_resource_manager_usage(man);
+                       total_vram_used_mb += DIV_ROUND_UP_ULL(vram_used, 1024 * 1024);
+               }
+       }
+
+       mutex_lock(&xe->d3cold.lock);
+
+       if (total_vram_used_mb < xe->d3cold.vram_threshold)
+               xe->d3cold.allowed = true;
+       else
+               xe->d3cold.allowed = false;
+
+       mutex_unlock(&xe->d3cold.lock);
+}

diff --git a/drivers/gpu/drm/xe/xe_pm.h b/drivers/gpu/drm/xe/xe_pm.h
index bbd91a5855cdf8effe37694810ea716ae54f2dc0..ee30cf025f646d20fb28160d8ada58aa07718d7d 100644 (file)
--- a/drivers/gpu/drm/xe/xe_pm.h
+++ b/drivers/gpu/drm/xe/xe_pm.h
@@ -25,5 +25,6 @@ bool xe_pm_runtime_resume_if_suspended(struct xe_device *xe);
 int xe_pm_runtime_get_if_active(struct xe_device *xe);
 void xe_pm_assert_unbounded_bridge(struct xe_device *xe);
 int xe_pm_set_vram_threshold(struct xe_device *xe, u32 threshold);
+void xe_pm_d3cold_allowed_toggle(struct xe_device *xe);
 
 #endif