[Intel-xe] [RFC] drm/xe/pm: d3cold policy

Thomas Hellström thomas.hellstrom at linux.intel.com
Fri May 12 13:13:05 UTC 2023


On Fri, 2023-05-12 at 15:06 +0530, Anshuman Gupta wrote:
> Adding pci d3cold capable check support.
> Adding a vram_save_restore_threshold modparam, that is the

Please use imperative language as per the Linux patch-submission
guidelines.

"Add pci d3cold capable check support."

Typos:
> permissisble threshold for vram save/restore. If vram used
permissible
> is more then
more than
>  the threshold value then disabllow
disallow
>  the d3cold
> to avoid the vram save/restore latency.
> 
> TODO: At resume vram save/restore only in case card really lost
> power.
> 
> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> Signed-off-by: Anshuman Gupta <anshuman.gupta at intel.com>
> ---
>  drivers/gpu/drm/xe/xe_device_types.h |  3 ++
>  drivers/gpu/drm/xe/xe_module.c       |  4 +++
>  drivers/gpu/drm/xe/xe_module.h       |  1 +
>  drivers/gpu/drm/xe/xe_pci.c          | 46
> ++++++++++++++++++++++++++++
>  drivers/gpu/drm/xe/xe_pm.c           | 20 ++++++++++++
>  drivers/gpu/drm/xe/xe_pm.h           |  1 +
>  6 files changed, 75 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_device_types.h
> b/drivers/gpu/drm/xe/xe_device_types.h
> index 1cb404e48aaa..1137f544575d 100644
> --- a/drivers/gpu/drm/xe/xe_device_types.h
> +++ b/drivers/gpu/drm/xe/xe_device_types.h
> @@ -263,6 +263,9 @@ struct xe_device {
>                 bool hold_rpm;
>         } mem_access;
>  
> +       /** d3cold_capable: Indicates if root port is d3cold capable
> */
> +       bool d3cold_capable;
> +
>         /** @d3cold_allowed: Indicates if d3cold is a valid device
> state */
>         bool d3cold_allowed;
>  
> diff --git a/drivers/gpu/drm/xe/xe_module.c
> b/drivers/gpu/drm/xe/xe_module.c
> index 6860586ce7f8..1dd515ed8a65 100644
> --- a/drivers/gpu/drm/xe/xe_module.c
> +++ b/drivers/gpu/drm/xe/xe_module.c
> @@ -26,6 +26,10 @@ u32 xe_force_vram_bar_size;
>  module_param_named(vram_bar_size, xe_force_vram_bar_size, uint,
> 0600);
>  MODULE_PARM_DESC(vram_bar_size, "Set the vram bar size(in MiB)");
>  
> +u32 xe_vram_save_restore_threshold = 300;
> +module_param_named(vram_save_restore_threshold,
> xe_vram_save_restore_threshold, uint, 0600);
> +MODULE_PARM_DESC(vram_save_restore_threshold, "Set the vram used
> threshold below which vram save/restore premissible (in MB)");

With one-driver-multiple-devices, Would we want to use this as the
default template and then have an interface to set it per-device?

Thanks,
Thomas



> +
>  int xe_guc_log_level = 5;
>  module_param_named(guc_log_level, xe_guc_log_level, int, 0600);
>  MODULE_PARM_DESC(guc_log_level, "GuC firmware logging level
> (0=disable, 1..5=enable with verbosity min..max)");
> diff --git a/drivers/gpu/drm/xe/xe_module.h
> b/drivers/gpu/drm/xe/xe_module.h
> index 7169907c3365..620d1b80cab6 100644
> --- a/drivers/gpu/drm/xe/xe_module.h
> +++ b/drivers/gpu/drm/xe/xe_module.h
> @@ -9,5 +9,6 @@
>  extern bool enable_guc;
>  extern bool enable_display;
>  extern u32 xe_force_vram_bar_size;
> +extern u32 xe_vram_save_restore_threshold;
>  extern int xe_guc_log_level;
>  extern char *xe_param_force_probe;
> diff --git a/drivers/gpu/drm/xe/xe_pci.c
> b/drivers/gpu/drm/xe/xe_pci.c
> index ee61a03d1afd..2c86a8ab727a 100644
> --- a/drivers/gpu/drm/xe/xe_pci.c
> +++ b/drivers/gpu/drm/xe/xe_pci.c
> @@ -592,6 +592,40 @@ static void
> xe_pci_unbounded_bridge_disable_pm(struct pci_dev *pdev)
>         }
>  }
>  
> +static bool xe_pci_d3cold_capable(struct pci_dev *pdev)
> +{
> +       struct pci_dev *root_pdev;
> +
> +       root_pdev = pcie_find_root_port(pdev);
> +       if (!root_pdev)
> +               return false;
> +
> +       /* D3Cold requires PME capability and _PR3 power resource */
> +       if (!pci_pme_capable(root_pdev, PCI_D3cold) ||
> !pci_pr3_present(root_pdev))
> +               return false;
> +
> +       return true;
> +}
> +
> +static void xe_pci_d3cold_enable_disable(struct pci_dev *pdev, bool
> enable)
> +{
> +       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;
> +
> +       if (enable)
> +               pci_d3cold_enable(pdev);
> +       else
> +               pci_d3cold_disable(pdev);
> +
> +}
> +
>  static int xe_pci_probe(struct pci_dev *pdev, const struct
> pci_device_id *ent)
>  {
>         const struct xe_device_desc *desc = (const void *)ent-
> >driver_data;
> @@ -669,6 +703,8 @@ static int xe_pci_probe(struct pci_dev *pdev,
> const struct pci_device_id *ent)
>                 return err;
>         }
>  
> +       xe->d3cold_capable = xe_pci_d3cold_capable(pdev);
> +
>         xe_pm_runtime_init(xe);
>  
>         return 0;
> @@ -741,6 +777,7 @@ static int xe_pci_runtime_suspend(struct device
> *dev)
>                 pci_set_power_state(pdev, PCI_D3cold);
>         } else {
>                 pci_set_power_state(pdev, PCI_D3hot);
> +               xe_pci_d3cold_enable_disable(pdev, false);
>         }
>  
>         return 0;
> @@ -764,6 +801,8 @@ static int xe_pci_runtime_resume(struct device
> *dev)
>                         return err;
>  
>                 pci_set_master(pdev);
> +       } else {
> +               xe_pci_d3cold_enable_disable(pdev, true);
>         }
>  
>         return xe_pm_runtime_resume(xe);
> @@ -774,6 +813,13 @@ static int xe_pci_runtime_idle(struct device
> *dev)
>         struct pci_dev *pdev = to_pci_dev(dev);
>         struct xe_device *xe = pdev_to_xe_device(pdev);
>  
> +       if (!xe->d3cold_capable) {
> +               xe->d3cold_allowed = false;
> +               return 0;
> +       }
> +
> +       xe->d3cold_allowed = xe_pm_vram_d3cold_allowed(xe);
> +
>         /*
>          * TODO: d3cold should be allowed (true) if
>          * (IS_DGFX(xe) && !xe_device_mem_access_ongoing(xe))
> diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
> index b7b57f10ba25..523d5f89ec89 100644
> --- a/drivers/gpu/drm/xe/xe_pm.c
> +++ b/drivers/gpu/drm/xe/xe_pm.c
> @@ -16,6 +16,7 @@
>  #include "xe_ggtt.h"
>  #include "xe_gt.h"
>  #include "xe_irq.h"
> +#include "xe_module.h"
>  #include "xe_pcode.h"
>  
>  /**
> @@ -117,6 +118,25 @@ int xe_pm_resume(struct xe_device *xe)
>         return 0;
>  }
>  
> +bool xe_pm_vram_d3cold_allowed(struct xe_device *xe)
> +{
> +       struct ttm_resource_manager *man;
> +       u64 vram_used;
> +       size_t total_vram_used_mb = 0;
> +       int i;
> +
> +       /* TODO: Extend the logic to beyond XE_PL_VRAM1 */
> +       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);
> +               }
> +       }
> +
> +       return total_vram_used_mb < xe_vram_save_restore_threshold;
> +}
> +
>  void xe_pm_runtime_init(struct xe_device *xe)
>  {
>         struct device *dev = xe->drm.dev;
> diff --git a/drivers/gpu/drm/xe/xe_pm.h b/drivers/gpu/drm/xe/xe_pm.h
> index 6a885585f653..33515d5c2cc2 100644
> --- a/drivers/gpu/drm/xe/xe_pm.h
> +++ b/drivers/gpu/drm/xe/xe_pm.h
> @@ -17,6 +17,7 @@ void xe_pm_runtime_init(struct xe_device *xe);
>  void xe_pm_runtime_fini(struct xe_device *xe);
>  int xe_pm_runtime_suspend(struct xe_device *xe);
>  int xe_pm_runtime_resume(struct xe_device *xe);
> +bool xe_pm_vram_d3cold_allowed(struct xe_device *xe);
>  int xe_pm_runtime_get(struct xe_device *xe);
>  int xe_pm_runtime_put(struct xe_device *xe);
>  bool xe_pm_runtime_resume_if_suspended(struct xe_device *xe);



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