[PATCH v4 1/2] drm/xe/xe_debugfs: Exposure of G-State and pcie link state residency counters through debugfs

[Poosa, Karthik]

On 17-06-2025 22:45, Soham Purkait wrote:
> Add two debugfs node named dgfx_pkg_residencies and dgfx_link_state_residencys
> in order to obtain the G-State residency counter values for G2, G6, G8, G10 &
> ModS and the pcie link state residency counter values for L0, L1 & L1.2
> respectively.
>
> V1 : Expose all G-State residency counter values under dgfx_pkg_residencies. (Anshuman)
>       Included runtime_get/put and removed drm_warn. (Riana)
>
> v2 : Moved dgfx_pkg_residencies from "/sys/kernel/debug/gtidle/" to "/sys/kernel/debug/".
>       Included dgfx_link_state_residencys for dgfx_link_state_residencys.       (Anshuman)
>
> v3 : Included check for BMG and dgfx and helper function for repetitive code.  (Riana)
>       Used drm_info_list to create the debugfs. (Karthik)
>
> Signed-off-by: Soham Purkait <soham.purkait at intel.com>
> ---
>   drivers/gpu/drm/xe/xe_debugfs.c | 71 +++++++++++++++++++++++++++++++++
>   1 file changed, 71 insertions(+)
>
> diff --git a/drivers/gpu/drm/xe/xe_debugfs.c b/drivers/gpu/drm/xe/xe_debugfs.c
> index d83cd6ed3fa8..39c5fce3e4fd 100644
> --- a/drivers/gpu/drm/xe/xe_debugfs.c
> +++ b/drivers/gpu/drm/xe/xe_debugfs.c
> @@ -11,16 +11,19 @@
>   
>   #include <drm/drm_debugfs.h>
>   
> +#include "regs/xe_pmt.h"
>   #include "xe_bo.h"
>   #include "xe_device.h"
>   #include "xe_force_wake.h"
>   #include "xe_gt_debugfs.h"
>   #include "xe_gt_printk.h"
>   #include "xe_guc_ads.h"
> +#include "xe_mmio.h"
>   #include "xe_pm.h"
>   #include "xe_pxp_debugfs.h"
>   #include "xe_sriov.h"
>   #include "xe_step.h"
> +#include "xe_vsec.h"
>   
>   #ifdef CONFIG_DRM_XE_DEBUG
>   #include "xe_bo_evict.h"
> @@ -30,6 +33,23 @@
>   
>   DECLARE_FAULT_ATTR(gt_reset_failure);
>   
> +static int read_residency_counter(struct xe_device *xe, struct xe_mmio *mmio,
> +				  u32 offset, char *name, struct drm_printer *p)
> +{
> +	u64 residency = 0;
> +	int ret;
> +
> +	ret = xe_pmt_telem_read(to_pci_dev(xe->drm.dev),
> +				xe_mmio_read32(mmio, PUNIT_TELEMETRY_GUID),
> +				&residency, offset, sizeof(residency));
> +	drm_printf(p, "%s : %llu\n", name, residency);
> +
> +	if (ret != sizeof(residency))
> +		drm_warn(&xe->drm, "%s counter failed to read, ret %d\n", name, ret);
> +
> +	return 0;
> +}
> +
>   static struct xe_device *node_to_xe(struct drm_info_node *node)
>   {
>   	return to_xe_device(node->minor->dev);
> @@ -82,11 +102,57 @@ static int sriov_info(struct seq_file *m, void *data)
>   	return 0;
>   }
>   
> +static int dgfx_pkg_residencies_show(struct seq_file *m, void *data)
> +{
> +	struct xe_device *xe;
> +	struct xe_mmio *mmio;
> +	struct drm_printer p;
> +
> +	xe = node_to_xe(m->private);
> +	p = drm_seq_file_printer(m);
> +	xe_pm_runtime_get(xe);
> +	mmio = xe_root_tile_mmio(xe);
> +
> +	read_residency_counter(xe, mmio, BMG_G2_RESIDENCY_OFFSET, "Package G2", &p);
> +	read_residency_counter(xe, mmio, BMG_G6_RESIDENCY_OFFSET, "Package G6", &p);
> +	read_residency_counter(xe, mmio, BMG_G8_RESIDENCY_OFFSET, "Package G8", &p);
> +	read_residency_counter(xe, mmio, BMG_G10_RESIDENCY_OFFSET, "Package G10", &p);
> +	read_residency_counter(xe, mmio, BMG_MODS_RESIDENCY_OFFSET, "Package ModS", &p);
> +	xe_pm_runtime_put(xe);
> +	return 0;
> +}
> +
> +static int dgfx_link_state_residencies_show(struct seq_file *m, void *data)
> +{
> +	struct xe_device *xe;
> +	struct xe_mmio *mmio;
> +	struct drm_printer p;
> +
> +	xe = node_to_xe(m->private);
> +	p = drm_seq_file_printer(m);
> +	xe_pm_runtime_get(xe);
> +	mmio = xe_root_tile_mmio(xe);
> +
> +	read_residency_counter(xe, mmio, PCIE_LINK_L0_RESIDENCY_COUNTER,
> +			       "PCIE LINK L0 RESIDENCY", &p);
> +	read_residency_counter(xe, mmio, PCIE_LINK_L0_RESIDENCY_COUNTER,

register offset is wrong!
it should be PCIE_LINK_L1_RESIDENCY_COUNTER

> +			       "PCIE LINK L1 RESIDENCY", &p);
> +	read_residency_counter(xe, mmio, PCIE_LINK_L0_RESIDENCY_COUNTER,
same as above offset should be PCIE_LINK_L1_2_RESIDENCY_COUNTER.
> +			       "PCIE LINK L1.2 RESIDENCY", &p);
> +	xe_pm_runtime_put(xe);
> +	return 0;
> +}
> +
>   static const struct drm_info_list debugfs_list[] = {
>   	{"info", info, 0},
>   	{ .name = "sriov_info", .show = sriov_info, },
>   };
>   
> +static const struct drm_info_list debugfs_residencies[] = {
> +	{ .name = "dgfx_pkg_residencies", .show = dgfx_pkg_residencies_show, },
> +	{ .name = "dgfx_link_state_residencies", .show = dgfx_link_state_residencies_show, },
> +};
> +
>   static int forcewake_open(struct inode *inode, struct file *file)
>   {
>   	struct xe_device *xe = inode->i_private;
> @@ -240,6 +306,11 @@ void xe_debugfs_register(struct xe_device *xe)
>   				 ARRAY_SIZE(debugfs_list),
>   				 root, minor);
>   
> +	if (IS_DGFX(xe) && xe->info.platform == XE_BATTLEMAGE)
> +		drm_debugfs_create_files(debugfs_residencies,
> +					 ARRAY_SIZE(debugfs_residencies),
> +					 root, minor);
> +
>   	debugfs_create_file("forcewake_all", 0400, root, xe,
>   			    &forcewake_all_fops);
>