[Intel-gfx] [PATCH v5 11/19] drm/i915/lmem: Enable lmem for platforms with Flat CCS

[Lucas De Marchi]

On Tue, Feb 01, 2022 at 04:11:24PM +0530, Ramalingam C wrote:
>From: Abdiel Janulgue <abdiel.janulgue at linux.intel.com>
>
>A portion of device memory is reserved for Flat CCS so usable
>device memory will be reduced by size of Flat CCS. Size of
>Flat CCS is specified in “XEHPSDV_FLAT_CCS_BASE_ADDR”.
>So to get effective device memory we need to subtract
>total device memory by Flat CCS memory size.
>
>v2:
>  Addressed the small bar related issue [Matt]
>  Removed a reduntant check [Matt]
>
>Cc: Matthew Auld <matthew.auld at intel.com>
>Signed-off-by: Abdiel Janulgue <abdiel.janulgue at linux.intel.com>
>Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
>---
> drivers/gpu/drm/i915/gt/intel_gt.c          | 19 ++++++++++++++++
> drivers/gpu/drm/i915/gt/intel_gt.h          |  1 +
> drivers/gpu/drm/i915/gt/intel_region_lmem.c | 24 +++++++++++++++++++--
> drivers/gpu/drm/i915/i915_reg.h             |  3 +++
> 4 files changed, 45 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c
>index f59933abbb3a..e40d98cb3a2d 100644
>--- a/drivers/gpu/drm/i915/gt/intel_gt.c
>+++ b/drivers/gpu/drm/i915/gt/intel_gt.c
>@@ -911,6 +911,25 @@ u32 intel_gt_read_register_fw(struct intel_gt *gt, i915_reg_t reg)
> 	return intel_uncore_read_fw(gt->uncore, reg);
> }
>
>+u32 intel_gt_read_register(struct intel_gt *gt, i915_reg_t reg)
>+{
>+	int type;
>+	u8 sliceid, subsliceid;
>+
>+	for (type = 0; type < NUM_STEERING_TYPES; type++) {
>+		if (intel_gt_reg_needs_read_steering(gt, reg, type)) {
>+			intel_gt_get_valid_steering(gt, type, &sliceid,
>+						    &subsliceid);
>+			return intel_uncore_read_with_mcr_steering(gt->uncore,
>+								   reg,
>+								   sliceid,
>+								   subsliceid);
>+		}
>+	}
>+
>+	return intel_uncore_read(gt->uncore, reg);
>+}
>+
> void intel_gt_info_print(const struct intel_gt_info *info,
> 			 struct drm_printer *p)
> {
>diff --git a/drivers/gpu/drm/i915/gt/intel_gt.h b/drivers/gpu/drm/i915/gt/intel_gt.h
>index 2dad46c3eff2..0f571c8ee22b 100644
>--- a/drivers/gpu/drm/i915/gt/intel_gt.h
>+++ b/drivers/gpu/drm/i915/gt/intel_gt.h
>@@ -85,6 +85,7 @@ static inline bool intel_gt_needs_read_steering(struct intel_gt *gt,
> }
>
> u32 intel_gt_read_register_fw(struct intel_gt *gt, i915_reg_t reg);
>+u32 intel_gt_read_register(struct intel_gt *gt, i915_reg_t reg);
>
> void intel_gt_info_print(const struct intel_gt_info *info,
> 			 struct drm_printer *p);
>diff --git a/drivers/gpu/drm/i915/gt/intel_region_lmem.c b/drivers/gpu/drm/i915/gt/intel_region_lmem.c
>index 21215a080088..f1d37b46b505 100644
>--- a/drivers/gpu/drm/i915/gt/intel_region_lmem.c
>+++ b/drivers/gpu/drm/i915/gt/intel_region_lmem.c
>@@ -205,8 +205,28 @@ static struct intel_memory_region *setup_lmem(struct intel_gt *gt)
> 	if (!IS_DGFX(i915))
> 		return ERR_PTR(-ENODEV);
>
>-	/* Stolen starts from GSMBASE on DG1 */
>-	lmem_size = intel_uncore_read64(uncore, GEN12_GSMBASE);
>+	if (HAS_FLAT_CCS(i915)) {
>+		u64 tile_stolen, flat_ccs_base_addr_reg, flat_ccs_base;
>+
>+		lmem_size = pci_resource_len(pdev, 2);
>+		flat_ccs_base_addr_reg = intel_gt_read_register(gt, XEHPSDV_FLAT_CCS_BASE_ADDR);

nit since this will need a respin due to conflicts:
we usually call _reg an i915_reg_t variable. But here you have the
value, not the register. Maybe "flat_ccs_base_addr"?


>+		flat_ccs_base = (flat_ccs_base_addr_reg >> XEHPSDV_CCS_BASE_SHIFT) * SZ_64K;
>+
>+		if (GEM_WARN_ON(lmem_size < flat_ccs_base))
>+			return ERR_PTR(-ENODEV);
>+
>+		tile_stolen = lmem_size - flat_ccs_base;
>+
>+		/* If the FLAT_CCS_BASE_ADDR register is not populated, flag an error */
>+		if (tile_stolen == lmem_size)
>+			DRM_ERROR("CCS_BASE_ADDR register did not have expected value\n");

drm_err()

>+
>+		lmem_size -= tile_stolen;
>+	} else {
>+		/* Stolen starts from GSMBASE without CCS */
>+		lmem_size = intel_uncore_read64(&i915->uncore, GEN12_GSMBASE);
>+	}
>+
>
> 	io_start = pci_resource_start(pdev, 2);
> 	if (GEM_WARN_ON(lmem_size > pci_resource_len(pdev, 2)))
>diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
>index 0f36af8dc3a1..9b5423572fe9 100644
>--- a/drivers/gpu/drm/i915/i915_reg.h
>+++ b/drivers/gpu/drm/i915/i915_reg.h
>@@ -11651,6 +11651,9 @@ enum skl_power_gate {
> #define   SGGI_DIS			REG_BIT(15)
> #define   SGR_DIS			REG_BIT(13)
>
>+#define XEHPSDV_FLAT_CCS_BASE_ADDR             _MMIO(0x4910)
>+#define   XEHPSDV_CCS_BASE_SHIFT               8
>+

you will have a conflict here... I fixed it locally by moving to
gt/intel_gt_regs.h


With the above,

Reviewed-by: Lucas De Marchi <lucas.demarchi at intel.com>

Lucas De Marchi

> /* gamt regs */
> #define GEN8_L3_LRA_1_GPGPU _MMIO(0x4dd4)
> #define   GEN8_L3_LRA_1_GPGPU_DEFAULT_VALUE_BDW  0x67F1427F /* max/min for LRA1/2 */
>-- 
>2.20.1
>