[Intel-gfx] [PATCH 2/2] drm/i915: Add lmem_bar_size modparam

[priyanka.dandamudi at intel.com]

From: Priyanka Dandamudi <priyanka.dandamudi at intel.com>

lmem_bar_size is used to resize lmem bar.
It sets to only one of the supported sizes.
Setting this param will be in MB unit.

Cc: Matthew Auld <matthew.auld at intel.com>
Signed-off-by: Priyanka Dandamudi <priyanka.dandamudi at intel.com>
---
 drivers/gpu/drm/i915/gt/intel_region_lmem.c |  3 +++
 drivers/gpu/drm/i915/i915_driver.c          | 25 ++++++++++++++++++++-
 drivers/gpu/drm/i915/i915_params.c          |  2 ++
 drivers/gpu/drm/i915/i915_params.h          |  1 +
 4 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_region_lmem.c b/drivers/gpu/drm/i915/gt/intel_region_lmem.c
index 119e53f5d9b1..d73d8b2adfa2 100644
--- a/drivers/gpu/drm/i915/gt/intel_region_lmem.c
+++ b/drivers/gpu/drm/i915/gt/intel_region_lmem.c
@@ -132,6 +132,9 @@ static struct intel_memory_region *setup_lmem(struct intel_gt *gt)
 				  mul_u32_u32(i915->params.lmem_size, SZ_1M));
 	}
 
+	if (i915->params.lmem_bar_size > 0)
+		lmem_size = pci_resource_len(pdev, 2);
+
 	io_start = pci_resource_start(pdev, 2);
 	io_size = min(pci_resource_len(pdev, 2), lmem_size);
 	if (!io_size)
diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
index 8d33a6a31675..2f5d7a1f1a7b 100644
--- a/drivers/gpu/drm/i915/i915_driver.c
+++ b/drivers/gpu/drm/i915/i915_driver.c
@@ -371,7 +371,30 @@ static void i915_resize_lmem_bar(struct drm_i915_private *i915)
 	u32 pci_cmd;
 	int i;
 
-	if (!rebar_size)
+	if (i915->params.lmem_bar_size > 0) {
+		u32 lmem_bar_size;
+		u32 set_bit;
+		u32 rebar;
+		u32 msb;
+		int k;
+
+		lmem_bar_size = i915->params.lmem_bar_size;
+		rebar = pci_rebar_get_possible_sizes(pdev, LMEM_BAR_NUM);
+		msb = __fls(rebar);
+
+		for (k = msb; k >= 0; k--) {
+			set_bit = (1 << k);
+
+			if (set_bit & rebar)
+				if (set_bit == lmem_bar_size) {
+					rebar_size = 1ULL << (__fls(lmem_bar_size) + BAR_SIZE_SHIFT);
+
+					if (rebar_size == pci_resource_len(pdev, LMEM_BAR_NUM))
+						return;
+					break;
+				}
+		}
+	} else if (!rebar_size)
 		return;
 
 	/* Find out if root bus contains 64bit memory addressing */
diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index 701fbc98afa0..6fc475a5db61 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -204,6 +204,8 @@ i915_param_named_unsafe(request_timeout_ms, uint, 0600,
 
 i915_param_named_unsafe(lmem_size, uint, 0400,
 			"Set the lmem size(in MiB) for each region. (default: 0, all memory)");
+i915_param_named_unsafe(lmem_bar_size, uint, 0400,
+			"Set the lmem bar size(in MiB).");
 
 static __always_inline void _print_param(struct drm_printer *p,
 					 const char *name,
diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h
index b5e7ea45d191..2733cb6cfe09 100644
--- a/drivers/gpu/drm/i915/i915_params.h
+++ b/drivers/gpu/drm/i915/i915_params.h
@@ -74,6 +74,7 @@ struct drm_printer;
 	param(char *, force_probe, CONFIG_DRM_I915_FORCE_PROBE, 0400) \
 	param(unsigned int, request_timeout_ms, CONFIG_DRM_I915_REQUEST_TIMEOUT, CONFIG_DRM_I915_REQUEST_TIMEOUT ? 0600 : 0) \
 	param(unsigned int, lmem_size, 0, 0400) \
+	param(unsigned int, lmem_bar_size, 0, 0400) \
 	/* leave bools at the end to not create holes */ \
 	param(bool, enable_hangcheck, true, 0600) \
 	param(bool, load_detect_test, false, 0600) \
-- 
2.27.0