On Fri, Feb 07, 2025 at 05:43:34PM +0100, Nirmoy Das wrote:
Top of stolen memory is wopcm which shouldn't be accessed so remove
that portion of memory from the stolen memory.
humn... we are already doing this for integrated. The copy & paste is
small here to deserve a refactor, but maybe mention that this is already
done for integrated and it was missed on the discrete side?
Fixes: d8b52a02cb40 ("drm/xe: Implement stolen memory.")
Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Cc: Matthew Auld <matthew.auld@xxxxxxxxx>
Cc: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # v6.8+
I'd rather do this 6.11+. It's not important before that as we didn't
have any platform out of force probe or close to be out of force probe.
We will most likely not be able to apply this patch on 6.8.
Signed-off-by: Nirmoy Das <nirmoy.das@xxxxxxxxx>
---
drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c | 54 ++++++++++++++------------
1 file changed, 30 insertions(+), 24 deletions(-)
diff --git a/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c b/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
index 423856cc18d4..d414421f8c13 100644
--- a/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
+++ b/drivers/gpu/drm/xe/xe_ttm_stolen_mgr.c
@@ -57,12 +57,35 @@ bool xe_ttm_stolen_cpu_access_needs_ggtt(struct xe_device *xe)
return GRAPHICS_VERx100(xe) < 1270 && !IS_DGFX(xe);
}
+static u32 get_wopcm_size(struct xe_device *xe)
+{
+ u32 wopcm_size;
+ u64 val;
+
+ val = xe_mmio_read64_2x32(xe_root_tile_mmio(xe), STOLEN_RESERVED);
+ val = REG_FIELD_GET64(WOPCM_SIZE_MASK, val);
+
+ switch (val) {
+ case 0x5 ... 0x6:
+ val--;
+ fallthrough;
+ case 0x0 ... 0x3:
+ wopcm_size = (1U << val) * SZ_1M;
+ break;
+ default:
+ WARN(1, "Missing case wopcm_size=%llx\n", val);
+ wopcm_size = 0;
+ }
+
+ return wopcm_size;
+}
Please also mention in the commit message the code movement here, that
is done just for the function to be called by detect_bar2_dgfx()
Other than that, Reviewed-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
thanks
Lucas De Marchi
+
static s64 detect_bar2_dgfx(struct xe_device *xe, struct xe_ttm_stolen_mgr *mgr)
{
struct xe_tile *tile = xe_device_get_root_tile(xe);
struct xe_mmio *mmio = xe_root_tile_mmio(xe);
struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
- u64 stolen_size;
+ u64 stolen_size, wopcm_size;
u64 tile_offset;
u64 tile_size;
@@ -74,7 +97,13 @@ static s64 detect_bar2_dgfx(struct xe_device *xe, struct xe_ttm_stolen_mgr *mgr)
if (drm_WARN_ON(&xe->drm, tile_size < mgr->stolen_base))
return 0;
+ /* Carve out the top of DSM as it contains the reserved WOPCM region */
+ wopcm_size = get_wopcm_size(xe);
+ if (drm_WARN_ON(&xe->drm, !wopcm_size))
+ return 0;
+
stolen_size = tile_size - mgr->stolen_base;
+ stolen_size -= wopcm_size;
/* Verify usage fits in the actual resource available */
if (mgr->stolen_base + stolen_size <= pci_resource_len(pdev, LMEM_BAR))
@@ -89,29 +118,6 @@ static s64 detect_bar2_dgfx(struct xe_device *xe, struct xe_ttm_stolen_mgr *mgr)
return ALIGN_DOWN(stolen_size, SZ_1M);
}
-static u32 get_wopcm_size(struct xe_device *xe)
-{
- u32 wopcm_size;
- u64 val;
-
- val = xe_mmio_read64_2x32(xe_root_tile_mmio(xe), STOLEN_RESERVED);
- val = REG_FIELD_GET64(WOPCM_SIZE_MASK, val);
-
- switch (val) {
- case 0x5 ... 0x6:
- val--;
- fallthrough;
- case 0x0 ... 0x3:
- wopcm_size = (1U << val) * SZ_1M;
- break;
- default:
- WARN(1, "Missing case wopcm_size=%llx\n", val);
- wopcm_size = 0;
- }
-
- return wopcm_size;
-}
-
static u32 detect_bar2_integrated(struct xe_device *xe, struct xe_ttm_stolen_mgr *mgr)
{
struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
--
2.46.0
