From fb19798cc366eaacd68b6f59226120045e0b8f7e Mon Sep 17 00:00:00 2001 From: Tejas Upadhyay Date: Thu, 3 Sep 2026 21:46:06 +0530 Subject: [PATCH] drm/xe: Expose bad VRAM pages via debugfs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add a debugfs file "vram_bad_pages" that shows offlined and queued VRAM pages across all tiles. Each entry displays the page frame number, GPU page size, and status flag (R=reserved, P=pending, F=failed). example, cat /sys/kernel/debug/dri/0/vram_bad_pages max_pages: 10000 0x0000000000000000 : 0x0000000000001000 : R 0x0000000000001234 : 0x0000000000001000 : P 0x0000000000080000 : 0x0000000000001000 : R ← tile 1 addr v3(Michal): -add kernel doc v2(Sashikoi/Michal/Himal): -Remove block iteration, use offline and queue list only -Move platform check inside api Reviewed-by: Himal Prasad Ghimiray Reviewed-by: Rodrigo Vivi Cc: Michal Wajdeczko Signed-off-by: Tejas Upadhyay Signed-off-by: Matthew Brost Link: https://patch.msgid.link/20260903161553.528932-30-tejas.upadhyay@intel.com --- drivers/gpu/drm/xe/xe_debugfs.c | 3 + drivers/gpu/drm/xe/xe_ttm_vram_mgr.c | 71 ++++++++++++++++++++++ drivers/gpu/drm/xe/xe_ttm_vram_mgr.h | 1 + drivers/gpu/drm/xe/xe_ttm_vram_mgr_types.h | 2 + 4 files changed, 77 insertions(+) diff --git a/drivers/gpu/drm/xe/xe_debugfs.c b/drivers/gpu/drm/xe/xe_debugfs.c index 28135f84e286..cb24e001b142 100644 --- a/drivers/gpu/drm/xe/xe_debugfs.c +++ b/drivers/gpu/drm/xe/xe_debugfs.c @@ -32,6 +32,7 @@ #include "xe_sriov_vf.h" #include "xe_step.h" #include "xe_tile_debugfs.h" +#include "xe_ttm_vram_mgr.h" #include "xe_vsec.h" #include "xe_wa.h" @@ -773,6 +774,8 @@ void xe_debugfs_register(struct xe_device *xe) if (man) ttm_resource_manager_create_debugfs(man, root, "stolen_mm"); + xe_ttm_vram_debugfs_init(xe, root); + for_each_tile(tile, xe, tile_id) xe_tile_debugfs_register(tile); diff --git a/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c b/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c index f4810cb961df..3dcee4590126 100644 --- a/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c +++ b/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c @@ -5,6 +5,7 @@ */ #include +#include #include #include @@ -915,3 +916,73 @@ int xe_ttm_vram_handle_addr_fault(struct xe_device *xe, u64 addr) return xe_ttm_vram_reserve_page_at_addr(xe, addr - vr->dpa_base, vram_mgr, mm); } EXPORT_SYMBOL(xe_ttm_vram_handle_addr_fault); + +static int vram_bad_pages_show(struct seq_file *m, void *unused) +{ + struct xe_device *xe = m->private; + struct xe_ttm_vram_offline_resource *pos; + struct ttm_resource_manager *man; + struct xe_ttm_vram_mgr *mgr; + struct xe_tile *tile; + u8 id; + + man = ttm_manager_type(&xe->ttm, XE_PL_VRAM0); + if (man) + /* TODO Hook with RAS to show max_pages fetched from FW */ + seq_printf(m, "max_pages: %d\n", + to_xe_ttm_vram_mgr(man)->max_pages); + + for_each_tile(tile, xe, id) { + struct xe_vram_region *vr = tile->mem.vram; + + man = ttm_manager_type(&xe->ttm, XE_PL_VRAM0 + id); + if (!man || !vr) + continue; + mgr = to_xe_ttm_vram_mgr(man); + + rcu_read_lock(); + + list_for_each_entry_rcu(pos, &mgr->offlined_pages, offlined_link) { + u64 pfn; + + pfn = (pos->addr + vr->dpa_base) >> PAGE_SHIFT; + seq_printf(m, "0x%016llx : 0x%016lx : R\n", pfn, PAGE_SIZE); + } + + list_for_each_entry_rcu(pos, &mgr->queued_pages, queued_link) { + u64 pfn; + + pfn = (pos->addr + vr->dpa_base) >> PAGE_SHIFT; + seq_printf(m, "0x%016llx : 0x%016lx : %c\n", + pfn, PAGE_SIZE, pos->status ? 'F' : 'P'); + } + + rcu_read_unlock(); + } + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(vram_bad_pages); + +/** + * xe_ttm_vram_debugfs_init - Initialize VRAM debugfs interfaces + * @xe: The xe device structure pointer + * @root: The root dentry of the debugfs directory + * + * This function registers platform-specific VRAM debugfs files used for + * testing and debugging. Currently, it exposes the "vram_bad_pages" interface + * to inspect marked faulty memory pages, restricted specifically to the + * %XE_CRESCENTISLAND platform. + * + * Return: Void. + */ +void xe_ttm_vram_debugfs_init(struct xe_device *xe, struct dentry *root) +{ + /* + * TODO: Replace platform check with xe->info + * once the feature flag is plumbed through device info. + */ + if (xe->info.platform != XE_CRESCENTISLAND) + return; + debugfs_create_file("vram_bad_pages", 0444, root, xe, &vram_bad_pages_fops); +} diff --git a/drivers/gpu/drm/xe/xe_ttm_vram_mgr.h b/drivers/gpu/drm/xe/xe_ttm_vram_mgr.h index 764d493b4d50..48f39fd20e44 100644 --- a/drivers/gpu/drm/xe/xe_ttm_vram_mgr.h +++ b/drivers/gpu/drm/xe/xe_ttm_vram_mgr.h @@ -17,6 +17,7 @@ int __xe_ttm_vram_mgr_init(struct xe_device *xe, struct xe_ttm_vram_mgr *mgr, u32 mem_type, u64 size, u64 io_size, u64 default_page_size); int xe_ttm_vram_mgr_init(struct xe_device *xe, struct xe_vram_region *vram); +void xe_ttm_vram_debugfs_init(struct xe_device *xe, struct dentry *root); int xe_ttm_vram_mgr_alloc_sgt(struct xe_device *xe, struct ttm_resource *res, u64 offset, u64 length, diff --git a/drivers/gpu/drm/xe/xe_ttm_vram_mgr_types.h b/drivers/gpu/drm/xe/xe_ttm_vram_mgr_types.h index dc97b0ad0e51..efcf3e1d4e80 100644 --- a/drivers/gpu/drm/xe/xe_ttm_vram_mgr_types.h +++ b/drivers/gpu/drm/xe/xe_ttm_vram_mgr_types.h @@ -37,6 +37,8 @@ struct xe_ttm_vram_mgr { struct mutex lock; /** @mem_type: The TTM memory type */ u32 mem_type; + /** @max_pages: max pages that can be in offline queue retrieved from FW */ + u16 max_pages; }; /**