drm/ttm: Add an allocation flag to propagate -ENOSPC on OOM

Some graphics APIs differentiate between out-of-graphics-memory and
out-of-host-memory (system memory). Add a device init flag to have -ENOSPC
propagated from the resource managers instead of being converted to
-ENOMEM, to aid driver stacks in determining what error code to return or
whether corrective action can be taken at the driver level.

Co-developed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Tvrtko Ursulin <tursulin@ursulin.net>
Link: https://lore.kernel.org/r/20251020115411.36818-7-tvrtko.ursulin@igalia.com

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 44559dbf62f906bc4aa60fb3c72348674051b1f5..c4e669686fd63ff982e7d310f807cccfac38a87c 100644 (file)
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -32,6 +32,7 @@
 #define pr_fmt(fmt) "[TTM] " fmt
 
 #include <drm/drm_print.h>
+#include <drm/ttm/ttm_allocation.h>
 #include <drm/ttm/ttm_bo.h>
 #include <drm/ttm/ttm_placement.h>
 #include <drm/ttm/ttm_tt.h>
@@ -878,7 +879,8 @@ bounce:
 
        /* For backward compatibility with userspace */
        if (ret == -ENOSPC)
-               return -ENOMEM;
+               return bo->bdev->alloc_flags & TTM_ALLOCATION_PROPAGATE_ENOSPC ?
+                      ret : -ENOMEM;
 
        /*
         * We might need to add a TTM.

diff --git a/drivers/gpu/drm/ttm/ttm_device.c b/drivers/gpu/drm/ttm/ttm_device.c
index 87c85ccb21ac092a22f43e262b536542eb7a6696..5c10e5fbf43b7f8c9f093aaf04193e18756d7b62 100644 (file)
--- a/drivers/gpu/drm/ttm/ttm_device.c
+++ b/drivers/gpu/drm/ttm/ttm_device.c
@@ -227,6 +227,7 @@ int ttm_device_init(struct ttm_device *bdev, const struct ttm_device_funcs *func
                return -ENOMEM;
        }
 
+       bdev->alloc_flags = alloc_flags;
        bdev->funcs = funcs;
 
        ttm_sys_man_init(bdev);

diff --git a/include/drm/ttm/ttm_allocation.h b/include/drm/ttm/ttm_allocation.h
index 8f85447603067006c375d2859ef65abd7cd3c7e6..655d1e44aba79f7f4f316cfcb9764548cd390756 100644 (file)
--- a/include/drm/ttm/ttm_allocation.h
+++ b/include/drm/ttm/ttm_allocation.h
@@ -7,5 +7,6 @@
 #define TTM_ALLOCATION_POOL_BENEFICIAL_ORDER(n)        ((n) & 0xff) /* Max order which caller can benefit from */
 #define TTM_ALLOCATION_POOL_USE_DMA_ALLOC      BIT(8) /* Use coherent DMA allocations. */
 #define TTM_ALLOCATION_POOL_USE_DMA32          BIT(9) /* Use GFP_DMA32 allocations. */
+#define TTM_ALLOCATION_PROPAGATE_ENOSPC                BIT(10) /* Do not convert ENOSPC from resource managers to ENOMEM. */
 
 #endif

diff --git a/include/drm/ttm/ttm_device.h b/include/drm/ttm/ttm_device.h
index 074b98572275b9f79aa28db56aeed4c571e53b61..d016360e5cebbc76d6918eccb44a7d01a40e412c 100644 (file)
--- a/include/drm/ttm/ttm_device.h
+++ b/include/drm/ttm/ttm_device.h
@@ -220,6 +220,11 @@ struct ttm_device {
         */
        struct list_head device_list;
 
+       /**
+        * @alloc_flags: TTM_ALLOCATION_ flags.
+        */
+       unsigned int alloc_flags;
+
        /**
         * @funcs: Function table for the device.
         * Constant after bo device init