From bfc9b713c82808174f6e7321461a1ef0cfeffd65 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>
Date: Mon, 13 Jul 2020 16:50:04 +0200
Subject: drm/ttm: cleanup io_mem interface with nouveau
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Git-commit: 4b8edc39a45f51eb304acb081020ec4f063d53a5
Patch-mainline: v5.9-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

Nouveau is the only user of this functionality and evicting io space
on -EAGAIN is really a misuse of the return code.

Instead switch to using -ENOSPC here which makes much more sense and
simplifies the code.

This could unbreak something as we now cleanly return EAGAIN, but the
chance for this are rather low.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/378237/
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/nouveau/nouveau_bo.c | 2 --
 drivers/gpu/drm/ttm/ttm_bo_util.c    | 4 ++--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index 61355cfb7335..a48652826f67 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -1505,8 +1505,6 @@ nouveau_ttm_io_mem_reserve(struct ttm_bo_device *bdev, struct ttm_mem_reg *reg)
 			if (ret != 1) {
 				if (WARN_ON(ret == 0))
 					return -EINVAL;
-				if (ret == -ENOSPC)
-					return -EAGAIN;
 				return ret;
 			}
 
diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index 5e0f3a9caedc..7d2c50fef456 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -116,7 +116,7 @@ static int ttm_mem_io_evict(struct ttm_mem_type_manager *man)
 	struct ttm_buffer_object *bo;
 
 	if (!man->use_io_reserve_lru || list_empty(&man->io_reserve_lru))
-		return -EAGAIN;
+		return -ENOSPC;
 
 	bo = list_first_entry(&man->io_reserve_lru,
 			      struct ttm_buffer_object,
@@ -143,7 +143,7 @@ int ttm_mem_io_reserve(struct ttm_bo_device *bdev,
 	    mem->bus.io_reserved_count++ == 0) {
 retry:
 		ret = bdev->driver->io_mem_reserve(bdev, mem);
-		if (ret == -EAGAIN) {
+		if (ret == -ENOSPC) {
 			ret = ttm_mem_io_evict(man);
 			if (ret == 0)
 				goto retry;
-- 
2.29.2