FAILED: patch "[PATCH] drm/i915/gt: Fix reservation address in ggtt_reserve_guc_top" failed to apply to 5.4-stable tree

The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x b7599d241778d0b10cdf7a5c755aa7db9b83250c
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2023100431-penalty-pegboard-c849@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From b7599d241778d0b10cdf7a5c755aa7db9b83250c Mon Sep 17 00:00:00 2001
From: Javier Pello <[email protected]>
Date: Sat, 2 Sep 2023 17:10:39 +0200
Subject: [PATCH] drm/i915/gt: Fix reservation address in ggtt_reserve_guc_top

There is an assertion in ggtt_reserve_guc_top that the global GTT is of size at least GUC_GGTT_TOP, which is not the case on a 32-bit platform; see commit 562d55d991b39ce376c492df2f7890fd6a541ffc ("drm/i915/bdw: Only use 2g GGTT for 32b platforms"). If GEM_BUG_ON is enabled, this triggers a BUG(); if GEM_BUG_ON is disabled, the subsequent reservation fails and the driver fails to initialise the device:

i915 0000:00:02.0: [drm:i915_init_ggtt [i915]] Failed to reserve top of GGTT for GuC
i915 0000:00:02.0: Device initialization failed (-28)
i915 0000:00:02.0: Please file a bug on drm/i915; see https://gitlab.freedesktop.org/drm/intel/-/wikis/How-to-file-i915-bugs for details.
i915: probe of 0000:00:02.0 failed with error -28

Make the reservation at the top of the available space, whatever that is, instead of assuming that the top will be GUC_GGTT_TOP.

index dd0ed941441a..da21f2786b5d 100644
@@ -511,20 +511,31 @@ void intel_ggtt_unbind_vma(struct i915_address_space *vm,
 	vm->clear_range(vm, vma_res->start, vma_res->vma_size);
 }
 
+/*
+ * Reserve the top of the GuC address space for firmware images. Addresses
+ * beyond GUC_GGTT_TOP in the GuC address space are inaccessible by GuC,
+ * which makes for a suitable range to hold GuC/HuC firmware images if the
+ * size of the GGTT is 4G. However, on a 32-bit platform the size of the GGTT
+ * is limited to 2G, which is less than GUC_GGTT_TOP, but we reserve a chunk
+ * of the same size anyway, which is far more than needed, to keep the logic
+ * in uc_fw_ggtt_offset() simple.
+ */
+#define GUC_TOP_RESERVE_SIZE (SZ_4G - GUC_GGTT_TOP)
+
 static int ggtt_reserve_guc_top(struct i915_ggtt *ggtt)
 {
-	u64 size;
+	u64 offset;
 	int ret;
 
 	if (!intel_uc_uses_guc(&ggtt->vm.gt->uc))
 		return 0;
 
-	GEM_BUG_ON(ggtt->vm.total <= GUC_GGTT_TOP);
-	size = ggtt->vm.total - GUC_GGTT_TOP;
+	GEM_BUG_ON(ggtt->vm.total <= GUC_TOP_RESERVE_SIZE);
+	offset = ggtt->vm.total - GUC_TOP_RESERVE_SIZE;
 
-	ret = i915_gem_gtt_reserve(&ggtt->vm, NULL, &ggtt->uc_fw, size,
-				   GUC_GGTT_TOP, I915_COLOR_UNEVICTABLE,
-				   PIN_NOEVICT);
+	ret = i915_gem_gtt_reserve(&ggtt->vm, NULL, &ggtt->uc_fw,
+				   GUC_TOP_RESERVE_SIZE, offset,
+				   I915_COLOR_UNEVICTABLE, PIN_NOEVICT);
 	if (ret)
 		drm_dbg(&ggtt->vm.i915->drm,
 			"Failed to reserve top of GGTT for GuC\n");