Attachment 127642 Details for Bug 98282 – drm/i915/gtt: Fix pte clear range

[patch] drm/i915/gtt: Fix pte clear range

0001-drm-i915-gtt-Fix-pte-clear-range.patch (text/plain), 2.61 KB, created by Mika Kuoppala on 2016-10-31 16:04:17 UTC

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Creator: Mika Kuoppala

Created: 2016-10-31 16:04:17 UTC

Size: 2.61 KB

patch

obsolete

>From 8a4cb9cc8a8bf0fa8c85159c6b908f097cd94825 Mon Sep 17 00:00:00 2001
>From: Mika Kuoppala <mika.kuoppala@intel.com>
>Date: Mon, 31 Oct 2016 15:02:18 +0200
>Subject: [PATCH 1/2] drm/i915/gtt: Fix pte clear range
>MIME-Version: 1.0
>Content-Type: text/plain; charset=UTF-8
>Content-Transfer-Encoding: 8bit
>
>Comparing pte index to a number of entries is wrong
>when clearing a range of pte entries. Use end marker
>of 'one past' to correctly point adequate number of
>ptes to the scratch page.
>
>v2: assert early instead of warning late (Chris)
>
>Fixes: d209b9c3cd28 ("drm/i915/gtt: Split gen8_ppgtt_clear_pte_range")
>References: https://bugs.freedesktop.org/show_bug.cgi?id=98282
>Cc: Chris Wilson <chris@chris-wilson.co.uk>
>Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
>Cc: Michel Thierry <michel.thierry@intel.com>
>Cc: MichaÅ Winiarski <michal.winiarski@intel.com>
>Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
>Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
>---
> drivers/gpu/drm/i915/i915_gem_gtt.c | 18 ++++++++++--------
> 1 file changed, 10 insertions(+), 8 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
>index e7afad5..5f5008f 100644
>--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
>+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
>@@ -712,13 +712,13 @@ static int gen8_48b_mm_switch(struct i915_hw_ppgtt *ppgtt,
>  */
> static bool gen8_ppgtt_clear_pt(struct i915_address_space *vm,
> 				struct i915_page_table *pt,
>-				uint64_t start,
>-				uint64_t length)
>+				const uint64_t start,
>+				const uint64_t length)
> {
> 	struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
>-	unsigned int pte_start = gen8_pte_index(start);
>-	unsigned int num_entries = gen8_pte_count(start, length);
>-	uint64_t pte;
>+	const unsigned int num_entries = gen8_pte_count(start, length);
>+	unsigned int pte = gen8_pte_index(start);
>+	unsigned int pte_end = pte + num_entries;
> 	gen8_pte_t *pt_vaddr;
> 	gen8_pte_t scratch_pte = gen8_pte_encode(vm->scratch_page.daddr,
> 						 I915_CACHE_LLC);
>@@ -726,7 +726,9 @@ static bool gen8_ppgtt_clear_pt(struct i915_address_space *vm,
> 	if (WARN_ON(!px_page(pt)))
> 		return false;
> 
>-	bitmap_clear(pt->used_ptes, pte_start, num_entries);
>+	GEM_BUG_ON(pte_end > GEN8_PTES);
>+
>+	bitmap_clear(pt->used_ptes, pte, num_entries);
> 
> 	if (bitmap_empty(pt->used_ptes, GEN8_PTES)) {
> 		free_pt(vm->dev, pt);
>@@ -735,8 +737,8 @@ static bool gen8_ppgtt_clear_pt(struct i915_address_space *vm,
> 
> 	pt_vaddr = kmap_px(pt);
> 
>-	for (pte = pte_start; pte < num_entries; pte++)
>-		pt_vaddr[pte] = scratch_pte;
>+	while (pte < pte_end)
>+		pt_vaddr[pte++] = scratch_pte;
> 
> 	kunmap_px(ppgtt, pt_vaddr);
> 
>-- 
>2.7.4
>

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Attachments on bug 98282: 127336 | 127337 | 127338 | 127339 | 127580 | 127642 | 127706

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