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From: Boris Brezillon <boris.brezillon@collabora.com>
To: Rob Herring <robh+dt@kernel.org>,
	Tomeu Vizoso <tomeu@tomeuvizoso.net>,
	Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>,
	Steven Price <steven.price@arm.com>,
	Robin Murphy <robin.murphy@arm.com>
Cc: dri-devel@lists.freedesktop.org,
	Boris Brezillon <boris.brezillon@collabora.com>,
	stable@vger.kernel.org
Subject: [PATCH 2/3] drm/panfrost: Don't try to map pages that are already mapped
Date: Mon,  1 Feb 2021 09:21:15 +0100	[thread overview]
Message-ID: <20210201082116.267208-3-boris.brezillon@collabora.com> (raw)
In-Reply-To: <20210201082116.267208-1-boris.brezillon@collabora.com>

We allocate 2MB chunks at a time, so it might appear that a page fault
has already been handled by a previous page fault when we reach
panfrost_mmu_map_fault_addr(). Bail out in that case to avoid mapping the
same area twice.

Cc: <stable@vger.kernel.org>
Fixes: 187d2929206e ("drm/panfrost: Add support for GPU heap allocations")
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
---
 drivers/gpu/drm/panfrost/panfrost_mmu.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
index 904d63450862..21e552d1ac71 100644
--- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
+++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
@@ -488,8 +488,14 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
 		}
 		bo->base.pages = pages;
 		bo->base.pages_use_count = 1;
-	} else
+	} else {
 		pages = bo->base.pages;
+		if (pages[page_offset]) {
+			/* Pages are already mapped, bail out. */
+			mutex_unlock(&bo->base.pages_lock);
+			goto out;
+		}
+	}
 
 	mapping = bo->base.base.filp->f_mapping;
 	mapping_set_unevictable(mapping);
@@ -522,6 +528,7 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
 
 	dev_dbg(pfdev->dev, "mapped page fault @ AS%d %llx", as, addr);
 
+out:
 	panfrost_gem_mapping_put(bomapping);
 
 	return 0;
-- 
2.26.2


WARNING: multiple messages have this Message-ID (diff)
From: Boris Brezillon <boris.brezillon@collabora.com>
To: Rob Herring <robh+dt@kernel.org>,
	Tomeu Vizoso <tomeu@tomeuvizoso.net>,
	Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>,
	Steven Price <steven.price@arm.com>,
	Robin Murphy <robin.murphy@arm.com>
Cc: Boris Brezillon <boris.brezillon@collabora.com>,
	stable@vger.kernel.org, dri-devel@lists.freedesktop.org
Subject: [PATCH 2/3] drm/panfrost: Don't try to map pages that are already mapped
Date: Mon,  1 Feb 2021 09:21:15 +0100	[thread overview]
Message-ID: <20210201082116.267208-3-boris.brezillon@collabora.com> (raw)
In-Reply-To: <20210201082116.267208-1-boris.brezillon@collabora.com>

We allocate 2MB chunks at a time, so it might appear that a page fault
has already been handled by a previous page fault when we reach
panfrost_mmu_map_fault_addr(). Bail out in that case to avoid mapping the
same area twice.

Cc: <stable@vger.kernel.org>
Fixes: 187d2929206e ("drm/panfrost: Add support for GPU heap allocations")
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
---
 drivers/gpu/drm/panfrost/panfrost_mmu.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
index 904d63450862..21e552d1ac71 100644
--- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
+++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
@@ -488,8 +488,14 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
 		}
 		bo->base.pages = pages;
 		bo->base.pages_use_count = 1;
-	} else
+	} else {
 		pages = bo->base.pages;
+		if (pages[page_offset]) {
+			/* Pages are already mapped, bail out. */
+			mutex_unlock(&bo->base.pages_lock);
+			goto out;
+		}
+	}
 
 	mapping = bo->base.base.filp->f_mapping;
 	mapping_set_unevictable(mapping);
@@ -522,6 +528,7 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
 
 	dev_dbg(pfdev->dev, "mapped page fault @ AS%d %llx", as, addr);
 
+out:
 	panfrost_gem_mapping_put(bomapping);
 
 	return 0;
-- 
2.26.2

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  parent reply	other threads:[~2021-02-01  8:22 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-01  8:21 [PATCH 0/3] drm/panfrost: MMU fixes Boris Brezillon
2021-02-01  8:21 ` [PATCH 1/3] drm/panfrost: Clear MMU irqs before handling the fault Boris Brezillon
2021-02-01  8:21   ` Boris Brezillon
2021-02-01 12:13   ` Steven Price
2021-02-01 12:13     ` Steven Price
2021-02-01  8:21 ` Boris Brezillon [this message]
2021-02-01  8:21   ` [PATCH 2/3] drm/panfrost: Don't try to map pages that are already mapped Boris Brezillon
2021-02-01 12:13   ` Steven Price
2021-02-01 12:13     ` Steven Price
2021-02-01  8:21 ` [PATCH 3/3] drm/panfrost: Stay in the threaded MMU IRQ handler until we've handled all IRQs Boris Brezillon
2021-02-01 12:13   ` Steven Price
2021-02-01 12:59     ` Boris Brezillon
2021-02-01 13:24       ` Steven Price
2021-02-01 13:47         ` Boris Brezillon
2021-02-03 14:45   ` Rob Herring
2021-02-03 15:43     ` Steven Price

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