swiotlb: suppress warning when __GFP_NOWARN is set

BugLink: http://bugs.launchpad.net/bugs/1749202
TTM tries to allocate coherent memory in chunks of 2MB first to improve
TLB efficiency and falls back to allocating 4K pages if that fails.

Suppress the warning when the 2MB allocations fails since there is a
valid fall back path.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reported-by: Mike Galbraith <efault@gmx.de>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=104082
CC: stable@vger.kernel.org
Signed-off-by: Christoph Hellwig <hch@lst.de>
(cherry picked from commit d0bc0c2a31c95002d37c3cc511ffdcab851b3256)
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>

diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index cea19aaf303c9f3c558dd8246205ed39f38dcc46..0d7f46fb993aa3d9f9a55d1332da5d0d20ca48b3 100644 (file)
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -586,7 +586,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
 
 not_found:
        spin_unlock_irqrestore(&io_tlb_lock, flags);
-       if (printk_ratelimit())
+       if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit())
                dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes)\n", size);
        return SWIOTLB_MAP_ERROR;
 found:
@@ -713,6 +713,7 @@ void *
 swiotlb_alloc_coherent(struct device *hwdev, size_t size,
                       dma_addr_t *dma_handle, gfp_t flags)
 {
+       bool warn = !(flags & __GFP_NOWARN);
        dma_addr_t dev_addr;
        void *ret;
        int order = get_order(size);
@@ -738,8 +739,8 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
                 * GFP_DMA memory; fall back on map_single(), which
                 * will grab memory from the lowest available address range.
                 */
-               phys_addr_t paddr = map_single(hwdev, 0, size,
-                                              DMA_FROM_DEVICE, 0);
+               phys_addr_t paddr = map_single(hwdev, 0, size, DMA_FROM_DEVICE,
+                                              warn ? 0 : DMA_ATTR_NO_WARN);
                if (paddr == SWIOTLB_MAP_ERROR)
                        goto err_warn;
 
@@ -769,9 +770,11 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
        return ret;
 
 err_warn:
-       pr_warn("swiotlb: coherent allocation failed for device %s size=%zu\n",
-               dev_name(hwdev), size);
-       dump_stack();
+       if (warn && printk_ratelimit()) {
+               pr_warn("swiotlb: coherent allocation failed for device %s size=%zu\n",
+                       dev_name(hwdev), size);
+               dump_stack();
+       }
 
        return NULL;
 }