From 94cc81f9a8f995923e35e2db936741dd62d18350 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Wed, 10 Jun 2015 17:49:40 +0200 Subject: [PATCH] swiotlb: Warn on allocation failure in swiotlb_alloc_coherent() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Print a warning when all allocation tries have been failed and the function is about to return NULL. This prepares for calling the function with __GFP_NOWARN to suppress allocation failure warnings before all fall-backs have failed - which we'll do to improve kdump behavior. Signed-off-by: Joerg Roedel Signed-off-by: Borislav Petkov Acked-by: Konrad Rzeszutek Wilk Acked-by: Baoquan He Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Young Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Jörg Rödel Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Vivek Goyal Cc: kexec@lists.infradead.org Link: http://lkml.kernel.org/r/1433500202-25531-2-git-send-email-joro@8bytes.org Signed-off-by: Ingo Molnar --- lib/swiotlb.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/lib/swiotlb.c b/lib/swiotlb.c index 3c365ab6cf5f..42e192decbfd 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -656,7 +656,7 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size, */ phys_addr_t paddr = map_single(hwdev, 0, size, DMA_FROM_DEVICE); if (paddr == SWIOTLB_MAP_ERROR) - return NULL; + goto err_warn; ret = phys_to_virt(paddr); dev_addr = phys_to_dma(hwdev, paddr); @@ -670,7 +670,7 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size, /* DMA_TO_DEVICE to avoid memcpy in unmap_single */ swiotlb_tbl_unmap_single(hwdev, paddr, size, DMA_TO_DEVICE); - return NULL; + goto err_warn; } } @@ -678,6 +678,13 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size, memset(ret, 0, size); return ret; + +err_warn: + pr_warn("swiotlb: coherent allocation failed for device %s size=%zu\n", + dev_name(hwdev), size); + dump_stack(); + + return NULL; } EXPORT_SYMBOL(swiotlb_alloc_coherent); -- 2.20.1