swiotlb: Warn on allocation failure in swiotlb_alloc_coherent()
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 <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jörg Rödel <joro@8bytes.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
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 <mingo@kernel.org>
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 3c365ab..42e192d 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -656,7 +656,7 @@
*/
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 @@
/* 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 @@
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);