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authorYinghai Lu <yinghai@kernel.org>2013-01-25 00:20:16 +0400
committerH. Peter Anvin <hpa@linux.intel.com>2013-01-30 07:36:53 +0400
commitac2cbab21f318e19bc176a7f38a120cec835220f (patch)
tree1348f7e5a7e50b85bf56a9e1155bed70be13cd51
parent38fa4175e60d98fb1c9815fb14f8057576dade73 (diff)
downloadlinux-ac2cbab21f318e19bc176a7f38a120cec835220f.tar.xz
x86: Don't panic if can not alloc buffer for swiotlb
Normal boot path on system with iommu support: swiotlb buffer will be allocated early at first and then try to initialize iommu, if iommu for intel or AMD could setup properly, swiotlb buffer will be freed. The early allocating is with bootmem, and could panic when we try to use kdump with buffer above 4G only, or with memmap to limit mem under 4G. for example: memmap=4095M$1M to remove memory under 4G. According to Eric, add _nopanic version and no_iotlb_memory to fail map single later if swiotlb is still needed. -v2: don't pass nopanic, and use -ENOMEM return value according to Eric. panic early instead of using swiotlb_full to panic...according to Eric/Konrad. -v3: make swiotlb_init to be notpanic, but will affect: arm64, ia64, powerpc, tile, unicore32, x86. -v4: cleanup swiotlb_init by removing swiotlb_init_with_default_size. Suggested-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1359058816-7615-36-git-send-email-yinghai@kernel.org Reviewed-and-tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Andrzej Pietrasiewicz <andrzej.p@samsung.com> Cc: linux-mips@linux-mips.org Cc: xen-devel@lists.xensource.com Cc: virtualization@lists.linux-foundation.org Cc: Shuah Khan <shuahkhan@gmail.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
-rw-r--r--arch/mips/cavium-octeon/dma-octeon.c3
-rw-r--r--drivers/xen/swiotlb-xen.c4
-rw-r--r--include/linux/swiotlb.h2
-rw-r--r--lib/swiotlb.c47
4 files changed, 35 insertions, 21 deletions
diff --git a/arch/mips/cavium-octeon/dma-octeon.c b/arch/mips/cavium-octeon/dma-octeon.c
index 41dd00884975..02f244475207 100644
--- a/arch/mips/cavium-octeon/dma-octeon.c
+++ b/arch/mips/cavium-octeon/dma-octeon.c
@@ -317,7 +317,8 @@ void __init plat_swiotlb_setup(void)
octeon_swiotlb = alloc_bootmem_low_pages(swiotlbsize);
- swiotlb_init_with_tbl(octeon_swiotlb, swiotlb_nslabs, 1);
+ if (swiotlb_init_with_tbl(octeon_swiotlb, swiotlb_nslabs, 1) == -ENOMEM)
+ panic("Cannot allocate SWIOTLB buffer");
mips_dma_map_ops = &octeon_linear_dma_map_ops.dma_map_ops;
}
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index af47e7594460..1d94316f0ea4 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -231,7 +231,9 @@ retry:
}
start_dma_addr = xen_virt_to_bus(xen_io_tlb_start);
if (early) {
- swiotlb_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs, verbose);
+ if (swiotlb_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs,
+ verbose))
+ panic("Cannot allocate SWIOTLB buffer");
rc = 0;
} else
rc = swiotlb_late_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs);
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 071d62c214a6..2de42f9401d2 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -23,7 +23,7 @@ extern int swiotlb_force;
#define IO_TLB_SHIFT 11
extern void swiotlb_init(int verbose);
-extern void swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose);
+int swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose);
extern unsigned long swiotlb_nr_tbl(void);
extern int swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs);
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 196b06984dec..bfe02b8fc55b 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -122,11 +122,18 @@ static dma_addr_t swiotlb_virt_to_bus(struct device *hwdev,
return phys_to_dma(hwdev, virt_to_phys(address));
}
+static bool no_iotlb_memory;
+
void swiotlb_print_info(void)
{
unsigned long bytes = io_tlb_nslabs << IO_TLB_SHIFT;
unsigned char *vstart, *vend;
+ if (no_iotlb_memory) {
+ pr_warn("software IO TLB: No low mem\n");
+ return;
+ }
+
vstart = phys_to_virt(io_tlb_start);
vend = phys_to_virt(io_tlb_end);
@@ -136,7 +143,7 @@ void swiotlb_print_info(void)
bytes >> 20, vstart, vend - 1);
}
-void __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
+int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
{
void *v_overflow_buffer;
unsigned long i, bytes;
@@ -150,9 +157,10 @@ void __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
/*
* Get the overflow emergency buffer
*/
- v_overflow_buffer = alloc_bootmem_low_pages(PAGE_ALIGN(io_tlb_overflow));
+ v_overflow_buffer = alloc_bootmem_low_pages_nopanic(
+ PAGE_ALIGN(io_tlb_overflow));
if (!v_overflow_buffer)
- panic("Cannot allocate SWIOTLB overflow buffer!\n");
+ return -ENOMEM;
io_tlb_overflow_buffer = __pa(v_overflow_buffer);
@@ -169,15 +177,19 @@ void __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
if (verbose)
swiotlb_print_info();
+
+ return 0;
}
/*
* Statically reserve bounce buffer space and initialize bounce buffer data
* structures for the software IO TLB used to implement the DMA API.
*/
-static void __init
-swiotlb_init_with_default_size(size_t default_size, int verbose)
+void __init
+swiotlb_init(int verbose)
{
+ /* default to 64MB */
+ size_t default_size = 64UL<<20;
unsigned char *vstart;
unsigned long bytes;
@@ -188,20 +200,16 @@ swiotlb_init_with_default_size(size_t default_size, int verbose)
bytes = io_tlb_nslabs << IO_TLB_SHIFT;
- /*
- * Get IO TLB memory from the low pages
- */
- vstart = alloc_bootmem_low_pages(PAGE_ALIGN(bytes));
- if (!vstart)
- panic("Cannot allocate SWIOTLB buffer");
-
- swiotlb_init_with_tbl(vstart, io_tlb_nslabs, verbose);
-}
+ /* Get IO TLB memory from the low pages */
+ vstart = alloc_bootmem_low_pages_nopanic(PAGE_ALIGN(bytes));
+ if (vstart && !swiotlb_init_with_tbl(vstart, io_tlb_nslabs, verbose))
+ return;
-void __init
-swiotlb_init(int verbose)
-{
- swiotlb_init_with_default_size(64 * (1<<20), verbose); /* default to 64MB */
+ if (io_tlb_start)
+ free_bootmem(io_tlb_start,
+ PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT));
+ pr_warn("Cannot allocate SWIOTLB buffer");
+ no_iotlb_memory = true;
}
/*
@@ -405,6 +413,9 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
unsigned long offset_slots;
unsigned long max_slots;
+ if (no_iotlb_memory)
+ panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer");
+
mask = dma_get_seg_boundary(hwdev);
tbl_dma_addr &= mask;