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author | Tiezhu Yang <yangtiezhu@loongson.cn> | 2020-04-21 19:59:46 +0800 |
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committer | Thomas Bogendoerfer <tsbogend@alpha.franken.de> | 2020-04-21 16:07:27 +0200 |
commit | 269b3a9ac538c4ae87f84be640b9fa89914a2489 (patch) | |
tree | f48c680cf9095b9c162f0d221b10e02668096c67 /arch/mips/kernel | |
parent | 2a3d47c94ebdfb97bd8aa95343c58b679cb11724 (diff) | |
download | linux-stable-269b3a9ac538c4ae87f84be640b9fa89914a2489.tar.gz linux-stable-269b3a9ac538c4ae87f84be640b9fa89914a2489.tar.bz2 linux-stable-269b3a9ac538c4ae87f84be640b9fa89914a2489.zip |
MIPS: Make sparse_init() using top-down allocation
In the current code, if CONFIG_SWIOTLB is set, when failed to get IO TLB
memory from the low pages by plat_swiotlb_setup(), it may lead to the boot
process failed with kernel panic.
(1) On the Loongson and SiByte platform
arch/mips/loongson64/dma.c
arch/mips/sibyte/common/dma.c
void __init plat_swiotlb_setup(void)
{
swiotlb_init(1);
}
kernel/dma/swiotlb.c
void __init
swiotlb_init(int verbose)
{
...
vstart = memblock_alloc_low(PAGE_ALIGN(bytes), PAGE_SIZE);
if (vstart && !swiotlb_init_with_tbl(vstart, io_tlb_nslabs, verbose))
return;
...
pr_warn("Cannot allocate buffer");
no_iotlb_memory = true;
}
phys_addr_t swiotlb_tbl_map_single()
{
...
if (no_iotlb_memory)
panic("Can not allocate SWIOTLB buffer earlier ...");
...
}
(2) On the Cavium OCTEON platform
arch/mips/cavium-octeon/dma-octeon.c
void __init plat_swiotlb_setup(void)
{
...
octeon_swiotlb = memblock_alloc_low(swiotlbsize, PAGE_SIZE);
if (!octeon_swiotlb)
panic("%s: Failed to allocate %zu bytes align=%lx\n",
__func__, swiotlbsize, PAGE_SIZE);
...
}
Because IO_TLB_DEFAULT_SIZE is 64M, if the rest size of low memory is less
than 64M when call plat_swiotlb_setup(), we can easily reproduce the panic
case.
In order to reduce the possibility of kernel panic when failed to get IO
TLB memory under CONFIG_SWIOTLB, it is better to allocate low memory as
small as possible before plat_swiotlb_setup(), so make sparse_init() using
top-down allocation.
Reported-by: Juxin Gao <gaojuxin@loongson.cn>
Co-developed-by: Juxin Gao <gaojuxin@loongson.cn>
Signed-off-by: Juxin Gao <gaojuxin@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Diffstat (limited to 'arch/mips/kernel')
-rw-r--r-- | arch/mips/kernel/setup.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c index 5481a0c68521..8db533cd816c 100644 --- a/arch/mips/kernel/setup.c +++ b/arch/mips/kernel/setup.c @@ -700,7 +700,17 @@ static void __init arch_mem_init(char **cmdline_p) memblock_reserve(crashk_res.start, resource_size(&crashk_res)); #endif device_tree_init(); + + /* + * In order to reduce the possibility of kernel panic when failed to + * get IO TLB memory under CONFIG_SWIOTLB, it is better to allocate + * low memory as small as possible before plat_swiotlb_setup(), so + * make sparse_init() using top-down allocation. + */ + memblock_set_bottom_up(false); sparse_init(); + memblock_set_bottom_up(true); + plat_swiotlb_setup(); dma_contiguous_reserve(PFN_PHYS(max_low_pfn)); |