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| author | Tiezhu Yang <yangtiezhu@loongson.cn> | 2020-04-21 14:59:46 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-06-20 11:25:10 +0300 |
| commit | 56d9d0fc5c5b2738b5c8d356d88eddd89e173302 (patch) | |
| tree | f5c73038316d17a5c3e66d33f9268e2ca8237f45 /arch | |
| parent | 1054080d29f0cd16fb0fc0bfedfb351aece27e32 (diff) | |
| download | linux-56d9d0fc5c5b2738b5c8d356d88eddd89e173302.tar.xz | |
MIPS: Make sparse_init() using top-down allocation
[ Upstream commit 269b3a9ac538c4ae87f84be640b9fa89914a2489 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch')
| -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 05ed4ed411c7..abd7ee9e90ab 100644 --- a/arch/mips/kernel/setup.c +++ b/arch/mips/kernel/setup.c @@ -911,7 +911,17 @@ static void __init arch_mem_init(char **cmdline_p) BOOTMEM_DEFAULT); #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)); |