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| author | Zhenhua Huang <quic_zhenhuah@quicinc.com> | 2023-09-07 16:03:56 +0800 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2023-09-08 05:58:32 -0300 |
| commit | f875db4f20f4ec2e4fa3b3be0e5081976e0b5dad (patch) | |
| tree | dd809d3d3467b37495982ce735fe5e9b500bc4c4 /kernel/dma/contiguous.c | |
| parent | 765aa6b3a462ed69ddcb1c41a6f7f93b8abb7d43 (diff) | |
Revert "dma-contiguous: check for memory region overlap"
This reverts commit 3fa6456ebe13adab3ba1817c8e515a5b88f95dce.
The Commit broke the CMA region creation through DT on arm64,
as showed below logs with "memblock=debug":
[ 0.000000] memblock_phys_alloc_range: 41943040 bytes align=0x200000
from=0x0000000000000000 max_addr=0x00000000ffffffff
early_init_dt_alloc_reserved_memory_arch+0x34/0xa0
[ 0.000000] memblock_reserve: [0x00000000fd600000-0x00000000ffdfffff]
memblock_alloc_range_nid+0xc0/0x19c
[ 0.000000] Reserved memory: overlap with other memblock reserved region
>From call flow, region we defined in DT was always reserved before entering
into rmem_cma_setup. Also, rmem_cma_setup has one routine cma_init_reserved_mem
to ensure the region was reserved. Checking the region not reserved here seems
not correct.
early_init_fdt_scan_reserved_mem:
fdt_scan_reserved_mem
__reserved_mem_reserve_reg
early_init_dt_reserve_memory
memblock_reserve(using “reg” prop case)
fdt_init_reserved_mem
__reserved_mem_alloc_size
*early_init_dt_alloc_reserved_memory_arch*
memblock_reserve(dynamic alloc case)
__reserved_mem_init_node
rmem_cma_setup(region overlap check here should always fail)
Example DT can be used to reproduce issue:
dump_mem: mem_dump_region {
compatible = "shared-dma-pool";
alloc-ranges = <0x0 0x00000000 0x0 0xffffffff>;
reusable;
size = <0 0x2800000>;
};
Signed-off-by: Zhenhua Huang <quic_zhenhuah@quicinc.com>
Diffstat (limited to 'kernel/dma/contiguous.c')
| -rw-r--r-- | kernel/dma/contiguous.c | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c index 88c595e49e34..f005c66f378c 100644 --- a/kernel/dma/contiguous.c +++ b/kernel/dma/contiguous.c @@ -473,11 +473,6 @@ static int __init rmem_cma_setup(struct reserved_mem *rmem) return -EBUSY; } - if (memblock_is_region_reserved(rmem->base, rmem->size)) { - pr_info("Reserved memory: overlap with other memblock reserved region\n"); - return -EBUSY; - } - if (!of_get_flat_dt_prop(node, "reusable", NULL) || of_get_flat_dt_prop(node, "no-map", NULL)) return -EINVAL; |