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authorAtish Patra <atish.patra@wdc.com>2020-10-07 14:51:59 -0700
committerPalmer Dabbelt <palmerdabbelt@google.com>2020-11-05 09:56:17 -0800
commit1bd14a66ee5200d6a24419cbd2e0a0fccd4da36f (patch)
tree41ae3dc2bf7ac062e0d5878cb03f3731d85ba025 /arch/riscv/mm
parent9d750c75bd2c3fcf20a3c15378d1bc6b2d4ec31f (diff)
downloadlinux-1bd14a66ee5200d6a24419cbd2e0a0fccd4da36f.tar.bz2
RISC-V: Remove any memblock representing unusable memory area
RISC-V limits the physical memory size by -PAGE_OFFSET. Any memory beyond that size from DRAM start is unusable. Just remove any memblock pointing to those memory region without worrying about computing the maximum size. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Diffstat (limited to 'arch/riscv/mm')
-rw-r--r--arch/riscv/mm/init.c18
1 files changed, 7 insertions, 11 deletions
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index ea933b789a88..42c14eb6bc43 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -154,9 +154,8 @@ disable:
void __init setup_bootmem(void)
{
- phys_addr_t mem_size = 0;
- phys_addr_t total_mem = 0;
- phys_addr_t mem_start, start, end = 0;
+ phys_addr_t mem_start = 0;
+ phys_addr_t start, end = 0;
phys_addr_t vmlinux_end = __pa_symbol(&_end);
phys_addr_t vmlinux_start = __pa_symbol(&_start);
u64 i;
@@ -164,21 +163,18 @@ void __init setup_bootmem(void)
/* Find the memory region containing the kernel */
for_each_mem_range(i, &start, &end) {
phys_addr_t size = end - start;
- if (!total_mem)
+ if (!mem_start)
mem_start = start;
if (start <= vmlinux_start && vmlinux_end <= end)
BUG_ON(size == 0);
- total_mem = total_mem + size;
}
/*
- * Remove memblock from the end of usable area to the
- * end of region
+ * The maximal physical memory size is -PAGE_OFFSET.
+ * Make sure that any memory beyond mem_start + (-PAGE_OFFSET) is removed
+ * as it is unusable by kernel.
*/
- mem_size = min(total_mem, (phys_addr_t)-PAGE_OFFSET);
- if (mem_start + mem_size < end)
- memblock_remove(mem_start + mem_size,
- end - mem_start - mem_size);
+ memblock_enforce_memory_limit(mem_start - PAGE_OFFSET);
/* Reserve from the start of the kernel to the end of the kernel */
memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);