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 <[email protected]>
---
Changes from v1->v2:
Used memblock_enforce_memory_limit instead of memblock_remove without
computing the maximum memory size.
---
arch/riscv/mm/init.c | 15 +++++----------
1 file changed, 5 insertions(+), 10 deletions(-)
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 787c75f751a5..ed6e83871112 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -146,8 +146,6 @@ static phys_addr_t dtb_early_pa __initdata;
void __init setup_bootmem(void)
{
struct memblock_region *reg;
- phys_addr_t mem_size = 0;
- phys_addr_t total_mem = 0;
phys_addr_t mem_start, end = 0;
phys_addr_t vmlinux_end = __pa_symbol(&_end);
phys_addr_t vmlinux_start = __pa_symbol(&_start);
@@ -155,21 +153,18 @@ void __init setup_bootmem(void)
/* Find the memory region containing the kernel */
for_each_memblock(memory, reg) {
end = reg->base + reg->size;
- if (!total_mem)
+ if (!mem_start)
mem_start = reg->base;
if (reg->base <= vmlinux_start && vmlinux_end <= end)
BUG_ON(reg->size == 0);
- total_mem = total_mem + reg->size;
}
/*
- * Remove memblock from the end of usable area to the
- * end of region
+ * The maximum physical memory supported 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);
--
2.25.1
On Thu, Sep 17, 2020 at 04:40:55PM -0700, Atish Patra wrote:
> 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 <[email protected]>
With one nit below
Reviewed-by: Mike Rapoport <[email protected]>
> ---
> Changes from v1->v2:
> Used memblock_enforce_memory_limit instead of memblock_remove without
> computing the maximum memory size.
> ---
> arch/riscv/mm/init.c | 15 +++++----------
> 1 file changed, 5 insertions(+), 10 deletions(-)
>
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index 787c75f751a5..ed6e83871112 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -146,8 +146,6 @@ static phys_addr_t dtb_early_pa __initdata;
> void __init setup_bootmem(void)
> {
> struct memblock_region *reg;
> - phys_addr_t mem_size = 0;
> - phys_addr_t total_mem = 0;
> phys_addr_t mem_start, end = 0;
> phys_addr_t vmlinux_end = __pa_symbol(&_end);
> phys_addr_t vmlinux_start = __pa_symbol(&_start);
> @@ -155,21 +153,18 @@ void __init setup_bootmem(void)
> /* Find the memory region containing the kernel */
> for_each_memblock(memory, reg) {
> end = reg->base + reg->size;
> - if (!total_mem)
> + if (!mem_start)
> mem_start = reg->base;
> if (reg->base <= vmlinux_start && vmlinux_end <= end)
> BUG_ON(reg->size == 0);
> - total_mem = total_mem + reg->size;
> }
>
> /*
> - * Remove memblock from the end of usable area to the
> - * end of region
> + * The maximum physical memory supported is -PAGE_OFFSET.
Maybe
The maximal supported 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);
> --
> 2.25.1
>
--
Sincerely yours,
Mike.