On Thu, Mar 23, 2023 at 05:33:47PM +0100, Alexandre Ghiti wrote:
> Now that the dtb early mapping was moved in the fixmap region, we can
> keep using this address since it is present in swapper_pg_dir, so remove
> the dtb relocation which was wrong anyway since early_memremap is
> restricted to 256K whereas the maximum fdt size is 2MB.
I feel bad making this comment since only one of us is a native speaker,
but for the future would you mind breaking up overly long sentences like
the above? Say:
Now that the dtb early mapping was moved in the fixmap region, we can
keep using this address since it is present in swapper_pg_dir, and
remove the dtb relocation.
The relocation was wrong anyway since early_memremap() is restricted to
256K whereas the maximum fdt size is 2MB.
>
> Signed-off-by: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
> ---
> arch/riscv/kernel/setup.c | 5 +----
> arch/riscv/mm/init.c | 21 ++-------------------
> 2 files changed, 3 insertions(+), 23 deletions(-)
>
> diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
> index 542eed85ad2c..a059b73f4ddb 100644
> --- a/arch/riscv/kernel/setup.c
> +++ b/arch/riscv/kernel/setup.c
> @@ -278,10 +278,7 @@ void __init setup_arch(char **cmdline_p)
> #if IS_ENABLED(CONFIG_BUILTIN_DTB)
> unflatten_and_copy_device_tree();
> #else
> - if (early_init_dt_verify(__va(XIP_FIXUP(dtb_early_pa))))
btw, how come it is safe now to drop this? This feels like a separate
change that should be its own commit, no?
Cheers,
Conor.
> - unflatten_device_tree();
> - else
> - pr_err("No DTB found in kernel mappings\n");
> + unflatten_device_tree();
> #endif
> misc_mem_init();
>
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index fb78d6bbabae..0f14f4a8d179 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -249,25 +249,8 @@ static void __init setup_bootmem(void)
> * early_init_fdt_reserve_self() since __pa() does
> * not work for DTB pointers that are fixmap addresses
> */
> - if (!IS_ENABLED(CONFIG_BUILTIN_DTB)) {
> - /*
> - * In case the DTB is not located in a memory region we won't
> - * be able to locate it later on via the linear mapping and
> - * get a segfault when accessing it via __va(dtb_early_pa).
> - * To avoid this situation copy DTB to a memory region.
> - * Note that memblock_phys_alloc will also reserve DTB region.
> - */
> - if (!memblock_is_memory(dtb_early_pa)) {
> - size_t fdt_size = fdt_totalsize(dtb_early_va);
> - phys_addr_t new_dtb_early_pa = memblock_phys_alloc(fdt_size, PAGE_SIZE);
> - void *new_dtb_early_va = early_memremap(new_dtb_early_pa, fdt_size);
> -
> - memcpy(new_dtb_early_va, dtb_early_va, fdt_size);
> - early_memunmap(new_dtb_early_va, fdt_size);
> - _dtb_early_pa = new_dtb_early_pa;
> - } else
> - memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
> - }
> + if (!IS_ENABLED(CONFIG_BUILTIN_DTB))
> + memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
>
> dma_contiguous_reserve(dma32_phys_limit);
> if (IS_ENABLED(CONFIG_64BIT))
> --
> 2.37.2
>
>
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