RISC-V Fix for 5.18-rc6

* A fix to relocate the DTB early in boot, in cases where the bootloader
   doesn't put the DTB in a region that will end up mapped by the kernel.
   This manifests as a crash early in boot on a handful of
   configurations.
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Merge tag 'riscv-for-linus-5.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V fix from Palmer Dabbelt:

 - A fix to relocate the DTB early in boot, in cases where the
   bootloader doesn't put the DTB in a region that will end up
   mapped by the kernel.

   This manifests as a crash early in boot on a handful of
   configurations.

* tag 'riscv-for-linus-5.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  RISC-V: relocate DTB if it's outside memory region
This commit is contained in:
Linus Torvalds 2022-05-06 11:30:59 -07:00
commit 497fe3bb19
1 changed files with 19 additions and 2 deletions

View File

@ -208,8 +208,25 @@ 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))
memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
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));
}
early_init_fdt_scan_reserved_mem();
dma_contiguous_reserve(dma32_phys_limit);