This is a note to let you know that I've just added the patch titled
riscv: No need to relocate the dtb as it lies in the fixmap region
to the 6.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
riscv-no-need-to-relocate-the-dtb-as-it-lies-in-the-fixmap-region.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 1b50f956c8fe9082bdee4a9cfd798149c52f7043 Mon Sep 17 00:00:00 2001
From: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
Date: Wed, 29 Mar 2023 10:19:32 +0200
Subject: riscv: No need to relocate the dtb as it lies in the fixmap region
From: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
commit 1b50f956c8fe9082bdee4a9cfd798149c52f7043 upstream.
We used to access the dtb via its linear mapping address but 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.
Note that 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>
Reviewed-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
Tested-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230329081932.79831-4-alexghiti@xxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/riscv/mm/init.c | 21 ++-------------------
1 file changed, 2 insertions(+), 19 deletions(-)
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -242,25 +242,8 @@ 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))
Patches currently in stable-queue which might be from alexghiti@xxxxxxxxxxxx are
queue-6.2/riscv-no-need-to-relocate-the-dtb-as-it-lies-in-the-fixmap-region.patch
queue-6.2/riscv-do-not-set-initial_boot_params-to-the-linear-address-of-the-dtb.patch
queue-6.2/riscv-move-early-dtb-mapping-into-the-fixmap-region.patch
