[PATCH -fixes 2/2] riscv: Do not set initial_boot_params to the linear address of the dtb

From: Alexandre Ghiti
Date: Thu Mar 23 2023 - 12:38:10 EST


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.

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))))
- 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