Re: [RFC PATCH v2 46/48] lmb: mark the EFI runtime memory regions as reserved

Hi Sughosh,

On Thu, 4 Jul 2024 at 08:38, Sughosh Ganu sughosh.ganu@linaro.org wrote:

Mark the EFI runtime memory region as reserved memory during board init so that it does not get allocated by the LMB module on subsequent memory requests.

Signed-off-by: Sughosh Ganu sughosh.ganu@linaro.org

Changes since V1: New patch

lib/lmb.c | 41 ++++++++++++++++++++--------------------- 1 file changed, 20 insertions(+), 21 deletions(-)

I see again that this is getting circular. Can you look at what is actually allocated by EFI on init (i.e. before anything is booted)?

diff --git a/lib/lmb.c b/lib/lmb.c index 387ec2ac65..6018f1de31 100644 --- a/lib/lmb.c +++ b/lib/lmb.c @@ -19,6 +19,7 @@ #include <asm/global_data.h> #include <asm/sections.h> #include <linux/kernel.h> +#include <linux/sizes.h>

DECLARE_GLOBAL_DATA_PTR;

@@ -212,33 +213,31 @@ void arch_lmb_reserve_generic(ulong sp, ulong end, ulong align) /**

• efi_lmb_reserve() - add reservations for EFI memory

• • Add reservations for all EFI memory areas that are not
• • EFI_CONVENTIONAL_MEMORY.

• • Add reservations for EFI runtime services memory

• • Return: 0 on success, 1 on failure

• • Return: None
  */

-static __maybe_unused int efi_lmb_reserve(void) +static __maybe_unused void efi_lmb_reserve(void) {

•   struct efi_mem_desc *memmap = NULL, *map;
  

•   efi_uintn_t i, map_size = 0;
  

•   efi_status_t ret;
  

•   phys_addr_t runtime_start, runtime_end;
  

•   unsigned long runtime_mask = EFI_PAGE_MASK;
  
  

•   ret = efi_get_memory_map_alloc(&map_size, &memmap);
  

•   if (ret != EFI_SUCCESS)
  

•           return 1;
  

+#if defined(__aarch64__)

•   /*
  

•    * Runtime Services must be 64KiB aligned according to the
  

•    * "AArch64 Platforms" section in the UEFI spec (2.7+).
  

•    */
  
  

•   for (i = 0, map = memmap; i < map_size / sizeof(*map); ++map, ++i) {
  

•           if (map->type != EFI_CONVENTIONAL_MEMORY) {
  

•                   lmb_reserve_flags(map_to_sysmem((void *)(uintptr_t)
  

•                                                   map->physical_start),
  

•                                     map->num_pages * EFI_PAGE_SIZE,
  

•                                     map->type == EFI_RESERVED_MEMORY_TYPE
  

•                                         ? LMB_NOMAP : LMB_NONE);
  

•           }
  

•   }
  

•   efi_free_pool(memmap);
  

•   runtime_mask = SZ_64K - 1;
  

+#endif

•   return 0;
  

•   /* Reserve the EFI runtime services memory */
  

•   runtime_start = (uintptr_t)__efi_runtime_start & ~runtime_mask;
  

•   runtime_end = (uintptr_t)__efi_runtime_stop;
  

•   runtime_end = (runtime_end + runtime_mask) & ~runtime_mask;
  

•   lmb_reserve_flags(runtime_start, runtime_end - runtime_start,
  

•                     LMB_NOOVERWRITE | LMB_NONOTIFY);
  

}

static void lmb_reserve_common(void *fdt_blob)

2.34.1

Regards, Simon