libpayload: refactor fetching cbmem pointers

There's a recurring pattern of reading cbtable entries that point into
cbmem entries. Move that pattern into its own function.

Coccinelle patch used for this:
  @@
  identifier T, T2;
  expression TARGET;
  @@
  -struct cb_cbmem_tab *const T2 = (struct cb_cbmem_tab *)T;
  -TARGET = phys_to_virt(T2->cbmem_tab);
  +TARGET = get_cbmem_ptr(T);

Change-Id: I7bd4a7ad8baeeaebf0fa7d4b4de6dbc719bc781f
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/35756
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

1 files changed, 1 insertions, 2 deletions

diff --git a/payloads/libpayload/arch/x86/coreboot.c b/payloads/libpayload/arch/x86/coreboot.c
index 3a9eb1a7be..07adee8917 100644
--- a/payloads/libpayload/arch/x86/coreboot.c
+++ b/payloads/libpayload/arch/x86/coreboot.c
@@ -50,8 +50,7 @@ static void cb_parse_x86_rom_var_mtrr(void *ptr, struct sysinfo_t *info)
 
 static void cb_parse_mrc_cache(void *ptr, struct sysinfo_t *info)
 {
-	struct cb_cbmem_tab *const cbmem = (struct cb_cbmem_tab *)ptr;
-	info->mrc_cache = phys_to_virt(cbmem->cbmem_tab);
+	info->mrc_cache = get_cbmem_ptr(ptr);
 }
 
 int cb_parse_arch_specific(struct cb_record *rec, struct sysinfo_t *info)