[coreboot-gerrit] Change in ...coreboot[master]: soc/intel/cannonlake: Do not read SPD again if index hasn't changed

[Furquan Shaikh (Code Review)]

Furquan Shaikh has submitted this change and it was merged. ( https://review.coreboot.org/c/coreboot/+/33137 )

Change subject: soc/intel/cannonlake: Do not read SPD again if index hasn't changed
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soc/intel/cannonlake: Do not read SPD again if index hasn't changed

With the recent refactoring of memory configuration in
CB:32513 ("soc/intel/cannonlake: Support different SPD read type for
each slot"), meminit_cbfs_spd_index ends up reading SPD from CBFS for
each slot. However, for mainboards that use the same SPD index for
each slot this is unneccessary. This change adds a check to see if
spd_data_ptr is not NULL and current spd index is the same as the last
call to decide if SPD read from CBFS should be skipped.

TEST=Verified that SPD gets read only once on hatch.

Change-Id: I91963b55cea534c92207b2cd9f0caa96df8f222b
Signed-off-by: Furquan Shaikh 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33137
Reviewed-by: Paul Menzel 
Reviewed-by: Aaron Durbin 
Reviewed-by: Tim Wawrzynczak 
Reviewed-by: Philip Chen 
Tested-by: build bot (Jenkins) 
---
M src/soc/intel/cannonlake/cnl_memcfg_init.c
1 file changed, 21 insertions(+), 10 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Paul Menzel: Looks good to me, but someone else must approve
  Aaron Durbin: Looks good to me, approved
  Philip Chen: Looks good to me, but someone else must approve
  Tim Wawrzynczak: Looks good to me, approved

diff --git a/src/soc/intel/cannonlake/cnl_memcfg_init.c b/src/soc/intel/cannonlake/cnl_memcfg_init.c
index 4ebd997..d3e5e83 100644
--- a/src/soc/intel/cannonlake/cnl_memcfg_init.c
+++ b/src/soc/intel/cannonlake/cnl_memcfg_init.c
@@ -91,18 +91,29 @@
 static void meminit_cbfs_spd_index(FSP_M_CONFIG *mem_cfg,
    			   int spd_index, uint8_t mem_slot)
 {
-	size_t spd_data_len;
-	uintptr_t spd_data_ptr;
-	struct region_device spd_rdev;
+	static size_t spd_data_len;
+	static uintptr_t spd_data_ptr;
+	static int last_spd_index;

assert(mem_slot < NUM_DIMM_SLOT);
-	printk(BIOS_DEBUG, "SPD INDEX = %d\n", spd_index);
-	if (get_spd_cbfs_rdev(&spd_rdev, spd_index) < 0)
-		die("spd.bin not found or incorrect index\n");
-	spd_data_len = region_device_sz(&spd_rdev);
-	/* Memory leak is ok since we have memory mapped boot media */
-	assert(CONFIG(BOOT_DEVICE_MEMORY_MAPPED));
-	spd_data_ptr = (uintptr_t)rdev_mmap_full(&spd_rdev);
+
+	if ((spd_data_ptr == 0) || (last_spd_index != spd_index)) {
+		struct region_device spd_rdev;
+
+		printk(BIOS_DEBUG, "SPD INDEX = %d\n", spd_index);
+
+		if (get_spd_cbfs_rdev(&spd_rdev, spd_index) < 0)
+			die("spd.bin not found or incorrect index\n");
+
+		spd_data_len = region_device_sz(&spd_rdev);
+
+		/* Memory leak is ok since we have memory mapped boot media */
+		assert(CONFIG(BOOT_DEVICE_MEMORY_MAPPED));
+
+		spd_data_ptr = (uintptr_t)rdev_mmap_full(&spd_rdev);
+		last_spd_index = spd_index;
+	}
+
    meminit_spd_data(mem_cfg, mem_slot, spd_data_len, spd_data_ptr);
 }