soc/intel: Assert if `pmc_/gpe0_dwX` values are not unique

This commit adds an assertion to ensure that the values of
pmc_/gpe0_dw0, pmc_/gpe0_dw1, and pmc_/gpe0_dw2 in the
soc_intel_<soc>_config structure are unique.

This check helps to catch potential configuration errors early on,
preventing unexpected behavior during system initialization.

TEST=Built and booted normally. No assertion failure observed.

Able to catch the hidden issue due to overlapping Tier 1 GPE
configuration.

[DEBUG]  CPU: Intel(R) Core(TM) 3 N355
[DEBUG]  CPU: ID b06e0, Alderlake-N Platform, ucode: 0000001a
[DEBUG]  CPU: AES supported, TXT supported, VT supported
...
...
[DEBUG]  MCH: device id 4617 (rev 00) is Alderlake-N
[DEBUG]  PCH: device id 5481 (rev 00) is Alderlake-N SKU
[DEBUG]  IGD: device id 46d3 (rev 00) is Twinlake GT1
[EMERG]  ASSERTION ERROR: file 'src/soc/intel/alderlake/pmutil.c',
         line 163

Change-Id: I6b4f2f90a858b9ec85145bce0542f1ce61d080be
Signed-off-by: Subrata Banik <subratabanik@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/85161
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Eric Lai <ericllai@google.com>
Reviewed-by: Kapil Porwal <kapilporwal@google.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/src/soc/intel/elkhartlake/pmutil.c b/src/soc/intel/elkhartlake/pmutil.c
index 2618798f38..a862bdd6e2 100644
--- a/src/soc/intel/elkhartlake/pmutil.c
+++ b/src/soc/intel/elkhartlake/pmutil.c
@@ -147,12 +147,23 @@ uint32_t *soc_pmc_etr_addr(void)
 	return (uint32_t *)(soc_read_pmc_base() + ETR);
 }
 
+static void pmc_gpe0_different_values(const struct soc_intel_elkhartlake_config *config)
+{
+	bool result = (config->pmc_gpe0_dw0 != config->pmc_gpe0_dw1) &&
+			 (config->pmc_gpe0_dw0 != config->pmc_gpe0_dw2) &&
+			 (config->pmc_gpe0_dw1 != config->pmc_gpe0_dw2);
+
+	assert(result);
+}
+
 void soc_get_gpi_gpe_configs(uint8_t *dw0, uint8_t *dw1, uint8_t *dw2)
 {
 	DEVTREE_CONST struct soc_intel_elkhartlake_config *config;
 
 	config = config_of_soc();
 
+	pmc_gpe0_different_values(config);
+
 	/* Assign to out variable */
 	*dw0 = config->pmc_gpe0_dw0;
 	*dw1 = config->pmc_gpe0_dw1;