soc/intel/xeon_sp: Skip empty sockets

The current Sapphire Rapids code assumes that all sockets have working
CPUs. On multi-socket platforms a CPU might be missing or was disabled
due to an error. The variable PlatformData.numofIIO and the variable
SystemStatus.numCpus reflect the working CPUs, but not the actual
socket count.

Update the code to iterate over sockets until PlatformData.numofIIO
IIOs have been found. This is required as FSP doesn't sort IIOs by
working/non working status.
This resolves invalid ACPI table generation and it fixes a crash
as commands were sent to a disabled CPU.

TEST: Disabled Socket1 on IBM/SBP1.

Change-Id: I237b6392764bbdb3b96013f577a10a4394ba9c6e
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/76559
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

2 files changed, 4 insertions, 2 deletions

diff --git a/src/soc/intel/xeon_sp/cpx/chip.c b/src/soc/intel/xeon_sp/cpx/chip.c
index a3d15abdbb..dd9c113491 100644
--- a/src/soc/intel/xeon_sp/cpx/chip.c
+++ b/src/soc/intel/xeon_sp/cpx/chip.c
@@ -115,7 +115,9 @@ static void iio_enable_masks(void)
 
 static void set_pcu_locks(void)
 {
-	for (uint32_t socket = 0; socket < soc_get_num_cpus(); ++socket) {
+	for (uint32_t socket = 0; socket < CONFIG_MAX_SOCKET; ++socket) {
+		if (!soc_cpu_is_enabled(socket))
+			continue;
 		uint32_t bus = get_socket_stack_busno(socket, PCU_IIO_STACK);
 
 		/* configure PCU_CR0_FUN csrs */
diff --git a/src/soc/intel/xeon_sp/cpx/soc_util.c b/src/soc/intel/xeon_sp/cpx/soc_util.c
index 031b2bb745..64efb612ca 100644
--- a/src/soc/intel/xeon_sp/cpx/soc_util.c
+++ b/src/soc/intel/xeon_sp/cpx/soc_util.c
@@ -45,7 +45,7 @@ uint32_t get_socket_stack_busno(uint32_t socket, uint32_t stack)
 {
 	const IIO_UDS *hob = get_iio_uds();
 
-	assert(socket < hob->SystemStatus.numCpus && stack < MAX_LOGIC_IIO_STACK);
+	assert(socket < CONFIG_MAX_SOCKET && stack < MAX_LOGIC_IIO_STACK);
 
 	return hob->PlatformData.IIO_resource[socket].StackRes[stack].BusBase;
 }