Fix code that would trip -Wtype-limits

This patch fixes up all code that would throw a -Wtype-limits warning.
This sometimes involves eliminating unnecessary checks, adding a few odd
but harmless casts or just pragma'ing out the warning for a whole file
-- I tried to find the path of least resistance. I think the overall
benefit of the warning outweighs the occasional weirdness.

Change-Id: Iacd37eb1fad388d9db7267ceccb03e6dcf1ad0d2
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32537
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/drivers/intel/fsp2_0/ppi/mp_service_ppi.c

@@ -45,9 +45,6 @@ static efi_return_status_t mp_get_processor_info(const
 	efi_uintn_t processor_number,
 	efi_processor_information *processor_info_buffer)
 {
-	if (cpu_index() < 0)
-		return FSP_DEVICE_ERROR;
-
 	if (processor_info_buffer == NULL)
 		return FSP_INVALID_PARAMETER;
 
@@ -71,9 +68,6 @@ static efi_return_status_t mp_startup_all_aps(const
 	efi_ap_procedure procedure, efi_boolean_t ignored3,
 	efi_uintn_t timeout_usec, void *argument)
 {
-	if (cpu_index() < 0)
-		return FSP_DEVICE_ERROR;
-
 	if (procedure == NULL)
 		return FSP_INVALID_PARAMETER;
 
@@ -91,9 +85,6 @@ static efi_return_status_t mp_startup_this_ap(const
 	efi_ap_procedure procedure, efi_uintn_t processor_number,
 	efi_uintn_t timeout_usec, void *argument)
 {
-	if (cpu_index() < 0)
-		return FSP_DEVICE_ERROR;
-
 	if (processor_number > get_cpu_count())
 		return FSP_NOT_FOUND;
 

src/drivers/pc80/rtc/mc146818rtc.c

@@ -39,6 +39,9 @@
 #define LB_CKS_LOC		0
 #endif
 
+/* Don't warn for checking >= LB_CKS_RANGE_START even though it may be 0. */
+#pragma GCC diagnostic ignored "-Wtype-limits"
+
 #include <smp/spinlock.h>
 
 #if (defined(__PRE_RAM__) &&	\

src/drivers/spi/spi_flash.c

@@ -339,7 +339,7 @@ int spi_flash_generic_probe(const struct spi_slave *spi,
 	printk(BIOS_INFO, "Manufacturer: %02x\n", *idp);
 
 	/* search the table for matches in shift and id */
-	for (i = 0; i < ARRAY_SIZE(flashes); ++i)
+	for (i = 0; i < (int)ARRAY_SIZE(flashes); ++i)
 		if (flashes[i].shift == shift && flashes[i].idcode == *idp) {
 			/* we have a match, call probe */
 			if (flashes[i].probe(spi, idp, flash) == 0) {