Check all mmap() calls and print helpful Linux error message

Corresponding to flashrom svn r386 and coreboot v2 svn r3890.
Signed-off-by: Peter Stuge <peter@stuge.se>
Acked-by: Peter Stuge <peter@stuge.se>

cbtable.c

@@ -191,6 +191,7 @@ int coreboot_init(void)
 		       0x00000000);
 	if (low_1MB == MAP_FAILED) {
 		perror("Can't mmap memory using " MEM_DEV);
+		mmap_errmsg();
 		exit(-2);
 	}
 	lb_table = 0;

chipset_enable.c

@@ -220,6 +220,7 @@ static int enable_flash_vt8237s_spi(struct pci_dev *dev, const char *name)
 
 	if (spibar == MAP_FAILED) {
 		perror("Can't mmap memory using " MEM_DEV);
+		mmap_errmsg();
 		exit(1);
 	}
 
@@ -255,6 +256,7 @@ static int enable_flash_ich_dc_spi(struct pci_dev *dev, const char *name,
 		    (off_t) tmp);
 	if (rcrb == MAP_FAILED) {
 		perror("Can't mmap memory using " MEM_DEV);
+		mmap_errmsg();
 		exit(1);
 	}
 
@@ -681,6 +683,7 @@ static int enable_flash_sb600(struct pci_dev *dev, const char *name)
 			    fd_mem, (off_t)tmp);
 	if (sb600_spibar == MAP_FAILED) {
 		perror("Can't mmap memory using " MEM_DEV);
+		mmap_errmsg();
 		exit(1);
 	}
 	sb600_spibar += low_bits;
@@ -837,6 +840,7 @@ static int get_flashbase_sc520(struct pci_dev *dev, const char *name)
 
 	if (mmcr == MAP_FAILED) {
 		perror("Can't mmap Elan SC520 specific registers using " MEM_DEV);
+		mmap_errmsg();
 		exit(1);
 	}
 

flash.h

@@ -480,6 +480,7 @@ extern int verbose;
 #define printf_debug(x...) { if (verbose) printf(x); }
 
 /* flashrom.c */
+void mmap_errmsg();
 int map_flash_registers(struct flashchip *flash);
 
 /* layout.c */

flashrom.c

@@ -84,6 +84,17 @@ struct pci_dev *pci_card_find(uint16_t vendor, uint16_t device,
 	return NULL;
 }
 
+void mmap_errmsg()
+{
+	if (EINVAL == errno) {
+		fprintf(stderr, "In Linux this error can be caused by the CONFIG_NONPROMISC_DEVMEM (<2.6.27),\n");
+		fprintf(stderr, "CONFIG_STRICT_DEVMEM (>=2.6.27) and CONFIG_X86_PAT kernel options.\n");
+		fprintf(stderr, "Please check if either is enabled in your kernel before reporting a failure.\n");
+		fprintf(stderr, "You can override CONFIG_X86_PAT at boot with the nopat kernel parameter but\n");
+		fprintf(stderr, "disabling the other option unfortunately requires a kernel recompile. Sorry!\n");
+	}
+}
+
 int map_flash_registers(struct flashchip *flash)
 {
 	volatile uint8_t *registers;
@@ -94,6 +105,7 @@ int map_flash_registers(struct flashchip *flash)
 
 	if (registers == MAP_FAILED) {
 		perror("Can't mmap registers using " MEM_DEV);
+		mmap_errmsg();
 		exit(1);
 	}
 	flash->virtual_registers = registers;
@@ -139,13 +151,7 @@ struct flashchip *probe_flash(struct flashchip *first_flash, int force)
 			    fd_mem, (off_t) base);
 		if (bios == MAP_FAILED) {
 			perror("Can't mmap memory using " MEM_DEV);
-			if (EINVAL == errno) {
-				fprintf(stderr, "In Linux this error can be caused by the CONFIG_NONPROMISC_DEVMEM (<2.6.27),\n");
-				fprintf(stderr, "CONFIG_STRICT_DEVMEM (>=2.6.27) and CONFIG_X86_PAT kernel options.\n");
-				fprintf(stderr, "Please check if either is enabled in your kernel before reporting a failure.\n");
-				fprintf(stderr, "You can override CONFIG_X86_PAT at boot with the nopat kernel parameter but\n");
-				fprintf(stderr, "disabling the other option unfortunately requires a kernel recompile. Sorry!\n");
-			}
+			mmap_errmsg();
 			exit(1);
 		}
 		flash->virtual_memory = bios;