Refine physical address mapping of flash chips

 - Create distinct functions for mapping and unmapping for flash chips.
 - Map only when needed: map before probing and unmap immediately
   after it. Map again when a single chip was probed successfully before
   taking any actual actions and clean up afterwards.
 - Map special function chip registers centrally together with flash space
   instead of within (some) probing methods after successful probes.
 - Save the used base addresses of the mappings in struct flashctx as well.
 - Do not try to (un)map the zero-sized chip definitions that are merely hacks.
   This also fixes the printing of wrong warnings for these chip definitions
   introduced in r1765.

Corresponding to flashrom svn r1847.
Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>

82802ab.c

@@ -83,9 +83,6 @@ int probe_82802ab(struct flashctx *flash)
 	if (id1 != flash->chip->manufacture_id || id2 != flash->chip->model_id)
 		return 0;
 
-	if (flash->chip->feature_bits & FEATURE_REGISTERMAP)
-		map_flash_registers(flash);
-
 	return 1;
 }
 

cli_classic.c

@@ -481,8 +481,14 @@ int main(int argc, char *argv[])
 				ret = 1;
 				goto out_shutdown;
 			}
+			if (map_flash(&flashes[0]) != 0) {
+				free(flashes[0].chip);
+				ret = 1;
+				goto out_shutdown;
+			}
 			msg_cinfo("Please note that forced reads most likely contain garbage.\n");
 			ret = read_flash_to_file(&flashes[0], filename);
+			unmap_flash(&flashes[0]);
 			free(flashes[0].chip);
 			goto out_shutdown;
 		}
@@ -525,6 +531,12 @@ int main(int argc, char *argv[])
 	if (write_it && !dont_verify_it)
 		verify_it = 1;
 
+	/* Map the selected flash chip again. */
+	if (map_flash(fill_flash) != 0) {
+		ret = 1;
+		goto out_shutdown;
+	}
+
 	/* FIXME: We should issue an unconditional chip reset here. This can be
 	 * done once we have a .reset function in struct flashchip.
 	 * Give the chip time to settle.
@@ -532,6 +544,7 @@ int main(int argc, char *argv[])
 	programmer_delay(100000);
 	ret |= doit(fill_flash, force, filename, read_it, write_it, erase_it, verify_it);
 
+	unmap_flash(fill_flash);
 out_shutdown:
 	programmer_shutdown();
 out:

flash.h

@@ -48,9 +48,9 @@ typedef uintptr_t chipaddr;
 /* Types and macros regarding the maximum flash space size supported by generic code. */
 typedef uint32_t chipoff_t; /* Able to store any addressable offset within a supported flash memory. */
 typedef uint32_t chipsize_t; /* Able to store the number of bytes of any supported flash memory. */
-#define FL_MAX_CHIPADDR_BITS (24)
-#define FL_MAX_CHIPADDR ((chipoff_t)(1ULL<<FL_MAX_CHIPADDR_BITS)-1)
-#define PRIxCHIPADDR "06"PRIx32
+#define FL_MAX_CHIPOFF_BITS (24)
+#define FL_MAX_CHIPOFF ((chipoff_t)(1ULL<<FL_MAX_CHIPOFF_BITS)-1)
+#define PRIxCHIPOFF "06"PRIx32
 #define PRIuCHIPSIZE PRIu32
 
 int register_shutdown(int (*function) (void *data), void *data);
@@ -209,8 +209,14 @@ struct flashchip {
 
 struct flashctx {
 	struct flashchip *chip;
+	/* FIXME: The memory mappings should be saved in a more structured way. */
+	/* The physical_* fields store the respective addresses in the physical address space of the CPU. */
+	uintptr_t physical_memory;
+	/* The virtual_* fields store where the respective physical address is mapped into flashrom's address
+	 * space. A value equivalent to (chipaddr)ERROR_PTR indicates an invalid mapping (or none at all). */
 	chipaddr virtual_memory;
-	/* Some flash devices have an additional register space. */
+	/* Some flash devices have an additional register space; semantics are like above. */
+	uintptr_t physical_registers;
 	chipaddr virtual_registers;
 	struct registered_master *mst;
 };
@@ -252,7 +258,8 @@ void tolower_string(char *str);
 /* flashrom.c */
 extern const char flashrom_version[];
 extern const char *chip_to_probe;
-void map_flash_registers(struct flashctx *flash);
+int map_flash(struct flashctx *flash);
+void unmap_flash(struct flashctx *flash);
 int read_memmapped(struct flashctx *flash, uint8_t *buf, unsigned int start, unsigned int len);
 int erase_flash(struct flashctx *flash);
 int probe_flash(struct registered_master *mst, int startchip, struct flashctx *fill_flash, int force);

flashrom.c

@@ -479,6 +479,7 @@ void *programmer_map_flash_region(const char *descr, uintptr_t phys_addr, size_t
 void programmer_unmap_flash_region(void *virt_addr, size_t len)
 {
 	programmer_table[programmer].unmap_flash_region(virt_addr, len);
+	msg_gspew("%s: unmapped 0x%0*" PRIxPTR "\n", __func__, PRIxPTR_WIDTH, (uintptr_t)virt_addr);
 }
 
 void chip_writeb(const struct flashctx *flash, uint8_t val, chipaddr addr)
@@ -528,14 +529,6 @@ void programmer_delay(unsigned int usecs)
 		programmer_table[programmer].delay(usecs);
 }
 
-void map_flash_registers(struct flashctx *flash)
-{
-	size_t size = flash->chip->total_size * 1024;
-	/* Flash registers live 4 MByte below the flash. */
-	/* FIXME: This is incorrect for nonstandard flashbase. */
-	flash->virtual_registers = (chipaddr)programmer_map_flash_region("flash chip registers", (0xFFFFFFFF - 0x400000 - size + 1), size);
-}
-
 int read_memmapped(struct flashctx *flash, uint8_t *buf, unsigned int start,
 		   int unsigned len)
 {
@@ -1052,12 +1045,64 @@ unsigned int count_max_decode_exceedings(const struct flashctx *flash)
 	return limitexceeded;
 }
 
+void unmap_flash(struct flashctx *flash)
+{
+	if (flash->virtual_registers != (chipaddr)ERROR_PTR) {
+		programmer_unmap_flash_region((void *)flash->virtual_registers, flash->chip->total_size * 1024);
+		flash->physical_registers = 0;
+		flash->virtual_registers = (chipaddr)ERROR_PTR;
+	}
+
+	if (flash->virtual_memory != (chipaddr)ERROR_PTR) {
+		programmer_unmap_flash_region((void *)flash->virtual_memory, flash->chip->total_size * 1024);
+		flash->physical_memory = 0;
+		flash->virtual_memory = (chipaddr)ERROR_PTR;
+	}
+}
+
+int map_flash(struct flashctx *flash)
+{
+	/* Init pointers to the fail-safe state to distinguish them later from legit values. */
+	flash->virtual_memory = (chipaddr)ERROR_PTR;
+	flash->virtual_registers = (chipaddr)ERROR_PTR;
+
+	/* FIXME: This avoids mapping (and unmapping) of flash chip definitions with size 0.
+	 * These are used for various probing-related hacks that would not map successfully anyway and should be
+	 * removed ASAP. */
+	if (flash->chip->total_size == 0)
+		return 0;
+
+	const chipsize_t size = flash->chip->total_size * 1024;
+	uintptr_t base = flashbase ? flashbase : (0xffffffff - size + 1);
+	void *addr = programmer_map_flash_region(flash->chip->name, base, size);
+	if (addr == ERROR_PTR) {
+		msg_perr("Could not map flash chip %s at 0x%0*" PRIxPTR ".\n",
+			 flash->chip->name, PRIxPTR_WIDTH, base);
+		return 1;
+	}
+	flash->physical_memory = base;
+	flash->virtual_memory = (chipaddr)addr;
+
+	/* FIXME: Special function registers normally live 4 MByte below flash space, but it might be somewhere
+	 * completely different on some chips and programmers, or not mappable at all.
+	 * Ignore these problems for now and always report success. */
+	if (flash->chip->feature_bits & FEATURE_REGISTERMAP) {
+		base = 0xffffffff - size - 0x400000 + 1;
+		addr = programmer_map_flash_region("flash chip registers", base, size);
+		if (addr == ERROR_PTR) {
+			msg_pdbg2("Could not map flash chip registers %s at 0x%0*" PRIxPTR ".\n",
+				 flash->chip->name, PRIxPTR_WIDTH, base);
+			return 0;
+		}
+		flash->physical_registers = base;
+		flash->virtual_registers = (chipaddr)addr;
+	}
+	return 0;
+}
+
 int probe_flash(struct registered_master *mst, int startchip, struct flashctx *flash, int force)
 {
 	const struct flashchip *chip;
-	unsigned long base = 0;
-	char location[64];
-	uint32_t size;
 	enum chipbustype buses_common;
 	char *tmp;
 
@@ -1082,9 +1127,8 @@ int probe_flash(struct registered_master *mst, int startchip, struct flashctx *f
 		memcpy(flash->chip, chip, sizeof(struct flashchip));
 		flash->mst = mst;
 
-		size = flash->chip->total_size * 1024;
-		base = flashbase ? flashbase : (0xffffffff - size + 1);
-		flash->virtual_memory = (chipaddr)programmer_map_flash_region("flash chip", base, size);
+		if (map_flash(flash) != 0)
+			return -1;
 
 		/* We handle a forced match like a real match, we just avoid probing. Note that probe_flash()
 		 * is only called with force=1 after normal probing failed.
@@ -1133,8 +1177,7 @@ int probe_flash(struct registered_master *mst, int startchip, struct flashctx *f
 			break;
 		/* Not the first flash chip detected on this bus, and it's just a generic match. Ignore it. */
 notfound:
-		programmer_unmap_flash_region((void *)flash->virtual_memory, size);
-		flash->virtual_memory = (chipaddr)NULL;
+		unmap_flash(flash);
 		free(flash->chip);
 		flash->chip = NULL;
 	}
@@ -1142,25 +1185,28 @@ notfound:
 	if (!flash->chip)
 		return -1;
 
+
+	tmp = flashbuses_to_text(flash->chip->bustype);
+	msg_cinfo("%s %s flash chip \"%s\" (%d kB, %s) ", force ? "Assuming" : "Found",
+		  flash->chip->vendor, flash->chip->name, flash->chip->total_size, tmp);
+	free(tmp);
 #if CONFIG_INTERNAL == 1
 	if (programmer_table[programmer].map_flash_region == physmap)
-		snprintf(location, sizeof(location), "at physical address 0x%lx", base);
+		msg_cinfo("mapped at physical address 0x%0*" PRIxPTR ".\n",
+			  PRIxPTR_WIDTH, flash->physical_memory);
 	else
 #endif
-		snprintf(location, sizeof(location), "on %s", programmer_table[programmer].name);
+		msg_cinfo("on %s.\n", programmer_table[programmer].name);
 
-	tmp = flashbuses_to_text(flash->chip->bustype);
-	msg_cinfo("%s %s flash chip \"%s\" (%d kB, %s) %s.\n", force ? "Assuming" : "Found",
-		  flash->chip->vendor, flash->chip->name, flash->chip->total_size, tmp, location);
-	free(tmp);
-
-	/* Flash registers will not be mapped if the chip was forced. Lock info
-	 * may be stored in registers, so avoid lock info printing.
-	 */
+	/* Flash registers may more likely not be mapped if the chip was forced.
+	 * Lock info may be stored in registers, so avoid lock info printing. */
 	if (!force)
 		if (flash->chip->printlock)
 			flash->chip->printlock(flash);
 
+	/* Get out of the way for later runs. */
+	unmap_flash(flash);
+
 	/* Return position of matching chip. */
 	return chip - flashchips;
 }

jedec.c

@@ -166,9 +166,6 @@ int probe_jedec_29gl(struct flashctx *flash)
 	if (man_id != chip->manufacture_id || dev_id != chip->model_id)
 		return 0;
 
-	if (chip->feature_bits & FEATURE_REGISTERMAP)
-		map_flash_registers(flash);
-
 	return 1;
 }
 
@@ -287,9 +284,6 @@ static int probe_jedec_common(struct flashctx *flash, unsigned int mask)
 	if (largeid1 != chip->manufacture_id || largeid2 != chip->model_id)
 		return 0;
 
-	if (chip->feature_bits & FEATURE_REGISTERMAP)
-		map_flash_registers(flash);
-
 	return 1;
 }