flashrom: Use WP-based unlocking on opaque masters

Flashrom only tries to use WP-based unlocking if it detects that WP
operations are supported. However WP support was detected in a way that
ignored WP operations provided by opaque masters.

This stopped flashrom from automatically unlocking with some opaque
masters, particularly linux_mtd.

This commit also deletes part of a test that required the chip unlock
function to be called before read/write/erase operations because WP
unlocking is now used instead of chip unlocking.

BUG=b:280111380
BRANCH=none
TEST=Checked flashrom automatically unlocked flash on strongbad (MTD)

Change-Id: I1774ad64d82ae47cd085df6045e17e283855c01f
Signed-off-by: Nikolai Artemiev <nartemiev@google.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/74930
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
---
M flashrom.c
M include/flash.h
M spi25_statusreg.c
M tests/chip.c
4 files changed, 32 insertions(+), 42 deletions(-)

diff --git a/flashrom.c b/flashrom.c
index 07ed0df..faffe51 100644
--- a/flashrom.c
+++ b/flashrom.c
@@ -2093,7 +2093,8 @@
 
 	/* Given the existence of read locks, we want to unlock for read, erase and write. */
 	int ret = 1;
-	if (flash->chip->decode_range != NO_DECODE_RANGE_FUNC) {
+	if (flash->chip->decode_range != NO_DECODE_RANGE_FUNC ||
+	   (flash->mst->buses_supported & BUS_PROG && flash->mst->opaque.wp_write_cfg)) {
 		ret = unlock_flash_wp(flash);
 		if (ret)
 			msg_cerr("Failed to unlock flash status reg with wp support.\n");
diff --git a/include/flash.h b/include/flash.h
index 3e9c885..0eace15 100644
--- a/include/flash.h
+++ b/include/flash.h
@@ -348,7 +348,6 @@
 	UNLOCK_LH28F008BJT,
 	UNLOCK_SST_FWHUB,
 	UNPROTECT_28SF040,
-	TEST_UNLOCK_INJECTOR, /* special case must come last. */
 };
 
 enum printlock_func {
diff --git a/spi25_statusreg.c b/spi25_statusreg.c
index 60e0b46..fa276f7 100644
--- a/spi25_statusreg.c
+++ b/spi25_statusreg.c
@@ -914,9 +914,6 @@
 	return spi_disable_blockprotect_bp2_srwd(flash);
 }
 
-/* special unit-test hook */
-blockprotect_func_t *g_test_unlock_injector;
-
 blockprotect_func_t *lookup_blockprotect_func_ptr(const struct flashchip *const chip)
 {
 	switch (chip->unlock) {
@@ -948,7 +945,6 @@
 			return lookup_82802ab_blockprotect_func_ptr(chip);
 		case UNLOCK_SST_FWHUB: return unlock_sst_fwhub; /* sst_fwhub.c */
 		case UNPROTECT_28SF040: return unprotect_28sf040; /* sst28sf040.c */
-		case TEST_UNLOCK_INJECTOR: return g_test_unlock_injector;
 	/* default: non-total function, 0 indicates no unlock function set.
 	 * We explicitly do not want a default catch-all case in the switch
 	 * to ensure unhandled enum's are compiler warnings.
diff --git a/tests/chip.c b/tests/chip.c
index 6a17d86..96be7b1 100644
--- a/tests/chip.c
+++ b/tests/chip.c
@@ -20,7 +20,7 @@
  * Example of test: erase_chip_test_success.
  *
  * 2) Mock chip operations backed by `dummyflasher` emulation.
- * Dummyflasher controls chip state and emulates read/write/unlock/erase.
+ * Dummyflasher controls chip state and emulates read/write/erase.
  * `g_chip_state` is NOT used for this type of tests.
  * Example of test: erase_chip_with_dummyflasher_test_success.
  */
@@ -40,20 +40,14 @@
 #define MOCK_CHIP_CONTENT 0xCC /* 0x00 is a zeroed heap and 0xFF is an erased chip. */
 
 static struct {
-	unsigned int unlock_calls; /* how many times unlock function was called */
 	uint8_t buf[MOCK_CHIP_SIZE]; /* buffer of total size of chip, to emulate a chip */
 } g_chip_state = {
-	.unlock_calls = 0,
 	.buf = { 0 },
 };
 
 static int read_chip(struct flashctx *flash, uint8_t *buf, unsigned int start, unsigned int len)
 {
 	printf("Read chip called with start=0x%x, len=0x%x\n", start, len);
-	if (!g_chip_state.unlock_calls) {
-		printf("Error while reading chip: unlock was not called.\n");
-		return 1;
-	}
 
 	assert_in_range(start + len, 0, MOCK_CHIP_SIZE);
 
@@ -64,10 +58,6 @@
 static int write_chip(struct flashctx *flash, const uint8_t *buf, unsigned int start, unsigned int len)
 {
 	printf("Write chip called with start=0x%x, len=0x%x\n", start, len);
-	if (!g_chip_state.unlock_calls) {
-		printf("Error while writing chip: unlock was not called.\n");
-		return 1;
-	}
 
 	assert_in_range(start + len, 0, MOCK_CHIP_SIZE);
 
@@ -75,26 +65,9 @@
 	return 0;
 }
 
-static int unlock_chip(struct flashctx *flash)
-{
-	printf("Unlock chip called\n");
-	g_chip_state.unlock_calls++;
-
-	if (g_chip_state.unlock_calls > 1) {
-		printf("Error: Unlock called twice\n");
-		return -1;
-	}
-
-	return 0;
-}
-
 static int block_erase_chip(struct flashctx *flash, unsigned int blockaddr, unsigned int blocklen)
 {
 	printf("Block erase called with blockaddr=0x%x, blocklen=0x%x\n", blockaddr, blocklen);
-	if (!g_chip_state.unlock_calls) {
-		printf("Error while erasing chip: unlock was not called.\n");
-		return 1;
-	}
 
 	assert_in_range(blockaddr + blocklen, 0, MOCK_CHIP_SIZE);
 
@@ -109,7 +82,6 @@
 
 	flashctx->chip = chip;
 
-	g_chip_state.unlock_calls = 0;
 	memset(g_chip_state.buf, MOCK_CHIP_CONTENT, sizeof(g_chip_state.buf));
 
 	printf("Creating layout with one included region... ");
@@ -149,7 +121,6 @@
 extern write_func_t *g_test_write_injector;
 extern read_func_t *g_test_read_injector;
 extern erasefunc_t *g_test_erase_injector;
-extern blockprotect_func_t *g_test_unlock_injector;
 
 static const struct flashchip chip_8MiB = {
 	.vendor		= "aklm",
@@ -157,7 +128,6 @@
 	.tested		= TEST_OK_PREW,
 	.read		= TEST_READ_INJECTOR,
 	.write		= TEST_WRITE_INJECTOR,
-	.unlock		= TEST_UNLOCK_INJECTOR,
 	.block_erasers	=
 	{{
 		 /* All blocks within total size of the chip. */
@@ -173,7 +143,6 @@
 	.tested		= TEST_OK_PREW,
 	.read		= SPI_CHIP_READ,
 	.write		= SPI_CHIP_WRITE256,
-	.unlock         = SPI_DISABLE_BLOCKPROTECT,
 	.page_size	= 256,
 	.block_erasers  =
 	{
@@ -211,7 +180,6 @@
 	g_test_write_injector = write_chip;
 	g_test_read_injector = read_chip;
 	g_test_erase_injector = block_erase_chip;
-	g_test_unlock_injector = unlock_chip;
 	struct flashrom_flashctx flashctx = { 0 };
 	struct flashrom_layout *layout;
 	struct flashchip mock_chip = chip_8MiB;
@@ -271,7 +239,6 @@
 	g_test_write_injector = write_chip;
 	g_test_read_injector = read_chip;
 	g_test_erase_injector = block_erase_chip;
-	g_test_unlock_injector = unlock_chip;
 	struct flashrom_flashctx flashctx = { 0 };
 	struct flashrom_layout *layout;
 	struct flashchip mock_chip = chip_8MiB;
@@ -347,7 +314,6 @@
 	g_test_write_injector = write_chip;
 	g_test_read_injector = read_chip;
 	g_test_erase_injector = block_erase_chip;
-	g_test_unlock_injector = unlock_chip;
 	struct flashrom_flashctx flashctx = { 0 };
 	struct flashrom_layout *layout;
 	struct flashchip mock_chip = chip_8MiB;
@@ -539,7 +505,6 @@
 	g_test_write_injector = write_chip;
 	g_test_read_injector = read_chip;
 	g_test_erase_injector = block_erase_chip;
-	g_test_unlock_injector = unlock_chip;
 	struct flashrom_flashctx flashctx = { 0 };
 	struct flashrom_layout *layout;
 	struct flashchip mock_chip = chip_8MiB;

