flash/nor/rp2040: fix memory leak of target stack workarea

While on it restore memory-mapped mode also after flash erase
(originally was restored after flash write only).

Change-Id: I5e153b79ac27a8439f57239ce90ce8a79c0bb8a1
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: https://review.openocd.org/c/openocd/+/7186
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

diff --git a/src/flash/nor/rp2040.c b/src/flash/nor/rp2040.c
index ba21d1c0f6dab53921175738fc7c4cf4dcb34a11..1c57424f914b0353ddd85671afc7a16cb3807fbe 100644 (file)
--- a/src/flash/nor/rp2040.c
+++ b/src/flash/nor/rp2040.c
@@ -138,6 +138,43 @@ static int rp2040_call_rom_func(struct target *target, struct rp2040_flash_bank
 
 }
 
+/* Finalize flash write/erase/read ID
+ * - flush cache
+ * - enters memory-mapped (XIP) mode to make flash data visible
+ * - deallocates target ROM func stack if previously allocated
+ */
+static int rp2040_finalize_stack_free(struct flash_bank *bank)
+{
+       struct rp2040_flash_bank *priv = bank->driver_priv;
+       struct target *target = bank->target;
+
+       /* Always flush before returning to execute-in-place, to invalidate stale
+        * cache contents. The flush call also restores regular hardware-controlled
+        * chip select following a rp2040_flash_exit_xip().
+        */
+       LOG_DEBUG("Flushing flash cache after write behind");
+       int err = rp2040_call_rom_func(target, priv, priv->jump_flush_cache, NULL, 0);
+       if (err != ERROR_OK) {
+               LOG_ERROR("Failed to flush flash cache");
+               /* Intentionally continue after error and try to setup xip anyway */
+       }
+
+       LOG_DEBUG("Configuring SSI for execute-in-place");
+       err = rp2040_call_rom_func(target, priv, priv->jump_enter_cmd_xip, NULL, 0);
+       if (err != ERROR_OK)
+               LOG_ERROR("Failed to set SSI to XIP mode");
+
+       target_free_working_area(target, priv->stack);
+       priv->stack = NULL;
+       return err;
+}
+
+/* Prepare flash write/erase/read ID
+ * - allocates a stack for target ROM func
+ * - switches the SPI interface from memory-mapped mode to direct command mode
+ * Always pair with a call of rp2040_finalize_stack_free()
+ * after flash operation finishes or fails.
+ */
 static int rp2040_stack_grab_and_prep(struct flash_bank *bank)
 {
        struct rp2040_flash_bank *priv = bank->driver_priv;
@@ -154,14 +191,14 @@ static int rp2040_stack_grab_and_prep(struct flash_bank *bank)
        LOG_DEBUG("Connecting internal flash");
        err = rp2040_call_rom_func(target, priv, priv->jump_connect_internal_flash, NULL, 0);
        if (err != ERROR_OK) {
-               LOG_ERROR("RP2040 erase: failed to connect internal flash");
+               LOG_ERROR("Failed to connect internal flash");
                return err;
        }
 
        LOG_DEBUG("Kicking flash out of XIP mode");
        err = rp2040_call_rom_func(target, priv, priv->jump_flash_exit_xip, NULL, 0);
        if (err != ERROR_OK) {
-               LOG_ERROR("RP2040 erase: failed to exit flash XIP mode");
+               LOG_ERROR("Failed to exit flash XIP mode");
                return err;
        }
 
@@ -174,16 +211,17 @@ static int rp2040_flash_write(struct flash_bank *bank, const uint8_t *buffer, ui
 
        struct rp2040_flash_bank *priv = bank->driver_priv;
        struct target *target = bank->target;
-       struct working_area *bounce;
+       struct working_area *bounce = NULL;
 
        int err = rp2040_stack_grab_and_prep(bank);
        if (err != ERROR_OK)
-               return err;
+               goto cleanup;
 
        const unsigned int chunk_size = target_get_working_area_avail(target);
-       if (target_alloc_working_area(target, chunk_size, &bounce) != ERROR_OK) {
+       err = target_alloc_working_area(target, chunk_size, &bounce);
+       if (err != ERROR_OK) {
                LOG_ERROR("Could not allocate bounce buffer for flash programming. Can't continue");
-               return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
+               goto cleanup;
        }
 
        LOG_DEBUG("Allocated flash bounce buffer @" TARGET_ADDR_FMT, bounce->address);
@@ -211,23 +249,12 @@ static int rp2040_flash_write(struct flash_bank *bank, const uint8_t *buffer, ui
                offset += write_size;
                count -= write_size;
        }
+
+cleanup:
        target_free_working_area(target, bounce);
 
-       if (err != ERROR_OK)
-               return err;
+       rp2040_finalize_stack_free(bank);
 
-       /* Flash is successfully programmed. We can now do a bit of poking to make the flash
-          contents visible to us via memory-mapped (XIP) interface in the 0x1... memory region */
-       LOG_DEBUG("Flushing flash cache after write behind");
-       err = rp2040_call_rom_func(bank->target, priv, priv->jump_flush_cache, NULL, 0);
-       if (err != ERROR_OK) {
-               LOG_ERROR("RP2040 write: failed to flush flash cache");
-               return err;
-       }
-       LOG_DEBUG("Configuring SSI for execute-in-place");
-       err = rp2040_call_rom_func(bank->target, priv, priv->jump_enter_cmd_xip, NULL, 0);
-       if (err != ERROR_OK)
-               LOG_ERROR("RP2040 write: failed to flush flash cache");
        return err;
 }
 
@@ -240,7 +267,7 @@ static int rp2040_flash_erase(struct flash_bank *bank, unsigned int first, unsig
 
        int err = rp2040_stack_grab_and_prep(bank);
        if (err != ERROR_OK)
-               return err;
+               goto cleanup;
 
        LOG_DEBUG("Remote call flash_range_erase");
 
@@ -258,11 +285,14 @@ static int rp2040_flash_erase(struct flash_bank *bank, unsigned int first, unsig
        https://github.com/raspberrypi/pico-bootrom/blob/master/bootrom/program_flash_generic.c
 
        In theory, the function algorithm provides for erasing both a smaller "sector" (4096 bytes) and
-       an optional larger "block" (size and command provided in args).  OpenOCD's spi.c only uses "block" sizes.
+       an optional larger "block" (size and command provided in args).
        */
 
        err = rp2040_call_rom_func(bank->target, priv, priv->jump_flash_range_erase, args, ARRAY_SIZE(args));
 
+cleanup:
+       rp2040_finalize_stack_free(bank);
+
        return err;
 }
 
@@ -376,11 +406,13 @@ static int rp2040_flash_probe(struct flash_bank *bank)
        }
 
        err = rp2040_stack_grab_and_prep(bank);
-       if (err != ERROR_OK)
-               return err;
 
        uint32_t device_id = 0;
-       err = rp2040_spi_read_flash_id(target, &device_id);
+       if (err == ERROR_OK)
+               err = rp2040_spi_read_flash_id(target, &device_id);
+
+       rp2040_finalize_stack_free(bank);
+
        if (err != ERROR_OK)
                return err;