Bootloader code will ignore any attempts to write data to any flash
area outside of [ZIIRAVE_FIRM_FLASH_MEMORY_START;
ZIIRAVE_FIRM_FLASH_MEMORY_END]. Firmware update code already have an
appropriate check to skip those areas when validating updated
firmware. Firmware programming code, OTOH, does not and will
needlessly send no-op I2C traffic. Add an appropriate check to
__ziirave_firm_write_pkt() so as to save all of that wasted effort.
While at it, normalize all of the address handling code to use full
32-bit address in units of bytes and convert it to an appropriate
value only in places where that is necessary.
Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
Cc: Chris Healy <cphealy@xxxxxxxxx>
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: Rick Ramstetter <rick@xxxxxxxxxxxxxxx>
Cc: linux-watchdog@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
drivers/watchdog/ziirave_wdt.c | 33 ++++++++++++++++++++++++---------
1 file changed, 24 insertions(+), 9 deletions(-)
diff --git a/drivers/watchdog/ziirave_wdt.c b/drivers/watchdog/ziirave_wdt.c
index f05095b08016..a3cc936858ad 100644
--- a/drivers/watchdog/ziirave_wdt.c
+++ b/drivers/watchdog/ziirave_wdt.c
@@ -51,8 +51,8 @@ static char *ziirave_reasons[] = {"power cycle", "hw watchdog", NULL, NULL,
#define ZIIRAVE_FIRM_PKT_TOTAL_SIZE 20
#define ZIIRAVE_FIRM_PKT_DATA_SIZE 16
-#define ZIIRAVE_FIRM_FLASH_MEMORY_START 0x1600
-#define ZIIRAVE_FIRM_FLASH_MEMORY_END 0x2bbf
+#define ZIIRAVE_FIRM_FLASH_MEMORY_START (2 * 0x1600)
+#define ZIIRAVE_FIRM_FLASH_MEMORY_END (2 * 0x2bbf)
#define ZIIRAVE_FIRM_PAGE_SIZE 128
/* Received and ready for next Download packet. */
@@ -195,12 +195,13 @@ static int ziirave_firm_wait_for_ack(struct watchdog_device *wdd)
return ret == ZIIRAVE_FIRM_DOWNLOAD_ACK ? 0 : -EIO;
}
-static int ziirave_firm_set_read_addr(struct watchdog_device *wdd, u16 addr)
+static int ziirave_firm_set_read_addr(struct watchdog_device *wdd, u32 addr)
{
struct i2c_client *client = to_i2c_client(wdd->parent);
+ const u16 addr16 = (u16)addr / 2;
u8 address[2];
- put_unaligned_le16(addr, address);
+ put_unaligned_le16(addr16, address);
return i2c_smbus_write_block_data(client,
ZIIRAVE_CMD_DOWNLOAD_SET_READ_ADDR,
@@ -234,6 +235,12 @@ static int ziirave_firm_write_byte(struct watchdog_device *wdd, u8 command,
wait_for_ack);
}
+static bool ziirave_firm_addr_readonly(u32 addr)
+{
+ return addr < ZIIRAVE_FIRM_FLASH_MEMORY_START ||
+ addr > ZIIRAVE_FIRM_FLASH_MEMORY_END;
+}
+
/*
* ziirave_firm_write_pkt() - Build and write a firmware packet
*
@@ -261,6 +268,16 @@ static int __ziirave_firm_write_pkt(struct watchdog_device *wdd,
return -EMSGSIZE;
}
+ /*
+ * Ignore packets that are targeting program memory outisde of
+ * app partition, since they will be ignored by the
+ * bootloader. At the same time, we need to make sure we'll
+ * allow zero length packet that will be sent as the last step
+ * of firmware update
+ */
+ if (len && ziirave_firm_addr_readonly(addr))
+ return 0;
+
/* Packet length */
packet[0] = len;
/* Packet address */
@@ -279,7 +296,7 @@ static int __ziirave_firm_write_pkt(struct watchdog_device *wdd,
if (ret)
dev_err(&client->dev,
"Failed to write firmware packet at address 0x%04x: %d\n",
- addr16, ret);
+ addr, ret);
return ret;
}
@@ -315,14 +332,12 @@ static int ziirave_firm_verify(struct watchdog_device *wdd,
const struct ihex_binrec *rec;
int i, ret;
u8 data[ZIIRAVE_FIRM_PKT_DATA_SIZE];
- u16 addr;
for (rec = (void *)fw->data; rec; rec = ihex_next_binrec(rec)) {
const u16 len = be16_to_cpu(rec->len);
+ const u32 addr = be32_to_cpu(rec->addr);
- addr = (be32_to_cpu(rec->addr) & 0xffff) >> 1;
- if (addr < ZIIRAVE_FIRM_FLASH_MEMORY_START ||
- addr > ZIIRAVE_FIRM_FLASH_MEMORY_END)
+ if (ziirave_firm_addr_readonly(addr))
continue;
ret = ziirave_firm_set_read_addr(wdd, addr);
--
2.21.0
