sfc: Handle firmware assertion failure while resetting

This allows the driver to recover if the MC firmware has crashed due
to an assertion failure.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/sfc/mcdi.c b/drivers/net/sfc/mcdi.c
index 9f035b9f03503245ca38c44d058cf350958d3884..e9f0e5ee4519aeb3c349d5ccb6a7b33f7f9121bf 100644 (file)
--- a/drivers/net/sfc/mcdi.c
+++ b/drivers/net/sfc/mcdi.c
@@ -896,29 +896,27 @@ fail:
        return rc;
 }
 
-int efx_mcdi_handle_assertion(struct efx_nic *efx)
+static int efx_mcdi_read_assertion(struct efx_nic *efx)
 {
-       union {
-               u8 asserts[MC_CMD_GET_ASSERTS_IN_LEN];
-               u8 reboot[MC_CMD_REBOOT_IN_LEN];
-       } inbuf;
-       u8 assertion[MC_CMD_GET_ASSERTS_OUT_LEN];
+       u8 inbuf[MC_CMD_GET_ASSERTS_IN_LEN];
+       u8 outbuf[MC_CMD_GET_ASSERTS_OUT_LEN];
        unsigned int flags, index, ofst;
        const char *reason;
        size_t outlen;
        int retry;
        int rc;
 
-       /* Check if the MC is in the assertion handler, retrying twice. Once
+       /* Attempt to read any stored assertion state before we reboot
+        * the mcfw out of the assertion handler. Retry twice, once
         * because a boot-time assertion might cause this command to fail
         * with EINTR. And once again because GET_ASSERTS can race with
         * MC_CMD_REBOOT running on the other port. */
        retry = 2;
        do {
-               MCDI_SET_DWORD(inbuf.asserts, GET_ASSERTS_IN_CLEAR, 0);
+               MCDI_SET_DWORD(inbuf, GET_ASSERTS_IN_CLEAR, 1);
                rc = efx_mcdi_rpc(efx, MC_CMD_GET_ASSERTS,
-                                 inbuf.asserts, MC_CMD_GET_ASSERTS_IN_LEN,
-                                 assertion, sizeof(assertion), &outlen);
+                                 inbuf, MC_CMD_GET_ASSERTS_IN_LEN,
+                                 outbuf, sizeof(outbuf), &outlen);
        } while ((rc == -EINTR || rc == -EIO) && retry-- > 0);
 
        if (rc)
@@ -926,21 +924,11 @@ int efx_mcdi_handle_assertion(struct efx_nic *efx)
        if (outlen < MC_CMD_GET_ASSERTS_OUT_LEN)
                return -EINVAL;
 
-       flags = MCDI_DWORD(assertion, GET_ASSERTS_OUT_GLOBAL_FLAGS);
+       /* Print out any recorded assertion state */
+       flags = MCDI_DWORD(outbuf, GET_ASSERTS_OUT_GLOBAL_FLAGS);
        if (flags == MC_CMD_GET_ASSERTS_FLAGS_NO_FAILS)
                return 0;
 
-       /* Reset the hardware atomically such that only one port with succeed.
-        * This command will succeed if a reboot is no longer required (because
-        * the other port did it first), but fail with EIO if it succeeds.
-        */
-       BUILD_BUG_ON(MC_CMD_REBOOT_OUT_LEN != 0);
-       MCDI_SET_DWORD(inbuf.reboot, REBOOT_IN_FLAGS,
-                      MC_CMD_REBOOT_FLAGS_AFTER_ASSERTION);
-       efx_mcdi_rpc(efx, MC_CMD_REBOOT, inbuf.reboot, MC_CMD_REBOOT_IN_LEN,
-                    NULL, 0, NULL);
-
-       /* Print out the assertion */
        reason = (flags == MC_CMD_GET_ASSERTS_FLAGS_SYS_FAIL)
                ? "system-level assertion"
                : (flags == MC_CMD_GET_ASSERTS_FLAGS_THR_FAIL)
@@ -949,20 +937,45 @@ int efx_mcdi_handle_assertion(struct efx_nic *efx)
                ? "watchdog reset"
                : "unknown assertion";
        EFX_ERR(efx, "MCPU %s at PC = 0x%.8x in thread 0x%.8x\n", reason,
-               MCDI_DWORD(assertion, GET_ASSERTS_OUT_SAVED_PC_OFFS),
-               MCDI_DWORD(assertion, GET_ASSERTS_OUT_THREAD_OFFS));
+               MCDI_DWORD(outbuf, GET_ASSERTS_OUT_SAVED_PC_OFFS),
+               MCDI_DWORD(outbuf, GET_ASSERTS_OUT_THREAD_OFFS));
 
        /* Print out the registers */
        ofst = MC_CMD_GET_ASSERTS_OUT_GP_REGS_OFFS_OFST;
        for (index = 1; index < 32; index++) {
                EFX_ERR(efx, "R%.2d (?): 0x%.8x\n", index,
-                       MCDI_DWORD2(assertion, ofst));
+                       MCDI_DWORD2(outbuf, ofst));
                ofst += sizeof(efx_dword_t);
        }
 
        return 0;
 }
 
+static void efx_mcdi_exit_assertion(struct efx_nic *efx)
+{
+       u8 inbuf[MC_CMD_REBOOT_IN_LEN];
+
+       /* Atomically reboot the mcfw out of the assertion handler */
+       BUILD_BUG_ON(MC_CMD_REBOOT_OUT_LEN != 0);
+       MCDI_SET_DWORD(inbuf, REBOOT_IN_FLAGS,
+                      MC_CMD_REBOOT_FLAGS_AFTER_ASSERTION);
+       efx_mcdi_rpc(efx, MC_CMD_REBOOT, inbuf, MC_CMD_REBOOT_IN_LEN,
+                    NULL, 0, NULL);
+}
+
+int efx_mcdi_handle_assertion(struct efx_nic *efx)
+{
+       int rc;
+
+       rc = efx_mcdi_read_assertion(efx);
+       if (rc)
+               return rc;
+
+       efx_mcdi_exit_assertion(efx);
+
+       return 0;
+}
+
 void efx_mcdi_set_id_led(struct efx_nic *efx, enum efx_led_mode mode)
 {
        u8 inbuf[MC_CMD_SET_ID_LED_IN_LEN];

diff --git a/drivers/net/sfc/siena.c b/drivers/net/sfc/siena.c
index f8c6771e66d861488bd12fc69d51346a0fedebb6..0e4c13abf0872e3ff79e096db9616ba885e12b99 100644 (file)
--- a/drivers/net/sfc/siena.c
+++ b/drivers/net/sfc/siena.c
@@ -181,6 +181,12 @@ static int siena_test_registers(struct efx_nic *efx)
 
 static int siena_reset_hw(struct efx_nic *efx, enum reset_type method)
 {
+       int rc;
+
+       /* Recover from a failed assertion pre-reset */
+       rc = efx_mcdi_handle_assertion(efx);
+       if (rc)
+               return rc;
 
        if (method == RESET_TYPE_WORLD)
                return efx_mcdi_reset_mc(efx);