sfc: add tracing of MCDI commands

MCDI tracing is conditional on CONFIG_SFC_MCDI_LOGGING, which is enabled
 by default.

Each MCDI command will produce a console line like
    sfc dom:bus:dev:fn ifname: MCDI RPC REQ: xxxxxxxx [yyyyyyyy...]
where xxxxxxxx etc. are the raw MCDI payload in 32-bit hex chunks.
The response will then produce a similar line with "RESP" instead of "REQ",
 and containing the MCDI response payload (if any).

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/sfc/Kconfig b/drivers/net/ethernet/sfc/Kconfig
index 0889212..c4ba42b 100644 (file)
--- a/drivers/net/ethernet/sfc/Kconfig
+++ b/drivers/net/ethernet/sfc/Kconfig
@@ -36,3 +36,11 @@ config SFC_SRIOV
          This enables support for the SFC9000 I/O Virtualization
          features, allowing accelerated network performance in
          virtualized environments.
+config SFC_MCDI_LOGGING
+       bool "Solarflare SFC9000/SFC9100-family MCDI logging support"
+       depends on SFC
+       default y
+       ---help---
+         This enables support for tracing of MCDI (Management-Controller-to-
+         Driver-Interface) commands and responses, allowing debugging of
+         driver/firmware interaction.

diff --git a/drivers/net/ethernet/sfc/ef10.c b/drivers/net/ethernet/sfc/ef10.c
index a547ceb..4eb6ab7 100644 (file)
--- a/drivers/net/ethernet/sfc/ef10.c
+++ b/drivers/net/ethernet/sfc/ef10.c
@@ -267,6 +267,9 @@ static int efx_ef10_probe(struct efx_nic *efx)
                return -ENOMEM;
        efx->nic_data = nic_data;
 
+       /* we assume later that we can copy from this buffer in dwords */
+       BUILD_BUG_ON(MCDI_CTL_SDU_LEN_MAX_V2 % 4);
+
        rc = efx_nic_alloc_buffer(efx, &nic_data->mcdi_buf,
                                  8 + MCDI_CTL_SDU_LEN_MAX_V2, GFP_KERNEL);
        if (rc)

diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c
index 8267a1c..31eda32 100644 (file)
--- a/drivers/net/ethernet/sfc/mcdi.c
+++ b/drivers/net/ethernet/sfc/mcdi.c
@@ -58,14 +58,20 @@ int efx_mcdi_init(struct efx_nic *efx)
 {
        struct efx_mcdi_iface *mcdi;
        bool already_attached;
-       int rc;
+       int rc = -ENOMEM;
 
        efx->mcdi = kzalloc(sizeof(*efx->mcdi), GFP_KERNEL);
        if (!efx->mcdi)
-               return -ENOMEM;
+               goto fail;
 
        mcdi = efx_mcdi(efx);
        mcdi->efx = efx;
+#ifdef CONFIG_SFC_MCDI_LOGGING
+       /* consuming code assumes buffer is page-sized */
+       mcdi->logging_buffer = (char *)__get_free_page(GFP_KERNEL);
+       if (!mcdi->logging_buffer)
+               goto fail1;
+#endif
        init_waitqueue_head(&mcdi->wq);
        spin_lock_init(&mcdi->iface_lock);
        mcdi->state = MCDI_STATE_QUIESCENT;
@@ -81,7 +87,7 @@ int efx_mcdi_init(struct efx_nic *efx)
        /* Recover from a failed assertion before probing */
        rc = efx_mcdi_handle_assertion(efx);
        if (rc)
-               return rc;
+               goto fail2;
 
        /* Let the MC (and BMC, if this is a LOM) know that the driver
         * is loaded. We should do this before we reset the NIC.
@@ -90,7 +96,7 @@ int efx_mcdi_init(struct efx_nic *efx)
        if (rc) {
                netif_err(efx, probe, efx->net_dev,
                          "Unable to register driver with MCPU\n");
-               return rc;
+               goto fail2;
        }
        if (already_attached)
                /* Not a fatal error */
@@ -102,6 +108,15 @@ int efx_mcdi_init(struct efx_nic *efx)
                efx->primary = efx;
 
        return 0;
+fail2:
+#ifdef CONFIG_SFC_MCDI_LOGGING
+       free_page((unsigned long)mcdi->logging_buffer);
+fail1:
+#endif
+       kfree(efx->mcdi);
+       efx->mcdi = NULL;
+fail:
+       return rc;
 }
 
 void efx_mcdi_fini(struct efx_nic *efx)
@@ -114,6 +129,10 @@ void efx_mcdi_fini(struct efx_nic *efx)
        /* Relinquish the device (back to the BMC, if this is a LOM) */
        efx_mcdi_drv_attach(efx, false, NULL);
 
+#ifdef CONFIG_SFC_MCDI_LOGGING
+       free_page((unsigned long)efx->mcdi->iface.logging_buffer);
+#endif
+
        kfree(efx->mcdi);
 }
 
@@ -121,6 +140,9 @@ static void efx_mcdi_send_request(struct efx_nic *efx, unsigned cmd,
                                  const efx_dword_t *inbuf, size_t inlen)
 {
        struct efx_mcdi_iface *mcdi = efx_mcdi(efx);
+#ifdef CONFIG_SFC_MCDI_LOGGING
+       char *buf = mcdi->logging_buffer; /* page-sized */
+#endif
        efx_dword_t hdr[2];
        size_t hdr_len;
        u32 xflags, seqno;
@@ -165,6 +187,31 @@ static void efx_mcdi_send_request(struct efx_nic *efx, unsigned cmd,
                hdr_len = 8;
        }
 
+#ifdef CONFIG_SFC_MCDI_LOGGING
+       if (!WARN_ON_ONCE(!buf)) {
+               int bytes = 0;
+               int i;
+               /* Lengths should always be a whole number of dwords, so scream
+                * if they're not.
+                */
+               WARN_ON_ONCE(hdr_len % 4);
+               WARN_ON_ONCE(inlen % 4);
+
+               /* We own the logging buffer, as only one MCDI can be in
+                * progress on a NIC at any one time.  So no need for locking.
+                */
+               for (i = 0; i < hdr_len / 4 && bytes < PAGE_SIZE; i++)
+                       bytes += snprintf(buf + bytes, PAGE_SIZE - bytes,
+                                         " %08x", le32_to_cpu(hdr[i].u32[0]));
+
+               for (i = 0; i < inlen / 4 && bytes < PAGE_SIZE; i++)
+                       bytes += snprintf(buf + bytes, PAGE_SIZE - bytes,
+                                         " %08x", le32_to_cpu(inbuf[i].u32[0]));
+
+               netif_info(efx, hw, efx->net_dev, "MCDI RPC REQ:%s\n", buf);
+       }
+#endif
+
        efx->type->mcdi_request(efx, hdr, hdr_len, inbuf, inlen);
 
        mcdi->new_epoch = false;
@@ -206,6 +253,9 @@ static void efx_mcdi_read_response_header(struct efx_nic *efx)
 {
        struct efx_mcdi_iface *mcdi = efx_mcdi(efx);
        unsigned int respseq, respcmd, error;
+#ifdef CONFIG_SFC_MCDI_LOGGING
+       char *buf = mcdi->logging_buffer; /* page-sized */
+#endif
        efx_dword_t hdr;
 
        efx->type->mcdi_read_response(efx, &hdr, 0, 4);
@@ -223,6 +273,39 @@ static void efx_mcdi_read_response_header(struct efx_nic *efx)
                        EFX_DWORD_FIELD(hdr, MC_CMD_V2_EXTN_IN_ACTUAL_LEN);
        }
 
+#ifdef CONFIG_SFC_MCDI_LOGGING
+       if (!WARN_ON_ONCE(!buf)) {
+               size_t hdr_len, data_len;
+               int bytes = 0;
+               int i;
+
+               WARN_ON_ONCE(mcdi->resp_hdr_len % 4);
+               hdr_len = mcdi->resp_hdr_len / 4;
+               /* MCDI_DECLARE_BUF ensures that underlying buffer is padded
+                * to dword size, and the MCDI buffer is always dword size
+                */
+               data_len = DIV_ROUND_UP(mcdi->resp_data_len, 4);
+
+               /* We own the logging buffer, as only one MCDI can be in
+                * progress on a NIC at any one time.  So no need for locking.
+                */
+               for (i = 0; i < hdr_len && bytes < PAGE_SIZE; i++) {
+                       efx->type->mcdi_read_response(efx, &hdr, (i * 4), 4);
+                       bytes += snprintf(buf + bytes, PAGE_SIZE - bytes,
+                                         " %08x", le32_to_cpu(hdr.u32[0]));
+               }
+
+               for (i = 0; i < data_len && bytes < PAGE_SIZE; i++) {
+                       efx->type->mcdi_read_response(efx, &hdr,
+                                       mcdi->resp_hdr_len + (i * 4), 4);
+                       bytes += snprintf(buf + bytes, PAGE_SIZE - bytes,
+                                         " %08x", le32_to_cpu(hdr.u32[0]));
+               }
+
+               netif_info(efx, hw, efx->net_dev, "MCDI RPC RESP:%s\n", buf);
+       }
+#endif
+
        if (error && mcdi->resp_data_len == 0) {
                netif_err(efx, hw, efx->net_dev, "MC rebooted\n");
                mcdi->resprc = -EIO;

diff --git a/drivers/net/ethernet/sfc/mcdi.h b/drivers/net/ethernet/sfc/mcdi.h
index 7afab2f..b783a2d 100644 (file)
--- a/drivers/net/ethernet/sfc/mcdi.h
+++ b/drivers/net/ethernet/sfc/mcdi.h
@@ -58,6 +58,7 @@ enum efx_mcdi_mode {
  *     enabled
  * @async_list: Queue of asynchronous requests
  * @async_timer: Timer for asynchronous request timeout
+ * @logging_buffer: buffer that may be used to build MCDI tracing messages
  */
 struct efx_mcdi_iface {
        struct efx_nic *efx;
@@ -74,6 +75,9 @@ struct efx_mcdi_iface {
        spinlock_t async_lock;
        struct list_head async_list;
        struct timer_list async_timer;
+#ifdef CONFIG_SFC_MCDI_LOGGING
+       char *logging_buffer;
+#endif
 };
 
 struct efx_mcdi_mon {