nfp: implement firmware flashing

Firmware flashing takes around 60s (specified to not take more than
70s). Prevent hogging the RTNL lock in this time and make use of the
longer timeout for the NSP command. The timeout is set to 2.5 * 70
seconds.

We only allow flashing the firmware from reprs or PF netdevs. VFs do not
have an app reference.
Signed-off-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c

@@ -47,6 +47,7 @@
 #include <linux/interrupt.h>
 #include <linux/pci.h>
 #include <linux/ethtool.h>
+#include <linux/firmware.h>
 
 #include "nfpcore/nfp.h"
 #include "nfpcore/nfp_nsp.h"
@@ -1269,6 +1270,57 @@ static int nfp_net_set_channels(struct net_device *netdev,
 	return nfp_net_set_num_rings(nn, total_rx, total_tx);
 }
 
+static int
+nfp_net_flash_device(struct net_device *netdev, struct ethtool_flash *flash)
+{
+	const struct firmware *fw;
+	struct nfp_app *app;
+	struct nfp_nsp *nsp;
+	struct device *dev;
+	int err;
+
+	if (flash->region != ETHTOOL_FLASH_ALL_REGIONS)
+		return -EOPNOTSUPP;
+
+	app = nfp_app_from_netdev(netdev);
+	if (!app)
+		return -EOPNOTSUPP;
+
+	dev = &app->pdev->dev;
+
+	nsp = nfp_nsp_open(app->cpp);
+	if (IS_ERR(nsp)) {
+		err = PTR_ERR(nsp);
+		dev_err(dev, "Failed to access the NSP: %d\n", err);
+		return err;
+	}
+
+	err = request_firmware_direct(&fw, flash->data, dev);
+	if (err)
+		goto exit_close_nsp;
+
+	dev_info(dev, "Please be patient while writing flash image: %s\n",
+		 flash->data);
+	dev_hold(netdev);
+	rtnl_unlock();
+
+	err = nfp_nsp_write_flash(nsp, fw);
+	if (err < 0) {
+		dev_err(dev, "Flash write failed: %d\n", err);
+		goto exit_rtnl_lock;
+	}
+	dev_info(dev, "Finished writing flash image\n");
+
+exit_rtnl_lock:
+	rtnl_lock();
+	dev_put(netdev);
+	release_firmware(fw);
+
+exit_close_nsp:
+	nfp_nsp_close(nsp);
+	return err;
+}
+
 static const struct ethtool_ops nfp_net_ethtool_ops = {
 	.get_drvinfo		= nfp_net_get_drvinfo,
 	.get_link		= ethtool_op_get_link,
@@ -1279,6 +1331,7 @@ static const struct ethtool_ops nfp_net_ethtool_ops = {
 	.get_sset_count		= nfp_net_get_sset_count,
 	.get_rxnfc		= nfp_net_get_rxnfc,
 	.set_rxnfc		= nfp_net_set_rxnfc,
+	.flash_device		= nfp_net_flash_device,
 	.get_rxfh_indir_size	= nfp_net_get_rxfh_indir_size,
 	.get_rxfh_key_size	= nfp_net_get_rxfh_key_size,
 	.get_rxfh		= nfp_net_get_rxfh,
@@ -1304,6 +1357,7 @@ const struct ethtool_ops nfp_port_ethtool_ops = {
 	.get_strings		= nfp_port_get_strings,
 	.get_ethtool_stats	= nfp_port_get_stats,
 	.get_sset_count		= nfp_port_get_sset_count,
+	.flash_device		= nfp_net_flash_device,
 	.set_dump		= nfp_app_set_dump,
 	.get_dump_flag		= nfp_app_get_dump_flag,
 	.get_dump_data		= nfp_app_get_dump_data,

drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.c

@@ -96,6 +96,7 @@ enum nfp_nsp_cmd {
 	SPCODE_FW_LOAD		= 6, /* Load fw from buffer, len in option */
 	SPCODE_ETH_RESCAN	= 7, /* Rescan ETHs, write ETH_TABLE to buf */
 	SPCODE_ETH_CONTROL	= 8, /* Update media config from buffer */
+	SPCODE_NSP_WRITE_FLASH	= 11, /* Load and flash image from buffer */
 	SPCODE_NSP_SENSORS	= 12, /* Read NSP sensor(s) */
 	SPCODE_NSP_IDENTIFY	= 13, /* Read NSP version */
 };
@@ -514,6 +515,17 @@ int nfp_nsp_load_fw(struct nfp_nsp *state, const struct firmware *fw)
 				   fw->size, NULL, 0);
 }
 
+int nfp_nsp_write_flash(struct nfp_nsp *state, const struct firmware *fw)
+{
+	/* The flash time is specified to take a maximum of 70s so we add an
+	 * additional factor to this spec time.
+	 */
+	u32 timeout_sec = 2.5 * 70;
+
+	return __nfp_nsp_command_buf(state, SPCODE_NSP_WRITE_FLASH, fw->size,
+				     fw->data, fw->size, NULL, 0, timeout_sec);
+}
+
 int nfp_nsp_read_eth_table(struct nfp_nsp *state, void *buf, unsigned int size)
 {
 	return nfp_nsp_command_buf(state, SPCODE_ETH_RESCAN, size, NULL, 0,

drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.h

@@ -48,6 +48,7 @@ u16 nfp_nsp_get_abi_ver_minor(struct nfp_nsp *state);
 int nfp_nsp_wait(struct nfp_nsp *state);
 int nfp_nsp_device_soft_reset(struct nfp_nsp *state);
 int nfp_nsp_load_fw(struct nfp_nsp *state, const struct firmware *fw);
+int nfp_nsp_write_flash(struct nfp_nsp *state, const struct firmware *fw);
 int nfp_nsp_mac_reinit(struct nfp_nsp *state);
 
 static inline bool nfp_nsp_has_mac_reinit(struct nfp_nsp *state)