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Commit 267d9d73 authored by Edward Cree's avatar Edward Cree Committed by David S. Miller
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sfc: Cope with permissions enforcement added to firmware for SR-IOV 



* Accept EPERM in some simple cases, the following cases are handled:
1) efx_mcdi_read_assertion()
Unprivileged PCI functions aren't allowed to GET_ASSERTS.
We return success as it's up to the primary PF to deal with asserts.
2) efx_mcdi_mon_probe() in efx_ef10_probe()
Unprivileged PCI functions aren't allowed to read sensor info, and
worrying about sensor data is the primary PF's job.
3) phy_op->reconfigure() in efx_init_port() and efx_reset_up()
Unprivileged functions aren't allowed to MC_CMD_SET_LINK, they just have
to accept the settings (including flow-control, which is what
efx_init_port() is worried about) they've been given.
4) Fallback to GET_WORKAROUNDS in efx_ef10_probe()
Unprivileged PCI functions aren't allowed to set workarounds. So if
efx_mcdi_set_workaround() fails EPERM, use efx_mcdi_get_workarounds()
to find out if workaround_35388 is enabled.
5) If DRV_ATTACH gets EPERM, try without specifying fw-variant
Unprivileged PCI functions have to use a FIRMWARE_ID of 0xffffffff
(MC_CMD_FW_DONT_CARE).
6) Don't try to exit_assertion unless one had fired
Previously we called efx_mcdi_exit_assertion even if
efx_mcdi_read_assertion had received MC_CMD_GET_ASSERTS_FLAGS_NO_FAILS.
This is unnecessary, and the resulting MC_CMD_REBOOT, even if the
AFTER_ASSERTION flag made it a no-op, would fail EPERM for unprivileged
PCI functions.
So make efx_mcdi_read_assertion return whether an assert happened, and only
call efx_mcdi_exit_assertion if it has.

Signed-off-by: default avatarShradha Shah <sshah@solarflare.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7b8c7b54

drivers/net/ethernet/sfc/ef10.c

+14 −2
Original line number Diff line number Diff line
@@ -286,10 +286,22 @@ static int efx_ef10_probe(struct efx_nic *efx) 
		goto fail3;

	efx->timer_quantum_ns = 1536000 / rc; /* 1536 cycles */



	/* Check whether firmware supports bug 35388 workaround */

	/* Check whether firmware supports bug 35388 workaround.

	 * First try to enable it, then if we get EPERM, just

	 * ask if it's already enabled

	 */

	rc = efx_mcdi_set_workaround(efx, MC_CMD_WORKAROUND_BUG35388, true);

	if (rc == 0)

		nic_data->workaround_35388 = true;

	else if (rc == -EPERM) {

		unsigned int enabled;



		rc = efx_mcdi_get_workarounds(efx, NULL, &enabled);

		if (rc)

			goto fail3;

		nic_data->workaround_35388 = enabled &

			MC_CMD_GET_WORKAROUNDS_OUT_BUG35388;

	}

	else if (rc != -ENOSYS && rc != -ENOENT)

		goto fail3;

	netif_dbg(efx, probe, efx->net_dev,
@@ -297,7 +309,7 @@ static int efx_ef10_probe(struct efx_nic *efx) 
		  nic_data->workaround_35388 ? "en" : "dis");



	rc = efx_mcdi_mon_probe(efx);

	if (rc)

	if (rc && rc != -EPERM)

		goto fail3;



	efx_ptp_probe(efx, NULL);

drivers/net/ethernet/sfc/efx.c

+3 −2
Original line number Diff line number Diff line
@@ -1046,7 +1046,7 @@ static int efx_init_port(struct efx_nic *efx) 


	/* Ensure the PHY advertises the correct flow control settings */

	rc = efx->phy_op->reconfigure(efx);

	if (rc)

	if (rc && rc != -EPERM)

		goto fail2;



	mutex_unlock(&efx->mac_lock);
@@ -2429,7 +2429,8 @@ int efx_reset_up(struct efx_nic *efx, enum reset_type method, bool ok) 
		rc = efx->phy_op->init(efx);

		if (rc)

			goto fail;

		if (efx->phy_op->reconfigure(efx))

		rc = efx->phy_op->reconfigure(efx);

		if (rc && rc != -EPERM)

			netif_err(efx, drv, efx->net_dev,

				  "could not restore PHY settings\n");

	}

drivers/net/ethernet/sfc/mcdi.c

+69 −13
Original line number Diff line number Diff line
@@ -1142,10 +1142,26 @@ static int efx_mcdi_drv_attach(struct efx_nic *efx, bool driver_operating, 
	MCDI_SET_DWORD(inbuf, DRV_ATTACH_IN_UPDATE, 1);

	MCDI_SET_DWORD(inbuf, DRV_ATTACH_IN_FIRMWARE_ID, MC_CMD_FW_LOW_LATENCY);



	rc = efx_mcdi_rpc(efx, MC_CMD_DRV_ATTACH, inbuf, sizeof(inbuf),

	rc = efx_mcdi_rpc_quiet(efx, MC_CMD_DRV_ATTACH, inbuf, sizeof(inbuf),

				outbuf, sizeof(outbuf), &outlen);

	if (rc)

	/* If we're not the primary PF, trying to ATTACH with a FIRMWARE_ID

	 * specified will fail with EPERM, and we have to tell the MC we don't

	 * care what firmware we get.

	 */

	if (rc == -EPERM) {

		netif_dbg(efx, probe, efx->net_dev,

			  "efx_mcdi_drv_attach with fw-variant setting failed EPERM, trying without it\n");

		MCDI_SET_DWORD(inbuf, DRV_ATTACH_IN_FIRMWARE_ID,

			       MC_CMD_FW_DONT_CARE);

		rc = efx_mcdi_rpc_quiet(efx, MC_CMD_DRV_ATTACH, inbuf,

					sizeof(inbuf), outbuf, sizeof(outbuf),

					&outlen);

	}

	if (rc) {

		efx_mcdi_display_error(efx, MC_CMD_DRV_ATTACH, sizeof(inbuf),

				       outbuf, outlen, rc);

		goto fail;

	}

	if (outlen < MC_CMD_DRV_ATTACH_OUT_LEN) {

		rc = -EIO;

		goto fail;
@@ -1377,6 +1393,9 @@ int efx_mcdi_nvram_test_all(struct efx_nic *efx) 
	return rc;

}



/* Returns 1 if an assertion was read, 0 if no assertion had fired,

 * negative on error.

 */

static int efx_mcdi_read_assertion(struct efx_nic *efx)

{

	MCDI_DECLARE_BUF(inbuf, MC_CMD_GET_ASSERTS_IN_LEN);
@@ -1398,6 +1417,8 @@ static int efx_mcdi_read_assertion(struct efx_nic *efx) 
		rc = efx_mcdi_rpc_quiet(efx, MC_CMD_GET_ASSERTS,

					inbuf, MC_CMD_GET_ASSERTS_IN_LEN,

					outbuf, sizeof(outbuf), &outlen);

		if (rc == -EPERM)

			return 0;

	} while ((rc == -EINTR || rc == -EIO) && retry-- > 0);



	if (rc) {
@@ -1435,24 +1456,31 @@ static int efx_mcdi_read_assertion(struct efx_nic *efx) 
			  MCDI_ARRAY_DWORD(outbuf, GET_ASSERTS_OUT_GP_REGS_OFFS,

					   index));



	return 0;

	return 1;

}



static void efx_mcdi_exit_assertion(struct efx_nic *efx)

static int efx_mcdi_exit_assertion(struct efx_nic *efx)

{

	MCDI_DECLARE_BUF(inbuf, MC_CMD_REBOOT_IN_LEN);

	int rc;



	/* If the MC is running debug firmware, it might now be

	 * waiting for a debugger to attach, but we just want it to

	 * reboot.  We set a flag that makes the command a no-op if it

	 * has already done so.  We don't know what return code to

	 * expect (0 or -EIO), so ignore it.

	 * has already done so.

	 * The MCDI will thus return either 0 or -EIO.

	 */

	BUILD_BUG_ON(MC_CMD_REBOOT_OUT_LEN != 0);

	MCDI_SET_DWORD(inbuf, REBOOT_IN_FLAGS,

		       MC_CMD_REBOOT_FLAGS_AFTER_ASSERTION);

	(void) efx_mcdi_rpc(efx, MC_CMD_REBOOT, inbuf, MC_CMD_REBOOT_IN_LEN,

	rc = efx_mcdi_rpc_quiet(efx, MC_CMD_REBOOT, inbuf, MC_CMD_REBOOT_IN_LEN,

				NULL, 0, NULL);

	if (rc == -EIO)

		rc = 0;

	if (rc)

		efx_mcdi_display_error(efx, MC_CMD_REBOOT, MC_CMD_REBOOT_IN_LEN,

				       NULL, 0, rc);

	return rc;

}



int efx_mcdi_handle_assertion(struct efx_nic *efx)
@@ -1460,12 +1488,10 @@ int efx_mcdi_handle_assertion(struct efx_nic *efx) 
	int rc;



	rc = efx_mcdi_read_assertion(efx);

	if (rc)

	if (rc <= 0)

		return rc;



	efx_mcdi_exit_assertion(efx);



	return 0;

	return efx_mcdi_exit_assertion(efx);

}



void efx_mcdi_set_id_led(struct efx_nic *efx, enum efx_led_mode mode)
@@ -1680,6 +1706,36 @@ int efx_mcdi_set_workaround(struct efx_nic *efx, u32 type, bool enabled) 
			    NULL, 0, NULL);

}



int efx_mcdi_get_workarounds(struct efx_nic *efx, unsigned int *impl_out,

			     unsigned int *enabled_out)

{

	MCDI_DECLARE_BUF_OUT_OR_ERR(outbuf, MC_CMD_GET_WORKAROUNDS_OUT_LEN);

	size_t outlen;

	int rc;



	rc = efx_mcdi_rpc(efx, MC_CMD_GET_WORKAROUNDS, NULL, 0,

			  outbuf, sizeof(outbuf), &outlen);

	if (rc)

		goto fail;



	if (outlen < MC_CMD_GET_WORKAROUNDS_OUT_LEN) {

		rc = -EIO;

		goto fail;

	}



	if (impl_out)

		*impl_out = MCDI_DWORD(outbuf, GET_WORKAROUNDS_OUT_IMPLEMENTED);



	if (enabled_out)

		*enabled_out = MCDI_DWORD(outbuf, GET_WORKAROUNDS_OUT_ENABLED);



	return 0;



fail:

	netif_err(efx, hw, efx->net_dev, "%s: failed rc=%d\n", __func__, rc);

	return rc;

}



#ifdef CONFIG_SFC_MTD



#define EFX_MCDI_NVRAM_LEN_MAX 128

drivers/net/ethernet/sfc/mcdi.h

+2 −0
Original line number Diff line number Diff line
@@ -339,6 +339,8 @@ bool efx_mcdi_mac_check_fault(struct efx_nic *efx); 
enum reset_type efx_mcdi_map_reset_reason(enum reset_type reason);

int efx_mcdi_reset(struct efx_nic *efx, enum reset_type method);

int efx_mcdi_set_workaround(struct efx_nic *efx, u32 type, bool enabled);

int efx_mcdi_get_workarounds(struct efx_nic *efx, unsigned int *impl_out,

			     unsigned int *enabled_out);



#ifdef CONFIG_SFC_MCDI_MON

int efx_mcdi_mon_probe(struct efx_nic *efx);

drivers/net/ethernet/sfc/mcdi_pcol.h

+23 −0
Original line number Diff line number Diff line
@@ -1875,6 +1875,8 @@ 
#define          MC_CMD_FW_FULL_FEATURED 0x0

/* enum: Prefer to use firmware with fewer features but lower latency */

#define          MC_CMD_FW_LOW_LATENCY 0x1

/* enum: Only this option is allowed for non-admin functions */

#define          MC_CMD_FW_DONT_CARE  0xffffffff



/* MC_CMD_DRV_ATTACH_OUT msgresponse */

#define    MC_CMD_DRV_ATTACH_OUT_LEN 4
@@ -4086,6 +4088,27 @@ 
#define       LICENSED_APP_ID_ID_WIDTH 32





/***********************************/

/* MC_CMD_GET_WORKAROUNDS

 * Read the list of all implemented and all currently enabled workarounds. The

 * enums here must correspond with those in MC_CMD_WORKAROUND.

 */

#define MC_CMD_GET_WORKAROUNDS 0x59



/* MC_CMD_GET_WORKAROUNDS_OUT msgresponse */

#define    MC_CMD_GET_WORKAROUNDS_OUT_LEN 8

/* Each workaround is represented by a single bit according to the enums below.

 */

#define       MC_CMD_GET_WORKAROUNDS_OUT_IMPLEMENTED_OFST 0

#define       MC_CMD_GET_WORKAROUNDS_OUT_ENABLED_OFST 4

/* enum: Bug 17230 work around. */

#define          MC_CMD_GET_WORKAROUNDS_OUT_BUG17230 0x2

/* enum: Bug 35388 work around (unsafe EVQ writes). */

#define          MC_CMD_GET_WORKAROUNDS_OUT_BUG35388 0x4

/* enum: Bug35017 workaround (A64 tables must be identity map) */

#define          MC_CMD_GET_WORKAROUNDS_OUT_BUG35017 0x8





/***********************************/

/* MC_CMD_READ_REGS

 * Get a dump of the MCPU registers