[PATCH net] bnx2x: Revert UNDI flushing mechanism

[PATCH net] bnx2x: Revert UNDI flushing mechanism

[Yuval Mintz]

Commit 91ebb929b6f8 ("bnx2x: Add support for Multi-Function UNDI") [which was
later supposedly fixed by de682941eef3 ("bnx2x: Fix UNDI driver unload")]
introduced a bug in which in some [yet-to-be-determined] scenarios the
alternative flushing mechanism which was to guarantee the Rx buffers are
empty before resetting them during device probe will fail.
If this happens, when device will be loaded once more a fatal attention will
occur; Since this most likely happens in boot from SAN scenarios, the machine
will fail to load.

Notice this may occur not only in the 'Multi-Function' scenario but in the
regular scenario as well, i.e., this introduced a regression in the driver's
ability to perform boot from SAN.

The patch reverts the mechanism and applies the old scheme to multi-function
devices as well as to single-function devices.

Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: Ariel Elior <Ariel.Elior@qlogic.com>
---
Hi Dave,

Please consider applying this patch to `net'.

Thanks,
Yuval Mintz
---
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c | 94 +++++-------------------
 1 file changed, 18 insertions(+), 76 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
index c13364b..c036426 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
@@ -10052,6 +10052,8 @@ static void bnx2x_prev_unload_close_mac(struct bnx2x *bp,
 }

 #define BNX2X_PREV_UNDI_PROD_ADDR(p) (BAR_TSTRORM_INTMEM + 0x1508 + ((p) << 4))
+#define BNX2X_PREV_UNDI_PROD_ADDR_H(f) (BAR_TSTRORM_INTMEM + \
+					0x1848 + ((f) << 4))
 #define BNX2X_PREV_UNDI_RCQ(val)	((val) & 0xffff)
 #define BNX2X_PREV_UNDI_BD(val)		((val) >> 16 & 0xffff)
 #define BNX2X_PREV_UNDI_PROD(rcq, bd)	((bd) << 16 | (rcq))
@@ -10059,8 +10061,6 @@ static void bnx2x_prev_unload_close_mac(struct bnx2x *bp,
 #define BCM_5710_UNDI_FW_MF_MAJOR	(0x07)
 #define BCM_5710_UNDI_FW_MF_MINOR	(0x08)
 #define BCM_5710_UNDI_FW_MF_VERS	(0x05)
-#define BNX2X_PREV_UNDI_MF_PORT(p) (BAR_TSTRORM_INTMEM + 0x150c + ((p) << 4))
-#define BNX2X_PREV_UNDI_MF_FUNC(f) (BAR_TSTRORM_INTMEM + 0x184c + ((f) << 4))

 static bool bnx2x_prev_is_after_undi(struct bnx2x *bp)
 {
@@ -10079,72 +10079,25 @@ static bool bnx2x_prev_is_after_undi(struct bnx2x *bp)
 	return false;
 }

-static bool bnx2x_prev_unload_undi_fw_supports_mf(struct bnx2x *bp)
-{
-	u8 major, minor, version;
-	u32 fw;
-
-	/* Must check that FW is loaded */
-	if (!(REG_RD(bp, MISC_REG_RESET_REG_1) &
-	     MISC_REGISTERS_RESET_REG_1_RST_XSEM)) {
-		BNX2X_DEV_INFO("XSEM is reset - UNDI MF FW is not loaded\n");
-		return false;
-	}
-
-	/* Read Currently loaded FW version */
-	fw = REG_RD(bp, XSEM_REG_PRAM);
-	major = fw & 0xff;
-	minor = (fw >> 0x8) & 0xff;
-	version = (fw >> 0x10) & 0xff;
-	BNX2X_DEV_INFO("Loaded FW: 0x%08x: Major 0x%02x Minor 0x%02x Version 0x%02x\n",
-		       fw, major, minor, version);
-
-	if (major > BCM_5710_UNDI_FW_MF_MAJOR)
-		return true;
-
-	if ((major == BCM_5710_UNDI_FW_MF_MAJOR) &&
-	    (minor > BCM_5710_UNDI_FW_MF_MINOR))
-		return true;
-
-	if ((major == BCM_5710_UNDI_FW_MF_MAJOR) &&
-	    (minor == BCM_5710_UNDI_FW_MF_MINOR) &&
-	    (version >= BCM_5710_UNDI_FW_MF_VERS))
-		return true;
-
-	return false;
-}
-
-static void bnx2x_prev_unload_undi_mf(struct bnx2x *bp)
-{
-	int i;
-
-	/* Due to legacy (FW) code, the first function on each engine has a
-	 * different offset macro from the rest of the functions.
-	 * Setting this for all 8 functions is harmless regardless of whether
-	 * this is actually a multi-function device.
-	 */
-	for (i = 0; i < 2; i++)
-		REG_WR(bp, BNX2X_PREV_UNDI_MF_PORT(i), 1);
-
-	for (i = 2; i < 8; i++)
-		REG_WR(bp, BNX2X_PREV_UNDI_MF_FUNC(i - 2), 1);
-
-	BNX2X_DEV_INFO("UNDI FW (MF) set to discard\n");
-}
-
-static void bnx2x_prev_unload_undi_inc(struct bnx2x *bp, u8 port, u8 inc)
+static void bnx2x_prev_unload_undi_inc(struct bnx2x *bp, u8 inc)
 {
 	u16 rcq, bd;
-	u32 tmp_reg = REG_RD(bp, BNX2X_PREV_UNDI_PROD_ADDR(port));
-
+	u32 addr, tmp_reg;
+
+	if (BP_FUNC(bp) < 2)
+		addr = BNX2X_PREV_UNDI_PROD_ADDR(BP_PORT(bp));
+	else
+		addr = BNX2X_PREV_UNDI_PROD_ADDR_H(BP_FUNC(bp) - 2);
+
+	tmp_reg = REG_RD(bp, addr);
 	rcq = BNX2X_PREV_UNDI_RCQ(tmp_reg) + inc;
 	bd = BNX2X_PREV_UNDI_BD(tmp_reg) + inc;

 	tmp_reg = BNX2X_PREV_UNDI_PROD(rcq, bd);
-	REG_WR(bp, BNX2X_PREV_UNDI_PROD_ADDR(port), tmp_reg);
+	REG_WR(bp, addr, tmp_reg);

-	BNX2X_DEV_INFO("UNDI producer [%d] rings bd -> 0x%04x, rcq -> 0x%04x\n",
-		       port, bd, rcq);
+	BNX2X_DEV_INFO("UNDI producer [%d/%d][%08x] rings bd -> 0x%04x, rcq -> 0x%04x\n",
+		       BP_PORT(bp), BP_FUNC(bp), addr, bd, rcq);
 }

 static int bnx2x_prev_mcp_done(struct bnx2x *bp)
@@ -10383,7 +10336,6 @@ static int bnx2x_prev_unload_common(struct bnx2x *bp)
 	/* Reset should be performed after BRB is emptied */
 	if (reset_reg & MISC_REGISTERS_RESET_REG_1_RST_BRB1) {
 		u32 timer_count = 1000;
-		bool need_write = true;

 		/* Close the MAC Rx to prevent BRB from filling up */
 		bnx2x_prev_unload_close_mac(bp, &mac_vals);
@@ -10420,20 +10372,10 @@ static int bnx2x_prev_unload_common(struct bnx2x *bp)
 			else
 				timer_count--;

-			/* New UNDI FW supports MF and contains better
-			 * cleaning methods - might be redundant but harmless.
-			 */
-			if (bnx2x_prev_unload_undi_fw_supports_mf(bp)) {
-				if (need_write) {
-					bnx2x_prev_unload_undi_mf(bp);
-					need_write = false;
-				}
-			} else if (prev_undi) {
-				/* If UNDI resides in memory,
-				 * manually increment it
-				 */
-				bnx2x_prev_unload_undi_inc(bp, BP_PORT(bp), 1);
-			}
+			/* If UNDI resides in memory, manually increment it */
+			if (prev_undi)
+				bnx2x_prev_unload_undi_inc(bp, 1);
+
 			udelay(10);
 		}

--
1.8.3.1

Re: [PATCH net] bnx2x: Revert UNDI flushing mechanism

[David Miller]

From: Yuval Mintz <Yuval.Mintz@qlogic.com>
Date: Mon, 18 Aug 2014 22:36:23 +0300

> Commit 91ebb929b6f8 ("bnx2x: Add support for Multi-Function UNDI") [which was
> later supposedly fixed by de682941eef3 ("bnx2x: Fix UNDI driver unload")]
> introduced a bug in which in some [yet-to-be-determined] scenarios the
> alternative flushing mechanism which was to guarantee the Rx buffers are
> empty before resetting them during device probe will fail.
> If this happens, when device will be loaded once more a fatal attention will
> occur; Since this most likely happens in boot from SAN scenarios, the machine
> will fail to load.
> 
> Notice this may occur not only in the 'Multi-Function' scenario but in the
> regular scenario as well, i.e., this introduced a regression in the driver's
> ability to perform boot from SAN.
> 
> The patch reverts the mechanism and applies the old scheme to multi-function
> devices as well as to single-function devices.
> 
> Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
> Signed-off-by: Ariel Elior <Ariel.Elior@qlogic.com>

Applied and queued up for -stable, thanks.