[TG3]: Refine nvram locking

Add nvram lock count so that calls to tg3_nvram_lock()/unlock() can
be nested. Add error checking to all callers of tg3_nvram_lock()
where appropriate. To prevent nvram lock failures after halting the
firmware, it is also necessary to release firmware's nvram lock in
tg3_halt_cpu().

Update version to 3.48.

Based on David Miller's initial patch.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 55 insertions, 28 deletions

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index eb86b059809b..f2d1dafde087 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -69,8 +69,8 @@
 
 #define DRV_MODULE_NAME         "tg3"
 #define PFX DRV_MODULE_NAME     ": "
-#define DRV_MODULE_VERSION      "3.47"
-#define DRV_MODULE_RELDATE      "Dec 28, 2005"
+#define DRV_MODULE_VERSION      "3.48"
+#define DRV_MODULE_RELDATE      "Jan 16, 2006"
 
 #define TG3_DEF_MAC_MODE        0
 #define TG3_DEF_RX_MODE         0
@@ -1325,10 +1325,12 @@ static int tg3_set_power_state(struct tg3 *tp, int state)
                 val &= ~((1 << 16) | (1 << 4) | (1 << 2) | (1 << 1) | 1);
                 tw32(0x7d00, val);
                 if (!(tp->tg3_flags & TG3_FLAG_ENABLE_ASF)) {
-                        tg3_nvram_lock(tp);
+                        int err;
+
+                        err = tg3_nvram_lock(tp);
                         tg3_halt_cpu(tp, RX_CPU_BASE);
-                        tw32_f(NVRAM_SWARB, SWARB_REQ_CLR0);
-                        tg3_nvram_unlock(tp);
+                        if (!err)
+                                tg3_nvram_unlock(tp);
                 }
         }
 
@@ -4193,14 +4195,19 @@ static int tg3_nvram_lock(struct tg3 *tp)
         if (tp->tg3_flags & TG3_FLAG_NVRAM) {
                 int i;
 
-                tw32(NVRAM_SWARB, SWARB_REQ_SET1);
-                for (i = 0; i < 8000; i++) {
-                        if (tr32(NVRAM_SWARB) & SWARB_GNT1)
-                                break;
-                        udelay(20);
+                if (tp->nvram_lock_cnt == 0) {
+                        tw32(NVRAM_SWARB, SWARB_REQ_SET1);
+                        for (i = 0; i < 8000; i++) {
+                                if (tr32(NVRAM_SWARB) & SWARB_GNT1)
+                                        break;
+                                udelay(20);
+                        }
+                        if (i == 8000) {
+                                tw32(NVRAM_SWARB, SWARB_REQ_CLR1);
+                                return -ENODEV;
+                        }
                 }
-                if (i == 8000)
-                        return -ENODEV;
+                tp->nvram_lock_cnt++;
         }
         return 0;
 }
@@ -4208,8 +4215,12 @@ static int tg3_nvram_lock(struct tg3 *tp)
 /* tp->lock is held. */
 static void tg3_nvram_unlock(struct tg3 *tp)
 {
-        if (tp->tg3_flags & TG3_FLAG_NVRAM)
-                tw32_f(NVRAM_SWARB, SWARB_REQ_CLR1);
+        if (tp->tg3_flags & TG3_FLAG_NVRAM) {
+                if (tp->nvram_lock_cnt > 0)
+                        tp->nvram_lock_cnt--;
+                if (tp->nvram_lock_cnt == 0)
+                        tw32_f(NVRAM_SWARB, SWARB_REQ_CLR1);
+        }
 }
 
 /* tp->lock is held. */
@@ -4320,8 +4331,13 @@ static int tg3_chip_reset(struct tg3 *tp)
         void (*write_op)(struct tg3 *, u32, u32);
         int i;
 
-        if (!(tp->tg3_flags2 & TG3_FLG2_SUN_570X))
+        if (!(tp->tg3_flags2 & TG3_FLG2_SUN_570X)) {
                 tg3_nvram_lock(tp);
+                /* No matching tg3_nvram_unlock() after this because
+                 * chip reset below will undo the nvram lock.
+                 */
+                tp->nvram_lock_cnt = 0;
+        }
 
         /*
          * We must avoid the readl() that normally takes place.
@@ -4717,6 +4733,10 @@ static int tg3_halt_cpu(struct tg3 *tp, u32 offset)
                        (offset == RX_CPU_BASE ? "RX" : "TX"));
                 return -ENODEV;
         }
+
+        /* Clear firmware's nvram arbitration. */
+        if (tp->tg3_flags & TG3_FLAG_NVRAM)
+                tw32(NVRAM_SWARB, SWARB_REQ_CLR0);
         return 0;
 }
 
@@ -4736,7 +4756,7 @@ struct fw_info {
 static int tg3_load_firmware_cpu(struct tg3 *tp, u32 cpu_base, u32 cpu_scratch_base,
                                  int cpu_scratch_size, struct fw_info *info)
 {
-        int err, i;
+        int err, lock_err, i;
         void (*write_op)(struct tg3 *, u32, u32);
 
         if (cpu_base == TX_CPU_BASE &&
@@ -4755,9 +4775,10 @@ static int tg3_load_firmware_cpu(struct tg3 *tp, u32 cpu_base, u32 cpu_scratch_b
         /* It is possible that bootcode is still loading at this point.
          * Get the nvram lock first before halting the cpu.
          */
-        tg3_nvram_lock(tp);
+        lock_err = tg3_nvram_lock(tp);
         err = tg3_halt_cpu(tp, cpu_base);
-        tg3_nvram_unlock(tp);
+        if (!lock_err)
+                tg3_nvram_unlock(tp);
         if (err)
                 goto out;
 
@@ -8182,7 +8203,7 @@ static void tg3_self_test(struct net_device *dev, struct ethtool_test *etest,
                 data[1] = 1;
         }
         if (etest->flags & ETH_TEST_FL_OFFLINE) {
-                int irq_sync = 0;
+                int err, irq_sync = 0;
 
                 if (netif_running(dev)) {
                         tg3_netif_stop(tp);
@@ -8192,11 +8213,12 @@ static void tg3_self_test(struct net_device *dev, struct ethtool_test *etest,
                 tg3_full_lock(tp, irq_sync);
 
                 tg3_halt(tp, RESET_KIND_SUSPEND, 1);
-                tg3_nvram_lock(tp);
+                err = tg3_nvram_lock(tp);
                 tg3_halt_cpu(tp, RX_CPU_BASE);
                 if (!(tp->tg3_flags2 & TG3_FLG2_5705_PLUS))
                         tg3_halt_cpu(tp, TX_CPU_BASE);
-                tg3_nvram_unlock(tp);
+                if (!err)
+                        tg3_nvram_unlock(tp);
 
                 if (tg3_test_registers(tp) != 0) {
                         etest->flags |= ETH_TEST_FL_FAILED;
@@ -8588,7 +8610,11 @@ static void __devinit tg3_nvram_init(struct tg3 *tp)
             GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5701) {
                 tp->tg3_flags |= TG3_FLAG_NVRAM;
 
-                tg3_nvram_lock(tp);
+                if (tg3_nvram_lock(tp)) {
+                        printk(KERN_WARNING PFX "%s: Cannot get nvarm lock, "
+                               "tg3_nvram_init failed.\n", tp->dev->name);
+                        return;
+                }
                 tg3_enable_nvram_access(tp);
 
                 if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5752)
@@ -8686,7 +8712,9 @@ static int tg3_nvram_read(struct tg3 *tp, u32 offset, u32 *val)
         if (offset > NVRAM_ADDR_MSK)
                 return -EINVAL;
 
-        tg3_nvram_lock(tp);
+        ret = tg3_nvram_lock(tp);
+        if (ret)
+                return ret;
 
         tg3_enable_nvram_access(tp);
 
@@ -8785,10 +8813,6 @@ static int tg3_nvram_write_block_unbuffered(struct tg3 *tp, u32 offset, u32 len,
 
                 offset = offset + (pagesize - page_off);
 
-                /* Nvram lock released by tg3_nvram_read() above,
-                 * so need to get it again.
-                 */
-                tg3_nvram_lock(tp);
                 tg3_enable_nvram_access(tp);
 
                 /*
@@ -8925,7 +8949,9 @@ static int tg3_nvram_write_block(struct tg3 *tp, u32 offset, u32 len, u8 *buf)
         else {
                 u32 grc_mode;
 
-                tg3_nvram_lock(tp);
+                ret = tg3_nvram_lock(tp);
+                if (ret)
+                        return ret;
 
                 tg3_enable_nvram_access(tp);
                 if ((tp->tg3_flags2 & TG3_FLG2_5750_PLUS) &&
diff --git a/drivers/net/tg3.h b/drivers/net/tg3.h
index 890e1635996b..e8243305f0e8 100644
--- a/drivers/net/tg3.h
+++ b/drivers/net/tg3.h
@@ -2275,6 +2275,7 @@ struct tg3 {
         dma_addr_t                      stats_mapping;
         struct work_struct              reset_task;
 
+        int                             nvram_lock_cnt;
         u32                             nvram_size;
         u32                             nvram_pagesize;
         u32                             nvram_jedecnum;