b43legacy: fix DMA for 30/32-bit DMA engines

This checks if the DMA address is bigger than what the controller can manage.
It will reallocate the buffers in the GFP_DMA zone in that case.

The patch by Michael Buesch has been ported to b43legacy.
Thanks to Matti Viljanen for reporting this.

Cc: Matti Viljanen <viljanen.matti@gmail.com>
Signed-off-by: Stefano Brivio <stefano.brivio@polimi.it>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 113 insertions, 87 deletions

diff --git a/drivers/net/wireless/b43legacy/dma.c b/drivers/net/wireless/b43legacy/dma.c
index 6e08405e8026..e87b427d5e43 100644
--- a/drivers/net/wireless/b43legacy/dma.c
+++ b/drivers/net/wireless/b43legacy/dma.c
@@ -354,7 +354,8 @@ return 0;
 }
 
 
-u16 b43legacy_dmacontroller_base(int dma64bit, int controller_idx)
+static u16 b43legacy_dmacontroller_base(enum b43legacy_dmatype type,
+                                        int controller_idx)
 {
         static const u16 map64[] = {
                 B43legacy_MMIO_DMA64_BASE0,
@@ -373,7 +374,7 @@ u16 b43legacy_dmacontroller_base(int dma64bit, int controller_idx)
                 B43legacy_MMIO_DMA32_BASE5,
         };
 
-        if (dma64bit) {
+        if (type == B43legacy_DMA_64BIT) {
                 B43legacy_WARN_ON(!(controller_idx >= 0 &&
                                   controller_idx < ARRAY_SIZE(map64)));
                 return map64[controller_idx];
@@ -480,8 +481,9 @@ static void free_ringmemory(struct b43legacy_dmaring *ring)
 }
 
 /* Reset the RX DMA channel */
-int b43legacy_dmacontroller_rx_reset(struct b43legacy_wldev *dev,
-                                     u16 mmio_base, int dma64)
+static int b43legacy_dmacontroller_rx_reset(struct b43legacy_wldev *dev,
+                                            u16 mmio_base,
+                                            enum b43legacy_dmatype type)
 {
         int i;
         u32 value;
@@ -489,13 +491,14 @@ int b43legacy_dmacontroller_rx_reset(struct b43legacy_wldev *dev,
 
         might_sleep();
 
-        offset = dma64 ? B43legacy_DMA64_RXCTL : B43legacy_DMA32_RXCTL;
+        offset = (type == B43legacy_DMA_64BIT) ?
+                 B43legacy_DMA64_RXCTL : B43legacy_DMA32_RXCTL;
         b43legacy_write32(dev, mmio_base + offset, 0);
         for (i = 0; i < 10; i++) {
-                offset = dma64 ? B43legacy_DMA64_RXSTATUS :
-                         B43legacy_DMA32_RXSTATUS;
+                offset = (type == B43legacy_DMA_64BIT) ?
+                         B43legacy_DMA64_RXSTATUS : B43legacy_DMA32_RXSTATUS;
                 value = b43legacy_read32(dev, mmio_base + offset);
-                if (dma64) {
+                if (type == B43legacy_DMA_64BIT) {
                         value &= B43legacy_DMA64_RXSTAT;
                         if (value == B43legacy_DMA64_RXSTAT_DISABLED) {
                                 i = -1;
@@ -519,8 +522,9 @@ int b43legacy_dmacontroller_rx_reset(struct b43legacy_wldev *dev,
 }
 
 /* Reset the RX DMA channel */
-int b43legacy_dmacontroller_tx_reset(struct b43legacy_wldev *dev,
-                                     u16 mmio_base, int dma64)
+static int b43legacy_dmacontroller_tx_reset(struct b43legacy_wldev *dev,
+                                            u16 mmio_base,
+                                            enum b43legacy_dmatype type)
 {
         int i;
         u32 value;
@@ -529,10 +533,10 @@ int b43legacy_dmacontroller_tx_reset(struct b43legacy_wldev *dev,
         might_sleep();
 
         for (i = 0; i < 10; i++) {
-                offset = dma64 ? B43legacy_DMA64_TXSTATUS :
-                         B43legacy_DMA32_TXSTATUS;
+                offset = (type == B43legacy_DMA_64BIT) ?
+                         B43legacy_DMA64_TXSTATUS : B43legacy_DMA32_TXSTATUS;
                 value = b43legacy_read32(dev, mmio_base + offset);
-                if (dma64) {
+                if (type == B43legacy_DMA_64BIT) {
                         value &= B43legacy_DMA64_TXSTAT;
                         if (value == B43legacy_DMA64_TXSTAT_DISABLED ||
                             value == B43legacy_DMA64_TXSTAT_IDLEWAIT ||
@@ -547,13 +551,14 @@ int b43legacy_dmacontroller_tx_reset(struct b43legacy_wldev *dev,
                 }
                 msleep(1);
         }
-        offset = dma64 ? B43legacy_DMA64_TXCTL : B43legacy_DMA32_TXCTL;
+        offset = (type == B43legacy_DMA_64BIT) ? B43legacy_DMA64_TXCTL :
+                                                 B43legacy_DMA32_TXCTL;
         b43legacy_write32(dev, mmio_base + offset, 0);
         for (i = 0; i < 10; i++) {
-                offset = dma64 ? B43legacy_DMA64_TXSTATUS :
-                         B43legacy_DMA32_TXSTATUS;
+                offset = (type == B43legacy_DMA_64BIT) ?
+                         B43legacy_DMA64_TXSTATUS : B43legacy_DMA32_TXSTATUS;
                 value = b43legacy_read32(dev, mmio_base + offset);
-                if (dma64) {
+                if (type == B43legacy_DMA_64BIT) {
                         value &= B43legacy_DMA64_TXSTAT;
                         if (value == B43legacy_DMA64_TXSTAT_DISABLED) {
                                 i = -1;
@@ -578,6 +583,32 @@ int b43legacy_dmacontroller_tx_reset(struct b43legacy_wldev *dev,
         return 0;
 }
 
+/* Check if a DMA mapping address is invalid. */
+static bool b43legacy_dma_mapping_error(struct b43legacy_dmaring *ring,
+                                        dma_addr_t addr,
+                                        size_t buffersize)
+{
+        if (unlikely(dma_mapping_error(addr)))
+                return 1;
+
+        switch (ring->type) {
+        case B43legacy_DMA_30BIT:
+                if ((u64)addr + buffersize > (1ULL << 30))
+                        return 1;
+                break;
+        case B43legacy_DMA_32BIT:
+                if ((u64)addr + buffersize > (1ULL << 32))
+                        return 1;
+                break;
+        case B43legacy_DMA_64BIT:
+                /* Currently we can't have addresses beyond 64 bits in the kernel. */
+                break;
+        }
+
+        /* The address is OK. */
+        return 0;
+}
+
 static int setup_rx_descbuffer(struct b43legacy_dmaring *ring,
                                struct b43legacy_dmadesc_generic *desc,
                                struct b43legacy_dmadesc_meta *meta,
@@ -595,7 +626,7 @@ static int setup_rx_descbuffer(struct b43legacy_dmaring *ring,
                 return -ENOMEM;
         dmaaddr = map_descbuffer(ring, skb->data,
                                  ring->rx_buffersize, 0);
-        if (dma_mapping_error(dmaaddr)) {
+        if (b43legacy_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize)) {
                 /* ugh. try to realloc in zone_dma */
                 gfp_flags |= GFP_DMA;
 
@@ -608,7 +639,7 @@ static int setup_rx_descbuffer(struct b43legacy_dmaring *ring,
                                          ring->rx_buffersize, 0);
         }
 
-        if (dma_mapping_error(dmaaddr)) {
+        if (b43legacy_dma_mapping_error(ring, dmaaddr, ring->rx_buffersize)) {
                 dev_kfree_skb_any(skb);
                 return -EIO;
         }
@@ -674,7 +705,7 @@ static int dmacontroller_setup(struct b43legacy_dmaring *ring)
         u32 trans = ssb_dma_translation(ring->dev->dev);
 
         if (ring->tx) {
-                if (ring->dma64) {
+                if (ring->type == B43legacy_DMA_64BIT) {
                         u64 ringbase = (u64)(ring->dmabase);
 
                         addrext = ((ringbase >> 32) & SSB_DMA_TRANSLATION_MASK)
@@ -709,7 +740,7 @@ static int dmacontroller_setup(struct b43legacy_dmaring *ring)
                 err = alloc_initial_descbuffers(ring);
                 if (err)
                         goto out;
-                if (ring->dma64) {
+                if (ring->type == B43legacy_DMA_64BIT) {
                         u64 ringbase = (u64)(ring->dmabase);
 
                         addrext = ((ringbase >> 32) & SSB_DMA_TRANSLATION_MASK)
@@ -760,16 +791,16 @@ static void dmacontroller_cleanup(struct b43legacy_dmaring *ring)
 {
         if (ring->tx) {
                 b43legacy_dmacontroller_tx_reset(ring->dev, ring->mmio_base,
-                                                 ring->dma64);
-                if (ring->dma64) {
+                                                 ring->type);
+                if (ring->type == B43legacy_DMA_64BIT) {
                         b43legacy_dma_write(ring, B43legacy_DMA64_TXRINGLO, 0);
                         b43legacy_dma_write(ring, B43legacy_DMA64_TXRINGHI, 0);
                 } else
                         b43legacy_dma_write(ring, B43legacy_DMA32_TXRING, 0);
         } else {
                 b43legacy_dmacontroller_rx_reset(ring->dev, ring->mmio_base,
-                                                 ring->dma64);
-                if (ring->dma64) {
+                                                 ring->type);
+                if (ring->type == B43legacy_DMA_64BIT) {
                         b43legacy_dma_write(ring, B43legacy_DMA64_RXRINGLO, 0);
                         b43legacy_dma_write(ring, B43legacy_DMA64_RXRINGHI, 0);
                 } else
@@ -824,11 +855,10 @@ static u64 supported_dma_mask(struct b43legacy_wldev *dev)
 
 /* Main initialization function. */
 static
-struct b43legacy_dmaring *b43legacy_setup_dmaring(
-                                        struct b43legacy_wldev *dev,
-                                        int controller_index,
-                                        int for_tx,
-                                        int dma64)
+struct b43legacy_dmaring *b43legacy_setup_dmaring(struct b43legacy_wldev *dev,
+                                                  int controller_index,
+                                                  int for_tx,
+                                                  enum b43legacy_dmatype type)
 {
         struct b43legacy_dmaring *ring;
         int err;
@@ -838,6 +868,7 @@ struct b43legacy_dmaring *b43legacy_setup_dmaring(
         ring = kzalloc(sizeof(*ring), GFP_KERNEL);
         if (!ring)
                 goto out;
+        ring->type = type;
 
         nr_slots = B43legacy_RXRING_SLOTS;
         if (for_tx)
@@ -855,12 +886,12 @@ struct b43legacy_dmaring *b43legacy_setup_dmaring(
                         goto err_kfree_meta;
 
                 /* test for ability to dma to txhdr_cache */
-                dma_test = dma_map_single(dev->dev->dev,
-                                ring->txhdr_cache,
-                                sizeof(struct b43legacy_txhdr_fw3),
-                                DMA_TO_DEVICE);
+                dma_test = dma_map_single(dev->dev->dev, ring->txhdr_cache,
+                                          sizeof(struct b43legacy_txhdr_fw3),
+                                          DMA_TO_DEVICE);
 
-                if (dma_mapping_error(dma_test)) {
+                if (b43legacy_dma_mapping_error(ring, dma_test,
+                                        sizeof(struct b43legacy_txhdr_fw3))) {
                         /* ugh realloc */
                         kfree(ring->txhdr_cache);
                         ring->txhdr_cache = kcalloc(nr_slots,
@@ -874,7 +905,8 @@ struct b43legacy_dmaring *b43legacy_setup_dmaring(
                                         sizeof(struct b43legacy_txhdr_fw3),
                                         DMA_TO_DEVICE);
 
-                        if (dma_mapping_error(dma_test))
+                        if (b43legacy_dma_mapping_error(ring, dma_test,
+                                        sizeof(struct b43legacy_txhdr_fw3)))
                                 goto err_kfree_txhdr_cache;
                 }
 
@@ -885,11 +917,9 @@ struct b43legacy_dmaring *b43legacy_setup_dmaring(
 
         ring->dev = dev;
         ring->nr_slots = nr_slots;
-        ring->mmio_base = b43legacy_dmacontroller_base(dma64,
-                                                       controller_index);
+        ring->mmio_base = b43legacy_dmacontroller_base(type, controller_index);
         ring->index = controller_index;
-        ring->dma64 = !!dma64;
-        if (dma64)
+        if (type == B43legacy_DMA_64BIT)
                 ring->ops = &dma64_ops;
         else
                 ring->ops = &dma32_ops;
@@ -939,10 +969,10 @@ static void b43legacy_destroy_dmaring(struct b43legacy_dmaring *ring)
         if (!ring)
                 return;
 
-        b43legacydbg(ring->dev->wl, "DMA-%s 0x%04X (%s) max used slots:"
-                     " %d/%d\n", (ring->dma64) ? "64" : "32", ring->mmio_base,
-                     (ring->tx) ? "TX" : "RX",
-                     ring->max_used_slots, ring->nr_slots);
+        b43legacydbg(ring->dev->wl, "DMA-%u 0x%04X (%s) max used slots:"
+                     " %d/%d\n", (unsigned int)(ring->type), ring->mmio_base,
+                     (ring->tx) ? "TX" : "RX", ring->max_used_slots,
+                     ring->nr_slots);
         /* Device IRQs are disabled prior entering this function,
          * so no need to take care of concurrency with rx handler stuff.
          */
@@ -988,11 +1018,22 @@ int b43legacy_dma_init(struct b43legacy_wldev *dev)
         struct b43legacy_dmaring *ring;
         int err;
         u64 dmamask;
-        int dma64 = 0;
+        enum b43legacy_dmatype type;
 
         dmamask = supported_dma_mask(dev);
-        if (dmamask == DMA_64BIT_MASK)
-                dma64 = 1;
+        switch (dmamask) {
+        default:
+                B43legacy_WARN_ON(1);
+        case DMA_30BIT_MASK:
+                type = B43legacy_DMA_30BIT;
+                break;
+        case DMA_32BIT_MASK:
+                type = B43legacy_DMA_32BIT;
+                break;
+        case DMA_64BIT_MASK:
+                type = B43legacy_DMA_64BIT;
+                break;
+        }
 
         err = ssb_dma_set_mask(dev->dev, dmamask);
         if (err) {
@@ -1010,52 +1051,50 @@ int b43legacy_dma_init(struct b43legacy_wldev *dev)
 
         err = -ENOMEM;
         /* setup TX DMA channels. */
-        ring = b43legacy_setup_dmaring(dev, 0, 1, dma64);
+        ring = b43legacy_setup_dmaring(dev, 0, 1, type);
         if (!ring)
                 goto out;
         dma->tx_ring0 = ring;
 
-        ring = b43legacy_setup_dmaring(dev, 1, 1, dma64);
+        ring = b43legacy_setup_dmaring(dev, 1, 1, type);
         if (!ring)
                 goto err_destroy_tx0;
         dma->tx_ring1 = ring;
 
-        ring = b43legacy_setup_dmaring(dev, 2, 1, dma64);
+        ring = b43legacy_setup_dmaring(dev, 2, 1, type);
         if (!ring)
                 goto err_destroy_tx1;
         dma->tx_ring2 = ring;
 
-        ring = b43legacy_setup_dmaring(dev, 3, 1, dma64);
+        ring = b43legacy_setup_dmaring(dev, 3, 1, type);
         if (!ring)
                 goto err_destroy_tx2;
         dma->tx_ring3 = ring;
 
-        ring = b43legacy_setup_dmaring(dev, 4, 1, dma64);
+        ring = b43legacy_setup_dmaring(dev, 4, 1, type);
         if (!ring)
                 goto err_destroy_tx3;
         dma->tx_ring4 = ring;
 
-        ring = b43legacy_setup_dmaring(dev, 5, 1, dma64);
+        ring = b43legacy_setup_dmaring(dev, 5, 1, type);
         if (!ring)
                 goto err_destroy_tx4;
         dma->tx_ring5 = ring;
 
         /* setup RX DMA channels. */
-        ring = b43legacy_setup_dmaring(dev, 0, 0, dma64);
+        ring = b43legacy_setup_dmaring(dev, 0, 0, type);
         if (!ring)
                 goto err_destroy_tx5;
         dma->rx_ring0 = ring;
 
         if (dev->dev->id.revision < 5) {
-                ring = b43legacy_setup_dmaring(dev, 3, 0, dma64);
+                ring = b43legacy_setup_dmaring(dev, 3, 0, type);
                 if (!ring)
                         goto err_destroy_rx0;
                 dma->rx_ring3 = ring;
         }
 
-        b43legacydbg(dev->wl, "%d-bit DMA initialized\n",
-               (dmamask == DMA_64BIT_MASK) ? 64 :
-               (dmamask == DMA_32BIT_MASK) ? 32 : 30);
+        b43legacydbg(dev->wl, "%u-bit DMA initialized\n", (unsigned int)type);
         err = 0;
 out:
         return err;
@@ -1194,9 +1233,13 @@ static int dma_tx_fragment(struct b43legacy_dmaring *ring,
         }
 
         meta_hdr->dmaaddr = map_descbuffer(ring, (unsigned char *)header,
-                                       sizeof(struct b43legacy_txhdr_fw3), 1);
-        if (dma_mapping_error(meta_hdr->dmaaddr))
+                                           sizeof(struct b43legacy_txhdr_fw3), 1);
+        if (b43legacy_dma_mapping_error(ring, meta_hdr->dmaaddr,
+                                        sizeof(struct b43legacy_txhdr_fw3))) {
+                ring->current_slot = old_top_slot;
+                ring->used_slots = old_used_slots;
                 return -EIO;
+        }
         ops->fill_descriptor(ring, desc, meta_hdr->dmaaddr,
                              sizeof(struct b43legacy_txhdr_fw3), 1, 0, 0);
 
@@ -1211,7 +1254,7 @@ static int dma_tx_fragment(struct b43legacy_dmaring *ring,
 
         meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
         /* create a bounce buffer in zone_dma on mapping failure. */
-        if (dma_mapping_error(meta->dmaaddr)) {
+        if (b43legacy_dma_mapping_error(ring, meta->dmaaddr, skb->len)) {
                 bounce_skb = __dev_alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
                 if (!bounce_skb) {
                         ring->current_slot = old_top_slot;
@@ -1225,7 +1268,7 @@ static int dma_tx_fragment(struct b43legacy_dmaring *ring,
                 skb = bounce_skb;
                 meta->skb = skb;
                 meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
-                if (dma_mapping_error(meta->dmaaddr)) {
+                if (b43legacy_dma_mapping_error(ring, meta->dmaaddr, skb->len)) {
                         ring->current_slot = old_top_slot;
                         ring->used_slots = old_used_slots;
                         err = -EIO;
diff --git a/drivers/net/wireless/b43legacy/dma.h b/drivers/net/wireless/b43legacy/dma.h
index 26f6ab08de75..2dd488c5be2d 100644
--- a/drivers/net/wireless/b43legacy/dma.h
+++ b/drivers/net/wireless/b43legacy/dma.h
@@ -218,6 +218,12 @@ struct b43legacy_dma_ops {
         void (*set_current_rxslot)(struct b43legacy_dmaring *ring, int slot);
 };
 
+enum b43legacy_dmatype {
+        B43legacy_DMA_30BIT = 30,
+        B43legacy_DMA_32BIT = 32,
+        B43legacy_DMA_64BIT = 64,
+};
+
 struct b43legacy_dmaring {
         /* Lowlevel DMA ops. */
         const struct b43legacy_dma_ops *ops;
@@ -250,8 +256,8 @@ struct b43legacy_dmaring {
         int index;
         /* Boolean. Is this a TX ring? */
         bool tx;
-        /* Boolean. 64bit DMA if true, 32bit DMA otherwise. */
-        bool dma64;
+        /* The type of DMA engine used. */
+        enum b43legacy_dmatype type;
         /* Boolean. Is this ring stopped at ieee80211 level? */
         bool stopped;
         /* Lock, only used for TX. */
@@ -284,15 +290,6 @@ void b43legacy_dma_write(struct b43legacy_dmaring *ring,
 int b43legacy_dma_init(struct b43legacy_wldev *dev);
 void b43legacy_dma_free(struct b43legacy_wldev *dev);
 
-int b43legacy_dmacontroller_rx_reset(struct b43legacy_wldev *dev,
-                                     u16 dmacontroller_mmio_base,
-                                     int dma64);
-int b43legacy_dmacontroller_tx_reset(struct b43legacy_wldev *dev,
-                                     u16 dmacontroller_mmio_base,
-                                     int dma64);
-
-u16 b43legacy_dmacontroller_base(int dma64bit, int dmacontroller_idx);
-
 void b43legacy_dma_tx_suspend(struct b43legacy_wldev *dev);
 void b43legacy_dma_tx_resume(struct b43legacy_wldev *dev);
 
@@ -320,20 +317,6 @@ void b43legacy_dma_free(struct b43legacy_wldev *dev)
 {
 }
 static inline
-int b43legacy_dmacontroller_rx_reset(struct b43legacy_wldev *dev,
-                                     u16 dmacontroller_mmio_base,
-                                     int dma64)
-{
-        return 0;
-}
-static inline
-int b43legacy_dmacontroller_tx_reset(struct b43legacy_wldev *dev,
-                                     u16 dmacontroller_mmio_base,
-                                     int dma64)
-{
-        return 0;
-}
-static inline
 void b43legacy_dma_get_tx_stats(struct b43legacy_wldev *dev,
                                 struct ieee80211_tx_queue_stats *stats)
 {