From f54a52021d7ad039c16fe5a1e094d8f0394d90ec Mon Sep 17 00:00:00 2001
From: Michael Buesch <mb@bu3sch.de>
Date: Fri, 6 Nov 2009 18:32:44 +0100
Subject: b43: Rewrite TX bounce buffer handling
Do not mess with the original skb, but allocate an independent bouncebuffer.
This protects against bad interference with mac80211's assumptions about
the skb (which already caused bugs).
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---
drivers/net/wireless/b43/dma.c | 48 ++++++++++++++++++------------------------
1 file changed, 20 insertions(+), 28 deletions(-)
(limited to 'drivers/net/wireless/b43/dma.c')
diff --git a/drivers/net/wireless/b43/dma.c b/drivers/net/wireless/b43/dma.c
index de4e804bedf..b5cd7f57055 100644
--- a/drivers/net/wireless/b43/dma.c
+++ b/drivers/net/wireless/b43/dma.c
@@ -1157,18 +1157,17 @@ struct b43_dmaring *parse_cookie(struct b43_wldev *dev, u16 cookie, int *slot)
}
static int dma_tx_fragment(struct b43_dmaring *ring,
- struct sk_buff **in_skb)
+ struct sk_buff *skb)
{
- struct sk_buff *skb = *in_skb;
const struct b43_dma_ops *ops = ring->ops;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
+ struct b43_private_tx_info *priv_info = b43_get_priv_tx_info(info);
u8 *header;
int slot, old_top_slot, old_used_slots;
int err;
struct b43_dmadesc_generic *desc;
struct b43_dmadesc_meta *meta;
struct b43_dmadesc_meta *meta_hdr;
- struct sk_buff *bounce_skb;
u16 cookie;
size_t hdrsize = b43_txhdr_size(ring->dev);
@@ -1212,34 +1211,28 @@ static int dma_tx_fragment(struct b43_dmaring *ring,
meta->skb = skb;
meta->is_last_fragment = 1;
+ priv_info->bouncebuffer = NULL;
meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
/* create a bounce buffer in zone_dma on mapping failure. */
if (b43_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
- bounce_skb = __dev_alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
- if (!bounce_skb) {
+ priv_info->bouncebuffer = kmalloc(skb->len, GFP_ATOMIC | GFP_DMA);
+ if (!priv_info->bouncebuffer) {
ring->current_slot = old_top_slot;
ring->used_slots = old_used_slots;
err = -ENOMEM;
goto out_unmap_hdr;
}
+ memcpy(priv_info->bouncebuffer, skb->data, skb->len);
- memcpy(skb_put(bounce_skb, skb->len), skb->data, skb->len);
- memcpy(bounce_skb->cb, skb->cb, sizeof(skb->cb));
- bounce_skb->dev = skb->dev;
- skb_set_queue_mapping(bounce_skb, skb_get_queue_mapping(skb));
- info = IEEE80211_SKB_CB(bounce_skb);
-
- dev_kfree_skb_any(skb);
- skb = bounce_skb;
- *in_skb = bounce_skb;
- meta->skb = skb;
- meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
+ meta->dmaaddr = map_descbuffer(ring, priv_info->bouncebuffer, skb->len, 1);
if (b43_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
+ kfree(priv_info->bouncebuffer);
+ priv_info->bouncebuffer = NULL;
ring->current_slot = old_top_slot;
ring->used_slots = old_used_slots;
err = -EIO;
- goto out_free_bounce;
+ goto out_unmap_hdr;
}
}
@@ -1256,8 +1249,6 @@ static int dma_tx_fragment(struct b43_dmaring *ring,
ops->poke_tx(ring, next_slot(ring, slot));
return 0;
-out_free_bounce:
- dev_kfree_skb_any(skb);
out_unmap_hdr:
unmap_descbuffer(ring, meta_hdr->dmaaddr,
hdrsize, 1);
@@ -1362,11 +1353,7 @@ int b43_dma_tx(struct b43_wldev *dev, struct sk_buff *skb)
* static, so we don't need to store it per frame. */
ring->queue_prio = skb_get_queue_mapping(skb);
- /* dma_tx_fragment might reallocate the skb, so invalidate pointers pointing
- * into the skb data or cb now. */
- hdr = NULL;
- info = NULL;
- err = dma_tx_fragment(ring, &skb);
+ err = dma_tx_fragment(ring, skb);
if (unlikely(err == -ENOKEY)) {
/* Drop this packet, as we don't have the encryption key
* anymore and must not transmit it unencrypted. */
@@ -1413,12 +1400,17 @@ void b43_dma_handle_txstatus(struct b43_wldev *dev,
B43_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
desc = ops->idx2desc(ring, slot, &meta);
- if (meta->skb)
- unmap_descbuffer(ring, meta->dmaaddr, meta->skb->len,
- 1);
- else
+ if (meta->skb) {
+ struct b43_private_tx_info *priv_info =
+ b43_get_priv_tx_info(IEEE80211_SKB_CB(meta->skb));
+
+ unmap_descbuffer(ring, meta->dmaaddr, meta->skb->len, 1);
+ kfree(priv_info->bouncebuffer);
+ priv_info->bouncebuffer = NULL;
+ } else {
unmap_descbuffer(ring, meta->dmaaddr,
b43_txhdr_size(dev), 1);
+ }
if (meta->is_last_fragment) {
struct ieee80211_tx_info *info;
--
cgit v1.2.3-70-g09d2
From 9bd568a50c446433038dec2a5186c5c57c3dbd23 Mon Sep 17 00:00:00 2001
From: Michael Buesch <mb@bu3sch.de>
Date: Wed, 18 Nov 2009 20:53:05 +0100
Subject: b43: Enforce DMA descriptor memory constraints
Enforce all device constraints on the descriptor memory region.
There are several constraints on the descriptor memory, as documented
in the specification. The current code does not enforce them and/or
incorrectly enforces them.
Those constraints are:
- The address limitations on 30/32bit engines, that also apply to
the skbs.
- The 4k alignment requirement on 30/32bit engines.
- The 8k alignment requirement on 64bit engines.
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---
drivers/net/wireless/b43/dma.c | 197 +++++++++++++++++++++++++++++++----------
drivers/net/wireless/b43/dma.h | 7 +-
2 files changed, 158 insertions(+), 46 deletions(-)
(limited to 'drivers/net/wireless/b43/dma.c')
diff --git a/drivers/net/wireless/b43/dma.c b/drivers/net/wireless/b43/dma.c
index b5cd7f57055..18b97c02b8a 100644
--- a/drivers/net/wireless/b43/dma.c
+++ b/drivers/net/wireless/b43/dma.c
@@ -383,44 +383,160 @@ static inline
}
}
+/* Check if a DMA region fits the device constraints.
+ * Returns true, if the region is OK for usage with this device. */
+static inline bool b43_dma_address_ok(struct b43_dmaring *ring,
+ dma_addr_t addr, size_t size)
+{
+ switch (ring->type) {
+ case B43_DMA_30BIT:
+ if ((u64)addr + size > (1ULL << 30))
+ return 0;
+ break;
+ case B43_DMA_32BIT:
+ if ((u64)addr + size > (1ULL << 32))
+ return 0;
+ break;
+ case B43_DMA_64BIT:
+ /* Currently we can't have addresses beyond
+ * 64bit in the kernel. */
+ break;
+ }
+ return 1;
+}
+
+#define is_4k_aligned(addr) (((u64)(addr) & 0x0FFFull) == 0)
+#define is_8k_aligned(addr) (((u64)(addr) & 0x1FFFull) == 0)
+
+static void b43_unmap_and_free_ringmem(struct b43_dmaring *ring, void *base,
+ dma_addr_t dmaaddr, size_t size)
+{
+ ssb_dma_unmap_single(ring->dev->dev, dmaaddr, size, DMA_TO_DEVICE);
+ free_pages((unsigned long)base, get_order(size));
+}
+
+static void * __b43_get_and_map_ringmem(struct b43_dmaring *ring,
+ dma_addr_t *dmaaddr, size_t size,
+ gfp_t gfp_flags)
+{
+ void *base;
+
+ base = (void *)__get_free_pages(gfp_flags, get_order(size));
+ if (!base)
+ return NULL;
+ memset(base, 0, size);
+ *dmaaddr = ssb_dma_map_single(ring->dev->dev, base, size,
+ DMA_TO_DEVICE);
+ if (ssb_dma_mapping_error(ring->dev->dev, *dmaaddr)) {
+ free_pages((unsigned long)base, get_order(size));
+ return NULL;
+ }
+
+ return base;
+}
+
+static void * b43_get_and_map_ringmem(struct b43_dmaring *ring,
+ dma_addr_t *dmaaddr, size_t size)
+{
+ void *base;
+
+ base = __b43_get_and_map_ringmem(ring, dmaaddr, size,
+ GFP_KERNEL);
+ if (!base) {
+ b43err(ring->dev->wl, "Failed to allocate or map pages "
+ "for DMA ringmemory\n");
+ return NULL;
+ }
+ if (!b43_dma_address_ok(ring, *dmaaddr, size)) {
+ /* The memory does not fit our device constraints.
+ * Retry with GFP_DMA set to get lower memory. */
+ b43_unmap_and_free_ringmem(ring, base, *dmaaddr, size);
+ base = __b43_get_and_map_ringmem(ring, dmaaddr, size,
+ GFP_KERNEL | GFP_DMA);
+ if (!base) {
+ b43err(ring->dev->wl, "Failed to allocate or map pages "
+ "in the GFP_DMA region for DMA ringmemory\n");
+ return NULL;
+ }
+ if (!b43_dma_address_ok(ring, *dmaaddr, size)) {
+ b43_unmap_and_free_ringmem(ring, base, *dmaaddr, size);
+ b43err(ring->dev->wl, "Failed to allocate DMA "
+ "ringmemory that fits device constraints\n");
+ return NULL;
+ }
+ }
+ /* We expect the memory to be 4k aligned, at least. */
+ if (B43_WARN_ON(!is_4k_aligned(*dmaaddr))) {
+ b43_unmap_and_free_ringmem(ring, base, *dmaaddr, size);
+ return NULL;
+ }
+
+ return base;
+}
+
static int alloc_ringmemory(struct b43_dmaring *ring)
{
- gfp_t flags = GFP_KERNEL;
-
- /* The specs call for 4K buffers for 30- and 32-bit DMA with 4K
- * alignment and 8K buffers for 64-bit DMA with 8K alignment. Testing
- * has shown that 4K is sufficient for the latter as long as the buffer
- * does not cross an 8K boundary.
- *
- * For unknown reasons - possibly a hardware error - the BCM4311 rev
- * 02, which uses 64-bit DMA, needs the ring buffer in very low memory,
- * which accounts for the GFP_DMA flag below.
- *
- * The flags here must match the flags in free_ringmemory below!
+ unsigned int required;
+ void *base;
+ dma_addr_t dmaaddr;
+
+ /* There are several requirements to the descriptor ring memory:
+ * - The memory region needs to fit the address constraints for the
+ * device (same as for frame buffers).
+ * - For 30/32bit DMA devices, the descriptor ring must be 4k aligned.
+ * - For 64bit DMA devices, the descriptor ring must be 8k aligned.
*/
+
if (ring->type == B43_DMA_64BIT)
- flags |= GFP_DMA;
- ring->descbase = ssb_dma_alloc_consistent(ring->dev->dev,
- B43_DMA_RINGMEMSIZE,
- &(ring->dmabase), flags);
- if (!ring->descbase) {
- b43err(ring->dev->wl, "DMA ringmemory allocation failed\n");
+ required = ring->nr_slots * sizeof(struct b43_dmadesc64);
+ else
+ required = ring->nr_slots * sizeof(struct b43_dmadesc32);
+ if (B43_WARN_ON(required > 0x1000))
+ return -ENOMEM;
+
+ ring->alloc_descsize = 0x1000;
+ base = b43_get_and_map_ringmem(ring, &dmaaddr, ring->alloc_descsize);
+ if (!base)
+ return -ENOMEM;
+ ring->alloc_descbase = base;
+ ring->alloc_dmabase = dmaaddr;
+
+ if ((ring->type != B43_DMA_64BIT) || is_8k_aligned(dmaaddr)) {
+ /* We're on <=32bit DMA, or we already got 8k aligned memory.
+ * That's all we need, so we're fine. */
+ ring->descbase = base;
+ ring->dmabase = dmaaddr;
+ return 0;
+ }
+ b43_unmap_and_free_ringmem(ring, base, dmaaddr, ring->alloc_descsize);
+
+ /* Ok, we failed at the 8k alignment requirement.
+ * Try to force-align the memory region now. */
+ ring->alloc_descsize = 0x2000;
+ base = b43_get_and_map_ringmem(ring, &dmaaddr, ring->alloc_descsize);
+ if (!base)
return -ENOMEM;
+ ring->alloc_descbase = base;
+ ring->alloc_dmabase = dmaaddr;
+
+ if (is_8k_aligned(dmaaddr)) {
+ /* We're already 8k aligned. That Ok, too. */
+ ring->descbase = base;
+ ring->dmabase = dmaaddr;
+ return 0;
}
- memset(ring->descbase, 0, B43_DMA_RINGMEMSIZE);
+ /* Force-align it to 8k */
+ ring->descbase = (void *)((u8 *)base + 0x1000);
+ ring->dmabase = dmaaddr + 0x1000;
+ B43_WARN_ON(!is_8k_aligned(ring->dmabase));
return 0;
}
static void free_ringmemory(struct b43_dmaring *ring)
{
- gfp_t flags = GFP_KERNEL;
-
- if (ring->type == B43_DMA_64BIT)
- flags |= GFP_DMA;
-
- ssb_dma_free_consistent(ring->dev->dev, B43_DMA_RINGMEMSIZE,
- ring->descbase, ring->dmabase, flags);
+ b43_unmap_and_free_ringmem(ring, ring->alloc_descbase,
+ ring->alloc_dmabase, ring->alloc_descsize);
}
/* Reset the RX DMA channel */
@@ -530,29 +646,14 @@ static bool b43_dma_mapping_error(struct b43_dmaring *ring,
if (unlikely(ssb_dma_mapping_error(ring->dev->dev, addr)))
return 1;
- switch (ring->type) {
- case B43_DMA_30BIT:
- if ((u64)addr + buffersize > (1ULL << 30))
- goto address_error;
- break;
- case B43_DMA_32BIT:
- if ((u64)addr + buffersize > (1ULL << 32))
- goto address_error;
- break;
- case B43_DMA_64BIT:
- /* Currently we can't have addresses beyond
- * 64bit in the kernel. */
- break;
+ if (!b43_dma_address_ok(ring, addr, buffersize)) {
+ /* We can't support this address. Unmap it again. */
+ unmap_descbuffer(ring, addr, buffersize, dma_to_device);
+ return 1;
}
/* The address is OK. */
return 0;
-
-address_error:
- /* We can't support this address. Unmap it again. */
- unmap_descbuffer(ring, addr, buffersize, dma_to_device);
-
- return 1;
}
static bool b43_rx_buffer_is_poisoned(struct b43_dmaring *ring, struct sk_buff *skb)
@@ -614,6 +715,9 @@ static int setup_rx_descbuffer(struct b43_dmaring *ring,
meta->dmaaddr = dmaaddr;
ring->ops->fill_descriptor(ring, desc, dmaaddr,
ring->rx_buffersize, 0, 0, 0);
+ ssb_dma_sync_single_for_device(ring->dev->dev,
+ ring->alloc_dmabase,
+ ring->alloc_descsize, DMA_TO_DEVICE);
return 0;
}
@@ -1246,6 +1350,9 @@ static int dma_tx_fragment(struct b43_dmaring *ring,
}
/* Now transfer the whole frame. */
wmb();
+ ssb_dma_sync_single_for_device(ring->dev->dev,
+ ring->alloc_dmabase,
+ ring->alloc_descsize, DMA_TO_DEVICE);
ops->poke_tx(ring, next_slot(ring, slot));
return 0;
diff --git a/drivers/net/wireless/b43/dma.h b/drivers/net/wireless/b43/dma.h
index f0b0838fb5b..356a0ff8f04 100644
--- a/drivers/net/wireless/b43/dma.h
+++ b/drivers/net/wireless/b43/dma.h
@@ -157,7 +157,6 @@ struct b43_dmadesc_generic {
} __attribute__ ((__packed__));
/* Misc DMA constants */
-#define B43_DMA_RINGMEMSIZE PAGE_SIZE
#define B43_DMA0_RX_FRAMEOFFSET 30
/* DMA engine tuning knobs */
@@ -243,6 +242,12 @@ struct b43_dmaring {
/* The QOS priority assigned to this ring. Only used for TX rings.
* This is the mac80211 "queue" value. */
u8 queue_prio;
+ /* Pointers and size of the originally allocated and mapped memory
+ * region for the descriptor ring. */
+ void *alloc_descbase;
+ dma_addr_t alloc_dmabase;
+ unsigned int alloc_descsize;
+ /* Pointer to our wireless device. */
struct b43_wldev *dev;
#ifdef CONFIG_B43_DEBUG
/* Maximum number of used slots. */
--
cgit v1.2.3-70-g09d2
From 07681e211d736ba2394ab7f29f77e93adecd22c5 Mon Sep 17 00:00:00 2001
From: Michael Buesch <mb@bu3sch.de>
Date: Thu, 19 Nov 2009 22:24:29 +0100
Subject: b43: Rewrite DMA Tx status handling sanity checks
This rewrites the error handling policies in the TX status handler.
It tries to be error-tolerant as in "try hard to not crash the machine".
It won't recover from errors (that are bugs in the firmware or driver),
because that's impossible. However, it will return a more or less useful
error message and bail out. It also tries hard to use rate-limited messages
to not flood the syslog in case of a failure.
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---
drivers/net/wireless/b43/dma.c | 67 ++++++++++++++++++++++++++++++++++--------
drivers/net/wireless/b43/dma.h | 6 +++-
2 files changed, 59 insertions(+), 14 deletions(-)
(limited to 'drivers/net/wireless/b43/dma.c')
diff --git a/drivers/net/wireless/b43/dma.c b/drivers/net/wireless/b43/dma.c
index 18b97c02b8a..027be275e03 100644
--- a/drivers/net/wireless/b43/dma.c
+++ b/drivers/net/wireless/b43/dma.c
@@ -874,7 +874,7 @@ static void free_all_descbuffers(struct b43_dmaring *ring)
for (i = 0; i < ring->nr_slots; i++) {
desc = ring->ops->idx2desc(ring, i, &meta);
- if (!meta->skb) {
+ if (!meta->skb || b43_dma_ptr_is_poisoned(meta->skb)) {
B43_WARN_ON(!ring->tx);
continue;
}
@@ -926,7 +926,7 @@ struct b43_dmaring *b43_setup_dmaring(struct b43_wldev *dev,
enum b43_dmatype type)
{
struct b43_dmaring *ring;
- int err;
+ int i, err;
dma_addr_t dma_test;
ring = kzalloc(sizeof(*ring), GFP_KERNEL);
@@ -941,6 +941,8 @@ struct b43_dmaring *b43_setup_dmaring(struct b43_wldev *dev,
GFP_KERNEL);
if (!ring->meta)
goto err_kfree_ring;
+ for (i = 0; i < ring->nr_slots; i++)
+ ring->meta->skb = B43_DMA_PTR_POISON;
ring->type = type;
ring->dev = dev;
@@ -1251,11 +1253,13 @@ struct b43_dmaring *parse_cookie(struct b43_wldev *dev, u16 cookie, int *slot)
case 0x5000:
ring = dma->tx_ring_mcast;
break;
- default:
- B43_WARN_ON(1);
}
*slot = (cookie & 0x0FFF);
- B43_WARN_ON(!(ring && *slot >= 0 && *slot < ring->nr_slots));
+ if (unlikely(!ring || *slot < 0 || *slot >= ring->nr_slots)) {
+ b43dbg(dev->wl, "TX-status contains "
+ "invalid cookie: 0x%04X\n", cookie);
+ return NULL;
+ }
return ring;
}
@@ -1494,19 +1498,40 @@ void b43_dma_handle_txstatus(struct b43_wldev *dev,
struct b43_dmaring *ring;
struct b43_dmadesc_generic *desc;
struct b43_dmadesc_meta *meta;
- int slot;
+ int slot, firstused;
bool frame_succeed;
ring = parse_cookie(dev, status->cookie, &slot);
if (unlikely(!ring))
return;
-
B43_WARN_ON(!ring->tx);
+
+ /* Sanity check: TX packets are processed in-order on one ring.
+ * Check if the slot deduced from the cookie really is the first
+ * used slot. */
+ firstused = ring->current_slot - ring->used_slots + 1;
+ if (firstused < 0)
+ firstused = ring->nr_slots + firstused;
+ if (unlikely(slot != firstused)) {
+ /* This possibly is a firmware bug and will result in
+ * malfunction, memory leaks and/or stall of DMA functionality. */
+ b43dbg(dev->wl, "Out of order TX status report on DMA ring %d. "
+ "Expected %d, but got %d\n",
+ ring->index, firstused, slot);
+ return;
+ }
+
ops = ring->ops;
while (1) {
- B43_WARN_ON(!(slot >= 0 && slot < ring->nr_slots));
+ B43_WARN_ON(slot < 0 || slot >= ring->nr_slots);
desc = ops->idx2desc(ring, slot, &meta);
+ if (b43_dma_ptr_is_poisoned(meta->skb)) {
+ b43dbg(dev->wl, "Poisoned TX slot %d (first=%d) "
+ "on ring %d\n",
+ slot, firstused, ring->index);
+ break;
+ }
if (meta->skb) {
struct b43_private_tx_info *priv_info =
b43_get_priv_tx_info(IEEE80211_SKB_CB(meta->skb));
@@ -1522,7 +1547,14 @@ void b43_dma_handle_txstatus(struct b43_wldev *dev,
if (meta->is_last_fragment) {
struct ieee80211_tx_info *info;
- BUG_ON(!meta->skb);
+ if (unlikely(!meta->skb)) {
+ /* This is a scatter-gather fragment of a frame, so
+ * the skb pointer must not be NULL. */
+ b43dbg(dev->wl, "TX status unexpected NULL skb "
+ "at slot %d (first=%d) on ring %d\n",
+ slot, firstused, ring->index);
+ break;
+ }
info = IEEE80211_SKB_CB(meta->skb);
@@ -1540,20 +1572,29 @@ void b43_dma_handle_txstatus(struct b43_wldev *dev,
#endif /* DEBUG */
ieee80211_tx_status(dev->wl->hw, meta->skb);
- /* skb is freed by ieee80211_tx_status() */
- meta->skb = NULL;
+ /* skb will be freed by ieee80211_tx_status().
+ * Poison our pointer. */
+ meta->skb = B43_DMA_PTR_POISON;
} else {
/* No need to call free_descriptor_buffer here, as
* this is only the txhdr, which is not allocated.
*/
- B43_WARN_ON(meta->skb);
+ if (unlikely(meta->skb)) {
+ b43dbg(dev->wl, "TX status unexpected non-NULL skb "
+ "at slot %d (first=%d) on ring %d\n",
+ slot, firstused, ring->index);
+ break;
+ }
}
/* Everything unmapped and free'd. So it's not used anymore. */
ring->used_slots--;
- if (meta->is_last_fragment)
+ if (meta->is_last_fragment) {
+ /* This is the last scatter-gather
+ * fragment of the frame. We are done. */
break;
+ }
slot = next_slot(ring, slot);
}
if (ring->stopped) {
diff --git a/drivers/net/wireless/b43/dma.h b/drivers/net/wireless/b43/dma.h
index 356a0ff8f04..e607b392314 100644
--- a/drivers/net/wireless/b43/dma.h
+++ b/drivers/net/wireless/b43/dma.h
@@ -1,7 +1,7 @@
#ifndef B43_DMA_H_
#define B43_DMA_H_
-#include <linux/ieee80211.h>
+#include <linux/err.h>
#include "b43.h"
@@ -164,6 +164,10 @@ struct b43_dmadesc_generic {
#define B43_RXRING_SLOTS 64
#define B43_DMA0_RX_BUFFERSIZE IEEE80211_MAX_FRAME_LEN
+/* Pointer poison */
+#define B43_DMA_PTR_POISON ((void *)ERR_PTR(-ENOMEM))
+#define b43_dma_ptr_is_poisoned(ptr) (unlikely((ptr) == B43_DMA_PTR_POISON))
+
struct sk_buff;
struct b43_private;
--
cgit v1.2.3-70-g09d2