Revert "b43: Enforce DMA descriptor memory constraints"
This reverts commit 9bd568a50c446433038dec2a5186c5c57c3dbd23.
That commit is shown to cause allocation failures during initialization
on some machines.
http://bugzilla.kernel.org/show_bug.cgi?id=14844
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/b43/dma.c b/drivers/net/wireless/b43/dma.c
index 027be27..88d1fd0 100644
--- a/drivers/net/wireless/b43/dma.c
+++ b/drivers/net/wireless/b43/dma.c
@@ -383,160 +383,44 @@
}
}
-/* 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)
{
- unsigned int required;
- void *base;
- dma_addr_t dmaaddr;
+ gfp_t flags = GFP_KERNEL;
- /* 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.
+ /* 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!
*/
-
if (ring->type == B43_DMA_64BIT)
- required = ring->nr_slots * sizeof(struct b43_dmadesc64);
- else
- required = ring->nr_slots * sizeof(struct b43_dmadesc32);
- if (B43_WARN_ON(required > 0x1000))
+ 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");
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;
- }
- /* Force-align it to 8k */
- ring->descbase = (void *)((u8 *)base + 0x1000);
- ring->dmabase = dmaaddr + 0x1000;
- B43_WARN_ON(!is_8k_aligned(ring->dmabase));
+ memset(ring->descbase, 0, B43_DMA_RINGMEMSIZE);
return 0;
}
static void free_ringmemory(struct b43_dmaring *ring)
{
- b43_unmap_and_free_ringmem(ring, ring->alloc_descbase,
- ring->alloc_dmabase, ring->alloc_descsize);
+ 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);
}
/* Reset the RX DMA channel */
@@ -646,14 +530,29 @@
if (unlikely(ssb_dma_mapping_error(ring->dev->dev, addr)))
return 1;
- 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;
+ 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;
}
/* 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)
@@ -715,9 +614,6 @@
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;
}
@@ -1354,9 +1250,6 @@
}
/* 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;