From: John W. Linville Date: Tue, 29 Dec 2009 19:07:42 +0000 (-0500) Subject: Revert "b43: Enforce DMA descriptor memory constraints" X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=55afc80b2ab100618c17af77915f75307b6bd5d1;p=openwrt%2Fstaging%2Fblogic.git 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 --- diff --git a/drivers/net/wireless/b43/dma.c b/drivers/net/wireless/b43/dma.c index 027be275e035..88d1fd02d40a 100644 --- a/drivers/net/wireless/b43/dma.c +++ b/drivers/net/wireless/b43/dma.c @@ -383,160 +383,44 @@ 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) { - 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. + 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! */ - 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 @@ static bool b43_dma_mapping_error(struct b43_dmaring *ring, 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 @@ 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; } @@ -1354,9 +1250,6 @@ 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 e607b392314c..f7ab37c4cdbc 100644 --- a/drivers/net/wireless/b43/dma.h +++ b/drivers/net/wireless/b43/dma.h @@ -157,6 +157,7 @@ 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 */ @@ -246,12 +247,6 @@ 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. */