diff options
Diffstat (limited to 'drivers/net/wireless/bcm43xx/bcm43xx_dma.c')
| -rw-r--r-- | drivers/net/wireless/bcm43xx/bcm43xx_dma.c | 1009 |
1 files changed, 1009 insertions, 0 deletions
diff --git a/drivers/net/wireless/bcm43xx/bcm43xx_dma.c b/drivers/net/wireless/bcm43xx/bcm43xx_dma.c new file mode 100644 index 0000000000000..df19fbfa9ea1a --- /dev/null +++ b/drivers/net/wireless/bcm43xx/bcm43xx_dma.c @@ -0,0 +1,1009 @@ +/* + + Broadcom BCM43xx wireless driver + + DMA ringbuffer and descriptor allocation/management + + Copyright (c) 2005 Michael Buesch <mbuesch@freenet.de> + + Some code in this file is derived from the b44.c driver + Copyright (C) 2002 David S. Miller + Copyright (C) Pekka Pietikainen + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; see the file COPYING. If not, write to + the Free Software Foundation, Inc., 51 Franklin Steet, Fifth Floor, + Boston, MA 02110-1301, USA. + +*/ + +#include "bcm43xx.h" +#include "bcm43xx_dma.h" +#include "bcm43xx_main.h" +#include "bcm43xx_debugfs.h" +#include "bcm43xx_power.h" + +#include <linux/dmapool.h> +#include <linux/pci.h> +#include <linux/delay.h> +#include <linux/skbuff.h> +#include <asm/semaphore.h> + + +static inline int free_slots(struct bcm43xx_dmaring *ring) +{ + return (ring->nr_slots - ring->used_slots); +} + +static inline int next_slot(struct bcm43xx_dmaring *ring, int slot) +{ + assert(slot >= -1 && slot <= ring->nr_slots - 1); + if (slot == ring->nr_slots - 1) + return 0; + return slot + 1; +} + +static inline int prev_slot(struct bcm43xx_dmaring *ring, int slot) +{ + assert(slot >= 0 && slot <= ring->nr_slots - 1); + if (slot == 0) + return ring->nr_slots - 1; + return slot - 1; +} + +/* Request a slot for usage. */ +static inline +int request_slot(struct bcm43xx_dmaring *ring) +{ + int slot; + + assert(ring->tx); + assert(!ring->suspended); + assert(free_slots(ring) != 0); + + slot = next_slot(ring, ring->current_slot); + ring->current_slot = slot; + ring->used_slots++; + + /* Check the number of available slots and suspend TX, + * if we are running low on free slots. + */ + if (unlikely(free_slots(ring) < ring->suspend_mark)) { + netif_stop_queue(ring->bcm->net_dev); + ring->suspended = 1; + } +#ifdef CONFIG_BCM43XX_DEBUG + if (ring->used_slots > ring->max_used_slots) + ring->max_used_slots = ring->used_slots; +#endif /* CONFIG_BCM43XX_DEBUG*/ + + return slot; +} + +/* Return a slot to the free slots. */ +static inline +void return_slot(struct bcm43xx_dmaring *ring, int slot) +{ + assert(ring->tx); + + ring->used_slots--; + + /* Check if TX is suspended and check if we have + * enough free slots to resume it again. + */ + if (unlikely(ring->suspended)) { + if (free_slots(ring) >= ring->resume_mark) { + ring->suspended = 0; + netif_wake_queue(ring->bcm->net_dev); + } + } +} + +static inline +dma_addr_t map_descbuffer(struct bcm43xx_dmaring *ring, + unsigned char *buf, + size_t len, + int tx) +{ + dma_addr_t dmaaddr; + + if (tx) { + dmaaddr = dma_map_single(&ring->bcm->pci_dev->dev, + buf, len, + DMA_TO_DEVICE); + } else { + dmaaddr = dma_map_single(&ring->bcm->pci_dev->dev, + buf, len, + DMA_FROM_DEVICE); + } + + return dmaaddr; +} + +static inline +void unmap_descbuffer(struct bcm43xx_dmaring *ring, + dma_addr_t addr, + size_t len, + int tx) +{ + if (tx) { + dma_unmap_single(&ring->bcm->pci_dev->dev, + addr, len, + DMA_TO_DEVICE); + } else { + dma_unmap_single(&ring->bcm->pci_dev->dev, + addr, len, + DMA_FROM_DEVICE); + } +} + +static inline +void sync_descbuffer_for_cpu(struct bcm43xx_dmaring *ring, + dma_addr_t addr, + size_t len) +{ + assert(!ring->tx); + + dma_sync_single_for_cpu(&ring->bcm->pci_dev->dev, + addr, len, DMA_FROM_DEVICE); +} + +static inline +void sync_descbuffer_for_device(struct bcm43xx_dmaring *ring, + dma_addr_t addr, + size_t len) +{ + assert(!ring->tx); + + dma_sync_single_for_device(&ring->bcm->pci_dev->dev, + addr, len, DMA_FROM_DEVICE); +} + +static inline +void mark_skb_mustfree(struct sk_buff *skb, + char mustfree) +{ + skb->cb[0] = mustfree; +} + +static inline +int skb_mustfree(struct sk_buff *skb) +{ + return (skb->cb[0] != 0); +} + +/* Unmap and free a descriptor buffer. */ +static inline +void free_descriptor_buffer(struct bcm43xx_dmaring *ring, + struct bcm43xx_dmadesc *desc, + struct bcm43xx_dmadesc_meta *meta, + int irq_context) +{ + assert(meta->skb); + if (skb_mustfree(meta->skb)) { + if (irq_context) + dev_kfree_skb_irq(meta->skb); + else + dev_kfree_skb(meta->skb); + } + meta->skb = NULL; + if (meta->txb) { + ieee80211_txb_free(meta->txb); + meta->txb = NULL; + } +} + +static int alloc_ringmemory(struct bcm43xx_dmaring *ring) +{ + struct device *dev = &(ring->bcm->pci_dev->dev); + + ring->vbase = dma_alloc_coherent(dev, BCM43xx_DMA_RINGMEMSIZE, + &(ring->dmabase), GFP_KERNEL); + if (!ring->vbase) { + printk(KERN_ERR PFX "DMA ringmemory allocation failed\n"); + return -ENOMEM; + } + if (ring->dmabase + BCM43xx_DMA_RINGMEMSIZE > BCM43xx_DMA_BUSADDRMAX) { + printk(KERN_ERR PFX ">>>FATAL ERROR<<< DMA RINGMEMORY >1G\n"); + dma_free_coherent(dev, BCM43xx_DMA_RINGMEMSIZE, + ring->vbase, ring->dmabase); + return -ENOMEM; + } + assert(!(ring->dmabase & 0x000003FF)); + memset(ring->vbase, 0, BCM43xx_DMA_RINGMEMSIZE); + + return 0; +} + +static void free_ringmemory(struct bcm43xx_dmaring *ring) +{ + struct device *dev = &(ring->bcm->pci_dev->dev); + + dma_free_coherent(dev, BCM43xx_DMA_RINGMEMSIZE, + ring->vbase, ring->dmabase); +} + +/* Reset the RX DMA channel */ +int bcm43xx_dmacontroller_rx_reset(struct bcm43xx_private *bcm, + u16 mmio_base) +{ + int i; + u32 value; + + bcm43xx_write32(bcm, + mmio_base + BCM43xx_DMA_RX_CONTROL, + 0x00000000); + for (i = 0; i < 1000; i++) { + value = bcm43xx_read32(bcm, + mmio_base + BCM43xx_DMA_RX_STATUS); + value &= BCM43xx_DMA_RXSTAT_STAT_MASK; + if (value == BCM43xx_DMA_RXSTAT_STAT_DISABLED) { + i = -1; + break; + } + udelay(10); + } + if (i != -1) { + printk(KERN_ERR PFX "Error: Wait on DMA RX status timed out.\n"); + return -ENODEV; + } + + return 0; +} + +static inline int dmacontroller_rx_reset(struct bcm43xx_dmaring *ring) +{ + assert(!ring->tx); + + return bcm43xx_dmacontroller_rx_reset(ring->bcm, ring->mmio_base); +} + +/* Reset the RX DMA channel */ +int bcm43xx_dmacontroller_tx_reset(struct bcm43xx_private *bcm, + u16 mmio_base) +{ + int i; + u32 value; + + for (i = 0; i < 1000; i++) { + value = bcm43xx_read32(bcm, + mmio_base + BCM43xx_DMA_TX_STATUS); + value &= BCM43xx_DMA_TXSTAT_STAT_MASK; + if (value == BCM43xx_DMA_TXSTAT_STAT_DISABLED || + value == BCM43xx_DMA_TXSTAT_STAT_IDLEWAIT || + value == BCM43xx_DMA_TXSTAT_STAT_STOPPED) + break; + udelay(10); + } + bcm43xx_write32(bcm, + mmio_base + BCM43xx_DMA_TX_CONTROL, + 0x00000000); + for (i = 0; i < 1000; i++) { + value = bcm43xx_read32(bcm, + mmio_base + BCM43xx_DMA_TX_STATUS); + value &= BCM43xx_DMA_TXSTAT_STAT_MASK; + if (value == BCM43xx_DMA_TXSTAT_STAT_DISABLED) { + i = -1; + break; + } + udelay(10); + } + if (i != -1) { + printk(KERN_ERR PFX "Error: Wait on DMA TX status timed out.\n"); + return -ENODEV; + } + /* ensure the reset is completed. */ + udelay(300); + + return 0; +} + +static inline int dmacontroller_tx_reset(struct bcm43xx_dmaring *ring) +{ + assert(ring->tx); + + return bcm43xx_dmacontroller_tx_reset(ring->bcm, ring->mmio_base); +} + +static int setup_rx_descbuffer(struct bcm43xx_dmaring *ring, + struct bcm43xx_dmadesc *desc, + struct bcm43xx_dmadesc_meta *meta, + gfp_t gfp_flags) +{ + struct bcm43xx_rxhdr *rxhdr; + dma_addr_t dmaaddr; + u32 desc_addr; + u32 desc_ctl; + const int slot = (int)(desc - ring->vbase); + struct sk_buff *skb; + + assert(slot >= 0 && slot < ring->nr_slots); + assert(!ring->tx); + + skb = __dev_alloc_skb(ring->rx_buffersize, gfp_flags); + if (unlikely(!skb)) + return -ENOMEM; + dmaaddr = map_descbuffer(ring, skb->data, ring->rx_buffersize, 0); + if (unlikely(dmaaddr + ring->rx_buffersize > BCM43xx_DMA_BUSADDRMAX)) { + unmap_descbuffer(ring, dmaaddr, ring->rx_buffersize, 0); + dev_kfree_skb_any(skb); + printk(KERN_ERR PFX ">>>FATAL ERROR<<< DMA RX SKB >1G\n"); + return -ENOMEM; + } + meta->skb = skb; + meta->dmaaddr = dmaaddr; + skb->dev = ring->bcm->net_dev; + mark_skb_mustfree(skb, 1); + desc_addr = (u32)(dmaaddr + ring->memoffset); + desc_ctl = (BCM43xx_DMADTOR_BYTECNT_MASK & + (u32)(ring->rx_buffersize - ring->frameoffset)); + if (slot == ring->nr_slots - 1) + desc_ctl |= BCM43xx_DMADTOR_DTABLEEND; + set_desc_addr(desc, desc_addr); + set_desc_ctl(desc, desc_ctl); + + rxhdr = (struct bcm43xx_rxhdr *)(skb->data); + rxhdr->frame_length = 0; + rxhdr->flags1 = 0; + + return 0; +} + +/* Allocate the initial descbuffers. + * This is used for an RX ring only. + */ +static int alloc_initial_descbuffers(struct bcm43xx_dmaring *ring) +{ + int i, err = -ENOMEM; + struct bcm43xx_dmadesc *desc = NULL; + struct bcm43xx_dmadesc_meta *meta; + + for (i = 0; i < ring->nr_slots; i++) { + desc = ring->vbase + i; + meta = ring->meta + i; + + err = setup_rx_descbuffer(ring, desc, meta, GFP_KERNEL); + if (err) + goto err_unwind; + + assert(ring->used_slots <= ring->nr_slots); + } + ring->used_slots = ring->nr_slots; + + err = 0; +out: + return err; + +err_unwind: + for ( ; i >= 0; i--) { + desc = ring->vbase + i; + meta = ring->meta + i; + + unmap_descbuffer(ring, meta->dmaaddr, ring->rx_buffersize, 0); + dev_kfree_skb(meta->skb); + } + ring->used_slots = 0; + goto out; +} + +/* Do initial setup of the DMA controller. + * Reset the controller, write the ring busaddress + * and switch the "enable" bit on. + */ +static int dmacontroller_setup(struct bcm43xx_dmaring *ring) +{ + int err = 0; + u32 value; + + if (ring->tx) { + /* Set Transmit Control register to "transmit enable" */ + bcm43xx_write32(ring->bcm, + ring->mmio_base + BCM43xx_DMA_TX_CONTROL, + BCM43xx_DMA_TXCTRL_ENABLE); + /* Set Transmit Descriptor ring address. */ + bcm43xx_write32(ring->bcm, + ring->mmio_base + BCM43xx_DMA_TX_DESC_RING, + ring->dmabase + ring->memoffset); + } else { + err = alloc_initial_descbuffers(ring); + if (err) + goto out; + /* Set Receive Control "receive enable" and frame offset */ + value = (ring->frameoffset << BCM43xx_DMA_RXCTRL_FRAMEOFF_SHIFT); + value |= BCM43xx_DMA_RXCTRL_ENABLE; + bcm43xx_write32(ring->bcm, + ring->mmio_base + BCM43xx_DMA_RX_CONTROL, + value); + /* Set Receive Descriptor ring address. */ + bcm43xx_write32(ring->bcm, + ring->mmio_base + BCM43xx_DMA_RX_DESC_RING, + ring->dmabase + ring->memoffset); + /* Init the descriptor pointer. */ + bcm43xx_write32(ring->bcm, + ring->mmio_base + BCM43xx_DMA_RX_DESC_INDEX, + 200); + } + +out: + return err; +} + +/* Shutdown the DMA controller. */ +static void dmacontroller_cleanup(struct bcm43xx_dmaring *ring) +{ + if (ring->tx) { + dmacontroller_tx_reset(ring); + /* Zero out Transmit Descriptor ring address. */ + bcm43xx_write32(ring->bcm, + ring->mmio_base + BCM43xx_DMA_TX_DESC_RING, + 0x00000000); + } else { + dmacontroller_rx_reset(ring); + /* Zero out Receive Descriptor ring address. */ + bcm43xx_write32(ring->bcm, + ring->mmio_base + BCM43xx_DMA_RX_DESC_RING, + 0x00000000); + } +} + +static void free_all_descbuffers(struct bcm43xx_dmaring *ring) +{ + struct bcm43xx_dmadesc *desc; + struct bcm43xx_dmadesc_meta *meta; + int i; + + if (!ring->used_slots) + return; + for (i = 0; i < ring->nr_slots; i++) { + desc = ring->vbase + i; + meta = ring->meta + i; + + if (!meta->skb) { + assert(ring->tx); + assert(!meta->txb); + continue; + } + if (ring->tx) { + unmap_descbuffer(ring, meta->dmaaddr, + meta->skb->len, 1); + } else { + unmap_descbuffer(ring, meta->dmaaddr, + ring->rx_buffersize, 0); + } + free_descriptor_buffer(ring, desc, meta, 0); + } +} + +/* Main initialization function. */ +static +struct bcm43xx_dmaring * bcm43xx_setup_dmaring(struct bcm43xx_private *bcm, + u16 dma_controller_base, + int nr_descriptor_slots, + int tx) +{ + struct bcm43xx_dmaring *ring; + int err; + + ring = kzalloc(sizeof(*ring), GFP_KERNEL); + if (!ring) + goto out; + + ring->meta = kzalloc(sizeof(*ring->meta) * nr_descriptor_slots, + GFP_KERNEL); + if (!ring->meta) + goto err_kfree_ring; + + ring->memoffset = BCM43xx_DMA_DMABUSADDROFFSET; +#ifdef CONFIG_BCM947XX + if (bcm->pci_dev->bus->number == 0) + ring->memoffset = 0; +#endif + + + spin_lock_init(&ring->lock); + ring->bcm = bcm; + ring->nr_slots = nr_descriptor_slots; + ring->suspend_mark = ring->nr_slots * BCM43xx_TXSUSPEND_PERCENT / 100; + ring->resume_mark = ring->nr_slots * BCM43xx_TXRESUME_PERCENT / 100; + assert(ring->suspend_mark < ring->resume_mark); + ring->mmio_base = dma_controller_base; + if (tx) { + ring->tx = 1; + ring->current_slot = -1; + } else { + switch (dma_controller_base) { + case BCM43xx_MMIO_DMA1_BASE: + ring->rx_buffersize = BCM43xx_DMA1_RXBUFFERSIZE; + ring->frameoffset = BCM43xx_DMA1_RX_FRAMEOFFSET; + break; + case BCM43xx_MMIO_DMA4_BASE: + ring->rx_buffersize = BCM43xx_DMA4_RXBUFFERSIZE; + ring->frameoffset = BCM43xx_DMA4_RX_FRAMEOFFSET; + break; + default: + assert(0); + } + } + + err = alloc_ringmemory(ring); + if (err) + goto err_kfree_meta; + err = dmacontroller_setup(ring); + if (err) + goto err_free_ringmemory; + +out: + return ring; + +err_free_ringmemory: + free_ringmemory(ring); +err_kfree_meta: + kfree(ring->meta); +err_kfree_ring: + kfree(ring); + ring = NULL; + goto out; +} + +/* Main cleanup function. */ +static void bcm43xx_destroy_dmaring(struct bcm43xx_dmaring *ring) +{ + if (!ring) + return; + + dprintk(KERN_INFO PFX "DMA 0x%04x (%s) max used slots: %d/%d\n", + 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. + */ + dmacontroller_cleanup(ring); + free_all_descbuffers(ring); + free_ringmemory(ring); + + kfree(ring->meta); + kfree(ring); +} + +void bcm43xx_dma_free(struct bcm43xx_private *bcm) +{ + bcm43xx_destroy_dmaring(bcm->current_core->dma->rx_ring1); + bcm->current_core->dma->rx_ring1 = NULL; + bcm43xx_destroy_dmaring(bcm->current_core->dma->rx_ring0); + bcm->current_core->dma->rx_ring0 = NULL; + bcm43xx_destroy_dmaring(bcm->current_core->dma->tx_ring3); + bcm->current_core->dma->tx_ring3 = NULL; + bcm43xx_destroy_dmaring(bcm->current_core->dma->tx_ring2); + bcm->current_core->dma->tx_ring2 = NULL; + bcm43xx_destroy_dmaring(bcm->current_core->dma->tx_ring1); + bcm->current_core->dma->tx_ring1 = NULL; + bcm43xx_destroy_dmaring(bcm->current_core->dma->tx_ring0); + bcm->current_core->dma->tx_ring0 = NULL; +} + +int bcm43xx_dma_init(struct bcm43xx_private *bcm) +{ + struct bcm43xx_dmaring *ring; + int err = -ENOMEM; + + /* setup TX DMA channels. */ + ring = bcm43xx_setup_dmaring(bcm, BCM43xx_MMIO_DMA1_BASE, + BCM43xx_TXRING_SLOTS, 1); + if (!ring) + goto out; + bcm->current_core->dma->tx_ring0 = ring; + + ring = bcm43xx_setup_dmaring(bcm, BCM43xx_MMIO_DMA2_BASE, + BCM43xx_TXRING_SLOTS, 1); + if (!ring) + goto err_destroy_tx0; + bcm->current_core->dma->tx_ring1 = ring; + + ring = bcm43xx_setup_dmaring(bcm, BCM43xx_MMIO_DMA3_BASE, + BCM43xx_TXRING_SLOTS, 1); + if (!ring) + goto err_destroy_tx1; + bcm->current_core->dma->tx_ring2 = ring; + + ring = bcm43xx_setup_dmaring(bcm, BCM43xx_MMIO_DMA4_BASE, + BCM43xx_TXRING_SLOTS, 1); + if (!ring) + goto err_destroy_tx2; + bcm->current_core->dma->tx_ring3 = ring; + + /* setup RX DMA channels. */ + ring = bcm43xx_setup_dmaring(bcm, BCM43xx_MMIO_DMA1_BASE, + BCM43xx_RXRING_SLOTS, 0); + if (!ring) + goto err_destroy_tx3; + bcm->current_core->dma->rx_ring0 = ring; + + if (bcm->current_core->rev < 5) { + ring = bcm43xx_setup_dmaring(bcm, BCM43xx_MMIO_DMA4_BASE, + BCM43xx_RXRING_SLOTS, 0); + if (!ring) + goto err_destroy_rx0; + bcm->current_core->dma->rx_ring1 = ring; + } + + dprintk(KERN_INFO PFX "DMA initialized\n"); + err = 0; +out: + return err; + +err_destroy_rx0: + bcm43xx_destroy_dmaring(bcm->current_core->dma->rx_ring0); + bcm->current_core->dma->rx_ring0 = NULL; +err_destroy_tx3: + bcm43xx_destroy_dmaring(bcm->current_core->dma->tx_ring3); + bcm->current_core->dma->tx_ring3 = NULL; +err_destroy_tx2: + bcm43xx_destroy_dmaring(bcm->current_core->dma->tx_ring2); + bcm->current_core->dma->tx_ring2 = NULL; +err_destroy_tx1: + bcm43xx_destroy_dmaring(bcm->current_core->dma->tx_ring1); + bcm->current_core->dma->tx_ring1 = NULL; +err_destroy_tx0: + bcm43xx_destroy_dmaring(bcm->current_core->dma->tx_ring0); + bcm->current_core->dma->tx_ring0 = NULL; + goto out; +} + +/* Generate a cookie for the TX header. */ +static inline +u16 generate_cookie(struct bcm43xx_dmaring *ring, + int slot) +{ + u16 cookie = 0x0000; + + /* Use the upper 4 bits of the cookie as + * DMA controller ID and store the slot number + * in the lower 12 bits + */ + switch (ring->mmio_base) { + default: + assert(0); + case BCM43xx_MMIO_DMA1_BASE: + break; + case BCM43xx_MMIO_DMA2_BASE: + cookie = 0x1000; + break; + case BCM43xx_MMIO_DMA3_BASE: + cookie = 0x2000; + break; + case BCM43xx_MMIO_DMA4_BASE: + cookie = 0x3000; + break; + } + assert(((u16)slot & 0xF000) == 0x0000); + cookie |= (u16)slot; + + return cookie; +} + +/* Inspect a cookie and find out to which controller/slot it belongs. */ +static inline +struct bcm43xx_dmaring * parse_cookie(struct bcm43xx_private *bcm, + u16 cookie, int *slot) +{ + struct bcm43xx_dmaring *ring = NULL; + + switch (cookie & 0xF000) { + case 0x0000: + ring = bcm->current_core->dma->tx_ring0; + break; + case 0x1000: + ring = bcm->current_core->dma->tx_ring1; + break; + case 0x2000: + ring = bcm->current_core->dma->tx_ring2; + break; + case 0x3000: + ring = bcm->current_core->dma->tx_ring3; + break; + default: + assert(0); + } + *slot = (cookie & 0x0FFF); + assert(*slot >= 0 && *slot < ring->nr_slots); + + return ring; +} + +static inline void dmacontroller_poke_tx(struct bcm43xx_dmaring *ring, + int slot) +{ + /* Everything is ready to start. Buffers are DMA mapped and + * associated with slots. + * "slot" is the last slot of the new frame we want to transmit. + * Close your seat belts now, please. + */ + wmb(); + slot = next_slot(ring, slot); + bcm43xx_write32(ring->bcm, + ring->mmio_base + BCM43xx_DMA_TX_DESC_INDEX, + (u32)(slot * sizeof(struct bcm43xx_dmadesc))); +} + +static inline +int dma_tx_fragment(struct bcm43xx_dmaring *ring, + struct sk_buff *skb, + struct ieee80211_txb *txb, + u8 cur_frag) +{ + int slot; + struct bcm43xx_dmadesc *desc; + struct bcm43xx_dmadesc_meta *meta; + u32 desc_ctl; + u32 desc_addr; + + assert(skb_shinfo(skb)->nr_frags == 0); + + slot = request_slot(ring); + desc = ring->vbase + slot; + meta = ring->meta + slot; + + if (cur_frag == 0) { + /* Save the txb pointer for freeing in xmitstatus IRQ */ + meta->txb = txb; + } + + /* Add a device specific TX header. */ + assert(skb_headroom(skb) >= sizeof(struct bcm43xx_txhdr)); + /* Reserve enough headroom for the device tx header. */ + __skb_push(skb, sizeof(struct bcm43xx_txhdr)); + /* Now calculate and add the tx header. + * The tx header includes the PLCP header. + */ + bcm43xx_generate_txhdr(ring->bcm, + (struct bcm43xx_txhdr *)skb->data, + skb->data + sizeof(struct bcm43xx_txhdr), + skb->len - sizeof(struct bcm43xx_txhdr), + (cur_frag == 0), + generate_cookie(ring, slot)); + + meta->skb = skb; + meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1); + if (unlikely(meta->dmaaddr + skb->len > BCM43xx_DMA_BUSADDRMAX)) { + return_slot(ring, slot); + printk(KERN_ERR PFX ">>>FATAL ERROR<<< DMA TX SKB >1G\n"); + return -ENOMEM; + } + + desc_addr = (u32)(meta->dmaaddr + ring->memoffset); + desc_ctl = BCM43xx_DMADTOR_FRAMESTART | BCM43xx_DMADTOR_FRAMEEND; + desc_ctl |= BCM43xx_DMADTOR_COMPIRQ; + desc_ctl |= (BCM43xx_DMADTOR_BYTECNT_MASK & + (u32)(meta->skb->len - ring->frameoffset)); + if (slot == ring->nr_slots - 1) + desc_ctl |= BCM43xx_DMADTOR_DTABLEEND; + + set_desc_ctl(desc, desc_ctl); + set_desc_addr(desc, desc_addr); + /* Now transfer the whole frame. */ + dmacontroller_poke_tx(ring, slot); + + return 0; +} + +static inline int dma_transfer_txb(struct bcm43xx_dmaring *ring, + struct ieee80211_txb *txb) +{ + /* We just received a packet from the kernel network subsystem. + * Add headers and DMA map the memory. Poke + * the device to send the stuff. + * Note that this is called from atomic context. + */ + u8 i; + struct sk_buff *skb; + + assert(ring->tx); + if (unlikely(free_slots(ring) < txb->nr_frags)) { + /* The queue should be stopped, + * if we are low on free slots. + * If this ever triggers, we have to lower the suspend_mark. + */ + dprintkl(KERN_ERR PFX "Out of DMA descriptor slots!\n"); + return -ENOMEM; + } + + assert(irqs_disabled()); + spin_lock(&ring->lock); + for (i = 0; i < txb->nr_frags; i++) { + skb = txb->fragments[i]; + /* We do not free the skb, as it is freed as + * part of the txb freeing. + */ + mark_skb_mustfree(skb, 0); + dma_tx_fragment(ring, skb, txb, i); + //TODO: handle failure of dma_tx_fragment + } + spin_unlock(&ring->lock); + + return 0; +} + +int fastcall +bcm43xx_dma_transfer_txb(struct bcm43xx_private *bcm, + struct ieee80211_txb *txb) +{ + return dma_transfer_txb(bcm->current_core->dma->tx_ring1, + txb); +} + +void fastcall +bcm43xx_dma_handle_xmitstatus(struct bcm43xx_private *bcm, + struct bcm43xx_xmitstatus *status) +{ + struct bcm43xx_dmaring *ring; + struct bcm43xx_dmadesc *desc; + struct bcm43xx_dmadesc_meta *meta; + int is_last_fragment; + int slot; + + ring = parse_cookie(bcm, status->cookie, &slot); + assert(ring); + assert(ring->tx); + assert(irqs_disabled()); + spin_lock(&ring->lock); + + assert(get_desc_ctl(ring->vbase + slot) & BCM43xx_DMADTOR_FRAMESTART); + while (1) { + assert(slot >= 0 && slot < ring->nr_slots); + desc = ring->vbase + slot; + meta = ring->meta + slot; + + is_last_fragment = !!(get_desc_ctl(desc) & BCM43xx_DMADTOR_FRAMEEND); + unmap_descbuffer(ring, meta->dmaaddr, meta->skb->len, 1); + free_descriptor_buffer(ring, desc, meta, 1); + /* Everything belonging to the slot is unmapped + * and freed, so we can return it. + */ + return_slot(ring, slot); + + if (is_last_fragment) + break; + slot = next_slot(ring, slot); + } + bcm->stats.last_tx = jiffies; + + spin_unlock(&ring->lock); +} + +static inline +void dma_rx(struct bcm43xx_dmaring *ring, + int *slot) +{ + struct bcm43xx_dmadesc *desc; + struct bcm43xx_dmadesc_meta *meta; + struct bcm43xx_rxhdr *rxhdr; + struct sk_buff *skb; + u16 len; + int err; + dma_addr_t dmaaddr; + + desc = ring->vbase + *slot; + meta = ring->meta + *slot; + + sync_descbuffer_for_cpu(ring, meta->dmaaddr, ring->rx_buffersize); + skb = meta->skb; + + if (ring->mmio_base == BCM43xx_MMIO_DMA4_BASE) { + /* We received an xmit status. */ + struct bcm43xx_hwxmitstatus *hw = (struct bcm43xx_hwxmitstatus *)skb->data; + struct bcm43xx_xmitstatus stat; + + stat.cookie = le16_to_cpu(hw->cookie); + stat.flags = hw->flags; + stat.cnt1 = hw->cnt1; + stat.cnt2 = hw->cnt2; + stat.seq = le16_to_cpu(hw->seq); + stat.unknown = le16_to_cpu(hw->unknown); + + bcm43xx_debugfs_log_txstat(ring->bcm, &stat); + bcm43xx_dma_handle_xmitstatus(ring->bcm, &stat); + /* recycle the descriptor buffer. */ + sync_descbuffer_for_device(ring, meta->dmaaddr, ring->rx_buffersize); + + return; + } + rxhdr = (struct bcm43xx_rxhdr *)skb->data; + len = le16_to_cpu(rxhdr->frame_length); + if (len == 0) { + int i = 0; + + do { + udelay(2); + barrier(); + len = le16_to_cpu(rxhdr->frame_length); + } while (len == 0 && i++ < 5); + if (len == 0) + goto drop; + } + if (unlikely(len > ring->rx_buffersize)) { + /* The data did not fit into one descriptor buffer + * and is split over multiple buffers. + * This should never happen, as we try to allocate buffers + * big enough. So simply ignore this packet. + */ + int cnt = 1; + s32 tmp = len - ring->rx_buffersize; + + for ( ; tmp > 0; tmp -= ring->rx_buffersize) { + *slot = next_slot(ring, *slot); + cnt++; + } + printkl(KERN_ERR PFX "DMA RX buffer too small. %d dropped.\n", + cnt); + goto drop; + } + len -= IEEE80211_FCS_LEN; + + dmaaddr = meta->dmaaddr; + err = setup_rx_descbuffer(ring, desc, meta, GFP_ATOMIC); + if (unlikely(err)) { + dprintkl(KERN_ERR PFX "DMA RX: setup_rx_descbuffer() failed\n"); + goto drop; + } + + unmap_descbuffer(ring, dmaaddr, ring->rx_buffersize, 0); + skb_put(skb, len + ring->frameoffset); + skb_pull(skb, ring->frameoffset); + + err = bcm43xx_rx(ring->bcm, skb, rxhdr); + if (err) { + dev_kfree_skb_irq(skb); + goto drop; + } + +drop: + return; +} + +void fastcall +bcm43xx_dma_rx(struct bcm43xx_dmaring *ring) +{ + u32 status; + u16 descptr; + int slot, current_slot; +#ifdef CONFIG_BCM43XX_DEBUG + int used_slots = 0; +#endif + + assert(!ring->tx); + assert(irqs_disabled()); + spin_lock(&ring->lock); + + status = bcm43xx_read32(ring->bcm, ring->mmio_base + BCM43xx_DMA_RX_STATUS); + descptr = (status & BCM43xx_DMA_RXSTAT_DPTR_MASK); + current_slot = descptr / sizeof(struct bcm43xx_dmadesc); + assert(current_slot >= 0 && current_slot < ring->nr_slots); + + slot = ring->current_slot; + for ( ; slot != current_slot; slot = next_slot(ring, slot)) { + dma_rx(ring, &slot); +#ifdef CONFIG_BCM43XX_DEBUG + if (++used_slots > ring->max_used_slots) + ring->max_used_slots = used_slots; +#endif + } + bcm43xx_write32(ring->bcm, + ring->mmio_base + BCM43xx_DMA_RX_DESC_INDEX, + (u32)(slot * sizeof(struct bcm43xx_dmadesc))); + ring->current_slot = slot; + + spin_unlock(&ring->lock); +} + +/* vim: set ts=8 sw=8 sts=8: */ |