linux/drivers/net/wireless/b43legacy/dma.h
Larry Finger 5d07a3d62f b43legacy: Avoid packet losses in the dma worker code
This patch addresses a bug in the dma worker code that keeps draining
packets even when the hardware queues are full. In such cases packets
can not be passed down to the device and are erroneusly dropped by the
code. It is based on commit bad6919469,
which fixes the same problem in b43.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-01-04 14:30:43 -05:00

231 lines
6.7 KiB
C

#ifndef B43legacy_DMA_H_
#define B43legacy_DMA_H_
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/linkage.h>
#include <linux/atomic.h>
#include "b43legacy.h"
/* DMA-Interrupt reasons. */
#define B43legacy_DMAIRQ_FATALMASK ((1 << 10) | (1 << 11) | (1 << 12) \
| (1 << 14) | (1 << 15))
#define B43legacy_DMAIRQ_NONFATALMASK (1 << 13)
#define B43legacy_DMAIRQ_RX_DONE (1 << 16)
/*** 32-bit DMA Engine. ***/
/* 32-bit DMA controller registers. */
#define B43legacy_DMA32_TXCTL 0x00
#define B43legacy_DMA32_TXENABLE 0x00000001
#define B43legacy_DMA32_TXSUSPEND 0x00000002
#define B43legacy_DMA32_TXLOOPBACK 0x00000004
#define B43legacy_DMA32_TXFLUSH 0x00000010
#define B43legacy_DMA32_TXADDREXT_MASK 0x00030000
#define B43legacy_DMA32_TXADDREXT_SHIFT 16
#define B43legacy_DMA32_TXRING 0x04
#define B43legacy_DMA32_TXINDEX 0x08
#define B43legacy_DMA32_TXSTATUS 0x0C
#define B43legacy_DMA32_TXDPTR 0x00000FFF
#define B43legacy_DMA32_TXSTATE 0x0000F000
#define B43legacy_DMA32_TXSTAT_DISABLED 0x00000000
#define B43legacy_DMA32_TXSTAT_ACTIVE 0x00001000
#define B43legacy_DMA32_TXSTAT_IDLEWAIT 0x00002000
#define B43legacy_DMA32_TXSTAT_STOPPED 0x00003000
#define B43legacy_DMA32_TXSTAT_SUSP 0x00004000
#define B43legacy_DMA32_TXERROR 0x000F0000
#define B43legacy_DMA32_TXERR_NOERR 0x00000000
#define B43legacy_DMA32_TXERR_PROT 0x00010000
#define B43legacy_DMA32_TXERR_UNDERRUN 0x00020000
#define B43legacy_DMA32_TXERR_BUFREAD 0x00030000
#define B43legacy_DMA32_TXERR_DESCREAD 0x00040000
#define B43legacy_DMA32_TXACTIVE 0xFFF00000
#define B43legacy_DMA32_RXCTL 0x10
#define B43legacy_DMA32_RXENABLE 0x00000001
#define B43legacy_DMA32_RXFROFF_MASK 0x000000FE
#define B43legacy_DMA32_RXFROFF_SHIFT 1
#define B43legacy_DMA32_RXDIRECTFIFO 0x00000100
#define B43legacy_DMA32_RXADDREXT_MASK 0x00030000
#define B43legacy_DMA32_RXADDREXT_SHIFT 16
#define B43legacy_DMA32_RXRING 0x14
#define B43legacy_DMA32_RXINDEX 0x18
#define B43legacy_DMA32_RXSTATUS 0x1C
#define B43legacy_DMA32_RXDPTR 0x00000FFF
#define B43legacy_DMA32_RXSTATE 0x0000F000
#define B43legacy_DMA32_RXSTAT_DISABLED 0x00000000
#define B43legacy_DMA32_RXSTAT_ACTIVE 0x00001000
#define B43legacy_DMA32_RXSTAT_IDLEWAIT 0x00002000
#define B43legacy_DMA32_RXSTAT_STOPPED 0x00003000
#define B43legacy_DMA32_RXERROR 0x000F0000
#define B43legacy_DMA32_RXERR_NOERR 0x00000000
#define B43legacy_DMA32_RXERR_PROT 0x00010000
#define B43legacy_DMA32_RXERR_OVERFLOW 0x00020000
#define B43legacy_DMA32_RXERR_BUFWRITE 0x00030000
#define B43legacy_DMA32_RXERR_DESCREAD 0x00040000
#define B43legacy_DMA32_RXACTIVE 0xFFF00000
/* 32-bit DMA descriptor. */
struct b43legacy_dmadesc32 {
__le32 control;
__le32 address;
} __packed;
#define B43legacy_DMA32_DCTL_BYTECNT 0x00001FFF
#define B43legacy_DMA32_DCTL_ADDREXT_MASK 0x00030000
#define B43legacy_DMA32_DCTL_ADDREXT_SHIFT 16
#define B43legacy_DMA32_DCTL_DTABLEEND 0x10000000
#define B43legacy_DMA32_DCTL_IRQ 0x20000000
#define B43legacy_DMA32_DCTL_FRAMEEND 0x40000000
#define B43legacy_DMA32_DCTL_FRAMESTART 0x80000000
/* Misc DMA constants */
#define B43legacy_DMA_RINGMEMSIZE PAGE_SIZE
#define B43legacy_DMA0_RX_FRAMEOFFSET 30
#define B43legacy_DMA3_RX_FRAMEOFFSET 0
/* DMA engine tuning knobs */
#define B43legacy_TXRING_SLOTS 128
#define B43legacy_RXRING_SLOTS 64
#define B43legacy_DMA0_RX_BUFFERSIZE (2304 + 100)
#define B43legacy_DMA3_RX_BUFFERSIZE 16
#ifdef CONFIG_B43LEGACY_DMA
struct sk_buff;
struct b43legacy_private;
struct b43legacy_txstatus;
struct b43legacy_dmadesc_meta {
/* The kernel DMA-able buffer. */
struct sk_buff *skb;
/* DMA base bus-address of the descriptor buffer. */
dma_addr_t dmaaddr;
/* ieee80211 TX status. Only used once per 802.11 frag. */
bool is_last_fragment;
};
enum b43legacy_dmatype {
B43legacy_DMA_30BIT = 30,
B43legacy_DMA_32BIT = 32,
};
struct b43legacy_dmaring {
/* Kernel virtual base address of the ring memory. */
void *descbase;
/* Meta data about all descriptors. */
struct b43legacy_dmadesc_meta *meta;
/* Cache of TX headers for each slot.
* This is to avoid an allocation on each TX.
* This is NULL for an RX ring.
*/
u8 *txhdr_cache;
/* (Unadjusted) DMA base bus-address of the ring memory. */
dma_addr_t dmabase;
/* Number of descriptor slots in the ring. */
int nr_slots;
/* Number of used descriptor slots. */
int used_slots;
/* Currently used slot in the ring. */
int current_slot;
/* Frameoffset in octets. */
u32 frameoffset;
/* Descriptor buffer size. */
u16 rx_buffersize;
/* The MMIO base register of the DMA controller. */
u16 mmio_base;
/* DMA controller index number (0-5). */
int index;
/* Boolean. Is this a TX ring? */
bool tx;
/* The type of DMA engine used. */
enum b43legacy_dmatype type;
/* Boolean. Is this ring stopped at ieee80211 level? */
bool stopped;
/* The QOS priority assigned to this ring. Only used for TX rings.
* This is the mac80211 "queue" value. */
u8 queue_prio;
struct b43legacy_wldev *dev;
#ifdef CONFIG_B43LEGACY_DEBUG
/* Maximum number of used slots. */
int max_used_slots;
/* Last time we injected a ring overflow. */
unsigned long last_injected_overflow;
#endif /* CONFIG_B43LEGACY_DEBUG*/
};
static inline
u32 b43legacy_dma_read(struct b43legacy_dmaring *ring,
u16 offset)
{
return b43legacy_read32(ring->dev, ring->mmio_base + offset);
}
static inline
void b43legacy_dma_write(struct b43legacy_dmaring *ring,
u16 offset, u32 value)
{
b43legacy_write32(ring->dev, ring->mmio_base + offset, value);
}
int b43legacy_dma_init(struct b43legacy_wldev *dev);
void b43legacy_dma_free(struct b43legacy_wldev *dev);
void b43legacy_dma_tx_suspend(struct b43legacy_wldev *dev);
void b43legacy_dma_tx_resume(struct b43legacy_wldev *dev);
int b43legacy_dma_tx(struct b43legacy_wldev *dev,
struct sk_buff *skb);
void b43legacy_dma_handle_txstatus(struct b43legacy_wldev *dev,
const struct b43legacy_txstatus *status);
void b43legacy_dma_rx(struct b43legacy_dmaring *ring);
#else /* CONFIG_B43LEGACY_DMA */
static inline
int b43legacy_dma_init(struct b43legacy_wldev *dev)
{
return 0;
}
static inline
void b43legacy_dma_free(struct b43legacy_wldev *dev)
{
}
static inline
int b43legacy_dma_tx(struct b43legacy_wldev *dev,
struct sk_buff *skb)
{
return 0;
}
static inline
void b43legacy_dma_handle_txstatus(struct b43legacy_wldev *dev,
const struct b43legacy_txstatus *status)
{
}
static inline
void b43legacy_dma_rx(struct b43legacy_dmaring *ring)
{
}
static inline
void b43legacy_dma_tx_suspend(struct b43legacy_wldev *dev)
{
}
static inline
void b43legacy_dma_tx_resume(struct b43legacy_wldev *dev)
{
}
#endif /* CONFIG_B43LEGACY_DMA */
#endif /* B43legacy_DMA_H_ */