drivers/net/wireless/broadcom/b43legacy/dma.h

Source file repositories/reference/linux-study-clean/drivers/net/wireless/broadcom/b43legacy/dma.h

File Facts

System
Linux kernel
Corpus path
drivers/net/wireless/broadcom/b43legacy/dma.h
Extension
.h
Size
6872 bytes
Lines
233
Domain
Driver Families
Bucket
drivers/net
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

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;

Annotation

Implementation Notes