drivers/net/ethernet/sfc/falcon/farch.c

Source file repositories/reference/linux-study-clean/drivers/net/ethernet/sfc/falcon/farch.c

File Facts

System
Linux kernel
Corpus path
drivers/net/ethernet/sfc/falcon/farch.c
Extension
.c
Size
85430 bytes
Lines
2860
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 ef4_farch_filter_spec {
	u8	type:4;
	u8	priority:4;
	u8	flags;
	u16	dmaq_id;
	u32	data[3];
};

struct ef4_farch_filter_table {
	enum ef4_farch_filter_table_id id;
	u32		offset;		/* address of table relative to BAR */
	unsigned	size;		/* number of entries */
	unsigned	step;		/* step between entries */
	unsigned	used;		/* number currently used */
	unsigned long	*used_bitmap;
	struct ef4_farch_filter_spec *spec;
	unsigned	search_limit[EF4_FARCH_FILTER_TYPE_COUNT];
};

struct ef4_farch_filter_state {
	struct ef4_farch_filter_table table[EF4_FARCH_FILTER_TABLE_COUNT];
};

static void
ef4_farch_filter_table_clear_entry(struct ef4_nic *efx,
				   struct ef4_farch_filter_table *table,
				   unsigned int filter_idx);

/* The filter hash function is LFSR polynomial x^16 + x^3 + 1 of a 32-bit
 * key derived from the n-tuple.  The initial LFSR state is 0xffff. */
static u16 ef4_farch_filter_hash(u32 key)
{
	u16 tmp;

	/* First 16 rounds */
	tmp = 0x1fff ^ key >> 16;
	tmp = tmp ^ tmp >> 3 ^ tmp >> 6;
	tmp = tmp ^ tmp >> 9;
	/* Last 16 rounds */
	tmp = tmp ^ tmp << 13 ^ key;
	tmp = tmp ^ tmp >> 3 ^ tmp >> 6;
	return tmp ^ tmp >> 9;
}

/* To allow for hash collisions, filter search continues at these
 * increments from the first possible entry selected by the hash. */
static u16 ef4_farch_filter_increment(u32 key)
{
	return key * 2 - 1;
}

static enum ef4_farch_filter_table_id
ef4_farch_filter_spec_table_id(const struct ef4_farch_filter_spec *spec)
{
	BUILD_BUG_ON(EF4_FARCH_FILTER_TABLE_RX_IP !=
		     (EF4_FARCH_FILTER_TCP_FULL >> 2));
	BUILD_BUG_ON(EF4_FARCH_FILTER_TABLE_RX_IP !=
		     (EF4_FARCH_FILTER_TCP_WILD >> 2));
	BUILD_BUG_ON(EF4_FARCH_FILTER_TABLE_RX_IP !=
		     (EF4_FARCH_FILTER_UDP_FULL >> 2));
	BUILD_BUG_ON(EF4_FARCH_FILTER_TABLE_RX_IP !=
		     (EF4_FARCH_FILTER_UDP_WILD >> 2));
	BUILD_BUG_ON(EF4_FARCH_FILTER_TABLE_RX_MAC !=
		     (EF4_FARCH_FILTER_MAC_FULL >> 2));
	BUILD_BUG_ON(EF4_FARCH_FILTER_TABLE_RX_MAC !=
		     (EF4_FARCH_FILTER_MAC_WILD >> 2));
	BUILD_BUG_ON(EF4_FARCH_FILTER_TABLE_TX_MAC !=
		     EF4_FARCH_FILTER_TABLE_RX_MAC + 2);
	return (spec->type >> 2) + ((spec->flags & EF4_FILTER_FLAG_TX) ? 2 : 0);
}

static void ef4_farch_filter_push_rx_config(struct ef4_nic *efx)
{
	struct ef4_farch_filter_state *state = efx->filter_state;
	struct ef4_farch_filter_table *table;
	ef4_oword_t filter_ctl;

	ef4_reado(efx, &filter_ctl, FR_BZ_RX_FILTER_CTL);

	table = &state->table[EF4_FARCH_FILTER_TABLE_RX_IP];
	EF4_SET_OWORD_FIELD(filter_ctl, FRF_BZ_TCP_FULL_SRCH_LIMIT,
			    table->search_limit[EF4_FARCH_FILTER_TCP_FULL] +
			    EF4_FARCH_FILTER_CTL_SRCH_FUDGE_FULL);
	EF4_SET_OWORD_FIELD(filter_ctl, FRF_BZ_TCP_WILD_SRCH_LIMIT,
			    table->search_limit[EF4_FARCH_FILTER_TCP_WILD] +
			    EF4_FARCH_FILTER_CTL_SRCH_FUDGE_WILD);
	EF4_SET_OWORD_FIELD(filter_ctl, FRF_BZ_UDP_FULL_SRCH_LIMIT,
			    table->search_limit[EF4_FARCH_FILTER_UDP_FULL] +
			    EF4_FARCH_FILTER_CTL_SRCH_FUDGE_FULL);
	EF4_SET_OWORD_FIELD(filter_ctl, FRF_BZ_UDP_WILD_SRCH_LIMIT,

Annotation

Implementation Notes