Micro-optimize the new arm inline bus_space implementation by grouping all

the data the inline functions access together at the start of the bus_space
struct.  The start-of part isn't so important, it's the grouping-together
that's the point: now all the most-accessed data should be in one cache line.

Suggested by:	  cognet
This commit is contained in:
ian 2015-01-21 20:12:35 +00:00
parent 1aa07d7ef4
commit 33d6283946
2 changed files with 23 additions and 16 deletions

View File

@ -150,7 +150,7 @@ static struct bus_space arm_base_bus_space = {
.bs_wr_2_s = generic_bs_wr_2,
.bs_wr_4_s = generic_bs_wr_4,
.bs_wr_8_s = BS_UNIMPLEMENTED,
};
} __aligned(CACHE_LINE_SIZE);
#ifdef FDT
bus_space_tag_t fdtbus_bs_tag = &arm_base_bus_space;

View File

@ -79,9 +79,27 @@
#define BUS_SPACE_MAP_LINEAR 0x02
#define BUS_SPACE_MAP_PREFETCHABLE 0x04
/*
* Bus space for ARM.
*
* The functions used most often are grouped together at the beginning to ensure
* that all the data fits into a single cache line. The inline implementations
* of single read/write access these values a lot.
*/
struct bus_space {
/* cookie */
void *bs_privdata;
/* Read/write single and barrier: the most commonly used functions. */
uint8_t (*bs_r_1)(bus_space_tag_t, bus_space_handle_t, bus_size_t);
uint32_t (*bs_r_4)(bus_space_tag_t, bus_space_handle_t, bus_size_t);
void (*bs_w_1)(bus_space_tag_t, bus_space_handle_t,
bus_size_t, uint8_t);
void (*bs_w_4)(bus_space_tag_t, bus_space_handle_t,
bus_size_t, uint32_t);
void (*bs_barrier)(bus_space_tag_t, bus_space_handle_t,
bus_size_t, bus_size_t, int);
/* Backlink to parent (if copied), and implementation private data. */
struct bus_space *bs_parent;
void *bs_privdata;
/* mapping/unmapping */
int (*bs_map) (bus_space_tag_t, bus_addr_t, bus_size_t,
@ -97,15 +115,8 @@ struct bus_space {
void (*bs_free) (bus_space_tag_t, bus_space_handle_t,
bus_size_t);
/* get kernel virtual address */
/* barrier */
void (*bs_barrier) (bus_space_tag_t, bus_space_handle_t,
bus_size_t, bus_size_t, int);
/* read (single) */
uint8_t (*bs_r_1) (bus_space_tag_t, bus_space_handle_t, bus_size_t);
/* Read single, the less commonly used functions. */
uint16_t (*bs_r_2) (bus_space_tag_t, bus_space_handle_t, bus_size_t);
uint32_t (*bs_r_4) (bus_space_tag_t, bus_space_handle_t, bus_size_t);
uint64_t (*bs_r_8) (bus_space_tag_t, bus_space_handle_t, bus_size_t);
/* read multiple */
@ -128,13 +139,9 @@ struct bus_space {
void (*bs_rr_8) (bus_space_tag_t, bus_space_handle_t,
bus_size_t, uint64_t *, bus_size_t);
/* write (single) */
void (*bs_w_1) (bus_space_tag_t, bus_space_handle_t,
bus_size_t, uint8_t);
/* Write single, the less commonly used functions. */
void (*bs_w_2) (bus_space_tag_t, bus_space_handle_t,
bus_size_t, uint16_t);
void (*bs_w_4) (bus_space_tag_t, bus_space_handle_t,
bus_size_t, uint32_t);
void (*bs_w_8) (bus_space_tag_t, bus_space_handle_t,
bus_size_t, uint64_t);