Cache

Data Structures
struct	cpu_cache_data_line
	Cache data line representing the data read from the cache. More...
struct	cpu_cache_data_way
	Cache data way. More...

Macros
#define	CPU_CACHE   0x00000000UL
	Partition designated for using the cache.
#define	CPU_CACHE_THROUGH   0x20000000UL
	Partition designated for bypassing the cache.
#define	CPU_CACHE_PURGE   0x40000000UL
	Partition designated for purging a specific line.
#define	CPU_CACHE_ADDRESS_RW   0x60000000UL
	Partition designated for accessing the address cache array directly.
#define	CPU_CACHE_DATA_RW   0xC0000000UL
	Partition designated for accessing the cache data directly.
#define	CPU_CACHE_IO   0xF0000000UL
	Partition designated for bypassing the cache (I/O area).
#define	CPU_ADDRESS_PARTITION_MASK   0xF0000000UL
	Partition address mask.
#define	CPU_CACHE_WAY_0_ADDR   0xC0000000UL
	Address for when accessing cache data directly.
#define	CPU_CACHE_WAY_1_ADDR   0xC0000400UL
	Address for when accessing cache data directly.
#define	CPU_CACHE_WAY_2_ADDR   0xC0000800UL
	Address for when accessing cache data directly.
#define	CPU_CACHE_WAY_3_ADDR   0xC0000C00UL
	Address for when accessing cache data directly.
#define	CPU_CACHE_WAY_SIZE   (CPU_CACHE_WAY_1_ADDR - CPU_CACHE_WAY_0_ADDR)
	The size in bytes of a cache way.
#define	CPU_CACHE_2_WAY_SIZE   (CPU_CACHE_WAY_2_ADDR - CPU_CACHE_WAY_0_ADDR)
	The size in bytes of the 2KiB RAM.
#define	CPU_CACHE_LINE_SIZE   16UL
	The size of a cache line in bytes.
#define	CPU_CACHE_TAG_ADDRESS(x)   ((uint32_t)(x) >> 10)
	Given the tag bits from cpu_cache_data_line, convert to a physical address.
#define	__uncached   __section(".uncached")
	Specify variable to be uncached.
#define	__uncached_function   __section(".uncached.function")
	Specify function to be uncached.

Typedefs
typedef enum cpu_cache_mode	cpu_cache_mode_t
	Cache mode.
typedef enum cpu_cache_type	cpu_cache_type_t
	Cache type.
typedef struct cpu_cache_data_line	cpu_cache_data_line_t
	Cache data line representing the data read from the cache.
typedef struct cpu_cache_data_way	cpu_cache_data_way_t
	Cache data way.

Enumerations
enum	cpu_cache_mode
	Cache mode. More...
enum	cpu_cache_type
	Cache type. More...

Functions
static void	cpu_cache_enable (void)
	Enable cache.
static void	cpu_cache_disable (void)
	Disable cache.
static void	cpu_cache_repl_enable (cpu_cache_type_t type)
	Enable type replacement.
static void	cpu_cache_repl_disable (cpu_cache_type_t type)
	Disable type replacement in the cache.
static void	cpu_cache_way_mode_set (cpu_cache_mode_t mode)
	Change the mode the cache operates.
void	cpu_cache_line_purge (void *address) __uncached_function
	Cache line of the specified address is purged.
void	cpu_cache_area_purge (void *address, uint32_t len) __uncached_function
	Cache lines of the specified address are purged.
void	cpu_cache_purge (void) __no_reorder __uncached_function
	Purge the entire cache.
void	cpu_cache_data_way_read (uint8_t way, cpu_cache_data_way_t *data_way) __uncached_function
	Walk one of the 4 ways the CPU cache and dump cache state bits.

Detailed Description

Description goes here.

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Data Structure Documentation

cpu_cache_data_line

struct cpu_cache_data_line

Cache data line representing the data read from the cache.

See also

cpu_cache_data_way_t

cpu_cache_data_way_read

Data Fields
unsigned int	tag:19	Tag bits.
unsigned int	lru:6	LRU bits.
unsigned int	valid:1	Validity bit.

cpu_cache_data_way

struct cpu_cache_data_way

Cache data way.

See also

cpu_cache_data_way_read

Data Fields
cpu_cache_data_line_t	data[CPU_CACHE_WAY_SIZE/CPU_CACHE_LINE_SIZE]	Data.

Macro Definition Documentation

CPU_CACHE_2_WAY_SIZE

#define CPU_CACHE_2_WAY_SIZE   (CPU_CACHE_WAY_2_ADDR - CPU_CACHE_WAY_0_ADDR)

The size in bytes of the 2KiB RAM.

See also

cpu_cache_way_mode_set

CPU_CACHE_TAG_ADDRESS

#define CPU_CACHE_TAG_ADDRESS

(

x

)

((uint32_t)(x) >> 10)

Given the tag bits from cpu_cache_data_line, convert to a physical address.

Parameters

x	The 32-bit address value.

See also

cpu_cache_data_line_t

Enumeration Type Documentation

cpu_cache_mode

enum cpu_cache_mode

Cache mode.

Enumerator
CPU_CACHE_MODE_4_WAY	Four-way set associative.
CPU_CACHE_MODE_2_WAY	Two-way set associate and 2KiB RAM.

cpu_cache_type

enum cpu_cache_type

Cache type.

Enumerator
CPU_CACHE_TYPE_I	Instruction cache type.
CPU_CACHE_TYPE_D	Data cache type.

Function Documentation

cpu_cache_repl_enable()

static void cpu_cache_repl_enable ( cpu_cache_type_t  type )

inlinestatic

Enable type replacement.

When either instruction and/or data is fetched from memory, the cache data is written.

Parameters

type	The cache type(s) to enable.

cpu_cache_repl_disable()

static void cpu_cache_repl_disable ( cpu_cache_type_t  type )

inlinestatic

Disable type replacement in the cache.

When either an instruction or data is fetched from memory, cache data is not written to the cache even if there is a cache miss.

Parameters

type	The cache type(s) to disable.

cpu_cache_way_mode_set()

static void cpu_cache_way_mode_set ( cpu_cache_mode_t  mode )

inlinestatic

Change the mode the cache operates.

The cache can be set to operate as a four-way set associative cache, or as a two-way associative cache and 2KiB RAM.

In the two-way mode, ways 0 and 1 are RAM.

Parameters

mode

Mode.

cpu_cache_line_purge()

void cpu_cache_line_purge

(

void *

address

)

Cache line of the specified address is purged.

The starting address to purge does not to be cache-line aligned. Calling this function will not pollute the cache.

Parameters

address

The address associated with cache line.

cpu_cache_area_purge()

void cpu_cache_area_purge	(	void *	address,
		uint32_t	len
	)

Cache lines of the specified address are purged.

The starting address to purge does not to be cache-line aligned. The area to cache purge does not have to be in multiples of the cache line size. Calling this function will not pollute the cache.

Parameters

address	The starting address.
len	The area in bytes.

cpu_cache_purge()

void cpu_cache_purge

(

void

)

Purge the entire cache.

All cache entries and all valid bits and LRU bits of all ways are initialized to 0. Calling this function will not pollute the cache.

cpu_cache_data_way_read()

void cpu_cache_data_way_read	(	uint8_t	way,
		cpu_cache_data_way_t *	data_way
	)

Walk one of the 4 ways the CPU cache and dump cache state bits.

It's imperative that the function that calls cpu_cache_data_way_read must be uncached so that it doesn't taint the cache itself.

Parameters

	way	The cache way to read from.
[in]	data_way	The cache way buffer to write to.