/*
* arch/metag/mm/cache.c
*
* Copyright (C) 2001, 2002, 2005, 2007, 2012 Imagination Technologies.
*
* This program is free software; you can redistribute it and/or modify it under
* the terms of the GNU General Public License version 2 as published by the
* Free Software Foundation.
*
* Cache control code
*/
#include <linux/export.h>
#include <linux/io.h>
#include <asm/cacheflush.h>
#include <asm/core_reg.h>
#include <asm/global_lock.h>
#include <asm/metag_isa.h>
#include <asm/metag_mem.h>
#include <asm/metag_regs.h>
#define DEFAULT_CACHE_WAYS_LOG2 2
/*
* Size of a set in the caches. Initialised for default 16K stride, adjusted
* according to values passed through TBI global heap segment via LDLK (on ATP)
* or config registers (on HTP/MTP)
*/
static int dcache_set_shift = METAG_TBI_CACHE_SIZE_BASE_LOG2
- DEFAULT_CACHE_WAYS_LOG2;
static int icache_set_shift = METAG_TBI_CACHE_SIZE_BASE_LOG2
- DEFAULT_CACHE_WAYS_LOG2;
/*
* The number of sets in the caches. Initialised for HTP/ATP, adjusted
* according to NOMMU setting in config registers
*/
static unsigned char dcache_sets_log2 = DEFAULT_CACHE_WAYS_LOG2;
static unsigned char icache_sets_log2 = DEFAULT_CACHE_WAYS_LOG2;
#ifndef CONFIG_METAG_META12
/**
* metag_lnkget_probe() - Probe whether lnkget/lnkset go around the cache
*/
static volatile u32 lnkget_testdata[16] __initdata __aligned(64);
#define LNKGET_CONSTANT 0xdeadbeef
static void __init metag_lnkget_probe(void)
{
int temp;
long flags;
/*
* It's conceivable the user has configured a globally coherent cache
* shared with non-Linux hardware threads, so use LOCK2 to prevent them
* from executing and causing cache eviction during the test.
*/
__global_lock2(flags);
/* read a value to bring it into the cache */
(void)lnkget_testdata[0];
lnkget_testdata[0] = 0;
/* lnkget/lnkset it to modify it */
asm volatile(
"1: LNKGETD %0, [%1]\n"
" LNKSETD [%1], %2\n"
" DEFR %0, TXSTAT\n"
" ANDT %0, %0, #HI(0x3f000000)\n"
" CMPT %0, #HI(0x02000000)\n"
" BNZ 1b\n"
: "=&d" (temp)
: "da" (&lnkget_testdata[0]), "bd" (LNKGET_CONSTANT)
: "cc");
/* re-read it to see if the cached value changed */
temp = lnkget_testdata[0];
__global_unlock2(flags);
/* flush the cache line to fix any incoherency */
__builtin_dcache_flush((void *)&lnkget_testdata[0]);
#if defined(CONFIG_METAG_LNKGET_AROUND_CACHE)
/* if the cache is right, LNKGET_AROUND_CACHE is unnecessary */
if (temp == LNKGET_CONSTANT)
pr_info("LNKGET/SET go through cache but CONFIG_METAG_LNKGET_AROUND_CACHE=y\n");
#elif defined(CONFIG_METAG_ATOMICITY_LNKGET)
/*
* if the cache is wrong, LNKGET_AROUND_CACHE is really necessary
* because the kernel is configured to use LNKGET/SET for atomicity
*/
WARN(temp != LNKGET_CONSTANT,
"LNKGET/SET go around cache but CONFIG_METAG_LNKGET_AROUND_CACHE=n\n"
"Expect kernel failure as it's used for atomicity primitives\n");
#elif defined(CONFIG_SMP)
/*
* if the cache is wrong, LNKGET_AROUND_CACHE should be used or the
* gateway page won't flush and userland could break.
*/
WARN(temp != LNKGET_CONSTANT,
"LNKGET/SET go around cache but CONFIG_METAG_LNKGET_AROUND_CACHE=n\n"
"Expect userland failure as it's used for user gateway page\n");
#else
/*
* if the cache is wrong, LNKGET_AROUND_CACHE is set wrong, but it
* doesn't actually matter as it doesn't have any effect on !SMP &&
* !ATOMICITY_LNKGET.
*/
if (temp != LNKGET_CONSTANT)
pr_warn("LNKGET/SET go around cache but CONFIG_METAG_LNKGET_AROUND_CACHE=n\n");
#endif
}
#endif /* !CONFIG_METAG_META12 */
/**
* metag_cache_probe() - Probe L1 cache configuration.
*
* Probe the L1 cache configuration to aid the L1 physical cache flushing
* functions.
*/
void __init metag_cache_probe(void)
{
#ifndef CONFIG_METAG_META12
int coreid = metag_in32(METAC_CORE_ID);
int config = metag_in32(METAC_CORE_CONFIG2);
int cfgcache = coreid & METAC_COREID_CFGCACHE_BITS;
if (cfgcache == METAC_COREID_CFGCACHE_TYPE0 ||
cfgcache == METAC_COREID_CFGCACHE_PRIVNOMMU) {
icache_sets_log2 = 1;
dcache_sets_log2 = 1;
}
/* For normal size caches, the smallest size is 4Kb.
For small caches, the smallest size is 64b */
icache_set_shift = (config & METAC_CORECFG2_ICSMALL_BIT)
? 6 : 12;
icache_set_shift += (config & METAC_CORE_C2ICSZ_BITS)
>> METAC_CORE_C2ICSZ_S;
icache_set_shift -= icache_sets_log2;
dcache_set_shift = (config & METAC_CORECFG2_DCSMALL_BIT)
? 6 : 12;
dcache_set_shift += (config & METAC_CORECFG2_DCSZ_BITS)
>> METAC_CORECFG2_DCSZ_S;
dcache_set_shift -= dcache_sets_log2;
metag_lnkget_probe();
#else
/* Extract cache sizes from global heap segment */
unsigned long val, u;
int width, shift, addend;
PTBISEG seg;
seg = __TBIFindSeg(NULL, TBID_SEG(TBID_THREAD_GLOBAL,
TBID_SEGSCOPE_GLOBAL,
TBID_SEGTYPE_HEAP));
if (seg != NULL) {
val = seg->Data[1];
/* Work out width of I-cache size bit-field */
u = ((unsigned long) METAG_TBI_ICACHE_SIZE_BITS)
>> METAG_TBI_ICACHE_SIZE_S;
width = 0;
while (u & 1) {
width++;
u >>= 1;
}
/* Extract sign-extended size addend value */
shift = 32 - (METAG_TBI_ICACHE_SIZE_S + width);
addend = (long) ((val & METAG_TBI_ICACHE_SIZE_BITS)
<< shift)
>> (shift + METAG_TBI_ICACHE_SIZE_S);
/* Now calculate I-cache set size */
icache_set_shift = (METAG_TBI_CACHE_SIZE_BASE_LOG2
- DEFAULT_CACHE_WAYS_LOG2)
+ addend;
/* Similarly for D-cache */
u = ((unsigned long) METAG_TBI_DCACHE_SIZE_BITS)
>> METAG_TBI_DCACHE_SIZE_S;
width = 0;
while (u & 1) {
width++;
u >>= 1;
}
shift = 32 - (METAG_TBI_DCACHE_SIZE_S + width);
addend = (long) ((val & METAG_TBI_DCACHE_SIZE_BITS)
<< shift)
>> (shift + METAG_TBI_DCACHE_SIZE_S);
dcache_set_shift = (METAG_TBI_CACHE_SIZE_BASE_LOG2
- DEFAULT_CACHE_WAYS_LOG2)
+ addend;
}
#endif
}
static void metag_phys_data_cache_flush(const void *start)
{
unsigned long flush0, flush1, flush2, flush3;
int loops, step;
int thread;
int part, offset;
int set_shift;
/* Use a sequence of writes to flush the cache region requested */
thread = (__core_reg_get(TXENABLE) & TXENABLE_THREAD_BITS)
>> TXENABLE_THREAD_S;
/* Cache is broken into sets which lie in contiguous RAMs */
set_shift = dcache_set_shift;
/* Move to the base of the physical cache flush region */
flush0 = LINSYSCFLUSH_DCACHE_LINE;
step = 64;
/* Get partition data for this thread */
part = metag_in32(SYSC_DCPART0 +
(SYSC_xCPARTn_STRIDE * thread));
if ((int)start < 0)
/* Access Global vs Local partition */
part >>= SYSC_xCPARTG_AND_S
- SYSC_xCPARTL_AND_S;
/* Extract offset and move SetOff */
offset = (part & SYSC_xCPARTL_OR_BITS)
>> SYSC_xCPARTL_OR_S;
flush0 += (offset << (set_shift - 4));
/* Shrink size */
part = (part & SYSC_xCPARTL_AND_BITS)
>> SYSC_xCPARTL_AND_S;
loops = ((part + 1) << (set_shift - 4));
/* Reduce loops by step of cache line size */
loops /= step;
flush1 = flush0 + (1 << set_shift);
flush2 = flush0 + (2 << set_shift);
flush3 = flush0 + (3 << set_shift);
if (dcache_sets_log2 == 1) {
flush2 = flush1;
flush3 = flush1 + step;
flush1 = flush0 + step;
step <<= 1;
loops >>= 1;
}
/* Clear loops ways in cache */
while (loops-- != 0) {
/* Clear the ways. */
#if 0
/*
* GCC doesn't generate very good code for this so we
* provide inline assembly instead.
*/
metag_out8(0, flush0);
metag_out8(0, flush1);
metag_out8(0, flush2);
metag_out8(0, flush3);
flush0 += step;
flush1 += step;
flush2 += step;
flush3 += step;
#else
asm volatile (
"SETB\t[%0+%4++],%5\n"
"SETB\t[%1+%4++],%5\n"
"SETB\t[%2+%4++],%5\n"
"SETB\t[%3+%4++],%5\n"
: "+e" (flush0),
"+e" (flush1),
"+e" (flush2),
"+e" (flush3)
: "e" (step), "a" (0));
#endif
}
}
void metag_data_cache_flush_all(const void *start)
{
if ((metag_in32(SYSC_CACHE_MMU_CONFIG) & SYSC_CMMUCFG_DC_ON_BIT) == 0)
/* No need to flush the data cache it's not actually enabled */
return;
metag_phys_data_cache_flush(start);
}
void metag_data_cache_flush(const void *start, int bytes)
{
unsigned long flush0;
int loops, step;
if ((metag_in32(SYSC_CACHE_MMU_CONFIG) & SYSC_CMMUCFG_DC_ON_BIT) == 0)
/* No need to flush the data cache it's not actually enabled */
return;
if (bytes >= 4096) {
metag_phys_data_cache_flush(start);
return;
}
/* Use linear cache flush mechanism on META IP */
flush0 = (int)start;
loops = ((int)start & (DCACHE_LINE_BYTES - 1)) + bytes +
(DCACHE_LINE_BYTES - 1);
loops >>= DCACHE_LINE_S;
#define PRIM_FLUSH(addr, offset) do { \
int __addr = ((int) (addr)) + ((offset) * 64); \
__builtin_dcache_flush((void *)(__addr)); \
} while (0)
#define LOOP_INC (4*64)
do {
/* By default stop */
step = 0;
switch (loops) {
/* Drop Thru Cases! */
default:
PRIM_FLUSH(flush0, 3);
loops -= 4;
step = 1;
case 3:
PRIM_FLUSH(flush0, 2);
case 2:
PRIM_FLUSH(flush0, 1);
case 1:
PRIM_FLUSH(flush0, 0);
flush0 += LOOP_INC;
case 0:
break;
}
} while (step);
}
EXPORT_SYMBOL(metag_data_cache_flush);
static void metag_phys_code_cache_flush(const void *start, int bytes)
{
unsigned long flush0, flush1, flush2, flush3, end_set;
int loops, step;
int thread;
int set_shift, set_size;
int part, offset;
/* Use a sequence of writes to flush the cache region requested */
thread = (__core_reg_get(TXENABLE) & TXENABLE_THREAD_BITS)
>> TXENABLE_THREAD_S;
set_shift = icache_set_shift;
/* Move to the base of the physical cache flush region */
flush0 = LINSYSCFLUSH_ICACHE_LINE;
step = 64;
/* Get partition code for this thread */
part = metag_in32(SYSC_ICPART0 +
(SYSC_xCPARTn_STRIDE * thread));
if ((int)start < 0)
/* Access Global vs Local partition */
part >>= SYSC_xCPARTG_AND_S-SYSC_xCPARTL_AND_S;
/* Extract offset and move SetOff */
offset = (part & SYSC_xCPARTL_OR_BITS)
>> SYSC_xCPARTL_OR_S;
flush0 += (offset << (set_shift - 4));
/* Shrink size */
part = (part & SYSC_xCPARTL_AND_BITS)
>> SYSC_xCPARTL_AND_S;
loops = ((part + 1) << (set_shift - 4));
/* Where does the Set end? */
end_set = flush0 + loops;
set_size = loops;
#ifdef CONFIG_METAG_META12
if ((bytes < 4096) && (bytes < loops)) {
/* Unreachable on HTP/MTP */
/* Only target the sets that could be relavent */
flush0 += (loops - step) & ((int) start);
loops = (((int) start) & (step-1)) + bytes + step - 1;
}
#endif
/* Reduce loops by step of cache line size */
loops /= step;
flush1 = flush0 + (1<<set_shift);
flush2 = flush0 + (2<<set_shift);
flush3 = flush0 + (3<<set_shift);
if (icache_sets_log2 == 1) {
flush2 = flush1;
flush3 = flush1 + step;
flush1 = flush0 + step;
#if 0
/* flush0 will stop one line early in this case
* (flush1 will do the final line).
* However we don't correct end_set here at the moment
* because it will never wrap on HTP/MTP
*/
end_set -= step;
#endif
step <<= 1;
loops >>= 1;
}
/* Clear loops ways in cache */
while (loops-- != 0) {
#if 0
/*
* GCC doesn't generate very good code for this so we
* provide inline assembly instead.
*/
/* Clear the ways */
metag_out8(0, flush0);
metag_out8(0, flush1);
metag_out8(0, flush2);
metag_out8(0, flush3);
flush0 += step;
flush1 += step;
flush2 += step;
flush3 += step;
#else
asm volatile (
"SETB\t[%0+%4++],%5\n"
"SETB\t[%1+%4++],%5\n"
"SETB\t[%2+%4++],%5\n"
"SETB\t[%3+%4++],%5\n"
: "+e" (flush0),
"+e" (flush1),
"+e" (flush2),
"+e" (flush3)
: "e" (step), "a" (0));
#endif
if (flush0 == end_set) {
/* Wrap within Set 0 */
flush0 -= set_size;
flush1 -= set_size;
flush2 -= set_size;
flush3 -= set_size;
}
}
}
void metag_code_cache_flush_all(const void *start)
{
if ((metag_in32(SYSC_CACHE_MMU_CONFIG) & SYSC_CMMUCFG_IC_ON_BIT) == 0)
/* No need to flush the code cache it's not actually enabled */
return;
metag_phys_code_cache_flush(start, 4096);
}
EXPORT_SYMBOL(metag_code_cache_flush_all);
void metag_code_cache_flush(const void *start, int bytes)
{
#ifndef CONFIG_METAG_META12
void *flush;
int loops, step;
#endif /* !CONFIG_METAG_META12 */
if ((metag_in32(SYSC_CACHE_MMU_CONFIG) & SYSC_CMMUCFG_IC_ON_BIT) == 0)
/* No need to flush the code cache it's not actually enabled */
return;
#ifdef CONFIG_METAG_META12
/* CACHEWD isn't available on Meta1, so always do full cache flush */
metag_phys_code_cache_flush(start, bytes);
#else /* CONFIG_METAG_META12 */
/* If large size do full physical cache flush */
if (bytes >= 4096) {
metag_phys_code_cache_flush(start, bytes);
return;
}
/* Use linear cache flush mechanism on META IP */
flush = (void *)((int)start & ~(ICACHE_LINE_BYTES-1));
loops = ((int)start & (ICACHE_LINE_BYTES-1)) + bytes +
(ICACHE_LINE_BYTES-1);
loops >>= ICACHE_LINE_S;
#define PRIM_IFLUSH(addr, offset) \
__builtin_meta2_cachewd(((addr) + ((offset) * 64)), CACHEW_ICACHE_BIT)
#define LOOP_INC (4*64)
do {
/* By default stop */
step = 0;
switch (loops) {
/* Drop Thru Cases! */
default:
PRIM_IFLUSH(flush, 3);
loops -= 4;
step = 1;
case 3:
PRIM_IFLUSH(flush, 2);
case 2:
PRIM_IFLUSH(flush, 1);
case 1:
PRIM_IFLUSH(flush, 0);
flush += LOOP_INC;
case 0:
break;
}
} while (step);
#endif /* !CONFIG_METAG_META12 */
}
EXPORT_SYMBOL(metag_code_cache_flush);