/*
* arch/sh/mm/cache-sh4.c
*
* Copyright (C) 1999, 2000, 2002 Niibe Yutaka
* Copyright (C) 2001 - 2007 Paul Mundt
* Copyright (C) 2003 Richard Curnow
* Copyright (c) 2007 STMicroelectronics (R&D) Ltd.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/io.h>
#include <linux/mutex.h>
#include <linux/fs.h>
#include <asm/mmu_context.h>
#include <asm/cacheflush.h>
/*
* The maximum number of pages we support up to when doing ranged dcache
* flushing. Anything exceeding this will simply flush the dcache in its
* entirety.
*/
#define MAX_DCACHE_PAGES 64 /* XXX: Tune for ways */
#define MAX_ICACHE_PAGES 32
static void __flush_cache_4096(unsigned long addr, unsigned long phys,
unsigned long exec_offset);
/*
* This is initialised here to ensure that it is not placed in the BSS. If
* that were to happen, note that cache_init gets called before the BSS is
* cleared, so this would get nulled out which would be hopeless.
*/
static void (*__flush_dcache_segment_fn)(unsigned long, unsigned long) =
(void (*)(unsigned long, unsigned long))0xdeadbeef;
/*
* Write back the range of D-cache, and purge the I-cache.
*
* Called from kernel/module.c:sys_init_module and routine for a.out format,
* signal handler code and kprobes code
*/
static void sh4_flush_icache_range(void *args)
{
struct flusher_data *data = args;
unsigned long start, end;
unsigned long flags, v;
int i;
start = data->addr1;
end = data->addr2;
/* If there are too many pages then just blow away the caches */
if (((end - start) >> PAGE_SHIFT) >= MAX_ICACHE_PAGES) {
local_flush_cache_all(NULL);
return;
}
/*
* Selectively flush d-cache then invalidate the i-cache.
* This is inefficient, so only use this for small ranges.
*/
start &= ~(L1_CACHE_BYTES-1);
end += L1_CACHE_BYTES-1;
end &= ~(L1_CACHE_BYTES-1);
local_irq_save(flags);
jump_to_uncached();
for (v = start; v < end; v += L1_CACHE_BYTES) {
unsigned long icacheaddr;
__ocbwb(v);
icacheaddr = CACHE_IC_ADDRESS_ARRAY | (v &
cpu_data->icache.entry_mask);
/* Clear i-cache line valid-bit */
for (i = 0; i < cpu_data->icache.ways; i++) {
__raw_writel(0, icacheaddr);
icacheaddr += cpu_data->icache.way_incr;
}
}
back_to_cached();
local_irq_restore(flags);
}
static inline void flush_cache_4096(unsigned long start,
unsigned long phys)
{
unsigned long flags, exec_offset = 0;
/*
* All types of SH-4 require PC to be in P2 to operate on the I-cache.
* Some types of SH-4 require PC to be in P2 to operate on the D-cache.
*/
if ((boot_cpu_data.flags & CPU_HAS_P2_FLUSH_BUG) ||
(start < CACHE_OC_ADDRESS_ARRAY))
exec_offset = 0x20000000;
local_irq_save(flags);
__flush_cache_4096(start | SH_CACHE_ASSOC,
P1SEGADDR(phys), exec_offset);
local_irq_restore(flags);
}
/*
* Write back & invalidate the D-cache of the page.
* (To avoid "alias" issues)
*/
static void sh4_flush_dcache_page(void *arg)
{
struct page *page = arg;
#ifndef CONFIG_SMP
struct address_space *mapping = page_mapping(page);
if (mapping && !mapping_mapped(mapping))
set_bit(PG_dcache_dirty, &page->flags);
else
#endif
{
unsigned long phys = PHYSADDR(page_address(page));
unsigned long addr = CACHE_OC_ADDRESS_ARRAY;
int i, n;
/* Loop all the D-cache */
n = boot_cpu_data.dcache.n_aliases;
for (i = 0; i < n; i++, addr += 4096)
flush_cache_4096(addr, phys);
}
wmb();
}
/* TODO: Selective icache invalidation through IC address array.. */
static void __uses_jump_to_uncached flush_icache_all(void)
{
unsigned long flags, ccr;
local_irq_save(flags);
jump_to_uncached();
/* Flush I-cache */
ccr = ctrl_inl(CCR);
ccr |= CCR_CACHE_ICI;
ctrl_outl(ccr, CCR);
/*
* back_to_cached() will take care of the barrier for us, don't add
* another one!
*/
back_to_cached();
local_irq_restore(flags);
}
static inline void flush_dcache_all(void)
{
(*__flush_dcache_segment_fn)(0UL, boot_cpu_data.dcache.way_size);
wmb();
}
static void sh4_flush_cache_all(void *unused)
{
flush_dcache_all();
flush_icache_all();
}
static void __flush_cache_mm(struct mm_struct *mm, unsigned long start,
unsigned long end)
{
unsigned long d = 0, p = start & PAGE_MASK;
unsigned long alias_mask = boot_cpu_data.dcache.alias_mask;
unsigned long n_aliases = boot_cpu_data.dcache.n_aliases;
unsigned long select_bit;
unsigned long all_aliases_mask;
unsigned long addr_offset;
pgd_t *dir;
pmd_t *pmd;
pud_t *pud;
pte_t *pte;
int i;
dir = pgd_offset(mm, p);
pud = pud_offset(dir, p);
pmd = pmd_offset(pud, p);
end = PAGE_ALIGN(end);
all_aliases_mask = (1 << n_aliases) - 1;
do {
if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd))) {
p &= PMD_MASK;
p += PMD_SIZE;
pmd++;
continue;
}
pte = pte_offset_kernel(pmd, p);
do {
unsigned long phys;
pte_t entry = *pte;
if (!(pte_val(entry) & _PAGE_PRESENT)) {
pte++;
p += PAGE_SIZE;
continue;
}
phys = pte_val(entry) & PTE_PHYS_MASK;
if ((p ^ phys) & alias_mask) {
d |= 1 << ((p & alias_mask) >> PAGE_SHIFT);
d |= 1 << ((phys & alias_mask) >> PAGE_SHIFT);
if (d == all_aliases_mask)
goto loop_exit;
}
pte++;
p += PAGE_SIZE;
} while (p < end && ((unsigned long)pte & ~PAGE_MASK));
pmd++;
} while (p < end);
loop_exit:
addr_offset = 0;
select_bit = 1;
for (i = 0; i < n_aliases; i++) {
if (d & select_bit) {
(*__flush_dcache_segment_fn)(addr_offset, PAGE_SIZE);
wmb();
}
select_bit <<= 1;
addr_offset += PAGE_SIZE;
}
}
/*
* Note : (RPC) since the caches are physically tagged, the only point
* of flush_cache_mm for SH-4 is to get rid of aliases from the
* D-cache. The assumption elsewhere, e.g. flush_cache_range, is that
* lines can stay resident so long as the virtual address they were
* accessed with (hence cache set) is in accord with the physical
* address (i.e. tag). It's no different here. So I reckon we don't
* need to flush the I-cache, since aliases don't matter for that. We
* should try that.
*
* Caller takes mm->mmap_sem.
*/
static void sh4_flush_cache_mm(void *arg)
{
struct mm_struct *mm = arg;
if (cpu_context(smp_processor_id(), mm) == NO_CONTEXT)
return;
/*
* If cache is only 4k-per-way, there are never any 'aliases'. Since
* the cache is physically tagged, the data can just be left in there.
*/
if (boot_cpu_data.dcache.n_aliases == 0)
return;
/*
* Don't bother groveling around the dcache for the VMA ranges
* if there are too many PTEs to make it worthwhile.
*/
if (mm->nr_ptes >= MAX_DCACHE_PAGES)
flush_dcache_all();
else {
struct vm_area_struct *vma;
/*
* In this case there are reasonably sized ranges to flush,
* iterate through the VMA list and take care of any aliases.
*/
for (vma = mm->mmap; vma; vma = vma->vm_next)
__flush_cache_mm(mm, vma->vm_start, vma->vm_end);
}
/* Only touch the icache if one of the VMAs has VM_EXEC set. */
if (mm->exec_vm)
flush_icache_all();
}
/*
* Write back and invalidate I/D-caches for the page.
*
* ADDR: Virtual Address (U0 address)
* PFN: Physical page number
*/
static void sh4_flush_cache_page(void *args)
{
struct flusher_data *data = args;
struct vm_area_struct *vma;
unsigned long address, pfn, phys;
unsigned int alias_mask;
vma = data->vma;
address = data->addr1;
pfn = data->addr2;
phys = pfn << PAGE_SHIFT;
if (cpu_context(smp_processor_id(), vma->vm_mm) == NO_CONTEXT)
return;
alias_mask = boot_cpu_data.dcache.alias_mask;
/* We only need to flush D-cache when we have alias */
if ((address^phys) & alias_mask) {
/* Loop 4K of the D-cache */
flush_cache_4096(
CACHE_OC_ADDRESS_ARRAY | (address & alias_mask),
phys);
/* Loop another 4K of the D-cache */
flush_cache_4096(
CACHE_OC_ADDRESS_ARRAY | (phys & alias_mask),
phys);
}
alias_mask = boot_cpu_data.icache.alias_mask;
if (vma->vm_flags & VM_EXEC) {
/*
* Evict entries from the portion of the cache from which code
* may have been executed at this address (virtual). There's
* no need to evict from the portion corresponding to the
* physical address as for the D-cache, because we know the
* kernel has never executed the code through its identity
* translation.
*/
flush_cache_4096(
CACHE_IC_ADDRESS_ARRAY | (address & alias_mask),
phys);
}
}
/*
* Write back and invalidate D-caches.
*
* START, END: Virtual Address (U0 address)
*
* NOTE: We need to flush the _physical_ page entry.
* Flushing the cache lines for U0 only isn't enough.
* We need to flush for P1 too, which may contain aliases.
*/
static void sh4_flush_cache_range(void *args)
{
struct flusher_data *data = args;
struct vm_area_struct *vma;
unsigned long start, end;
vma = data->vma;
start = data->addr1;
end = data->addr2;
if (cpu_context(smp_processor_id(), vma->vm_mm) == NO_CONTEXT)
return;
/*
* If cache is only 4k-per-way, there are never any 'aliases'. Since
* the cache is physically tagged, the data can just be left in there.
*/
if (boot_cpu_data.dcache.n_aliases == 0)
return;
/*
* Don't bother with the lookup and alias check if we have a
* wide range to cover, just blow away the dcache in its
* entirety instead. -- PFM.
*/
if (((end - start) >> PAGE_SHIFT) >= MAX_DCACHE_PAGES)
flush_dcache_all();
else
__flush_cache_mm(vma->vm_mm, start, end);
if (vma->vm_flags & VM_EXEC) {
/*
* TODO: Is this required??? Need to look at how I-cache
* coherency is assured when new programs are loaded to see if
* this matters.
*/
flush_icache_all();
}
}
/**
* __flush_cache_4096
*
* @addr: address in memory mapped cache array
* @phys: P1 address to flush (has to match tags if addr has 'A' bit
* set i.e. associative write)
* @exec_offset: set to 0x20000000 if flush has to be executed from P2
* region else 0x0
*
* The offset into the cache array implied by 'addr' selects the
* 'colour' of the virtual address range that will be flushed. The
* operation (purge/write-back) is selected by the lower 2 bits of
* 'phys'.
*/
static void __flush_cache_4096(unsigned long addr, unsigned long phys,
unsigned long exec_offset)
{
int way_count;
unsigned long base_addr = addr;
struct cache_info *dcache;
unsigned long way_incr;
unsigned long a, ea, p;
unsigned long temp_pc;
dcache = &boot_cpu_data.dcache;
/* Write this way for better assembly. */
way_count = dcache->ways;
way_incr = dcache->way_incr;
/*
* Apply exec_offset (i.e. branch to P2 if required.).
*
* FIXME:
*
* If I write "=r" for the (temp_pc), it puts this in r6 hence
* trashing exec_offset before it's been added on - why? Hence
* "=&r" as a 'workaround'
*/
asm volatile("mov.l 1f, %0\n\t"
"add %1, %0\n\t"
"jmp @%0\n\t"
"nop\n\t"
".balign 4\n\t"
"1: .long 2f\n\t"
"2:\n" : "=&r" (temp_pc) : "r" (exec_offset));
/*
* We know there will be >=1 iteration, so write as do-while to avoid
* pointless nead-of-loop check for 0 iterations.
*/
do {
ea = base_addr + PAGE_SIZE;
a = base_addr;
p = phys;
do {
*(volatile unsigned long *)a = p;
/*
* Next line: intentionally not p+32, saves an add, p
* will do since only the cache tag bits need to
* match.
*/
*(volatile unsigned long *)(a+32) = p;
a += 64;
p += 64;
} while (a < ea);
base_addr += way_incr;
} while (--way_count != 0);
}
/*
* Break the 1, 2 and 4 way variants of this out into separate functions to
* avoid nearly all the overhead of having the conditional stuff in the function
* bodies (+ the 1 and 2 way cases avoid saving any registers too).
*
* We want to eliminate unnecessary bus transactions, so this code uses
* a non-obvious technique.
*
* Loop over a cache way sized block of, one cache line at a time. For each
* line, use movca.a to cause the current cache line contents to be written
* back, but without reading anything from main memory. However this has the
* side effect that the cache is now caching that memory location. So follow
* this with a cache invalidate to mark the cache line invalid. And do all
* this with interrupts disabled, to avoid the cache line being accidently
* evicted while it is holding garbage.
*
* This also breaks in a number of circumstances:
* - if there are modifications to the region of memory just above
* empty_zero_page (for example because a breakpoint has been placed
* there), then these can be lost.
*
* This is because the the memory address which the cache temporarily
* caches in the above description is empty_zero_page. So the
* movca.l hits the cache (it is assumed that it misses, or at least
* isn't dirty), modifies the line and then invalidates it, losing the
* required change.
*
* - If caches are disabled or configured in write-through mode, then
* the movca.l writes garbage directly into memory.
*/
static void __flush_dcache_segment_writethrough(unsigned long start,
unsigned long extent_per_way)
{
unsigned long addr;
int i;
addr = CACHE_OC_ADDRESS_ARRAY | (start & cpu_data->dcache.entry_mask);
while (extent_per_way) {
for (i = 0; i < cpu_data->dcache.ways; i++)
__raw_writel(0, addr + cpu_data->dcache.way_incr * i);
addr += cpu_data->dcache.linesz;
extent_per_way -= cpu_data->dcache.linesz;
}
}
static void __flush_dcache_segment_1way(unsigned long start,
unsigned long extent_per_way)
{
unsigned long orig_sr, sr_with_bl;
unsigned long base_addr;
unsigned long way_incr, linesz, way_size;
struct cache_info *dcache;
register unsigned long a0, a0e;
asm volatile("stc sr, %0" : "=r" (orig_sr));
sr_with_bl = orig_sr | (1<<28);
base_addr = ((unsigned long)&empty_zero_page[0]);
/*
* The previous code aligned base_addr to 16k, i.e. the way_size of all
* existing SH-4 D-caches. Whilst I don't see a need to have this
* aligned to any better than the cache line size (which it will be
* anyway by construction), let's align it to at least the way_size of
* any existing or conceivable SH-4 D-cache. -- RPC
*/
base_addr = ((base_addr >> 16) << 16);
base_addr |= start;
dcache = &boot_cpu_data.dcache;
linesz = dcache->linesz;
way_incr = dcache->way_incr;
way_size = dcache->way_size;
a0 = base_addr;
a0e = base_addr + extent_per_way;
do {
asm volatile("ldc %0, sr" : : "r" (sr_with_bl));
asm volatile("movca.l r0, @%0\n\t"
"ocbi @%0" : : "r" (a0));
a0 += linesz;
asm volatile("movca.l r0, @%0\n\t"
"ocbi @%0" : : "r" (a0));
a0 += linesz;
asm volatile("movca.l r0, @%0\n\t"
"ocbi @%0" : : "r" (a0));
a0 += linesz;
asm volatile("movca.l r0, @%0\n\t"
"ocbi @%0" : : "r" (a0));
asm volatile("ldc %0, sr" : : "r" (orig_sr));
a0 += linesz;
} while (a0 < a0e);
}
static void __flush_dcache_segment_2way(unsigned long start,
unsigned long extent_per_way)
{
unsigned long orig_sr, sr_with_bl;
unsigned long base_addr;
unsigned long way_incr, linesz, way_size;
struct cache_info *dcache;
register unsigned long a0, a1, a0e;
asm volatile("stc sr, %0" : "=r" (orig_sr));
sr_with_bl = orig_sr | (1<<28);
base_addr = ((unsigned long)&empty_zero_page[0]);
/* See comment under 1-way above */
base_addr = ((base_addr >> 16) << 16);
base_addr |= start;
dcache = &boot_cpu_data.dcache;
linesz = dcache->linesz;
way_incr = dcache->way_incr;
way_size = dcache->way_size;
a0 = base_addr;
a1 = a0 + way_incr;
a0e = base_addr + extent_per_way;
do {
asm volatile("ldc %0, sr" : : "r" (sr_with_bl));
asm volatile("movca.l r0, @%0\n\t"
"movca.l r0, @%1\n\t"
"ocbi @%0\n\t"
"ocbi @%1" : :
"r" (a0), "r" (a1));
a0 += linesz;
a1 += linesz;
asm volatile("movca.l r0, @%0\n\t"
"movca.l r0, @%1\n\t"
"ocbi @%0\n\t"
"ocbi @%1" : :
"r" (a0), "r" (a1));
a0 += linesz;
a1 += linesz;
asm volatile("movca.l r0, @%0\n\t"
"movca.l r0, @%1\n\t"
"ocbi @%0\n\t"
"ocbi @%1" : :
"r" (a0), "r" (a1));
a0 += linesz;
a1 += linesz;
asm volatile("movca.l r0, @%0\n\t"
"movca.l r0, @%1\n\t"
"ocbi @%0\n\t"
"ocbi @%1" : :
"r" (a0), "r" (a1));
asm volatile("ldc %0, sr" : : "r" (orig_sr));
a0 += linesz;
a1 += linesz;
} while (a0 < a0e);
}
static void __flush_dcache_segment_4way(unsigned long start,
unsigned long extent_per_way)
{
unsigned long orig_sr, sr_with_bl;
unsigned long base_addr;
unsigned long way_incr, linesz, way_size;
struct cache_info *dcache;
register unsigned long a0, a1, a2, a3, a0e;
asm volatile("stc sr, %0" : "=r" (orig_sr));
sr_with_bl = orig_sr | (1<<28);
base_addr = ((unsigned long)&empty_zero_page[0]);
/* See comment under 1-way above */
base_addr = ((base_addr >> 16) << 16);
base_addr |= start;
dcache = &boot_cpu_data.dcache;
linesz = dcache->linesz;
way_incr = dcache->way_incr;
way_size = dcache->way_size;
a0 = base_addr;
a1 = a0 + way_incr;
a2 = a1 + way_incr;
a3 = a2 + way_incr;
a0e = base_addr + extent_per_way;
do {
asm volatile("ldc %0, sr" : : "r" (sr_with_bl));
asm volatile("movca.l r0, @%0\n\t"
"movca.l r0, @%1\n\t"
"movca.l r0, @%2\n\t"
"movca.l r0, @%3\n\t"
"ocbi @%0\n\t"
"ocbi @%1\n\t"
"ocbi @%2\n\t"
"ocbi @%3\n\t" : :
"r" (a0), "r" (a1), "r" (a2), "r" (a3));
a0 += linesz;
a1 += linesz;
a2 += linesz;
a3 += linesz;
asm volatile("movca.l r0, @%0\n\t"
"movca.l r0, @%1\n\t"
"movca.l r0, @%2\n\t"
"movca.l r0, @%3\n\t"
"ocbi @%0\n\t"
"ocbi @%1\n\t"
"ocbi @%2\n\t"
"ocbi @%3\n\t" : :
"r" (a0), "r" (a1), "r" (a2), "r" (a3));
a0 += linesz;
a1 += linesz;
a2 += linesz;
a3 += linesz;
asm volatile("movca.l r0, @%0\n\t"
"movca.l r0, @%1\n\t"
"movca.l r0, @%2\n\t"
"movca.l r0, @%3\n\t"
"ocbi @%0\n\t"
"ocbi @%1\n\t"
"ocbi @%2\n\t"
"ocbi @%3\n\t" : :
"r" (a0), "r" (a1), "r" (a2), "r" (a3));
a0 += linesz;
a1 += linesz;
a2 += linesz;
a3 += linesz;
asm volatile("movca.l r0, @%0\n\t"
"movca.l r0, @%1\n\t"
"movca.l r0, @%2\n\t"
"movca.l r0, @%3\n\t"
"ocbi @%0\n\t"
"ocbi @%1\n\t"
"ocbi @%2\n\t"
"ocbi @%3\n\t" : :
"r" (a0), "r" (a1), "r" (a2), "r" (a3));
asm volatile("ldc %0, sr" : : "r" (orig_sr));
a0 += linesz;
a1 += linesz;
a2 += linesz;
a3 += linesz;
} while (a0 < a0e);
}
extern void __weak sh4__flush_region_init(void);
/*
* SH-4 has virtually indexed and physically tagged cache.
*/
void __init sh4_cache_init(void)
{
unsigned int wt_enabled = !!(__raw_readl(CCR) & CCR_CACHE_WT);
printk("PVR=%08x CVR=%08x PRR=%08x\n",
ctrl_inl(CCN_PVR),
ctrl_inl(CCN_CVR),
ctrl_inl(CCN_PRR));
if (wt_enabled)
__flush_dcache_segment_fn = __flush_dcache_segment_writethrough;
else {
switch (boot_cpu_data.dcache.ways) {
case 1:
__flush_dcache_segment_fn = __flush_dcache_segment_1way;
break;
case 2:
__flush_dcache_segment_fn = __flush_dcache_segment_2way;
break;
case 4:
__flush_dcache_segment_fn = __flush_dcache_segment_4way;
break;
default:
panic("unknown number of cache ways\n");
break;
}
}
local_flush_icache_range = sh4_flush_icache_range;
local_flush_dcache_page = sh4_flush_dcache_page;
local_flush_cache_all = sh4_flush_cache_all;
local_flush_cache_mm = sh4_flush_cache_mm;
local_flush_cache_dup_mm = sh4_flush_cache_mm;
local_flush_cache_page = sh4_flush_cache_page;
local_flush_cache_range = sh4_flush_cache_range;
sh4__flush_region_init();
}
