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linux/arch/mips/mm/c-r3k.c
James Hogan 01882b4d5e MIPS: c-r4k: Split user/kernel flush_icache_range() 
flush_icache_range() is used for both user addresses (i.e.
cacheflush(2)), and kernel addresses (as the API documentation
describes).

This isn't really suitable however for Enhanced Virtual Addressing (EVA)
where cache operations on usermode addresses must use a different
instruction, and the protected cache ops assume user addresses, making
flush_icache_range() ineffective on kernel addresses.

Split out a new __flush_icache_user_range() and
__local_flush_icache_user_range() for users which actually want to flush
usermode addresses (note that flush_icache_user_range() already exists
on various architectures but with different arguments).

The implementation of flush_icache_range() will be changed in an
upcoming commit to use unprotected normal cache ops so as to always work
on the kernel mode address space.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14152/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-10-04 16:13:57 +02:00

349 lines
8.0 KiB
C
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/*
* r2300.c: R2000 and R3000 specific mmu/cache code.
*
* Copyright (C) 1996 David S. Miller (davem@davemloft.net)
*
* with a lot of changes to make this thing work for R3000s
* Tx39XX R4k style caches added. HK
* Copyright (C) 1998, 1999, 2000 Harald Koerfgen
* Copyright (C) 1998 Gleb Raiko & Vladimir Roganov
* Copyright (C) 2001, 2004, 2007 Maciej W. Rozycki
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/mm.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/mmu_context.h>
#include <asm/isadep.h>
#include <asm/io.h>
#include <asm/bootinfo.h>
#include <asm/cpu.h>
static unsigned long icache_size, dcache_size; /* Size in bytes */
static unsigned long icache_lsize, dcache_lsize; /* Size in bytes */
unsigned long r3k_cache_size(unsigned long ca_flags)
{
unsigned long flags, status, dummy, size;
volatile unsigned long *p;
p = (volatile unsigned long *) KSEG0;
flags = read_c0_status();
/* isolate cache space */
write_c0_status((ca_flags|flags)&~ST0_IEC);
*p = 0xa5a55a5a;
dummy = *p;
status = read_c0_status();
if (dummy != 0xa5a55a5a || (status & ST0_CM)) {
size = 0;
} else {
for (size = 128; size <= 0x40000; size <<= 1)
*(p + size) = 0;
*p = -1;
for (size = 128;
(size <= 0x40000) && (*(p + size) == 0);
size <<= 1)
;
if (size > 0x40000)
size = 0;
}
write_c0_status(flags);
return size * sizeof(*p);
}
unsigned long r3k_cache_lsize(unsigned long ca_flags)
{
unsigned long flags, status, lsize, i;
volatile unsigned long *p;
p = (volatile unsigned long *) KSEG0;
flags = read_c0_status();
/* isolate cache space */
write_c0_status((ca_flags|flags)&~ST0_IEC);
for (i = 0; i < 128; i++)
*(p + i) = 0;
*(volatile unsigned char *)p = 0;
for (lsize = 1; lsize < 128; lsize <<= 1) {
*(p + lsize);
status = read_c0_status();
if (!(status & ST0_CM))
break;
}
for (i = 0; i < 128; i += lsize)
*(volatile unsigned char *)(p + i) = 0;
write_c0_status(flags);
return lsize * sizeof(*p);
}
static void r3k_probe_cache(void)
{
dcache_size = r3k_cache_size(ST0_ISC);
if (dcache_size)
dcache_lsize = r3k_cache_lsize(ST0_ISC);
icache_size = r3k_cache_size(ST0_ISC|ST0_SWC);
if (icache_size)
icache_lsize = r3k_cache_lsize(ST0_ISC|ST0_SWC);
}
static void r3k_flush_icache_range(unsigned long start, unsigned long end)
{
unsigned long size, i, flags;
volatile unsigned char *p;
size = end - start;
if (size > icache_size || KSEGX(start) != KSEG0) {
start = KSEG0;
size = icache_size;
}
p = (char *)start;
flags = read_c0_status();
/* isolate cache space */
write_c0_status((ST0_ISC|ST0_SWC|flags)&~ST0_IEC);
for (i = 0; i < size; i += 0x080) {
asm( "sb\t$0, 0x000(%0)\n\t"
"sb\t$0, 0x004(%0)\n\t"
"sb\t$0, 0x008(%0)\n\t"
"sb\t$0, 0x00c(%0)\n\t"
"sb\t$0, 0x010(%0)\n\t"
"sb\t$0, 0x014(%0)\n\t"
"sb\t$0, 0x018(%0)\n\t"
"sb\t$0, 0x01c(%0)\n\t"
"sb\t$0, 0x020(%0)\n\t"
"sb\t$0, 0x024(%0)\n\t"
"sb\t$0, 0x028(%0)\n\t"
"sb\t$0, 0x02c(%0)\n\t"
"sb\t$0, 0x030(%0)\n\t"
"sb\t$0, 0x034(%0)\n\t"
"sb\t$0, 0x038(%0)\n\t"
"sb\t$0, 0x03c(%0)\n\t"
"sb\t$0, 0x040(%0)\n\t"
"sb\t$0, 0x044(%0)\n\t"
"sb\t$0, 0x048(%0)\n\t"
"sb\t$0, 0x04c(%0)\n\t"
"sb\t$0, 0x050(%0)\n\t"
"sb\t$0, 0x054(%0)\n\t"
"sb\t$0, 0x058(%0)\n\t"
"sb\t$0, 0x05c(%0)\n\t"
"sb\t$0, 0x060(%0)\n\t"
"sb\t$0, 0x064(%0)\n\t"
"sb\t$0, 0x068(%0)\n\t"
"sb\t$0, 0x06c(%0)\n\t"
"sb\t$0, 0x070(%0)\n\t"
"sb\t$0, 0x074(%0)\n\t"
"sb\t$0, 0x078(%0)\n\t"
"sb\t$0, 0x07c(%0)\n\t"
: : "r" (p) );
p += 0x080;
}
write_c0_status(flags);
}
static void r3k_flush_dcache_range(unsigned long start, unsigned long end)
{
unsigned long size, i, flags;
volatile unsigned char *p;
size = end - start;
if (size > dcache_size || KSEGX(start) != KSEG0) {
start = KSEG0;
size = dcache_size;
}
p = (char *)start;
flags = read_c0_status();
/* isolate cache space */
write_c0_status((ST0_ISC|flags)&~ST0_IEC);
for (i = 0; i < size; i += 0x080) {
asm( "sb\t$0, 0x000(%0)\n\t"
"sb\t$0, 0x004(%0)\n\t"
"sb\t$0, 0x008(%0)\n\t"
"sb\t$0, 0x00c(%0)\n\t"
"sb\t$0, 0x010(%0)\n\t"
"sb\t$0, 0x014(%0)\n\t"
"sb\t$0, 0x018(%0)\n\t"
"sb\t$0, 0x01c(%0)\n\t"
"sb\t$0, 0x020(%0)\n\t"
"sb\t$0, 0x024(%0)\n\t"
"sb\t$0, 0x028(%0)\n\t"
"sb\t$0, 0x02c(%0)\n\t"
"sb\t$0, 0x030(%0)\n\t"
"sb\t$0, 0x034(%0)\n\t"
"sb\t$0, 0x038(%0)\n\t"
"sb\t$0, 0x03c(%0)\n\t"
"sb\t$0, 0x040(%0)\n\t"
"sb\t$0, 0x044(%0)\n\t"
"sb\t$0, 0x048(%0)\n\t"
"sb\t$0, 0x04c(%0)\n\t"
"sb\t$0, 0x050(%0)\n\t"
"sb\t$0, 0x054(%0)\n\t"
"sb\t$0, 0x058(%0)\n\t"
"sb\t$0, 0x05c(%0)\n\t"
"sb\t$0, 0x060(%0)\n\t"
"sb\t$0, 0x064(%0)\n\t"
"sb\t$0, 0x068(%0)\n\t"
"sb\t$0, 0x06c(%0)\n\t"
"sb\t$0, 0x070(%0)\n\t"
"sb\t$0, 0x074(%0)\n\t"
"sb\t$0, 0x078(%0)\n\t"
"sb\t$0, 0x07c(%0)\n\t"
: : "r" (p) );
p += 0x080;
}
write_c0_status(flags);
}
static inline void r3k_flush_cache_all(void)
{
}
static inline void r3k___flush_cache_all(void)
{
r3k_flush_dcache_range(KSEG0, KSEG0 + dcache_size);
r3k_flush_icache_range(KSEG0, KSEG0 + icache_size);
}
static void r3k_flush_cache_mm(struct mm_struct *mm)
{
}
static void r3k_flush_cache_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
}
static void r3k_flush_cache_page(struct vm_area_struct *vma,
unsigned long addr, unsigned long pfn)
{
unsigned long kaddr = KSEG0ADDR(pfn << PAGE_SHIFT);
int exec = vma->vm_flags & VM_EXEC;
struct mm_struct *mm = vma->vm_mm;
pgd_t *pgdp;
pud_t *pudp;
pmd_t *pmdp;
pte_t *ptep;
pr_debug("cpage[%08lx,%08lx]\n",
cpu_context(smp_processor_id(), mm), addr);
/* No ASID => no such page in the cache. */
if (cpu_context(smp_processor_id(), mm) == 0)
return;
pgdp = pgd_offset(mm, addr);
pudp = pud_offset(pgdp, addr);
pmdp = pmd_offset(pudp, addr);
ptep = pte_offset(pmdp, addr);
/* Invalid => no such page in the cache. */
if (!(pte_val(*ptep) & _PAGE_PRESENT))
return;
r3k_flush_dcache_range(kaddr, kaddr + PAGE_SIZE);
if (exec)
r3k_flush_icache_range(kaddr, kaddr + PAGE_SIZE);
}
static void local_r3k_flush_data_cache_page(void *addr)
{
}
static void r3k_flush_data_cache_page(unsigned long addr)
{
}
static void r3k_flush_cache_sigtramp(unsigned long addr)
{
unsigned long flags;
pr_debug("csigtramp[%08lx]\n", addr);
flags = read_c0_status();
write_c0_status(flags&~ST0_IEC);
/* Fill the TLB to avoid an exception with caches isolated. */
asm( "lw\t$0, 0x000(%0)\n\t"
"lw\t$0, 0x004(%0)\n\t"
: : "r" (addr) );
write_c0_status((ST0_ISC|ST0_SWC|flags)&~ST0_IEC);
asm( "sb\t$0, 0x000(%0)\n\t"
"sb\t$0, 0x004(%0)\n\t"
: : "r" (addr) );
write_c0_status(flags);
}
static void r3k_flush_kernel_vmap_range(unsigned long vaddr, int size)
{
BUG();
}
static void r3k_dma_cache_wback_inv(unsigned long start, unsigned long size)
{
/* Catch bad driver code */
BUG_ON(size == 0);
iob();
r3k_flush_dcache_range(start, start + size);
}
void r3k_cache_init(void)
{
extern void build_clear_page(void);
extern void build_copy_page(void);
r3k_probe_cache();
flush_cache_all = r3k_flush_cache_all;
__flush_cache_all = r3k___flush_cache_all;
flush_cache_mm = r3k_flush_cache_mm;
flush_cache_range = r3k_flush_cache_range;
flush_cache_page = r3k_flush_cache_page;
flush_icache_range = r3k_flush_icache_range;
local_flush_icache_range = r3k_flush_icache_range;
__flush_icache_user_range = r3k_flush_icache_range;
__local_flush_icache_user_range = r3k_flush_icache_range;
__flush_kernel_vmap_range = r3k_flush_kernel_vmap_range;
flush_cache_sigtramp = r3k_flush_cache_sigtramp;
local_flush_data_cache_page = local_r3k_flush_data_cache_page;
flush_data_cache_page = r3k_flush_data_cache_page;
_dma_cache_wback_inv = r3k_dma_cache_wback_inv;
_dma_cache_wback = r3k_dma_cache_wback_inv;
_dma_cache_inv = r3k_dma_cache_wback_inv;
printk("Primary instruction cache %ldkB, linesize %ld bytes.\n",
icache_size >> 10, icache_lsize);
printk("Primary data cache %ldkB, linesize %ld bytes.\n",
dcache_size >> 10, dcache_lsize);
build_clear_page();
build_copy_page();
}
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