#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <asm/memory.h>
#include <asm/ptrace.h>
#include <asm/cacheflush.h>
#include <asm/traps.h>
extern struct cpu_cache_fns blk_cache_fns;
#define HARVARD_CACHE
/*
* blk_flush_kern_dcache_page(kaddr)
*
* Ensure that the data held in the page kaddr is written back
* to the page in question.
*
* - kaddr - kernel address (guaranteed to be page aligned)
*/
static void __attribute__((naked))
blk_flush_kern_dcache_page(void *kaddr)
{
asm(
"add r1, r0, %0 \n\
sub r1, r1, %1 \n\
1: .word 0xec401f0e @ mcrr p15, 0, r0, r1, c14, 0 @ blocking \n\
mov r0, #0 \n\
mcr p15, 0, r0, c7, c5, 0 \n\
mcr p15, 0, r0, c7, c10, 4 \n\
mov pc, lr"
:
: "I" (PAGE_SIZE), "I" (L1_CACHE_BYTES));
}
/*
* blk_dma_inv_range(start,end)
*
* Invalidate the data cache within the specified region; we will
* be performing a DMA operation in this region and we want to
* purge old data in the cache.
*
* - start - virtual start address of region
* - end - virtual end address of region
*/
static void __attribute__((naked))
blk_dma_inv_range_unified(unsigned long start, unsigned long end)
{
asm(
"tst r0, %0 \n\
mcrne p15, 0, r0, c7, c11, 1 @ clean unified line \n\
tst r1, %0 \n\
mcrne p15, 0, r1, c7, c15, 1 @ clean & invalidate unified line\n\
.word 0xec401f06 @ mcrr p15, 0, r1, r0, c6, 0 @ blocking \n\
mov r0, #0 \n\
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer \n\
mov pc, lr"
:
: "I" (L1_CACHE_BYTES - 1));
}
static void __attribute__((naked))
blk_dma_inv_range_harvard(unsigned long start, unsigned long end)
{
asm(
"tst r0, %0 \n\
mcrne p15, 0, r0, c7, c10, 1 @ clean D line \n\
tst r1, %0 \n\
mcrne p15, 0, r1, c7, c14, 1 @ clean & invalidate D line \n\
.word 0xec401f06 @ mcrr p15, 0, r1, r0, c6, 0 @ blocking \n\
mov r0, #0 \n\
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer \n\
mov pc, lr"
:
: "I" (L1_CACHE_BYTES - 1));
}
/*
* blk_dma_clean_range(start,end)
* - start - virtual start address of region
* - end - virtual end address of region
*/
static void __attribute__((naked))
blk_dma_clean_range(unsigned long start, unsigned long end)
{
asm(
".word 0xec401f0c @ mcrr p15, 0, r1, r0, c12, 0 @ blocking \n\
mov r0, #0 \n\
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer \n\
mov pc, lr");
}
/*
* blk_dma_flush_range(start,end)
* - start - virtual start address of region
* - end - virtual end address of region
*/
static void __attribute__((naked))
blk_dma_flush_range(unsigned long start, unsigned long end)
{
asm(
".word 0xec401f0e @ mcrr p15, 0, r1, r0, c14, 0 @ blocking \n\
mov pc, lr");
}
static int blockops_trap(struct pt_regs *regs, unsigned int instr)
{
regs->ARM_r4 |= regs->ARM_r2;
regs->ARM_pc += 4;
return 0;
}
static char *func[] = {
"Prefetch data range",
"Clean+Invalidate data range",
"Clean data range",
"Invalidate data range",
"Invalidate instr range"
};
static struct undef_hook blockops_hook __initdata = {
.instr_mask = 0x0fffffd0,
.instr_val = 0x0c401f00,
.cpsr_mask = PSR_T_BIT,
.cpsr_val = 0,
.fn = blockops_trap,
};
static int __init blockops_check(void)
{
register unsigned int err asm("r4") = 0;
unsigned int err_pos = 1;
unsigned int cache_type;
int i;
asm("mrc p15, 0, %0, c0, c0, 1" : "=r" (cache_type));
printk("Checking V6 block cache operations:\n");
register_undef_hook(&blockops_hook);
__asm__ ("mov r0, %0\n\t"
"mov r1, %1\n\t"
"mov r2, #1\n\t"
".word 0xec401f2c @ mcrr p15, 0, r1, r0, c12, 2\n\t"
"mov r2, #2\n\t"
".word 0xec401f0e @ mcrr p15, 0, r1, r0, c14, 0\n\t"
"mov r2, #4\n\t"
".word 0xec401f0c @ mcrr p15, 0, r1, r0, c12, 0\n\t"
"mov r2, #8\n\t"
".word 0xec401f06 @ mcrr p15, 0, r1, r0, c6, 0\n\t"
"mov r2, #16\n\t"
".word 0xec401f05 @ mcrr p15, 0, r1, r0, c5, 0\n\t"
:
: "r" (PAGE_OFFSET), "r" (PAGE_OFFSET + 128)
: "r0", "r1", "r2");
unregister_undef_hook(&blockops_hook);
for (i = 0; i < ARRAY_SIZE(func); i++, err_pos <<= 1)
printk("%30s: %ssupported\n", func[i], err & err_pos ? "not " : "");
if ((err & 8) == 0) {
printk(" --> Using %s block cache invalidate\n",
cache_type & (1 << 24) ? "harvard" : "unified");
if (cache_type & (1 << 24))
cpu_cache.dma_inv_range = blk_dma_inv_range_harvard;
else
cpu_cache.dma_inv_range = blk_dma_inv_range_unified;
}
if ((err & 4) == 0) {
printk(" --> Using block cache clean\n");
cpu_cache.dma_clean_range = blk_dma_clean_range;
}
if ((err & 2) == 0) {
printk(" --> Using block cache clean+invalidate\n");
cpu_cache.dma_flush_range = blk_dma_flush_range;
cpu_cache.flush_kern_dcache_page = blk_flush_kern_dcache_page;
}
return 0;
}
__initcall(blockops_check);
