linux/arch/arm/mm/cache-xsc3l2.c
Nicolas Pitre 25cbe45440 ARM: fix cache-xsc3l2 after stack based kmap_atomic()
Since commit 3e4d3af501 "mm: stack based kmap_atomic()", it is actively
wrong to rely on fixed kmap type indices (namely KM_L2_CACHE) as
kmap_atomic() totally ignores them and a concurrent instance of it may
happily reuse any slot for any purpose.  Because kmap_atomic() is now
able to deal with reentrancy, we can get rid of the ad hoc mapping here,
and we even don't have to disable IRQs anymore (highmem case).

While the code is made much simpler, there is a needless cache flush
introduced by the usage of __kunmap_atomic().  It is not clear if the
performance difference to remove that is worth the cost in code
maintenance (I don't think there are that many highmem users on that
platform if at all anyway).

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
2010-12-19 12:57:08 -05:00

221 lines
4.9 KiB
C

/*
* arch/arm/mm/cache-xsc3l2.c - XScale3 L2 cache controller support
*
* Copyright (C) 2007 ARM Limited
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/init.h>
#include <linux/highmem.h>
#include <asm/system.h>
#include <asm/cputype.h>
#include <asm/cacheflush.h>
#define CR_L2 (1 << 26)
#define CACHE_LINE_SIZE 32
#define CACHE_LINE_SHIFT 5
#define CACHE_WAY_PER_SET 8
#define CACHE_WAY_SIZE(l2ctype) (8192 << (((l2ctype) >> 8) & 0xf))
#define CACHE_SET_SIZE(l2ctype) (CACHE_WAY_SIZE(l2ctype) >> CACHE_LINE_SHIFT)
static inline int xsc3_l2_present(void)
{
unsigned long l2ctype;
__asm__("mrc p15, 1, %0, c0, c0, 1" : "=r" (l2ctype));
return !!(l2ctype & 0xf8);
}
static inline void xsc3_l2_clean_mva(unsigned long addr)
{
__asm__("mcr p15, 1, %0, c7, c11, 1" : : "r" (addr));
}
static inline void xsc3_l2_inv_mva(unsigned long addr)
{
__asm__("mcr p15, 1, %0, c7, c7, 1" : : "r" (addr));
}
static inline void xsc3_l2_inv_all(void)
{
unsigned long l2ctype, set_way;
int set, way;
__asm__("mrc p15, 1, %0, c0, c0, 1" : "=r" (l2ctype));
for (set = 0; set < CACHE_SET_SIZE(l2ctype); set++) {
for (way = 0; way < CACHE_WAY_PER_SET; way++) {
set_way = (way << 29) | (set << 5);
__asm__("mcr p15, 1, %0, c7, c11, 2" : : "r"(set_way));
}
}
dsb();
}
static inline void l2_unmap_va(unsigned long va)
{
#ifdef CONFIG_HIGHMEM
if (va != -1)
kunmap_atomic((void *)va);
#endif
}
static inline unsigned long l2_map_va(unsigned long pa, unsigned long prev_va)
{
#ifdef CONFIG_HIGHMEM
unsigned long va = prev_va & PAGE_MASK;
unsigned long pa_offset = pa << (32 - PAGE_SHIFT);
if (unlikely(pa_offset < (prev_va << (32 - PAGE_SHIFT)))) {
/*
* Switching to a new page. Because cache ops are
* using virtual addresses only, we must put a mapping
* in place for it.
*/
l2_unmap_va(prev_va);
va = (unsigned long)kmap_atomic_pfn(pa >> PAGE_SHIFT);
}
return va + (pa_offset >> (32 - PAGE_SHIFT));
#else
return __phys_to_virt(pa);
#endif
}
static void xsc3_l2_inv_range(unsigned long start, unsigned long end)
{
unsigned long vaddr;
if (start == 0 && end == -1ul) {
xsc3_l2_inv_all();
return;
}
vaddr = -1; /* to force the first mapping */
/*
* Clean and invalidate partial first cache line.
*/
if (start & (CACHE_LINE_SIZE - 1)) {
vaddr = l2_map_va(start & ~(CACHE_LINE_SIZE - 1), vaddr);
xsc3_l2_clean_mva(vaddr);
xsc3_l2_inv_mva(vaddr);
start = (start | (CACHE_LINE_SIZE - 1)) + 1;
}
/*
* Invalidate all full cache lines between 'start' and 'end'.
*/
while (start < (end & ~(CACHE_LINE_SIZE - 1))) {
vaddr = l2_map_va(start, vaddr);
xsc3_l2_inv_mva(vaddr);
start += CACHE_LINE_SIZE;
}
/*
* Clean and invalidate partial last cache line.
*/
if (start < end) {
vaddr = l2_map_va(start, vaddr);
xsc3_l2_clean_mva(vaddr);
xsc3_l2_inv_mva(vaddr);
}
l2_unmap_va(vaddr);
dsb();
}
static void xsc3_l2_clean_range(unsigned long start, unsigned long end)
{
unsigned long vaddr;
vaddr = -1; /* to force the first mapping */
start &= ~(CACHE_LINE_SIZE - 1);
while (start < end) {
vaddr = l2_map_va(start, vaddr);
xsc3_l2_clean_mva(vaddr);
start += CACHE_LINE_SIZE;
}
l2_unmap_va(vaddr);
dsb();
}
/*
* optimize L2 flush all operation by set/way format
*/
static inline void xsc3_l2_flush_all(void)
{
unsigned long l2ctype, set_way;
int set, way;
__asm__("mrc p15, 1, %0, c0, c0, 1" : "=r" (l2ctype));
for (set = 0; set < CACHE_SET_SIZE(l2ctype); set++) {
for (way = 0; way < CACHE_WAY_PER_SET; way++) {
set_way = (way << 29) | (set << 5);
__asm__("mcr p15, 1, %0, c7, c15, 2" : : "r"(set_way));
}
}
dsb();
}
static void xsc3_l2_flush_range(unsigned long start, unsigned long end)
{
unsigned long vaddr;
if (start == 0 && end == -1ul) {
xsc3_l2_flush_all();
return;
}
vaddr = -1; /* to force the first mapping */
start &= ~(CACHE_LINE_SIZE - 1);
while (start < end) {
vaddr = l2_map_va(start, vaddr);
xsc3_l2_clean_mva(vaddr);
xsc3_l2_inv_mva(vaddr);
start += CACHE_LINE_SIZE;
}
l2_unmap_va(vaddr);
dsb();
}
static int __init xsc3_l2_init(void)
{
if (!cpu_is_xsc3() || !xsc3_l2_present())
return 0;
if (get_cr() & CR_L2) {
pr_info("XScale3 L2 cache enabled.\n");
xsc3_l2_inv_all();
outer_cache.inv_range = xsc3_l2_inv_range;
outer_cache.clean_range = xsc3_l2_clean_range;
outer_cache.flush_range = xsc3_l2_flush_range;
}
return 0;
}
core_initcall(xsc3_l2_init);