kernel_optimize_test/arch/arm/mm/cache-xsc3l2.c
Nicolas Pitre 3902a15e78 [ARM] xsc3: add highmem support to L2 cache handling code
On xsc3, L2 cache ops are possible only on virtual addresses.  The code
is rearranged so to have a linear progression requiring the least amount
of pte setups in the highmem case.  To protect the virtual mapping so
created, interrupts must be disabled currently up to a page worth of
address range.

The interrupt disabling is done in a way to minimize the overhead within
the inner loop.  The alternative would consist in separate code for
the highmem and non highmem compilation which is less preferable.

Signed-off-by: Nicolas Pitre <nico@marvell.com>
2009-03-15 21:01:21 -04:00

237 lines
5.7 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 <asm/system.h>
#include <asm/cputype.h>
#include <asm/cacheflush.h>
#include <asm/kmap_types.h>
#include <asm/fixmap.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include "mm.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();
}
#ifdef CONFIG_HIGHMEM
#define l2_map_save_flags(x) raw_local_save_flags(x)
#define l2_map_restore_flags(x) raw_local_irq_restore(x)
#else
#define l2_map_save_flags(x) ((x) = 0)
#define l2_map_restore_flags(x) ((void)(x))
#endif
static inline unsigned long l2_map_va(unsigned long pa, unsigned long prev_va,
unsigned long flags)
{
#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. We also enable interrupts for a
* short while and disable them again to protect this
* mapping.
*/
unsigned long idx;
raw_local_irq_restore(flags);
idx = KM_L2_CACHE + KM_TYPE_NR * smp_processor_id();
va = __fix_to_virt(FIX_KMAP_BEGIN + idx);
raw_local_irq_restore(flags | PSR_I_BIT);
set_pte_ext(TOP_PTE(va), pfn_pte(pa >> PAGE_SHIFT, PAGE_KERNEL), 0);
local_flush_tlb_kernel_page(va);
}
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, flags;
if (start == 0 && end == -1ul) {
xsc3_l2_inv_all();
return;
}
vaddr = -1; /* to force the first mapping */
l2_map_save_flags(flags);
/*
* Clean and invalidate partial first cache line.
*/
if (start & (CACHE_LINE_SIZE - 1)) {
vaddr = l2_map_va(start & ~(CACHE_LINE_SIZE - 1), vaddr, flags);
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, flags);
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, flags);
xsc3_l2_clean_mva(vaddr);
xsc3_l2_inv_mva(vaddr);
}
l2_map_restore_flags(flags);
dsb();
}
static void xsc3_l2_clean_range(unsigned long start, unsigned long end)
{
unsigned long vaddr, flags;
vaddr = -1; /* to force the first mapping */
l2_map_save_flags(flags);
start &= ~(CACHE_LINE_SIZE - 1);
while (start < end) {
vaddr = l2_map_va(start, vaddr, flags);
xsc3_l2_clean_mva(vaddr);
start += CACHE_LINE_SIZE;
}
l2_map_restore_flags(flags);
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, flags;
if (start == 0 && end == -1ul) {
xsc3_l2_flush_all();
return;
}
vaddr = -1; /* to force the first mapping */
l2_map_save_flags(flags);
start &= ~(CACHE_LINE_SIZE - 1);
while (start < end) {
vaddr = l2_map_va(start, vaddr, flags);
xsc3_l2_clean_mva(vaddr);
xsc3_l2_inv_mva(vaddr);
start += CACHE_LINE_SIZE;
}
l2_map_restore_flags(flags);
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");
adjust_cr(CR_L2, CR_L2);
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);