linux/arch/arm/mm/cache-xsc3l2.c
Haojian Zhuang dc8601a224 [ARM] pxa: do not enable L2 after MMU is enabled
Outer cache checked whether L2 is enabled or not. If L2 isn't enabled in XSC3,
it would enable L2. This operation is evil that would make system hang.

In XSC3 core document, these words are mentioned in below.

"Following reset, the L2 Unified Cache Enable bit is cleared. To enable the L2
Cache, software may set the bit to a '1' before or at the same time as enabling
the MMU. Enabling the L2 Cache after the MMU has been enabled or disabling the
L2 Cache after the L2 Cache has been enabled, may result in unpredictable
behavior of the processor."

When outer cache is initialized, the MMU is already enabled. We couldn't enable
L2 after MMU enabled.

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
2010-01-01 15:50:34 +08:00

235 lines
5.6 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");
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);