linux/arch/arm/mm/cache-l2x0.c
Will Deacon 38a8914f9a ARM: 6987/1: l2x0: fix disabling function to avoid deadlock
The l2x0_disable function attempts to writel with the l2x0_lock held.
This results in deadlock when the writel contains an outer_sync call
for the platform since the l2x0_lock is already held by the disable
function. A further problem is that disabling the L2 without flushing it
first can lead to the spin_lock operation becoming visible after the
spin_unlock, causing any subsequent L2 maintenance to deadlock.

This patch replaces the writel with a call to writel_relaxed in the
disabling code and adds a flush before disabling in the control
register, preventing livelock from occurring.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-06 20:48:08 +01:00

354 lines
8.4 KiB
C

/*
* arch/arm/mm/cache-l2x0.c - L210/L220 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/spinlock.h>
#include <linux/io.h>
#include <asm/cacheflush.h>
#include <asm/hardware/cache-l2x0.h>
#define CACHE_LINE_SIZE 32
static void __iomem *l2x0_base;
static DEFINE_SPINLOCK(l2x0_lock);
static uint32_t l2x0_way_mask; /* Bitmask of active ways */
static uint32_t l2x0_size;
static inline void cache_wait_way(void __iomem *reg, unsigned long mask)
{
/* wait for cache operation by line or way to complete */
while (readl_relaxed(reg) & mask)
;
}
#ifdef CONFIG_CACHE_PL310
static inline void cache_wait(void __iomem *reg, unsigned long mask)
{
/* cache operations by line are atomic on PL310 */
}
#else
#define cache_wait cache_wait_way
#endif
static inline void cache_sync(void)
{
void __iomem *base = l2x0_base;
#ifdef CONFIG_ARM_ERRATA_753970
/* write to an unmmapped register */
writel_relaxed(0, base + L2X0_DUMMY_REG);
#else
writel_relaxed(0, base + L2X0_CACHE_SYNC);
#endif
cache_wait(base + L2X0_CACHE_SYNC, 1);
}
static inline void l2x0_clean_line(unsigned long addr)
{
void __iomem *base = l2x0_base;
cache_wait(base + L2X0_CLEAN_LINE_PA, 1);
writel_relaxed(addr, base + L2X0_CLEAN_LINE_PA);
}
static inline void l2x0_inv_line(unsigned long addr)
{
void __iomem *base = l2x0_base;
cache_wait(base + L2X0_INV_LINE_PA, 1);
writel_relaxed(addr, base + L2X0_INV_LINE_PA);
}
#if defined(CONFIG_PL310_ERRATA_588369) || defined(CONFIG_PL310_ERRATA_727915)
#define debug_writel(val) outer_cache.set_debug(val)
static void l2x0_set_debug(unsigned long val)
{
writel_relaxed(val, l2x0_base + L2X0_DEBUG_CTRL);
}
#else
/* Optimised out for non-errata case */
static inline void debug_writel(unsigned long val)
{
}
#define l2x0_set_debug NULL
#endif
#ifdef CONFIG_PL310_ERRATA_588369
static inline void l2x0_flush_line(unsigned long addr)
{
void __iomem *base = l2x0_base;
/* Clean by PA followed by Invalidate by PA */
cache_wait(base + L2X0_CLEAN_LINE_PA, 1);
writel_relaxed(addr, base + L2X0_CLEAN_LINE_PA);
cache_wait(base + L2X0_INV_LINE_PA, 1);
writel_relaxed(addr, base + L2X0_INV_LINE_PA);
}
#else
static inline void l2x0_flush_line(unsigned long addr)
{
void __iomem *base = l2x0_base;
cache_wait(base + L2X0_CLEAN_INV_LINE_PA, 1);
writel_relaxed(addr, base + L2X0_CLEAN_INV_LINE_PA);
}
#endif
static void l2x0_cache_sync(void)
{
unsigned long flags;
spin_lock_irqsave(&l2x0_lock, flags);
cache_sync();
spin_unlock_irqrestore(&l2x0_lock, flags);
}
static void __l2x0_flush_all(void)
{
debug_writel(0x03);
writel_relaxed(l2x0_way_mask, l2x0_base + L2X0_CLEAN_INV_WAY);
cache_wait_way(l2x0_base + L2X0_CLEAN_INV_WAY, l2x0_way_mask);
cache_sync();
debug_writel(0x00);
}
static void l2x0_flush_all(void)
{
unsigned long flags;
/* clean all ways */
spin_lock_irqsave(&l2x0_lock, flags);
__l2x0_flush_all();
spin_unlock_irqrestore(&l2x0_lock, flags);
}
static void l2x0_clean_all(void)
{
unsigned long flags;
/* clean all ways */
spin_lock_irqsave(&l2x0_lock, flags);
writel_relaxed(l2x0_way_mask, l2x0_base + L2X0_CLEAN_WAY);
cache_wait_way(l2x0_base + L2X0_CLEAN_WAY, l2x0_way_mask);
cache_sync();
spin_unlock_irqrestore(&l2x0_lock, flags);
}
static void l2x0_inv_all(void)
{
unsigned long flags;
/* invalidate all ways */
spin_lock_irqsave(&l2x0_lock, flags);
/* Invalidating when L2 is enabled is a nono */
BUG_ON(readl(l2x0_base + L2X0_CTRL) & 1);
writel_relaxed(l2x0_way_mask, l2x0_base + L2X0_INV_WAY);
cache_wait_way(l2x0_base + L2X0_INV_WAY, l2x0_way_mask);
cache_sync();
spin_unlock_irqrestore(&l2x0_lock, flags);
}
static void l2x0_inv_range(unsigned long start, unsigned long end)
{
void __iomem *base = l2x0_base;
unsigned long flags;
spin_lock_irqsave(&l2x0_lock, flags);
if (start & (CACHE_LINE_SIZE - 1)) {
start &= ~(CACHE_LINE_SIZE - 1);
debug_writel(0x03);
l2x0_flush_line(start);
debug_writel(0x00);
start += CACHE_LINE_SIZE;
}
if (end & (CACHE_LINE_SIZE - 1)) {
end &= ~(CACHE_LINE_SIZE - 1);
debug_writel(0x03);
l2x0_flush_line(end);
debug_writel(0x00);
}
while (start < end) {
unsigned long blk_end = start + min(end - start, 4096UL);
while (start < blk_end) {
l2x0_inv_line(start);
start += CACHE_LINE_SIZE;
}
if (blk_end < end) {
spin_unlock_irqrestore(&l2x0_lock, flags);
spin_lock_irqsave(&l2x0_lock, flags);
}
}
cache_wait(base + L2X0_INV_LINE_PA, 1);
cache_sync();
spin_unlock_irqrestore(&l2x0_lock, flags);
}
static void l2x0_clean_range(unsigned long start, unsigned long end)
{
void __iomem *base = l2x0_base;
unsigned long flags;
if ((end - start) >= l2x0_size) {
l2x0_clean_all();
return;
}
spin_lock_irqsave(&l2x0_lock, flags);
start &= ~(CACHE_LINE_SIZE - 1);
while (start < end) {
unsigned long blk_end = start + min(end - start, 4096UL);
while (start < blk_end) {
l2x0_clean_line(start);
start += CACHE_LINE_SIZE;
}
if (blk_end < end) {
spin_unlock_irqrestore(&l2x0_lock, flags);
spin_lock_irqsave(&l2x0_lock, flags);
}
}
cache_wait(base + L2X0_CLEAN_LINE_PA, 1);
cache_sync();
spin_unlock_irqrestore(&l2x0_lock, flags);
}
static void l2x0_flush_range(unsigned long start, unsigned long end)
{
void __iomem *base = l2x0_base;
unsigned long flags;
if ((end - start) >= l2x0_size) {
l2x0_flush_all();
return;
}
spin_lock_irqsave(&l2x0_lock, flags);
start &= ~(CACHE_LINE_SIZE - 1);
while (start < end) {
unsigned long blk_end = start + min(end - start, 4096UL);
debug_writel(0x03);
while (start < blk_end) {
l2x0_flush_line(start);
start += CACHE_LINE_SIZE;
}
debug_writel(0x00);
if (blk_end < end) {
spin_unlock_irqrestore(&l2x0_lock, flags);
spin_lock_irqsave(&l2x0_lock, flags);
}
}
cache_wait(base + L2X0_CLEAN_INV_LINE_PA, 1);
cache_sync();
spin_unlock_irqrestore(&l2x0_lock, flags);
}
static void l2x0_disable(void)
{
unsigned long flags;
spin_lock_irqsave(&l2x0_lock, flags);
__l2x0_flush_all();
writel_relaxed(0, l2x0_base + L2X0_CTRL);
dsb();
spin_unlock_irqrestore(&l2x0_lock, flags);
}
void __init l2x0_init(void __iomem *base, __u32 aux_val, __u32 aux_mask)
{
__u32 aux;
__u32 cache_id;
__u32 way_size = 0;
int ways;
const char *type;
l2x0_base = base;
cache_id = readl_relaxed(l2x0_base + L2X0_CACHE_ID);
aux = readl_relaxed(l2x0_base + L2X0_AUX_CTRL);
aux &= aux_mask;
aux |= aux_val;
/* Determine the number of ways */
switch (cache_id & L2X0_CACHE_ID_PART_MASK) {
case L2X0_CACHE_ID_PART_L310:
if (aux & (1 << 16))
ways = 16;
else
ways = 8;
type = "L310";
break;
case L2X0_CACHE_ID_PART_L210:
ways = (aux >> 13) & 0xf;
type = "L210";
break;
default:
/* Assume unknown chips have 8 ways */
ways = 8;
type = "L2x0 series";
break;
}
l2x0_way_mask = (1 << ways) - 1;
/*
* L2 cache Size = Way size * Number of ways
*/
way_size = (aux & L2X0_AUX_CTRL_WAY_SIZE_MASK) >> 17;
way_size = 1 << (way_size + 3);
l2x0_size = ways * way_size * SZ_1K;
/*
* Check if l2x0 controller is already enabled.
* If you are booting from non-secure mode
* accessing the below registers will fault.
*/
if (!(readl_relaxed(l2x0_base + L2X0_CTRL) & 1)) {
/* l2x0 controller is disabled */
writel_relaxed(aux, l2x0_base + L2X0_AUX_CTRL);
l2x0_inv_all();
/* enable L2X0 */
writel_relaxed(1, l2x0_base + L2X0_CTRL);
}
outer_cache.inv_range = l2x0_inv_range;
outer_cache.clean_range = l2x0_clean_range;
outer_cache.flush_range = l2x0_flush_range;
outer_cache.sync = l2x0_cache_sync;
outer_cache.flush_all = l2x0_flush_all;
outer_cache.inv_all = l2x0_inv_all;
outer_cache.disable = l2x0_disable;
outer_cache.set_debug = l2x0_set_debug;
printk(KERN_INFO "%s cache controller enabled\n", type);
printk(KERN_INFO "l2x0: %d ways, CACHE_ID 0x%08x, AUX_CTRL 0x%08x, Cache size: %d B\n",
ways, cache_id, aux, l2x0_size);
}