Workaround for errata 4713: Concurrent access to some of the devices
in the SOC will result in a bus hang.
To avoid this, we introduce the lbi_lock, and grab it in the drivers
in question. Not a pretty solution, but adequate for now.
Index: mainline/arch/powerpc/platforms/pasemi/setup.c
===================================================================
--- mainline.orig/arch/powerpc/platforms/pasemi/setup.c
+++ mainline/arch/powerpc/platforms/pasemi/setup.c
@@ -42,6 +42,8 @@
static void __iomem *reset_reg;
void __iomem *mem_errsta0, *mem_errsta1;
+DEFINE_SPINLOCK(lbi_lock);
+
static void pas_restart(char *cmd)
{
printk("Restarting...\n");
Index: mainline/drivers/i2c/busses/i2c-pasemi.c
===================================================================
--- mainline.orig/drivers/i2c/busses/i2c-pasemi.c
+++ mainline/drivers/i2c/busses/i2c-pasemi.c
@@ -59,17 +59,24 @@ struct pasemi_smbus {
#define CLK_100K_DIV 84
#define CLK_400K_DIV 21
+extern spinlock_t lbi_lock;
+
static inline void reg_write(struct pasemi_smbus *smbus, int reg, int val)
{
+ int flags;
dev_dbg(&smbus->dev->dev, "smbus write reg %lx val %08x\n",
smbus->base + reg, val);
+ spin_lock_irqsave(&lbi_lock, flags);
outl(val, smbus->base + reg);
+ spin_unlock_irqrestore(&lbi_lock, flags);
}
static inline int reg_read(struct pasemi_smbus *smbus, int reg)
{
- int ret;
+ int ret, flags;
+ spin_lock_irqsave(&lbi_lock, flags);
ret = inl(smbus->base + reg);
+ spin_unlock_irqrestore(&lbi_lock, flags);
dev_dbg(&smbus->dev->dev, "smbus read reg %lx val %08x\n",
smbus->base + reg, ret);
return ret;
Index: mainline/drivers/serial/8250.c
===================================================================
--- mainline.orig/drivers/serial/8250.c
+++ mainline/drivers/serial/8250.c
@@ -342,39 +342,51 @@ static inline int map_8250_out_reg(struc
#endif
+extern spinlock_t lbi_lock;
+
static unsigned int serial_in(struct uart_8250_port *up, int offset)
{
unsigned int tmp;
+ int ret, flags;
offset = map_8250_in_reg(up, offset) << up->port.regshift;
+ spin_lock_irqsave(&lbi_lock, flags);
switch (up->port.iotype) {
case UPIO_HUB6:
outb(up->port.hub6 - 1 + offset, up->port.iobase);
- return inb(up->port.iobase + 1);
+ ret = inb(up->port.iobase + 1);
+ break;
case UPIO_MEM:
case UPIO_DWAPB:
- return readb(up->port.membase + offset);
+ ret = readb(up->port.membase + offset);
+ break;
case UPIO_RM9000:
case UPIO_MEM32:
- return readl(up->port.membase + offset);
+ ret = readl(up->port.membase + offset);
+ break;
#ifdef CONFIG_SERIAL_8250_AU1X00
case UPIO_AU:
- return __raw_readl(up->port.membase + offset);
+ ret = __raw_readl(up->port.membase + offset);
+ break;
#endif
case UPIO_TSI:
if (offset == UART_IIR) {
tmp = readl(up->port.membase + (UART_IIR & ~3));
- return (tmp >> 16) & 0xff; /* UART_IIR % 4 == 2 */
+ ret = (tmp >> 16) & 0xff; /* UART_IIR % 4 == 2 */
} else
- return readb(up->port.membase + offset);
+ ret = readb(up->port.membase + offset);
+ break;
default:
- return inb(up->port.iobase + offset);
+ ret = inb(up->port.iobase + offset);
+ break;
}
+ spin_unlock_irqrestore(&lbi_lock, flags);
+ return ret;
}
static void
@@ -382,8 +394,10 @@ serial_out(struct uart_8250_port *up, in
{
/* Save the offset before it's remapped */
int save_offset = offset;
+ int flags;
offset = map_8250_out_reg(up, offset) << up->port.regshift;
+ spin_lock_irqsave(&lbi_lock, flags);
switch (up->port.iotype) {
case UPIO_HUB6:
outb(up->port.hub6 - 1 + offset, up->port.iobase);
@@ -424,6 +438,7 @@ serial_out(struct uart_8250_port *up, in
default:
outb(value, up->port.iobase + offset);
}
+ spin_unlock_irqrestore(&lbi_lock, flags);
}
static void
@@ -1239,10 +1254,7 @@ static void serial8250_start_tx(struct u
unsigned char lsr, iir;
lsr = serial_in(up, UART_LSR);
iir = serial_in(up, UART_IIR) & 0x0f;
- if ((up->port.type == PORT_RM9000) ?
- (lsr & UART_LSR_THRE &&
- (iir == UART_IIR_NO_INT || iir ==
UART_IIR_THRI)) :
- (lsr & UART_LSR_TEMT && !(iir &
UART_IIR_NO_INT)))
+ if (lsr & UART_LSR_TEMT && !(iir & UART_IIR_NO_INT))
transmit_chars(up);
}
}
@@ -1879,7 +1891,7 @@ static int serial8250_startup(struct uar
if (lsr & UART_LSR_TEMT && !(iir & UART_IIR_NO_INT)) {
if (!(up->bugs & UART_BUG_TXEN)) {
up->bugs |= UART_BUG_TXEN;
- pr_debug("ttyS%d - enabling bad tx status
workarounds\n",
+ printk("ttyS%d - enabling bad tx status workarounds\n",
port->line);
}
} else {
Index: mainline/arch/powerpc/kernel/iomap.c
===================================================================
--- mainline.orig/arch/powerpc/kernel/iomap.c
+++ mainline/arch/powerpc/kernel/iomap.c
@@ -8,29 +8,51 @@
#include <linux/mm.h>
#include <asm/io.h>
+extern spinlock_t lbi_lock;
+
/*
* Here comes the ppc64 implementation of the IOMAP
* interfaces.
*/
unsigned int ioread8(void __iomem *addr)
{
- return readb(addr);
+ int ret, flags;
+ spin_lock_irqsave(&lbi_lock, flags);
+ ret = readb(addr);
+ spin_unlock_irqrestore(&lbi_lock, flags);
+ return ret;
}
unsigned int ioread16(void __iomem *addr)
{
- return readw(addr);
+ int ret, flags;
+ spin_lock_irqsave(&lbi_lock, flags);
+ ret = readw(addr);
+ spin_unlock_irqrestore(&lbi_lock, flags);
+ return ret;
}
unsigned int ioread16be(void __iomem *addr)
{
- return in_be16(addr);
+ int ret, flags;
+ spin_lock_irqsave(&lbi_lock, flags);
+ ret = in_be16(addr);
+ spin_unlock_irqrestore(&lbi_lock, flags);
+ return ret;
}
unsigned int ioread32(void __iomem *addr)
{
- return readl(addr);
+ int ret, flags;
+ spin_lock_irqsave(&lbi_lock, flags);
+ ret = readl(addr);
+ spin_unlock_irqrestore(&lbi_lock, flags);
+ return ret;
}
unsigned int ioread32be(void __iomem *addr)
{
- return in_be32(addr);
+ int ret, flags;
+ spin_lock_irqsave(&lbi_lock, flags);
+ ret = in_be32(addr);
+ spin_unlock_irqrestore(&lbi_lock, flags);
+ return ret;
}
EXPORT_SYMBOL(ioread8);
EXPORT_SYMBOL(ioread16);
@@ -40,23 +62,38 @@ EXPORT_SYMBOL(ioread32be);
void iowrite8(u8 val, void __iomem *addr)
{
+ int flags;
+ spin_lock_irqsave(&lbi_lock, flags);
writeb(val, addr);
+ spin_unlock_irqrestore(&lbi_lock, flags);
}
void iowrite16(u16 val, void __iomem *addr)
{
+ int ret, flags;
+ spin_lock_irqsave(&lbi_lock, flags);
writew(val, addr);
+ spin_unlock_irqrestore(&lbi_lock, flags);
}
void iowrite16be(u16 val, void __iomem *addr)
{
+ int flags;
+ spin_lock_irqsave(&lbi_lock, flags);
out_be16(addr, val);
+ spin_unlock_irqrestore(&lbi_lock, flags);
}
void iowrite32(u32 val, void __iomem *addr)
{
+ int flags;
+ spin_lock_irqsave(&lbi_lock, flags);
writel(val, addr);
+ spin_unlock_irqrestore(&lbi_lock, flags);
}
void iowrite32be(u32 val, void __iomem *addr)
{
+ int flags;
+ spin_lock_irqsave(&lbi_lock, flags);
out_be32(addr, val);
+ spin_unlock_irqrestore(&lbi_lock, flags);
}
EXPORT_SYMBOL(iowrite8);
EXPORT_SYMBOL(iowrite16);
@@ -74,15 +111,24 @@ EXPORT_SYMBOL(iowrite32be);
*/
void ioread8_rep(void __iomem *addr, void *dst, unsigned long count)
{
+ int flags;
+ spin_lock_irqsave(&lbi_lock, flags);
_insb((u8 __iomem *) addr, dst, count);
+ spin_unlock_irqrestore(&lbi_lock, flags);
}
void ioread16_rep(void __iomem *addr, void *dst, unsigned long count)
{
+ int flags;
+ spin_lock_irqsave(&lbi_lock, flags);
_insw_ns((u16 __iomem *) addr, dst, count);
+ spin_unlock_irqrestore(&lbi_lock, flags);
}
void ioread32_rep(void __iomem *addr, void *dst, unsigned long count)
{
+ int flags;
+ spin_lock_irqsave(&lbi_lock, flags);
_insl_ns((u32 __iomem *) addr, dst, count);
+ spin_unlock_irqrestore(&lbi_lock, flags);
}
EXPORT_SYMBOL(ioread8_rep);
EXPORT_SYMBOL(ioread16_rep);
@@ -90,15 +136,24 @@ EXPORT_SYMBOL(ioread32_rep);
void iowrite8_rep(void __iomem *addr, const void *src, unsigned long count)
{
+ int flags;
+ spin_lock_irqsave(&lbi_lock, flags);
_outsb((u8 __iomem *) addr, src, count);
+ spin_unlock_irqrestore(&lbi_lock, flags);
}
void iowrite16_rep(void __iomem *addr, const void *src, unsigned long count)
{
+ int flags;
+ spin_lock_irqsave(&lbi_lock, flags);
_outsw_ns((u16 __iomem *) addr, src, count);
+ spin_unlock_irqrestore(&lbi_lock, flags);
}
void iowrite32_rep(void __iomem *addr, const void *src, unsigned long count)
{
+ int flags;
+ spin_lock_irqsave(&lbi_lock, flags);
_outsl_ns((u32 __iomem *) addr, src, count);
+ spin_unlock_irqrestore(&lbi_lock, flags);
}
EXPORT_SYMBOL(iowrite8_rep);
EXPORT_SYMBOL(iowrite16_rep);
--
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