linux/arch/mips/lib/iomap.c
Markos Chandras 0845bb721e MIPS: iomap: Use __mem_{read,write}{b,w,l} for MMIO
Using the __raw_{read,write}{b,w,l} functions to perform
repeatable MMIO could result in problems if the host bus
does not match the endianness of the PCI/ISA. This problem
is visible on big-endian SEAD3 configurations after commit
2925f6c0c7
"net: smc911x: use io{read,write}*_rep accessors". This effectively
moves away from using the __mem_* variants to __raw_* ones
and causes a kernel bug as follows:

Call Trace:
CPU 0 Unable to handle kernel paging request at virtual address 00000000,
epc == 00000000, ra == 8012b3b0
Oops[#1]:
Cpu 0
$ 0   : 00000000 00000065 00000000 00000004
$ 4   : 00000000 00000000 9a82dd60 00000000
$ 8   : 00000000 00000000 a00ae278 00000007
$12   : 0000000e 00000011 804c4228 ffff9411
$16   : 00000100 00000000 80560000 807fc6d0
$20   : 807fc8d0 807fcad0 807fbec0 00000100
$24   : 00009150 80109be0
$28   : 9a82c000 9a82dd28 00000001 8012b3b0
Hi    : 00000000
Lo    : 00000000
epc   : 00000000   (null)
    Not tainted
ra    : 8012b3b0 call_timer_fn.isra.39+0x24/0x84
Status: 10009503    KERNEL EXL IE
Cause : 00800808
BadVA : 00000000
PrId  : 00019c20 (MIPS M14Kc)
Modules linked in:
Process swapper (pid: 1, threadinfo=9a82c000, task=9a82ba18, tls=00000000)
Stack : 00000040 00000000 00000007 8056732c 80580000 00000001 9a82dd60 00200200
        80560000 8012b598 8056732c 80580000 00000001 00000000 9a82dd60 9a82dd60
        00000000 807fbd44 807fbd40 805664e0 0000000a 80800000 00000004 80125924
        0000fda0 000007f0 80000000 00000001 80800000 007f0000 00200140 80166338
        00000000 8100fda0 0000fda0 000007f0 80000000 00000001 80800000 007f0000
        ...
Call Trace:
[<8012b598>] run_timer_softirq+0x188/0x1f4
[<80125924>] __do_softirq+0xc4/0x18c
[<80166338>] handle_percpu_irq+0x54/0x84
[<80125aa4>] do_softirq+0x68/0x70
[<80103b50>] do_IRQ+0x18/0x28
[<80125d1c>] irq_exit+0x94/0xc0
[<80125aa4>] do_softirq+0x68/0x70
[<80102130>] ret_from_irq+0x0/0x4
[<80102130>] ret_from_irq+0x0/0x4
[<80125d1c>] irq_exit+0x94/0xc0
[<803165b0>] __bzero+0xd4/0x164
[<80346d0c>] mem32_serial_out+0x0/0x1c
[<8010d4ac>] free_init_pages+0x98/0xfc
[<80180a08>] free_hot_cold_page+0x2c/0x1c4
[<80180bd8>] __free_pages+0x38/0x98
[<8010d4a0>] free_init_pages+0x8c/0xfc
[<8010d4ac>] free_init_pages+0x98/0xfc
[<8049fb04>] kernel_init+0x28/0x15c
[<80147484>] schedule_tail+0x1c/0x60
[<8049fadc>] kernel_init+0x0/0x15c
[<80102178>] ret_from_kernel_thread+0x14/0x1c
[<8040a06f>] skb_pad+0xe7/0x13c

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: Steve Glendinning <steve.glendinning@shawell.net>
Cc: Ben Boeckel <mathstuf@gmail.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Cc: Jeffrey Deans <Jeffrey.Deans@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6672/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:42 +01:00

227 lines
4.5 KiB
C

/*
* Implement the default iomap interfaces
*
* (C) Copyright 2004 Linus Torvalds
* (C) Copyright 2006 Ralf Baechle <ralf@linux-mips.org>
* (C) Copyright 2007 MIPS Technologies, Inc.
* written by Ralf Baechle <ralf@linux-mips.org>
*/
#include <linux/module.h>
#include <asm/io.h>
/*
* Read/write from/to an (offsettable) iomem cookie. It might be a PIO
* access or a MMIO access, these functions don't care. The info is
* encoded in the hardware mapping set up by the mapping functions
* (or the cookie itself, depending on implementation and hw).
*
* The generic routines don't assume any hardware mappings, and just
* encode the PIO/MMIO as part of the cookie. They coldly assume that
* the MMIO IO mappings are not in the low address range.
*
* Architectures for which this is not true can't use this generic
* implementation and should do their own copy.
*/
#define PIO_MASK 0x0ffffUL
unsigned int ioread8(void __iomem *addr)
{
return readb(addr);
}
EXPORT_SYMBOL(ioread8);
unsigned int ioread16(void __iomem *addr)
{
return readw(addr);
}
EXPORT_SYMBOL(ioread16);
unsigned int ioread16be(void __iomem *addr)
{
return be16_to_cpu(__raw_readw(addr));
}
EXPORT_SYMBOL(ioread16be);
unsigned int ioread32(void __iomem *addr)
{
return readl(addr);
}
EXPORT_SYMBOL(ioread32);
unsigned int ioread32be(void __iomem *addr)
{
return be32_to_cpu(__raw_readl(addr));
}
EXPORT_SYMBOL(ioread32be);
void iowrite8(u8 val, void __iomem *addr)
{
writeb(val, addr);
}
EXPORT_SYMBOL(iowrite8);
void iowrite16(u16 val, void __iomem *addr)
{
writew(val, addr);
}
EXPORT_SYMBOL(iowrite16);
void iowrite16be(u16 val, void __iomem *addr)
{
__raw_writew(cpu_to_be16(val), addr);
}
EXPORT_SYMBOL(iowrite16be);
void iowrite32(u32 val, void __iomem *addr)
{
writel(val, addr);
}
EXPORT_SYMBOL(iowrite32);
void iowrite32be(u32 val, void __iomem *addr)
{
__raw_writel(cpu_to_be32(val), addr);
}
EXPORT_SYMBOL(iowrite32be);
/*
* These are the "repeat MMIO read/write" functions.
* Note the "__mem" accesses, since we want to convert
* to CPU byte order if the host bus happens to not match the
* endianness of PCI/ISA (see mach-generic/mangle-port.h).
*/
static inline void mmio_insb(void __iomem *addr, u8 *dst, int count)
{
while (--count >= 0) {
u8 data = __mem_readb(addr);
*dst = data;
dst++;
}
}
static inline void mmio_insw(void __iomem *addr, u16 *dst, int count)
{
while (--count >= 0) {
u16 data = __mem_readw(addr);
*dst = data;
dst++;
}
}
static inline void mmio_insl(void __iomem *addr, u32 *dst, int count)
{
while (--count >= 0) {
u32 data = __mem_readl(addr);
*dst = data;
dst++;
}
}
static inline void mmio_outsb(void __iomem *addr, const u8 *src, int count)
{
while (--count >= 0) {
__mem_writeb(*src, addr);
src++;
}
}
static inline void mmio_outsw(void __iomem *addr, const u16 *src, int count)
{
while (--count >= 0) {
__mem_writew(*src, addr);
src++;
}
}
static inline void mmio_outsl(void __iomem *addr, const u32 *src, int count)
{
while (--count >= 0) {
__mem_writel(*src, addr);
src++;
}
}
void ioread8_rep(void __iomem *addr, void *dst, unsigned long count)
{
mmio_insb(addr, dst, count);
}
EXPORT_SYMBOL(ioread8_rep);
void ioread16_rep(void __iomem *addr, void *dst, unsigned long count)
{
mmio_insw(addr, dst, count);
}
EXPORT_SYMBOL(ioread16_rep);
void ioread32_rep(void __iomem *addr, void *dst, unsigned long count)
{
mmio_insl(addr, dst, count);
}
EXPORT_SYMBOL(ioread32_rep);
void iowrite8_rep(void __iomem *addr, const void *src, unsigned long count)
{
mmio_outsb(addr, src, count);
}
EXPORT_SYMBOL(iowrite8_rep);
void iowrite16_rep(void __iomem *addr, const void *src, unsigned long count)
{
mmio_outsw(addr, src, count);
}
EXPORT_SYMBOL(iowrite16_rep);
void iowrite32_rep(void __iomem *addr, const void *src, unsigned long count)
{
mmio_outsl(addr, src, count);
}
EXPORT_SYMBOL(iowrite32_rep);
/*
* Create a virtual mapping cookie for an IO port range
*
* This uses the same mapping are as the in/out family which has to be setup
* by the platform initialization code.
*
* Just to make matters somewhat more interesting on MIPS systems with
* multiple host bridge each will have it's own ioport address space.
*/
static void __iomem *ioport_map_legacy(unsigned long port, unsigned int nr)
{
return (void __iomem *) (mips_io_port_base + port);
}
void __iomem *ioport_map(unsigned long port, unsigned int nr)
{
if (port > PIO_MASK)
return NULL;
return ioport_map_legacy(port, nr);
}
EXPORT_SYMBOL(ioport_map);
void ioport_unmap(void __iomem *addr)
{
/* Nothing to do */
}
EXPORT_SYMBOL(ioport_unmap);