![Hitoshi Mitake](/assets/img/avatar_default.png)
This provides unified readq()/writeq() helper functions for 32-bit
drivers.
For some cases, readq/writeq without atomicity is harmful, and order of
io access has to be specified explicitly. So in this patch, new two
header files which contain non-atomic readq/writeq are added.
- <asm-generic/io-64-nonatomic-lo-hi.h> provides non-atomic readq/
writeq with the order of lower address -> higher address
- <asm-generic/io-64-nonatomic-hi-lo.h> provides non-atomic readq/
writeq with reversed order
This allows us to remove some readq()s that were added drivers when the
default non-atomic ones were removed in commit dbee8a0aff
("x86:
remove 32-bit versions of readq()/writeq()")
The drivers which need readq/writeq but can do with the non-atomic ones
must add the line:
#include <asm-generic/io-64-nonatomic-lo-hi.h> /* or hi-lo.h */
But this will be nop in 64-bit environments, and no other #ifdefs are
required. So I believe that this patch can solve the problem of
1. driver-specific readq/writeq
2. atomicity and order of io access
This patch is tested with building allyesconfig and allmodconfig as
ARCH=x86 and ARCH=i386 on top of tip/master.
Cc: Kashyap Desai <Kashyap.Desai@lsi.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Ravi Anand <ravi.anand@qlogic.com>
Cc: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Jason Uhlenkott <juhlenko@akamai.com>
Cc: James Bottomley <James.Bottomley@parallels.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: James Bottomley <jbottomley@parallels.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Hitoshi Mitake <h.mitake@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
329 lines
8.1 KiB
C
329 lines
8.1 KiB
C
/*
|
|
* IBM Real-Time Linux driver
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* 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.
|
|
*
|
|
* Copyright (C) IBM Corporation, 2010
|
|
*
|
|
* Author: Keith Mannthey <kmannth@us.ibm.com>
|
|
* Vernon Mauery <vernux@us.ibm.com>
|
|
*
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/module.h>
|
|
#include <linux/io.h>
|
|
#include <linux/dmi.h>
|
|
#include <linux/efi.h>
|
|
#include <linux/mutex.h>
|
|
#include <asm/bios_ebda.h>
|
|
|
|
#include <asm-generic/io-64-nonatomic-lo-hi.h>
|
|
|
|
static bool force;
|
|
module_param(force, bool, 0);
|
|
MODULE_PARM_DESC(force, "Force driver load, ignore DMI data");
|
|
|
|
static bool debug;
|
|
module_param(debug, bool, 0644);
|
|
MODULE_PARM_DESC(debug, "Show debug output");
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Keith Mannthey <kmmanth@us.ibm.com>");
|
|
MODULE_AUTHOR("Vernon Mauery <vernux@us.ibm.com>");
|
|
|
|
#define RTL_ADDR_TYPE_IO 1
|
|
#define RTL_ADDR_TYPE_MMIO 2
|
|
|
|
#define RTL_CMD_ENTER_PRTM 1
|
|
#define RTL_CMD_EXIT_PRTM 2
|
|
|
|
/* The RTL table as presented by the EBDA: */
|
|
struct ibm_rtl_table {
|
|
char signature[5]; /* signature should be "_RTL_" */
|
|
u8 version;
|
|
u8 rt_status;
|
|
u8 command;
|
|
u8 command_status;
|
|
u8 cmd_address_type;
|
|
u8 cmd_granularity;
|
|
u8 cmd_offset;
|
|
u16 reserve1;
|
|
u32 cmd_port_address; /* platform dependent address */
|
|
u32 cmd_port_value; /* platform dependent value */
|
|
} __attribute__((packed));
|
|
|
|
/* to locate "_RTL_" signature do a masked 5-byte integer compare */
|
|
#define RTL_SIGNATURE 0x0000005f4c54525fULL
|
|
#define RTL_MASK 0x000000ffffffffffULL
|
|
|
|
#define RTL_DEBUG(fmt, ...) \
|
|
do { \
|
|
if (debug) \
|
|
pr_info(fmt, ##__VA_ARGS__); \
|
|
} while (0)
|
|
|
|
static DEFINE_MUTEX(rtl_lock);
|
|
static struct ibm_rtl_table __iomem *rtl_table;
|
|
static void __iomem *ebda_map;
|
|
static void __iomem *rtl_cmd_addr;
|
|
static u8 rtl_cmd_type;
|
|
static u8 rtl_cmd_width;
|
|
|
|
static void __iomem *rtl_port_map(phys_addr_t addr, unsigned long len)
|
|
{
|
|
if (rtl_cmd_type == RTL_ADDR_TYPE_MMIO)
|
|
return ioremap(addr, len);
|
|
return ioport_map(addr, len);
|
|
}
|
|
|
|
static void rtl_port_unmap(void __iomem *addr)
|
|
{
|
|
if (addr && rtl_cmd_type == RTL_ADDR_TYPE_MMIO)
|
|
iounmap(addr);
|
|
else
|
|
ioport_unmap(addr);
|
|
}
|
|
|
|
static int ibm_rtl_write(u8 value)
|
|
{
|
|
int ret = 0, count = 0;
|
|
static u32 cmd_port_val;
|
|
|
|
RTL_DEBUG("%s(%d)\n", __func__, value);
|
|
|
|
value = value == 1 ? RTL_CMD_ENTER_PRTM : RTL_CMD_EXIT_PRTM;
|
|
|
|
mutex_lock(&rtl_lock);
|
|
|
|
if (ioread8(&rtl_table->rt_status) != value) {
|
|
iowrite8(value, &rtl_table->command);
|
|
|
|
switch (rtl_cmd_width) {
|
|
case 8:
|
|
cmd_port_val = ioread8(&rtl_table->cmd_port_value);
|
|
RTL_DEBUG("cmd_port_val = %u\n", cmd_port_val);
|
|
iowrite8((u8)cmd_port_val, rtl_cmd_addr);
|
|
break;
|
|
case 16:
|
|
cmd_port_val = ioread16(&rtl_table->cmd_port_value);
|
|
RTL_DEBUG("cmd_port_val = %u\n", cmd_port_val);
|
|
iowrite16((u16)cmd_port_val, rtl_cmd_addr);
|
|
break;
|
|
case 32:
|
|
cmd_port_val = ioread32(&rtl_table->cmd_port_value);
|
|
RTL_DEBUG("cmd_port_val = %u\n", cmd_port_val);
|
|
iowrite32(cmd_port_val, rtl_cmd_addr);
|
|
break;
|
|
}
|
|
|
|
while (ioread8(&rtl_table->command)) {
|
|
msleep(10);
|
|
if (count++ > 500) {
|
|
pr_err("Hardware not responding to "
|
|
"mode switch request\n");
|
|
ret = -EIO;
|
|
break;
|
|
}
|
|
|
|
}
|
|
|
|
if (ioread8(&rtl_table->command_status)) {
|
|
RTL_DEBUG("command_status reports failed command\n");
|
|
ret = -EIO;
|
|
}
|
|
}
|
|
|
|
mutex_unlock(&rtl_lock);
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t rtl_show_version(struct device *dev,
|
|
struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", (int)ioread8(&rtl_table->version));
|
|
}
|
|
|
|
static ssize_t rtl_show_state(struct device *dev,
|
|
struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
return sprintf(buf, "%d\n", ioread8(&rtl_table->rt_status));
|
|
}
|
|
|
|
static ssize_t rtl_set_state(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf,
|
|
size_t count)
|
|
{
|
|
ssize_t ret;
|
|
|
|
if (count < 1 || count > 2)
|
|
return -EINVAL;
|
|
|
|
switch (buf[0]) {
|
|
case '0':
|
|
ret = ibm_rtl_write(0);
|
|
break;
|
|
case '1':
|
|
ret = ibm_rtl_write(1);
|
|
break;
|
|
default:
|
|
ret = -EINVAL;
|
|
}
|
|
if (ret >= 0)
|
|
ret = count;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static struct bus_type rtl_subsys = {
|
|
.name = "ibm_rtl",
|
|
.dev_name = "ibm_rtl",
|
|
};
|
|
|
|
static DEVICE_ATTR(version, S_IRUGO, rtl_show_version, NULL);
|
|
static DEVICE_ATTR(state, 0600, rtl_show_state, rtl_set_state);
|
|
|
|
static struct device_attribute *rtl_attributes[] = {
|
|
&dev_attr_version,
|
|
&dev_attr_state,
|
|
NULL
|
|
};
|
|
|
|
|
|
static int rtl_setup_sysfs(void) {
|
|
int ret, i;
|
|
|
|
ret = subsys_system_register(&rtl_subsys, NULL);
|
|
if (!ret) {
|
|
for (i = 0; rtl_attributes[i]; i ++)
|
|
device_create_file(rtl_subsys.dev_root, rtl_attributes[i]);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void rtl_teardown_sysfs(void) {
|
|
int i;
|
|
for (i = 0; rtl_attributes[i]; i ++)
|
|
device_remove_file(rtl_subsys.dev_root, rtl_attributes[i]);
|
|
bus_unregister(&rtl_subsys);
|
|
}
|
|
|
|
|
|
static struct dmi_system_id __initdata ibm_rtl_dmi_table[] = {
|
|
{ \
|
|
.matches = { \
|
|
DMI_MATCH(DMI_SYS_VENDOR, "IBM"), \
|
|
}, \
|
|
},
|
|
{ }
|
|
};
|
|
|
|
static int __init ibm_rtl_init(void) {
|
|
unsigned long ebda_addr, ebda_size;
|
|
unsigned int ebda_kb;
|
|
int ret = -ENODEV, i;
|
|
|
|
if (force)
|
|
pr_warn("module loaded by force\n");
|
|
/* first ensure that we are running on IBM HW */
|
|
else if (efi_enabled || !dmi_check_system(ibm_rtl_dmi_table))
|
|
return -ENODEV;
|
|
|
|
/* Get the address for the Extended BIOS Data Area */
|
|
ebda_addr = get_bios_ebda();
|
|
if (!ebda_addr) {
|
|
RTL_DEBUG("no BIOS EBDA found\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
ebda_map = ioremap(ebda_addr, 4);
|
|
if (!ebda_map)
|
|
return -ENOMEM;
|
|
|
|
/* First word in the EDBA is the Size in KB */
|
|
ebda_kb = ioread16(ebda_map);
|
|
RTL_DEBUG("EBDA is %d kB\n", ebda_kb);
|
|
|
|
if (ebda_kb == 0)
|
|
goto out;
|
|
|
|
iounmap(ebda_map);
|
|
ebda_size = ebda_kb*1024;
|
|
|
|
/* Remap the whole table */
|
|
ebda_map = ioremap(ebda_addr, ebda_size);
|
|
if (!ebda_map)
|
|
return -ENOMEM;
|
|
|
|
/* search for the _RTL_ signature at the start of the table */
|
|
for (i = 0 ; i < ebda_size/sizeof(unsigned int); i++) {
|
|
struct ibm_rtl_table __iomem * tmp;
|
|
tmp = (struct ibm_rtl_table __iomem *) (ebda_map+i);
|
|
if ((readq(&tmp->signature) & RTL_MASK) == RTL_SIGNATURE) {
|
|
phys_addr_t addr;
|
|
unsigned int plen;
|
|
RTL_DEBUG("found RTL_SIGNATURE at %p\n", tmp);
|
|
rtl_table = tmp;
|
|
/* The address, value, width and offset are platform
|
|
* dependent and found in the ibm_rtl_table */
|
|
rtl_cmd_width = ioread8(&rtl_table->cmd_granularity);
|
|
rtl_cmd_type = ioread8(&rtl_table->cmd_address_type);
|
|
RTL_DEBUG("rtl_cmd_width = %u, rtl_cmd_type = %u\n",
|
|
rtl_cmd_width, rtl_cmd_type);
|
|
addr = ioread32(&rtl_table->cmd_port_address);
|
|
RTL_DEBUG("addr = %#llx\n", (unsigned long long)addr);
|
|
plen = rtl_cmd_width/sizeof(char);
|
|
rtl_cmd_addr = rtl_port_map(addr, plen);
|
|
RTL_DEBUG("rtl_cmd_addr = %p\n", rtl_cmd_addr);
|
|
if (!rtl_cmd_addr) {
|
|
ret = -ENOMEM;
|
|
break;
|
|
}
|
|
ret = rtl_setup_sysfs();
|
|
break;
|
|
}
|
|
}
|
|
|
|
out:
|
|
if (ret) {
|
|
iounmap(ebda_map);
|
|
rtl_port_unmap(rtl_cmd_addr);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void __exit ibm_rtl_exit(void)
|
|
{
|
|
if (rtl_table) {
|
|
RTL_DEBUG("cleaning up");
|
|
/* do not leave the machine in SMI-free mode */
|
|
ibm_rtl_write(0);
|
|
/* unmap, unlink and remove all traces */
|
|
rtl_teardown_sysfs();
|
|
iounmap(ebda_map);
|
|
rtl_port_unmap(rtl_cmd_addr);
|
|
}
|
|
}
|
|
|
|
module_init(ibm_rtl_init);
|
|
module_exit(ibm_rtl_exit);
|