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[S390] pm: xpram driver power management callbacks

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Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Michael Holzheu 2009-06-16 10:30:27 +02:00 committed by Martin Schwidefsky
parent 7db11a363f
commit 14532095df
1 changed files with 126 additions and 3 deletions
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129
drivers/s390/block/xpram.c
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@ -39,7 +39,10 @@
#include <linux/hdreg.h> /* HDIO_GETGEO */
#include <linux/sysdev.h>
#include <linux/bio.h>
#include <linux/suspend.h>
#include <linux/platform_device.h>
#include <asm/uaccess.h>
#include <asm/checksum.h>
#define XPRAM_NAME "xpram"
#define XPRAM_DEVS 1 /* one partition */
@ -48,6 +51,7 @@
typedef struct {
unsigned int size; /* size of xpram segment in pages */
unsigned int offset; /* start page of xpram segment */
unsigned int csum; /* partition checksum for suspend */
} xpram_device_t;
static xpram_device_t xpram_devices[XPRAM_MAX_DEVS];
@ -138,7 +142,7 @@ static long xpram_page_out (unsigned long page_addr, unsigned int xpage_index)
/*
* Check if xpram is available.
*/
static int __init xpram_present(void)
static int xpram_present(void)
{
unsigned long mem_page;
int rc;
@ -154,7 +158,7 @@ static int __init xpram_present(void)
/*
* Return index of the last available xpram page.
*/
static unsigned long __init xpram_highest_page_index(void)
static unsigned long xpram_highest_page_index(void)
{
unsigned int page_index, add_bit;
unsigned long mem_page;
@ -382,6 +386,106 @@ static int __init xpram_setup_blkdev(void)
return rc;
}
/*
* Save checksums for all partitions.
*/
static int xpram_save_checksums(void)
{
unsigned long mem_page;
int rc, i;
rc = 0;
mem_page = (unsigned long) __get_free_page(GFP_KERNEL);
if (!mem_page)
return -ENOMEM;
for (i = 0; i < xpram_devs; i++) {
rc = xpram_page_in(mem_page, xpram_devices[i].offset);
if (rc)
goto fail;
xpram_devices[i].csum = csum_partial((const void *) mem_page,
PAGE_SIZE, 0);
}
fail:
free_page(mem_page);
return rc ? -ENXIO : 0;
}
/*
* Verify checksums for all partitions.
*/
static int xpram_validate_checksums(void)
{
unsigned long mem_page;
unsigned int csum;
int rc, i;
rc = 0;
mem_page = (unsigned long) __get_free_page(GFP_KERNEL);
if (!mem_page)
return -ENOMEM;
for (i = 0; i < xpram_devs; i++) {
rc = xpram_page_in(mem_page, xpram_devices[i].offset);
if (rc)
goto fail;
csum = csum_partial((const void *) mem_page, PAGE_SIZE, 0);
if (xpram_devices[i].csum != csum) {
rc = -EINVAL;
goto fail;
}
}
fail:
free_page(mem_page);
return rc ? -ENXIO : 0;
}
/*
* Resume failed: Print error message and call panic.
*/
static void xpram_resume_error(const char *message)
{
pr_err("Resume error: %s\n", message);
panic("xpram resume error\n");
}
/*
* Check if xpram setup changed between suspend and resume.
*/
static int xpram_restore(struct device *dev)
{
if (!xpram_pages)
return 0;
if (xpram_present() != 0)
xpram_resume_error("xpram disappeared");
if (xpram_pages != xpram_highest_page_index() + 1)
xpram_resume_error("Size of xpram changed");
if (xpram_validate_checksums())
xpram_resume_error("Data of xpram changed");
return 0;
}
/*
* Save necessary state in suspend.
*/
static int xpram_freeze(struct device *dev)
{
return xpram_save_checksums();
}
static struct dev_pm_ops xpram_pm_ops = {
.freeze = xpram_freeze,
.restore = xpram_restore,
};
static struct platform_driver xpram_pdrv = {
.driver = {
.name = XPRAM_NAME,
.owner = THIS_MODULE,
.pm = &xpram_pm_ops,
},
};
static struct platform_device *xpram_pdev;
/*
* Finally, the init/exit functions.
*/
@ -394,6 +498,8 @@ static void __exit xpram_exit(void)
put_disk(xpram_disks[i]);
}
unregister_blkdev(XPRAM_MAJOR, XPRAM_NAME);
platform_device_unregister(xpram_pdev);
platform_driver_unregister(&xpram_pdrv);
}
static int __init xpram_init(void)
@ -411,7 +517,24 @@ static int __init xpram_init(void)
rc = xpram_setup_sizes(xpram_pages);
if (rc)
return rc;
return xpram_setup_blkdev();
rc = platform_driver_register(&xpram_pdrv);
if (rc)
return rc;
xpram_pdev = platform_device_register_simple(XPRAM_NAME, -1, NULL, 0);
if (IS_ERR(xpram_pdev)) {
rc = PTR_ERR(xpram_pdev);
goto fail_platform_driver_unregister;
}
rc = xpram_setup_blkdev();
if (rc)
goto fail_platform_device_unregister;
return 0;
fail_platform_device_unregister:
platform_device_unregister(xpram_pdev);
fail_platform_driver_unregister:
platform_driver_unregister(&xpram_pdrv);
return rc;
}
module_init(xpram_init);