diff options
Diffstat (limited to 'drivers/s390/block/xpram.c')
| -rw-r--r-- | drivers/s390/block/xpram.c | 129 |
1 files changed, 126 insertions, 3 deletions
diff --git a/drivers/s390/block/xpram.c b/drivers/s390/block/xpram.c index 0ae0c83ef87..2e9e1ecd6d8 100644 --- a/drivers/s390/block/xpram.c +++ b/drivers/s390/block/xpram.c @@ -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; @@ -383,6 +387,106 @@ out: } /* + * 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. */ static void __exit xpram_exit(void) @@ -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); |