From: Michael Holzheu <holzheu@xxxxxxxxxx>
Signed-off-by: Michael Holzheu <holzheu@xxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
---
drivers/s390/block/xpram.c | 129 +++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 126 insertions(+), 3 deletions(-)
Index: linux-2.6/drivers/s390/block/xpram.c
===================================================================
--- linux-2.6.orig/drivers/s390/block/xpram.c
+++ linux-2.6/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 lon
/*
* 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);
--
blue skies,
Martin.
"Reality continues to ruin my life." - Calvin.
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