[S390] pm: xpram driver power management callbacks

Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/drivers/s390/block/xpram.c b/drivers/s390/block/xpram.c
index 0ae0c83..2e9e1ec 100644 (file)
--- 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);