[S390] pm: xpram driver power management callbacks (14532095) · Commits · e / devices / android_kernel_teracube_emerald

drivers/s390/block/xpram.c

+126 −3

Original line number	Diff line number	Diff line
		@@ -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);