1 files changed, 539 insertions, 0 deletions

diff --git a/drivers/s390/block/xpram.c b/drivers/s390/block/xpram.c
new file mode 100644
index 000000000000..d428c909b8a0
--- /dev/null
+++ b/drivers/s390/block/xpram.c
@@ -0,0 +1,539 @@
+/*
+ * Xpram.c -- the S/390 expanded memory RAM-disk
+ *           
+ * significant parts of this code are based on
+ * the sbull device driver presented in
+ * A. Rubini: Linux Device Drivers
+ *
+ * Author of XPRAM specific coding: Reinhard Buendgen
+ *                                  buendgen@de.ibm.com
+ * Rewrite for 2.5: Martin Schwidefsky <schwidefsky@de.ibm.com>
+ *
+ * External interfaces:
+ *   Interfaces to linux kernel
+ *        xpram_setup: read kernel parameters
+ *   Device specific file operations
+ *        xpram_iotcl
+ *        xpram_open
+ *
+ * "ad-hoc" partitioning:
+ *    the expanded memory can be partitioned among several devices 
+ *    (with different minors). The partitioning set up can be
+ *    set by kernel or module parameters (int devs & int sizes[])
+ *
+ * Potential future improvements:
+ *   generic hard disk support to replace ad-hoc partitioning
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/ctype.h>  /* isdigit, isxdigit */
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/blkdev.h>
+#include <linux/blkpg.h>
+#include <linux/hdreg.h>  /* HDIO_GETGEO */
+#include <linux/sysdev.h>
+#include <linux/bio.h>
+#include <linux/devfs_fs_kernel.h>
+#include <asm/uaccess.h>
+
+#define XPRAM_NAME      "xpram"
+#define XPRAM_DEVS      1       /* one partition */
+#define XPRAM_MAX_DEVS  32      /* maximal number of devices (partitions) */
+
+#define PRINT_DEBUG(x...)       printk(KERN_DEBUG XPRAM_NAME " debug:" x)
+#define PRINT_INFO(x...)        printk(KERN_INFO XPRAM_NAME " info:" x)
+#define PRINT_WARN(x...)        printk(KERN_WARNING XPRAM_NAME " warning:" x)
+#define PRINT_ERR(x...)         printk(KERN_ERR XPRAM_NAME " error:" x)
+
+
+static struct sysdev_class xpram_sysclass = {
+        set_kset_name("xpram"),
+};
+
+static struct sys_device xpram_sys_device = {
+        .id     = 0,
+        .cls    = &xpram_sysclass,
+}; 
+
+typedef struct {
+        unsigned int    size;           /* size of xpram segment in pages */
+        unsigned int    offset;         /* start page of xpram segment */
+} xpram_device_t;
+
+static xpram_device_t xpram_devices[XPRAM_MAX_DEVS];
+static unsigned int xpram_sizes[XPRAM_MAX_DEVS];
+static struct gendisk *xpram_disks[XPRAM_MAX_DEVS];
+static unsigned int xpram_pages;
+static int xpram_devs;
+
+/*
+ * Parameter parsing functions.
+ */
+static int devs = XPRAM_DEVS;
+static unsigned int sizes[XPRAM_MAX_DEVS];
+
+module_param(devs, int, 0);
+module_param_array(sizes, int, NULL, 0);
+
+MODULE_PARM_DESC(devs, "number of devices (\"partitions\"), " \
+                 "the default is " __MODULE_STRING(XPRAM_DEVS) "\n");
+MODULE_PARM_DESC(sizes, "list of device (partition) sizes " \
+                 "the defaults are 0s \n" \
+                 "All devices with size 0 equally partition the "
+                 "remaining space on the expanded strorage not "
+                 "claimed by explicit sizes\n");
+MODULE_LICENSE("GPL");
+
+#ifndef MODULE
+/*
+ * Parses the kernel parameters given in the kernel parameter line.
+ * The expected format is
+ *           <number_of_partitions>[","<partition_size>]*
+ * where
+ *           devices is a positive integer that initializes xpram_devs
+ *           each size is a non-negative integer possibly followed by a
+ *           magnitude (k,K,m,M,g,G), the list of sizes initialises
+ *           xpram_sizes
+ *
+ * Arguments
+ *           str: substring of kernel parameter line that contains xprams
+ *                kernel parameters.
+ *
+ * Result    0 on success, -EINVAL else -- only for Version > 2.3
+ *
+ * Side effects
+ *           the global variabls devs is set to the value of
+ *           <number_of_partitions> and sizes[i] is set to the i-th
+ *           partition size (if provided). A parsing error of a value
+ *           results in this value being set to -EINVAL.
+ */
+static int __init xpram_setup (char *str)
+{
+        char *cp;
+        int i;
+
+        devs = simple_strtoul(str, &cp, 10);
+        if (cp <= str || devs > XPRAM_MAX_DEVS)
+                return 0;
+        for (i = 0; (i < devs) && (*cp++ == ','); i++) {
+                sizes[i] = simple_strtoul(cp, &cp, 10);
+                if (*cp == 'g' || *cp == 'G') {
+                        sizes[i] <<= 20;
+                        cp++;
+                } else if (*cp == 'm' || *cp == 'M') {
+                        sizes[i] <<= 10;
+                        cp++;
+                } else if (*cp == 'k' || *cp == 'K')
+                        cp++;
+                while (isspace(*cp)) cp++;
+        }
+        if (*cp == ',' && i >= devs)
+                PRINT_WARN("partition sizes list has too many entries.\n");
+        else if (*cp != 0)
+                PRINT_WARN("ignored '%s' at end of parameter string.\n", cp);
+        return 1;
+}
+
+__setup("xpram_parts=", xpram_setup);
+#endif
+
+/*
+ * Copy expanded memory page (4kB) into main memory                  
+ * Arguments                                                         
+ *           page_addr:    address of target page                    
+ *           xpage_index:  index of expandeded memory page           
+ * Return value                                                      
+ *           0:            if operation succeeds
+ *           -EIO:         if pgin failed
+ *           -ENXIO:       if xpram has vanished
+ */
+static int xpram_page_in (unsigned long page_addr, unsigned int xpage_index)
+{
+        int cc;
+
+        __asm__ __volatile__ (
+                "   lhi   %0,2\n"  /* return unused cc 2 if pgin traps */
+                "   .insn rre,0xb22e0000,%1,%2\n"  /* pgin %1,%2 */
+                "0: ipm   %0\n"
+                "   srl   %0,28\n"
+                "1:\n"
+#ifndef CONFIG_ARCH_S390X
+                ".section __ex_table,\"a\"\n"
+                "   .align 4\n"
+                "   .long  0b,1b\n"
+                ".previous"
+#else
+                ".section __ex_table,\"a\"\n"
+                "   .align 8\n"
+                "   .quad 0b,1b\n"
+                ".previous"
+#endif
+                : "=&d" (cc) 
+                : "a" (__pa(page_addr)), "a" (xpage_index) 
+                : "cc" );
+        if (cc == 3)
+                return -ENXIO;
+        if (cc == 2) {
+                PRINT_ERR("expanded storage lost!\n");
+                return -ENXIO;
+        }
+        if (cc == 1) {
+                PRINT_ERR("page in failed for page index %u.\n",
+                          xpage_index);
+                return -EIO;
+        }
+        return 0;
+}
+
+/*
+ * Copy a 4kB page of main memory to an expanded memory page          
+ * Arguments                                                          
+ *           page_addr:    address of source page                     
+ *           xpage_index:  index of expandeded memory page            
+ * Return value                                                       
+ *           0:            if operation succeeds
+ *           -EIO:         if pgout failed
+ *           -ENXIO:       if xpram has vanished
+ */
+static long xpram_page_out (unsigned long page_addr, unsigned int xpage_index)
+{
+        int cc;
+
+        __asm__ __volatile__ (
+                "   lhi   %0,2\n"  /* return unused cc 2 if pgout traps */
+                "   .insn rre,0xb22f0000,%1,%2\n"  /* pgout %1,%2 */
+                "0: ipm   %0\n"
+                "   srl   %0,28\n"
+                "1:\n"
+#ifndef CONFIG_ARCH_S390X
+                ".section __ex_table,\"a\"\n"
+                "   .align 4\n"
+                "   .long  0b,1b\n"
+                ".previous"
+#else
+                ".section __ex_table,\"a\"\n"
+                "   .align 8\n"
+                "   .quad 0b,1b\n"
+                ".previous"
+#endif
+                : "=&d" (cc) 
+                : "a" (__pa(page_addr)), "a" (xpage_index) 
+                : "cc" );
+        if (cc == 3)
+                return -ENXIO;
+        if (cc == 2) {
+                PRINT_ERR("expanded storage lost!\n");
+                return -ENXIO;
+        }
+        if (cc == 1) {
+                PRINT_ERR("page out failed for page index %u.\n",
+                          xpage_index);
+                return -EIO;
+        }
+        return 0;
+}
+
+/*
+ * Check if xpram is available.
+ */
+static int __init xpram_present(void)
+{
+        unsigned long mem_page;
+        int rc;
+
+        mem_page = (unsigned long) __get_free_page(GFP_KERNEL);
+        if (!mem_page)
+                return -ENOMEM;
+        rc = xpram_page_in(mem_page, 0);
+        free_page(mem_page);
+        return rc ? -ENXIO : 0;
+}
+
+/*
+ * Return index of the last available xpram page.
+ */
+static unsigned long __init xpram_highest_page_index(void)
+{
+        unsigned int page_index, add_bit;
+        unsigned long mem_page;
+
+        mem_page = (unsigned long) __get_free_page(GFP_KERNEL);
+        if (!mem_page)
+                return 0;
+
+        page_index = 0;
+        add_bit = 1ULL << (sizeof(unsigned int)*8 - 1);
+        while (add_bit > 0) {
+                if (xpram_page_in(mem_page, page_index | add_bit) == 0)
+                        page_index |= add_bit;
+                add_bit >>= 1;
+        }
+
+        free_page (mem_page);
+
+        return page_index;
+}
+
+/*
+ * Block device make request function.
+ */
+static int xpram_make_request(request_queue_t *q, struct bio *bio)
+{
+        xpram_device_t *xdev = bio->bi_bdev->bd_disk->private_data;
+        struct bio_vec *bvec;
+        unsigned int index;
+        unsigned long page_addr;
+        unsigned long bytes;
+        int i;
+
+        if ((bio->bi_sector & 7) != 0 || (bio->bi_size & 4095) != 0)
+                /* Request is not page-aligned. */
+                goto fail;
+        if ((bio->bi_size >> 12) > xdev->size)
+                /* Request size is no page-aligned. */
+                goto fail;
+        if ((bio->bi_sector >> 3) > 0xffffffffU - xdev->offset)
+                goto fail;
+        index = (bio->bi_sector >> 3) + xdev->offset;
+        bio_for_each_segment(bvec, bio, i) {
+                page_addr = (unsigned long)
+                        kmap(bvec->bv_page) + bvec->bv_offset;
+                bytes = bvec->bv_len;
+                if ((page_addr & 4095) != 0 || (bytes & 4095) != 0)
+                        /* More paranoia. */
+                        goto fail;
+                while (bytes > 0) {
+                        if (bio_data_dir(bio) == READ) {
+                                if (xpram_page_in(page_addr, index) != 0)
+                                        goto fail;
+                        } else {
+                                if (xpram_page_out(page_addr, index) != 0)
+                                        goto fail;
+                        }
+                        page_addr += 4096;
+                        bytes -= 4096;
+                        index++;
+                }
+        }
+        set_bit(BIO_UPTODATE, &bio->bi_flags);
+        bytes = bio->bi_size;
+        bio->bi_size = 0;
+        bio->bi_end_io(bio, bytes, 0);
+        return 0;
+fail:
+        bio_io_error(bio, bio->bi_size);
+        return 0;
+}
+
+static int xpram_ioctl (struct inode *inode, struct file *filp,
+                 unsigned int cmd, unsigned long arg)
+{
+        struct hd_geometry __user *geo;
+        unsigned long size;
+        if (cmd != HDIO_GETGEO)
+                return -EINVAL;
+        /*
+         * get geometry: we have to fake one...  trim the size to a
+         * multiple of 64 (32k): tell we have 16 sectors, 4 heads,
+         * whatever cylinders. Tell also that data starts at sector. 4.
+         */
+        geo = (struct hd_geometry __user *) arg;
+        size = (xpram_pages * 8) & ~0x3f;
+        put_user(size >> 6, &geo->cylinders);
+        put_user(4, &geo->heads);
+        put_user(16, &geo->sectors);
+        put_user(4, &geo->start);
+        return 0;
+}
+
+static struct block_device_operations xpram_devops =
+{
+        .owner  = THIS_MODULE,
+        .ioctl  = xpram_ioctl,
+};
+
+/*
+ * Setup xpram_sizes array.
+ */
+static int __init xpram_setup_sizes(unsigned long pages)
+{
+        unsigned long mem_needed;
+        unsigned long mem_auto;
+        int mem_auto_no;
+        int i;
+
+        /* Check number of devices. */
+        if (devs <= 0 || devs > XPRAM_MAX_DEVS) {
+                PRINT_ERR("invalid number %d of devices\n",devs);
+                return -EINVAL;
+        }
+        xpram_devs = devs;
+
+        /*
+         * Copy sizes array to xpram_sizes and align partition
+         * sizes to page boundary.
+         */
+        mem_needed = 0;
+        mem_auto_no = 0;
+        for (i = 0; i < xpram_devs; i++) {
+                xpram_sizes[i] = (sizes[i] + 3) & -4UL;
+                if (xpram_sizes[i])
+                        mem_needed += xpram_sizes[i];
+                else
+                        mem_auto_no++;
+        }
+        
+        PRINT_INFO("  number of devices (partitions): %d \n", xpram_devs);
+        for (i = 0; i < xpram_devs; i++) {
+                if (xpram_sizes[i])
+                        PRINT_INFO("  size of partition %d: %u kB\n",
+                                   i, xpram_sizes[i]);
+                else
+                        PRINT_INFO("  size of partition %d to be set "
+                                   "automatically\n",i);
+        }
+        PRINT_DEBUG("  memory needed (for sized partitions): %lu kB\n",
+                    mem_needed);
+        PRINT_DEBUG("  partitions to be sized automatically: %d\n",
+                    mem_auto_no);
+
+        if (mem_needed > pages * 4) {
+                PRINT_ERR("Not enough expanded memory available\n");
+                return -EINVAL;
+        }
+
+        /*
+         * partitioning:
+         * xpram_sizes[i] != 0; partition i has size xpram_sizes[i] kB
+         * else:             ; all partitions with zero xpram_sizes[i]
+         *                     partition equally the remaining space
+         */
+        if (mem_auto_no) {
+                mem_auto = ((pages - mem_needed / 4) / mem_auto_no) * 4;
+                PRINT_INFO("  automatically determined "
+                           "partition size: %lu kB\n", mem_auto);
+                for (i = 0; i < xpram_devs; i++)
+                        if (xpram_sizes[i] == 0)
+                                xpram_sizes[i] = mem_auto;
+        }
+        return 0;
+}
+
+static struct request_queue *xpram_queue;
+
+static int __init xpram_setup_blkdev(void)
+{
+        unsigned long offset;
+        int i, rc = -ENOMEM;
+
+        for (i = 0; i < xpram_devs; i++) {
+                struct gendisk *disk = alloc_disk(1);
+                if (!disk)
+                        goto out;
+                xpram_disks[i] = disk;
+        }
+
+        /*
+         * Register xpram major.
+         */
+        rc = register_blkdev(XPRAM_MAJOR, XPRAM_NAME);
+        if (rc < 0)
+                goto out;
+
+        devfs_mk_dir("slram");
+
+        /*
+         * Assign the other needed values: make request function, sizes and
+         * hardsect size. All the minor devices feature the same value.
+         */
+        xpram_queue = blk_alloc_queue(GFP_KERNEL);
+        if (!xpram_queue) {
+                rc = -ENOMEM;
+                goto out_unreg;
+        }
+        blk_queue_make_request(xpram_queue, xpram_make_request);
+        blk_queue_hardsect_size(xpram_queue, 4096);
+
+        /*
+         * Setup device structures.
+         */
+        offset = 0;
+        for (i = 0; i < xpram_devs; i++) {
+                struct gendisk *disk = xpram_disks[i];
+
+                xpram_devices[i].size = xpram_sizes[i] / 4;
+                xpram_devices[i].offset = offset;
+                offset += xpram_devices[i].size;
+                disk->major = XPRAM_MAJOR;
+                disk->first_minor = i;
+                disk->fops = &xpram_devops;
+                disk->private_data = &xpram_devices[i];
+                disk->queue = xpram_queue;
+                sprintf(disk->disk_name, "slram%d", i);
+                sprintf(disk->devfs_name, "slram/%d", i);
+                set_capacity(disk, xpram_sizes[i] << 1);
+                add_disk(disk);
+        }
+
+        return 0;
+out_unreg:
+        devfs_remove("slram");
+        unregister_blkdev(XPRAM_MAJOR, XPRAM_NAME);
+out:
+        while (i--)
+                put_disk(xpram_disks[i]);
+        return rc;
+}
+
+/*
+ * Finally, the init/exit functions.
+ */
+static void __exit xpram_exit(void)
+{
+        int i;
+        for (i = 0; i < xpram_devs; i++) {
+                del_gendisk(xpram_disks[i]);
+                put_disk(xpram_disks[i]);
+        }
+        unregister_blkdev(XPRAM_MAJOR, XPRAM_NAME);
+        devfs_remove("slram");
+        blk_cleanup_queue(xpram_queue);
+        sysdev_unregister(&xpram_sys_device);
+        sysdev_class_unregister(&xpram_sysclass);
+}
+
+static int __init xpram_init(void)
+{
+        int rc;
+
+        /* Find out size of expanded memory. */
+        if (xpram_present() != 0) {
+                PRINT_WARN("No expanded memory available\n");
+                return -ENODEV;
+        }
+        xpram_pages = xpram_highest_page_index();
+        PRINT_INFO("  %u pages expanded memory found (%lu KB).\n",
+                   xpram_pages, (unsigned long) xpram_pages*4);
+        rc = xpram_setup_sizes(xpram_pages);
+        if (rc)
+                return rc;
+        rc = sysdev_class_register(&xpram_sysclass);
+        if (rc)
+                return rc;
+
+        rc = sysdev_register(&xpram_sys_device);
+        if (rc) {
+                sysdev_class_unregister(&xpram_sysclass);
+                return rc;
+        }
+        rc = xpram_setup_blkdev();
+        if (rc)
+                sysdev_unregister(&xpram_sys_device);
+        return rc;
+}
+
+module_init(xpram_init);
+module_exit(xpram_exit);