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Diffstat (limited to 'drivers/s390/block/xpram.c')
-rw-r--r--drivers/s390/block/xpram.c539
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 00000000000..d428c909b8a
--- /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);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-05 00:03:03 +0000