diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/s390/block/xpram.c |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/s390/block/xpram.c')
-rw-r--r-- | drivers/s390/block/xpram.c | 539 |
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); |