| /* |
| * 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 <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 __initdata devs = XPRAM_DEVS; |
| static char __initdata *sizes[XPRAM_MAX_DEVS]; |
| |
| module_param(devs, int, 0); |
| module_param_array(sizes, charp, 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"); |
| |
| /* |
| * 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_64BIT |
| ".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_64BIT |
| ".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_getgeo(struct block_device *bdev, struct hd_geometry *geo) |
| { |
| unsigned long size; |
| |
| /* |
| * 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. |
| */ |
| size = (xpram_pages * 8) & ~0x3f; |
| geo->cylinders = size >> 6; |
| geo->heads = 4; |
| geo->sectors = 16; |
| geo->start = 4; |
| return 0; |
| } |
| |
| static struct block_device_operations xpram_devops = |
| { |
| .owner = THIS_MODULE, |
| .getgeo = xpram_getgeo, |
| }; |
| |
| /* |
| * Setup xpram_sizes array. |
| */ |
| static int __init xpram_setup_sizes(unsigned long pages) |
| { |
| unsigned long mem_needed; |
| unsigned long mem_auto; |
| unsigned long long size; |
| 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++) { |
| if (sizes[i]) { |
| size = simple_strtoull(sizes[i], &sizes[i], 0); |
| switch (sizes[i][0]) { |
| case 'g': |
| case 'G': |
| size <<= 20; |
| break; |
| case 'm': |
| case 'M': |
| size <<= 10; |
| } |
| xpram_sizes[i] = (size + 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; |
| |
| /* |
| * 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); |
| set_capacity(disk, xpram_sizes[i] << 1); |
| add_disk(disk); |
| } |
| |
| return 0; |
| out_unreg: |
| 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); |
| 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); |
