+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0
-/*
- * 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
- */
-
-#define KMSG_COMPONENT "xpram"
-#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
-
-#include <linux/module.h>
-#include <linux/moduleparam.h>
-#include <linux/ctype.h> /* isdigit, isxdigit */
-#include <linux/errno.h>
-#include <linux/init.h>
-#include <linux/blkdev.h>
-#include <linux/blkpg.h>
-#include <linux/hdreg.h> /* HDIO_GETGEO */
-#include <linux/device.h>
-#include <linux/bio.h>
-#include <linux/gfp.h>
-#include <linux/uaccess.h>
-
-#define XPRAM_NAME "xpram"
-#define XPRAM_DEVS 1 /* one partition */
-#define XPRAM_MAX_DEVS 32 /* maximal number of devices (partitions) */
-
-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 char *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 = 2; /* return unused cc 2 if pgin traps */
-
- asm volatile(
- " .insn rre,0xb22e0000,%1,%2\n" /* pgin %1,%2 */
- "0: ipm %0\n"
- " srl %0,28\n"
- "1:\n"
- EX_TABLE(0b,1b)
- : "+d" (cc) : "a" (__pa(page_addr)), "d" (xpage_index) : "cc");
- if (cc == 3)
- return -ENXIO;
- if (cc == 2)
- return -ENXIO;
- if (cc == 1)
- 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 = 2; /* return unused cc 2 if pgin traps */
-
- asm volatile(
- " .insn rre,0xb22f0000,%1,%2\n" /* pgout %1,%2 */
- "0: ipm %0\n"
- " srl %0,28\n"
- "1:\n"
- EX_TABLE(0b,1b)
- : "+d" (cc) : "a" (__pa(page_addr)), "d" (xpage_index) : "cc");
- if (cc == 3)
- return -ENXIO;
- if (cc == 2)
- return -ENXIO;
- if (cc == 1)
- 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 blk_qc_t xpram_submit_bio(struct bio *bio)
-{
- xpram_device_t *xdev = bio->bi_bdev->bd_disk->private_data;
- struct bio_vec bvec;
- struct bvec_iter iter;
- unsigned int index;
- unsigned long page_addr;
- unsigned long bytes;
-
- blk_queue_split(&bio);
-
- if ((bio->bi_iter.bi_sector & 7) != 0 ||
- (bio->bi_iter.bi_size & 4095) != 0)
- /* Request is not page-aligned. */
- goto fail;
- if ((bio->bi_iter.bi_size >> 12) > xdev->size)
- /* Request size is no page-aligned. */
- goto fail;
- if ((bio->bi_iter.bi_sector >> 3) > 0xffffffffU - xdev->offset)
- goto fail;
- index = (bio->bi_iter.bi_sector >> 3) + xdev->offset;
- bio_for_each_segment(bvec, bio, iter) {
- 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++;
- }
- }
- bio_endio(bio);
- return BLK_QC_T_NONE;
-fail:
- bio_io_error(bio);
- return BLK_QC_T_NONE;
-}
-
-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 const struct block_device_operations xpram_devops =
-{
- .owner = THIS_MODULE,
- .submit_bio = xpram_submit_bio,
- .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;
- char *sizes_end;
- int mem_auto_no;
- int i;
-
- /* Check number of devices. */
- if (devs <= 0 || devs > XPRAM_MAX_DEVS) {
- pr_err("%d is not a valid number of XPRAM 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_end, 0);
- switch (*sizes_end) {
- 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++;
- }
-
- pr_info(" number of devices (partitions): %d \n", xpram_devs);
- for (i = 0; i < xpram_devs; i++) {
- if (xpram_sizes[i])
- pr_info(" size of partition %d: %u kB\n",
- i, xpram_sizes[i]);
- else
- pr_info(" size of partition %d to be set "
- "automatically\n",i);
- }
- pr_info(" memory needed (for sized partitions): %lu kB\n",
- mem_needed);
- pr_info(" partitions to be sized automatically: %d\n",
- mem_auto_no);
-
- if (mem_needed > pages * 4) {
- pr_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;
- pr_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 int __init xpram_setup_blkdev(void)
-{
- unsigned long offset;
- int i, rc = -ENOMEM;
-
- for (i = 0; i < xpram_devs; i++) {
- xpram_disks[i] = blk_alloc_disk(NUMA_NO_NODE);
- if (!xpram_disks[i])
- goto out;
- blk_queue_flag_set(QUEUE_FLAG_NONROT, xpram_disks[i]->queue);
- blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM,
- xpram_disks[i]->queue);
- blk_queue_logical_block_size(xpram_disks[i]->queue, 4096);
- }
-
- /*
- * Register xpram major.
- */
- rc = register_blkdev(XPRAM_MAJOR, XPRAM_NAME);
- if (rc < 0)
- goto out;
-
- /*
- * 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->minors = 1;
- disk->fops = &xpram_devops;
- disk->private_data = &xpram_devices[i];
- sprintf(disk->disk_name, "slram%d", i);
- set_capacity(disk, xpram_sizes[i] << 1);
- add_disk(disk);
- }
-
- return 0;
-out:
- while (i--)
- blk_cleanup_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]);
- blk_cleanup_disk(xpram_disks[i]);
- }
- unregister_blkdev(XPRAM_MAJOR, XPRAM_NAME);
-}
-
-static int __init xpram_init(void)
-{
- int rc;
-
- /* Find out size of expanded memory. */
- if (xpram_present() != 0) {
- pr_err("No expanded memory available\n");
- return -ENODEV;
- }
- xpram_pages = xpram_highest_page_index() + 1;
- pr_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;
- return xpram_setup_blkdev();
-}
-
-module_init(xpram_init);
-module_exit(xpram_exit);
projects / linux-2.6-microblaze.git / commitdiff