s390: remove xpram device driver

Support for expanded storage was only available until z13 and z/VM 6.3
respectively. However there haven't been any use cases a long time
before for this device driver.
Therefore remove it.
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

arch/s390/configs/defconfig

@@ -397,7 +397,6 @@ CONFIG_BLK_DEV_DRBD=m
 CONFIG_BLK_DEV_NBD=m
 CONFIG_BLK_DEV_RAM=y
 CONFIG_BLK_DEV_RAM_SIZE=32768
-# CONFIG_BLK_DEV_XPRAM is not set
 CONFIG_VIRTIO_BLK=y
 CONFIG_BLK_DEV_RBD=m
 CONFIG_BLK_DEV_NVME=m

arch/s390/configs/zfcpdump_defconfig

@@ -35,7 +35,6 @@ CONFIG_NET=y
 # CONFIG_ETHTOOL_NETLINK is not set
 CONFIG_DEVTMPFS=y
 CONFIG_BLK_DEV_RAM=y
-# CONFIG_BLK_DEV_XPRAM is not set
 # CONFIG_DCSSBLK is not set
 # CONFIG_DASD is not set
 CONFIG_ENCLOSURE_SERVICES=y

drivers/s390/block/Kconfig

@@ -2,17 +2,6 @@
 comment "S/390 block device drivers"
 	depends on S390 && BLOCK
 
-config BLK_DEV_XPRAM
-	def_tristate m
-	prompt "XPRAM disk support"
-	depends on S390 && BLOCK
-	help
-	  Select this option if you want to use your expanded storage on S/390
-	  or zSeries as a disk.  This is useful as a _fast_ swap device if you
-	  want to access more than 2G of memory when running in 31 bit mode.
-	  This option is also available as a module which will be called
-	  xpram.  If unsure, say "N".
-
 config DCSSBLK
 	def_tristate m
 	select FS_DAX_LIMITED

drivers/s390/block/Makefile

@@ -16,7 +16,6 @@ obj-$(CONFIG_DASD) += dasd_mod.o
 obj-$(CONFIG_DASD_DIAG) += dasd_diag_mod.o
 obj-$(CONFIG_DASD_ECKD) += dasd_eckd_mod.o
 obj-$(CONFIG_DASD_FBA)  += dasd_fba_mod.o
-obj-$(CONFIG_BLK_DEV_XPRAM) += xpram.o
 obj-$(CONFIG_DCSSBLK) += dcssblk.o
 
 scm_block-objs := scm_drv.o scm_blk.o

drivers/s390/block/xpram.c

-// 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);