1 // SPDX-License-Identifier: GPL-2.0
3  * Xpram.c -- the S/390 expanded memory RAM-disk
20  * "ad-hoc" partitioning:
26  *   generic hard disk support to replace ad-hoc partitioning
53 	unsigned int	offset;		/* start page of xpram segment */
82  * Copy expanded memory page (4kB) into main memory                  
84  *           page_addr:    address of target page                    
85  *           xpage_index:  index of expandeded memory page           
88  *           -EIO:         if pgin failed
89  *           -ENXIO:       if xpram has vanished
103 		return -ENXIO;  in xpram_page_in()
105 		return -ENXIO;  in xpram_page_in()
107 		return -EIO;  in xpram_page_in()
112  * Copy a 4kB page of main memory to an expanded memory page          
114  *           page_addr:    address of source page                     
115  *           xpage_index:  index of expandeded memory page            
118  *           -EIO:         if pgout failed
119  *           -ENXIO:       if xpram has vanished
133 		return -ENXIO;  in xpram_page_out()
135 		return -ENXIO;  in xpram_page_out()
137 		return -EIO;  in xpram_page_out()
151 		return -ENOMEM;  in xpram_present()
154 	return rc ? -ENXIO : 0;  in xpram_present()
158  * Return index of the last available xpram page.
170 	add_bit = 1ULL << (sizeof(unsigned int)*8 - 1);  in xpram_highest_page_index()
187 	xpram_device_t *xdev = bio->bi_disk->private_data;  in xpram_submit_bio()
196 	if ((bio->bi_iter.bi_sector & 7) != 0 ||  in xpram_submit_bio()
197 	    (bio->bi_iter.bi_size & 4095) != 0)  in xpram_submit_bio()
198 		/* Request is not page-aligned. */  in xpram_submit_bio()
200 	if ((bio->bi_iter.bi_size >> 12) > xdev->size)  in xpram_submit_bio()
201 		/* Request size is no page-aligned. */  in xpram_submit_bio()
203 	if ((bio->bi_iter.bi_sector >> 3) > 0xffffffffU - xdev->offset)  in xpram_submit_bio()
205 	index = (bio->bi_iter.bi_sector >> 3) + xdev->offset;  in xpram_submit_bio()
222 			bytes -= 4096;  in xpram_submit_bio()
239 	 * multiple of 64 (32k): tell we have 16 sectors, 4 heads,  in xpram_getgeo()
240 	 * whatever cylinders. Tell also that data starts at sector. 4.  in xpram_getgeo()
243 	geo->cylinders = size >> 6;  in xpram_getgeo()
244 	geo->heads = 4;  in xpram_getgeo()
245 	geo->sectors = 16;  in xpram_getgeo()
246 	geo->start = 4;  in xpram_getgeo()
272 		return -EINVAL;  in xpram_setup_sizes()
278 	 * sizes to page boundary.  in xpram_setup_sizes()
294 			xpram_sizes[i] = (size + 3) & -4UL;  in xpram_setup_sizes()
305 			pr_info("  size of partition %d: %u kB\n",  in xpram_setup_sizes()
311 	pr_info("  memory needed (for sized partitions): %lu kB\n",  in xpram_setup_sizes()
316 	if (mem_needed > pages * 4) {  in xpram_setup_sizes()
318 		return -EINVAL;  in xpram_setup_sizes()
323 	 * xpram_sizes[i] != 0; partition i has size xpram_sizes[i] kB  in xpram_setup_sizes()
328 		mem_auto = ((pages - mem_needed / 4) / mem_auto_no) * 4;  in xpram_setup_sizes()
330 			"partition size: %lu kB\n", mem_auto);  in xpram_setup_sizes()
341 	int i, rc = -ENOMEM;  in xpram_setup_blkdev()
371 		xpram_devices[i].size = xpram_sizes[i] / 4;  in xpram_setup_blkdev()
374 		disk->major = XPRAM_MAJOR;  in xpram_setup_blkdev()
375 		disk->first_minor = i;  in xpram_setup_blkdev()
376 		disk->fops = &xpram_devops;  in xpram_setup_blkdev()
377 		disk->private_data = &xpram_devices[i];  in xpram_setup_blkdev()
378 		disk->queue = xpram_queues[i];  in xpram_setup_blkdev()
379 		sprintf(disk->disk_name, "slram%d", i);  in xpram_setup_blkdev()
386 	while (i--) {  in xpram_setup_blkdev()
452 		return -ENODEV;  in xpram_init()
455 	pr_info("  %u pages expanded memory found (%lu KB).\n",  in xpram_init()
456 		xpram_pages, (unsigned long) xpram_pages*4);  in xpram_init()
463 	xpram_pdev = platform_device_register_simple(XPRAM_NAME, -1, NULL, 0);  in xpram_init()