| /* |
| * (C) Copyright IBM Deutschland Entwicklung GmbH 2006 |
| * |
| * Author: Maxim Shchetynin <maxim@de.ibm.com> |
| * |
| * Axon DDR2 device driver. |
| * It registers one block device per Axon's DDR2 memory bank found on a system. |
| * Block devices are called axonram?, their major and minor numbers are |
| * available in /proc/devices, /proc/partitions or in /sys/block/axonram?/dev. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2, or (at your option) |
| * any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| */ |
| |
| #include <linux/bio.h> |
| #include <linux/blkdev.h> |
| #include <linux/buffer_head.h> |
| #include <linux/device.h> |
| #include <linux/errno.h> |
| #include <linux/fs.h> |
| #include <linux/genhd.h> |
| #include <linux/interrupt.h> |
| #include <linux/io.h> |
| #include <linux/ioport.h> |
| #include <linux/irq.h> |
| #include <linux/irqreturn.h> |
| #include <linux/kernel.h> |
| #include <linux/mm.h> |
| #include <linux/mod_devicetable.h> |
| #include <linux/module.h> |
| #include <linux/slab.h> |
| #include <linux/string.h> |
| #include <linux/types.h> |
| #include <asm/of_device.h> |
| #include <asm/of_platform.h> |
| #include <asm/page.h> |
| #include <asm/prom.h> |
| |
| #define AXON_RAM_MODULE_NAME "axonram" |
| #define AXON_RAM_DEVICE_NAME "axonram" |
| #define AXON_RAM_MINORS_PER_DISK 16 |
| #define AXON_RAM_BLOCK_SHIFT PAGE_SHIFT |
| #define AXON_RAM_BLOCK_SIZE 1 << AXON_RAM_BLOCK_SHIFT |
| #define AXON_RAM_SECTOR_SHIFT 9 |
| #define AXON_RAM_SECTOR_SIZE 1 << AXON_RAM_SECTOR_SHIFT |
| #define AXON_RAM_IRQ_FLAGS IRQF_SHARED | IRQF_TRIGGER_RISING |
| |
| struct axon_ram_bank { |
| struct of_device *device; |
| struct gendisk *disk; |
| unsigned int irq_id; |
| unsigned long ph_addr; |
| unsigned long io_addr; |
| unsigned long size; |
| unsigned long ecc_counter; |
| }; |
| |
| static ssize_t |
| axon_ram_sysfs_ecc(struct device *dev, struct device_attribute *attr, char *buf) |
| { |
| struct of_device *device = to_of_device(dev); |
| struct axon_ram_bank *bank = device->dev.platform_data; |
| |
| BUG_ON(!bank); |
| |
| return sprintf(buf, "%ld\n", bank->ecc_counter); |
| } |
| |
| static DEVICE_ATTR(ecc, S_IRUGO, axon_ram_sysfs_ecc, NULL); |
| |
| /** |
| * axon_ram_irq_handler - interrupt handler for Axon RAM ECC |
| * @irq: interrupt ID |
| * @dev: pointer to of_device |
| */ |
| static irqreturn_t |
| axon_ram_irq_handler(int irq, void *dev) |
| { |
| struct of_device *device = dev; |
| struct axon_ram_bank *bank = device->dev.platform_data; |
| |
| BUG_ON(!bank); |
| |
| dev_err(&device->dev, "Correctable memory error occured\n"); |
| bank->ecc_counter++; |
| return IRQ_HANDLED; |
| } |
| |
| /** |
| * axon_ram_make_request - make_request() method for block device |
| * @queue, @bio: see blk_queue_make_request() |
| */ |
| static int |
| axon_ram_make_request(struct request_queue *queue, struct bio *bio) |
| { |
| struct axon_ram_bank *bank = bio->bi_bdev->bd_disk->private_data; |
| unsigned long phys_mem, phys_end; |
| void *user_mem; |
| struct bio_vec *vec; |
| unsigned int transfered; |
| unsigned short idx; |
| int rc = 0; |
| |
| phys_mem = bank->io_addr + (bio->bi_sector << AXON_RAM_SECTOR_SHIFT); |
| phys_end = bank->io_addr + bank->size; |
| transfered = 0; |
| bio_for_each_segment(vec, bio, idx) { |
| if (unlikely(phys_mem + vec->bv_len > phys_end)) { |
| bio_io_error(bio, bio->bi_size); |
| rc = -ERANGE; |
| break; |
| } |
| |
| user_mem = page_address(vec->bv_page) + vec->bv_offset; |
| if (bio_data_dir(bio) == READ) |
| memcpy(user_mem, (void *) phys_mem, vec->bv_len); |
| else |
| memcpy((void *) phys_mem, user_mem, vec->bv_len); |
| |
| phys_mem += vec->bv_len; |
| transfered += vec->bv_len; |
| } |
| bio_endio(bio, transfered, 0); |
| |
| return rc; |
| } |
| |
| /** |
| * axon_ram_direct_access - direct_access() method for block device |
| * @device, @sector, @data: see block_device_operations method |
| */ |
| static int |
| axon_ram_direct_access(struct block_device *device, sector_t sector, |
| unsigned long *data) |
| { |
| struct axon_ram_bank *bank = device->bd_disk->private_data; |
| loff_t offset; |
| |
| offset = sector << AXON_RAM_SECTOR_SHIFT; |
| if (offset >= bank->size) { |
| dev_err(&bank->device->dev, "Access outside of address space\n"); |
| return -ERANGE; |
| } |
| |
| *data = bank->ph_addr + offset; |
| |
| return 0; |
| } |
| |
| static struct block_device_operations axon_ram_devops = { |
| .owner = THIS_MODULE, |
| .direct_access = axon_ram_direct_access |
| }; |
| |
| /** |
| * axon_ram_probe - probe() method for platform driver |
| * @device, @device_id: see of_platform_driver method |
| */ |
| static int |
| axon_ram_probe(struct of_device *device, const struct of_device_id *device_id) |
| { |
| static int axon_ram_bank_id = -1; |
| struct axon_ram_bank *bank; |
| struct resource resource; |
| int rc = 0; |
| |
| axon_ram_bank_id++; |
| |
| dev_info(&device->dev, "Found memory controller on %s\n", |
| device->node->full_name); |
| |
| bank = kzalloc(sizeof(struct axon_ram_bank), GFP_KERNEL); |
| if (bank == NULL) { |
| dev_err(&device->dev, "Out of memory\n"); |
| rc = -ENOMEM; |
| goto failed; |
| } |
| |
| device->dev.platform_data = bank; |
| |
| bank->device = device; |
| |
| if (of_address_to_resource(device->node, 0, &resource) != 0) { |
| dev_err(&device->dev, "Cannot access device tree\n"); |
| rc = -EFAULT; |
| goto failed; |
| } |
| |
| bank->size = resource.end - resource.start + 1; |
| |
| if (bank->size == 0) { |
| dev_err(&device->dev, "No DDR2 memory found for %s%d\n", |
| AXON_RAM_DEVICE_NAME, axon_ram_bank_id); |
| rc = -ENODEV; |
| goto failed; |
| } |
| |
| dev_info(&device->dev, "Register DDR2 memory device %s%d with %luMB\n", |
| AXON_RAM_DEVICE_NAME, axon_ram_bank_id, bank->size >> 20); |
| |
| bank->ph_addr = resource.start; |
| bank->io_addr = (unsigned long) ioremap_flags( |
| bank->ph_addr, bank->size, _PAGE_NO_CACHE); |
| if (bank->io_addr == 0) { |
| dev_err(&device->dev, "ioremap() failed\n"); |
| rc = -EFAULT; |
| goto failed; |
| } |
| |
| bank->disk = alloc_disk(AXON_RAM_MINORS_PER_DISK); |
| if (bank->disk == NULL) { |
| dev_err(&device->dev, "Cannot register disk\n"); |
| rc = -EFAULT; |
| goto failed; |
| } |
| |
| bank->disk->first_minor = 0; |
| bank->disk->fops = &axon_ram_devops; |
| bank->disk->private_data = bank; |
| bank->disk->driverfs_dev = &device->dev; |
| |
| sprintf(bank->disk->disk_name, "%s%d", |
| AXON_RAM_DEVICE_NAME, axon_ram_bank_id); |
| bank->disk->major = register_blkdev(0, bank->disk->disk_name); |
| if (bank->disk->major < 0) { |
| dev_err(&device->dev, "Cannot register block device\n"); |
| rc = -EFAULT; |
| goto failed; |
| } |
| |
| bank->disk->queue = blk_alloc_queue(GFP_KERNEL); |
| if (bank->disk->queue == NULL) { |
| dev_err(&device->dev, "Cannot register disk queue\n"); |
| rc = -EFAULT; |
| goto failed; |
| } |
| |
| set_capacity(bank->disk, bank->size >> AXON_RAM_SECTOR_SHIFT); |
| blk_queue_make_request(bank->disk->queue, axon_ram_make_request); |
| blk_queue_hardsect_size(bank->disk->queue, AXON_RAM_SECTOR_SIZE); |
| add_disk(bank->disk); |
| |
| bank->irq_id = irq_of_parse_and_map(device->node, 0); |
| if (bank->irq_id == NO_IRQ) { |
| dev_err(&device->dev, "Cannot access ECC interrupt ID\n"); |
| rc = -EFAULT; |
| goto failed; |
| } |
| |
| rc = request_irq(bank->irq_id, axon_ram_irq_handler, |
| AXON_RAM_IRQ_FLAGS, bank->disk->disk_name, device); |
| if (rc != 0) { |
| dev_err(&device->dev, "Cannot register ECC interrupt handler\n"); |
| bank->irq_id = NO_IRQ; |
| rc = -EFAULT; |
| goto failed; |
| } |
| |
| rc = device_create_file(&device->dev, &dev_attr_ecc); |
| if (rc != 0) { |
| dev_err(&device->dev, "Cannot create sysfs file\n"); |
| rc = -EFAULT; |
| goto failed; |
| } |
| |
| return 0; |
| |
| failed: |
| if (bank != NULL) { |
| if (bank->irq_id != NO_IRQ) |
| free_irq(bank->irq_id, device); |
| if (bank->disk != NULL) { |
| if (bank->disk->queue != NULL) |
| blk_cleanup_queue(bank->disk->queue); |
| if (bank->disk->major > 0) |
| unregister_blkdev(bank->disk->major, |
| bank->disk->disk_name); |
| del_gendisk(bank->disk); |
| } |
| device->dev.platform_data = NULL; |
| if (bank->io_addr != 0) |
| iounmap((void __iomem *) bank->io_addr); |
| kfree(bank); |
| } |
| |
| return rc; |
| } |
| |
| /** |
| * axon_ram_remove - remove() method for platform driver |
| * @device: see of_platform_driver method |
| */ |
| static int |
| axon_ram_remove(struct of_device *device) |
| { |
| struct axon_ram_bank *bank = device->dev.platform_data; |
| |
| BUG_ON(!bank || !bank->disk); |
| |
| device_remove_file(&device->dev, &dev_attr_ecc); |
| free_irq(bank->irq_id, device); |
| blk_cleanup_queue(bank->disk->queue); |
| unregister_blkdev(bank->disk->major, bank->disk->disk_name); |
| del_gendisk(bank->disk); |
| iounmap((void __iomem *) bank->io_addr); |
| kfree(bank); |
| |
| return 0; |
| } |
| |
| static struct of_device_id axon_ram_device_id[] = { |
| { |
| .type = "dma-memory" |
| }, |
| {} |
| }; |
| |
| static struct of_platform_driver axon_ram_driver = { |
| .owner = THIS_MODULE, |
| .name = AXON_RAM_MODULE_NAME, |
| .match_table = axon_ram_device_id, |
| .probe = axon_ram_probe, |
| .remove = axon_ram_remove |
| }; |
| |
| /** |
| * axon_ram_init |
| */ |
| static int __init |
| axon_ram_init(void) |
| { |
| return of_register_platform_driver(&axon_ram_driver); |
| } |
| |
| /** |
| * axon_ram_exit |
| */ |
| static void __exit |
| axon_ram_exit(void) |
| { |
| of_unregister_platform_driver(&axon_ram_driver); |
| } |
| |
| module_init(axon_ram_init); |
| module_exit(axon_ram_exit); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Maxim Shchetynin <maxim@de.ibm.com>"); |
| MODULE_DESCRIPTION("Axon DDR2 RAM device driver for IBM Cell BE"); |