--- /dev/null
+/*
+ * (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_correctable;
+ unsigned int irq_uncorrectable;
+ 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);
+
+ if (irq == bank->irq_correctable) {
+ dev_err(&device->dev, "Correctable memory error occured\n");
+ bank->ecc_counter++;
+ return IRQ_HANDLED;
+ } else if (irq == bank->irq_uncorrectable) {
+ dev_err(&device->dev, "Uncorrectable memory error occured\n");
+ panic("Critical ECC error on %s", device->node->full_name);
+ }
+
+ return IRQ_NONE;
+}
+
+/**
+ * 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_correctable = irq_of_parse_and_map(device->node, 0);
+ bank->irq_uncorrectable = irq_of_parse_and_map(device->node, 1);
+ if ((bank->irq_correctable <= 0) || (bank->irq_uncorrectable <= 0)) {
+ dev_err(&device->dev, "Cannot access ECC interrupt ID\n");
+ rc = -EFAULT;
+ goto failed;
+ }
+
+ rc = request_irq(bank->irq_correctable, 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_correctable = bank->irq_uncorrectable = 0;
+ rc = -EFAULT;
+ goto failed;
+ }
+
+ rc = request_irq(bank->irq_uncorrectable, 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_uncorrectable = 0;
+ 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_uncorrectable > 0)
+ free_irq(bank->irq_uncorrectable, device);
+ if (bank->irq_correctable > 0)
+ free_irq(bank->irq_correctable, 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_uncorrectable, device);
+ free_irq(bank->irq_correctable, 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");
projects / users / hch / xfs.git / commitdiff