diff mbox series

powerpc/cell: Remove axonram driver

Message ID 1509666992-4649-1-git-send-email-mpe@ellerman.id.au
State Accepted
Commit 1d65b1c886be6111f2347bd1a548bec58da17ccf
Headers show
Series powerpc/cell: Remove axonram driver | expand

Commit Message

Michael Ellerman Nov. 2, 2017, 11:56 p.m. UTC
The QS21/22 IBM Cell blades had a southbridge chip called Axon. This
could have DDR DIMMs attached to it, though they were not directly
usable as RAM, instead they could be used as some sort of buffer, if
applications were written specifically to use the block device
provided by the driver.

Although the driver supposedly had direct access support, it was
apparently never tested (see commit 91117a20245b ("axonram: Fix bug in
direct_access")).

These machines have not been available for over 5 years, and were
never widely in use. It seems highly unlikely anyone is using this
driver.

In general we're happy to leave old drivers in the tree, but because
DAX is involved this driver is caught up in the ongoing work in that
area, but none of the DAX folks are able to test it.

So remove the driver, if any one *is* using it, we'll be happy to put
it back.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 Documentation/filesystems/dax.txt |   1 -
 arch/powerpc/platforms/Kconfig    |  11 --
 arch/powerpc/sysdev/Makefile      |   1 -
 arch/powerpc/sysdev/axonram.c     | 383 --------------------------------------
 4 files changed, 396 deletions(-)
 delete mode 100644 arch/powerpc/sysdev/axonram.c

Comments

Michael Ellerman Jan. 29, 2018, 4:13 a.m. UTC | #1
On Thu, 2017-11-02 at 23:56:32 UTC, Michael Ellerman wrote:
> The QS21/22 IBM Cell blades had a southbridge chip called Axon. This
> could have DDR DIMMs attached to it, though they were not directly
> usable as RAM, instead they could be used as some sort of buffer, if
> applications were written specifically to use the block device
> provided by the driver.
> 
> Although the driver supposedly had direct access support, it was
> apparently never tested (see commit 91117a20245b ("axonram: Fix bug in
> direct_access")).
> 
> These machines have not been available for over 5 years, and were
> never widely in use. It seems highly unlikely anyone is using this
> driver.
> 
> In general we're happy to leave old drivers in the tree, but because
> DAX is involved this driver is caught up in the ongoing work in that
> area, but none of the DAX folks are able to test it.
> 
> So remove the driver, if any one *is* using it, we'll be happy to put
> it back.
> 
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Applied to powerpc next.

https://git.kernel.org/powerpc/c/1d65b1c886be6111f2347bd1a548be

cheers
diff mbox series

Patch

diff --git a/Documentation/filesystems/dax.txt b/Documentation/filesystems/dax.txt
index 3be3b266be41..70cb68bed2e8 100644
--- a/Documentation/filesystems/dax.txt
+++ b/Documentation/filesystems/dax.txt
@@ -46,7 +46,6 @@  stall the CPU for an extended period, you should also not attempt to
 implement direct_access.
 
 These block devices may be used for inspiration:
-- axonram: Axon DDR2 device driver
 - brd: RAM backed block device driver
 - dcssblk: s390 dcss block device driver
 - pmem: NVDIMM persistent memory driver
diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig
index 4fd64d3f5c44..7a05658f7637 100644
--- a/arch/powerpc/platforms/Kconfig
+++ b/arch/powerpc/platforms/Kconfig
@@ -292,17 +292,6 @@  config CPM2
 	  you wish to build a kernel for a machine with a CPM2 coprocessor
 	  on it (826x, 827x, 8560).
 
-config AXON_RAM
-	tristate "Axon DDR2 memory device driver"
-	depends on PPC_IBM_CELL_BLADE && BLOCK
-	select DAX
-	default m
-	help
-	  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.
-
 config FSL_ULI1575
 	bool
 	default n
diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile
index 79416fa2e3ba..3d6d4f8b30c2 100644
--- a/arch/powerpc/sysdev/Makefile
+++ b/arch/powerpc/sysdev/Makefile
@@ -31,7 +31,6 @@  mv64x60-$(CONFIG_PCI)		+= mv64x60_pci.o
 obj-$(CONFIG_MV64X60)		+= $(mv64x60-y) mv64x60_pic.o mv64x60_dev.o \
 				   mv64x60_udbg.o
 obj-$(CONFIG_RTC_DRV_CMOS)	+= rtc_cmos_setup.o
-obj-$(CONFIG_AXON_RAM)		+= axonram.o
 
 obj-$(CONFIG_PPC_INDIRECT_PCI)	+= indirect_pci.o
 obj-$(CONFIG_PPC_I8259)		+= i8259.o
diff --git a/arch/powerpc/sysdev/axonram.c b/arch/powerpc/sysdev/axonram.c
deleted file mode 100644
index 1b307c80b401..000000000000
--- a/arch/powerpc/sysdev/axonram.c
+++ /dev/null
@@ -1,383 +0,0 @@ 
-/*
- * (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/dax.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 <linux/of_device.h>
-#include <linux/of_platform.h>
-#include <linux/pfn_t.h>
-#include <linux/uio.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
-
-static int azfs_major, azfs_minor;
-
-struct axon_ram_bank {
-	struct platform_device	*device;
-	struct gendisk		*disk;
-	struct dax_device	*dax_dev;
-	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 platform_device *device = to_platform_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 platform_device *device = dev;
-	struct axon_ram_bank *bank = device->dev.platform_data;
-
-	BUG_ON(!bank);
-
-	dev_err(&device->dev, "Correctable memory error occurred\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 blk_qc_t
-axon_ram_make_request(struct request_queue *queue, struct bio *bio)
-{
-	struct axon_ram_bank *bank = bio->bi_disk->private_data;
-	unsigned long phys_mem, phys_end;
-	void *user_mem;
-	struct bio_vec vec;
-	unsigned int transfered;
-	struct bvec_iter iter;
-
-	phys_mem = bank->io_addr + (bio->bi_iter.bi_sector <<
-				    AXON_RAM_SECTOR_SHIFT);
-	phys_end = bank->io_addr + bank->size;
-	transfered = 0;
-	bio_for_each_segment(vec, bio, iter) {
-		if (unlikely(phys_mem + vec.bv_len > phys_end)) {
-			bio_io_error(bio);
-			return BLK_QC_T_NONE;
-		}
-
-		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);
-	return BLK_QC_T_NONE;
-}
-
-static const struct block_device_operations axon_ram_devops = {
-	.owner		= THIS_MODULE,
-};
-
-static long
-__axon_ram_direct_access(struct axon_ram_bank *bank, pgoff_t pgoff, long nr_pages,
-		       void **kaddr, pfn_t *pfn)
-{
-	resource_size_t offset = pgoff * PAGE_SIZE;
-
-	*kaddr = (void *) bank->io_addr + offset;
-	*pfn = phys_to_pfn_t(bank->ph_addr + offset, PFN_DEV);
-	return (bank->size - offset) / PAGE_SIZE;
-}
-
-static long
-axon_ram_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
-		       void **kaddr, pfn_t *pfn)
-{
-	struct axon_ram_bank *bank = dax_get_private(dax_dev);
-
-	return __axon_ram_direct_access(bank, pgoff, nr_pages, kaddr, pfn);
-}
-
-static size_t axon_ram_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
-		void *addr, size_t bytes, struct iov_iter *i)
-{
-	return copy_from_iter(addr, bytes, i);
-}
-
-static const struct dax_operations axon_ram_dax_ops = {
-	.direct_access = axon_ram_dax_direct_access,
-	.copy_from_iter = axon_ram_copy_from_iter,
-};
-
-/**
- * axon_ram_probe - probe() method for platform driver
- * @device: see platform_driver method
- */
-static int axon_ram_probe(struct platform_device *device)
-{
-	static int axon_ram_bank_id = -1;
-	struct axon_ram_bank *bank;
-	struct resource resource;
-	int rc;
-
-	axon_ram_bank_id++;
-
-	dev_info(&device->dev, "Found memory controller on %pOF\n",
-			device->dev.of_node);
-
-	bank = kzalloc(sizeof(*bank), GFP_KERNEL);
-	if (!bank)
-		return -ENOMEM;
-
-	device->dev.platform_data = bank;
-
-	bank->device = device;
-
-	if (of_address_to_resource(device->dev.of_node, 0, &resource) != 0) {
-		dev_err(&device->dev, "Cannot access device tree\n");
-		rc = -EFAULT;
-		goto failed;
-	}
-
-	bank->size = resource_size(&resource);
-
-	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_prot(
-			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->major = azfs_major;
-	bank->disk->first_minor = azfs_minor;
-	bank->disk->fops = &axon_ram_devops;
-	bank->disk->private_data = bank;
-
-	sprintf(bank->disk->disk_name, "%s%d",
-			AXON_RAM_DEVICE_NAME, axon_ram_bank_id);
-
-	bank->dax_dev = alloc_dax(bank, bank->disk->disk_name,
-			&axon_ram_dax_ops);
-	if (!bank->dax_dev) {
-		rc = -ENOMEM;
-		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_logical_block_size(bank->disk->queue, AXON_RAM_SECTOR_SIZE);
-	device_add_disk(&device->dev, bank->disk);
-
-	bank->irq_id = irq_of_parse_and_map(device->dev.of_node, 0);
-	if (!bank->irq_id) {
-		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 = 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;
-	}
-
-	azfs_minor += bank->disk->minors;
-
-	return 0;
-
-failed:
-	if (bank->irq_id)
-		free_irq(bank->irq_id, device);
-	if (bank->disk != NULL) {
-		if (bank->disk->major > 0)
-			unregister_blkdev(bank->disk->major,
-					bank->disk->disk_name);
-		if (bank->disk->flags & GENHD_FL_UP)
-			del_gendisk(bank->disk);
-		put_disk(bank->disk);
-	}
-	kill_dax(bank->dax_dev);
-	put_dax(bank->dax_dev);
-	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 platform_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);
-	kill_dax(bank->dax_dev);
-	put_dax(bank->dax_dev);
-	del_gendisk(bank->disk);
-	put_disk(bank->disk);
-	iounmap((void __iomem *) bank->io_addr);
-	kfree(bank);
-
-	return 0;
-}
-
-static const struct of_device_id axon_ram_device_id[] = {
-	{
-		.type	= "dma-memory"
-	},
-	{}
-};
-MODULE_DEVICE_TABLE(of, axon_ram_device_id);
-
-static struct platform_driver axon_ram_driver = {
-	.probe		= axon_ram_probe,
-	.remove		= axon_ram_remove,
-	.driver = {
-		.name = AXON_RAM_MODULE_NAME,
-		.of_match_table = axon_ram_device_id,
-	},
-};
-
-/**
- * axon_ram_init
- */
-static int __init
-axon_ram_init(void)
-{
-	azfs_major = register_blkdev(azfs_major, AXON_RAM_DEVICE_NAME);
-	if (azfs_major < 0) {
-		printk(KERN_ERR "%s cannot become block device major number\n",
-				AXON_RAM_MODULE_NAME);
-		return -EFAULT;
-	}
-	azfs_minor = 0;
-
-	return platform_driver_register(&axon_ram_driver);
-}
-
-/**
- * axon_ram_exit
- */
-static void __exit
-axon_ram_exit(void)
-{
-	platform_driver_unregister(&axon_ram_driver);
-	unregister_blkdev(azfs_major, AXON_RAM_DEVICE_NAME);
-}
-
-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");