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powerpc/cell: Remove axonram driver

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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 91117a2024 ("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>
This commit is contained in:
Michael Ellerman 2017-11-03 10:56:32 +11:00
parent 5b8b580630
commit 1d65b1c886
4 changed files with 0 additions and 396 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
Documentation/filesystems/dax.txt
View File

@ -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

11
arch/powerpc/platforms/Kconfig
View File

@ -293,17 +293,6 @@ 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

1
arch/powerpc/sysdev/Makefile
View File

@ -32,7 +32,6 @@ 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

383
arch/powerpc/sysdev/axonram.c
View File

@ -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, 0444, 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");