Revision dda50e716dc9451f40eebfb2902c260e4f62cf34 authored by Andi Kleen on 17 May 2005, 04:53:25 UTC, committed by Linus Torvalds on 17 May 2005, 14:59:14 UTC
The new TSC sync algorithm recently submitted did not work too well. The result was that some MP machines where the TSC came up of the BIOS very unsynchronized and that did not have HPET support were nearly unusable because the time would jump forwards and backwards between CPUs. After a lot of research ;-) and some more prototypes I ended up with just using the one from IA64 which looks best. It has some internal self tuning that should adapt to changing interconnect latencies. It holds up in my tests so far. I believe it was originally written by David Mosberger, I just ported it over to x86-64. See the inline comment for a description. This cleans up the code because it uses smp_call_function for syncing instead of having custom hooks in SMP bootup. Please note that the cycle numbers it outputs are too optimistic because they do not take into account the latency of WRMSR and RDTSC, which can be hundreds of cycles. It seems to be able to sync a dual Opteron to 200-300 cycles, which is probably good enough. There is a timing window during AP bootup where interrupts can see inconsistent time before the TSC is synced. It is hard to avoid unfortunately because we can only do the TSC sync after some setup, and we need to enable interrupts before that. I just ignored it for now. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1 parent 93ef70a
mmc_block.c
/*
* Block driver for media (i.e., flash cards)
*
* Copyright 2002 Hewlett-Packard Company
*
* Use consistent with the GNU GPL is permitted,
* provided that this copyright notice is
* preserved in its entirety in all copies and derived works.
*
* HEWLETT-PACKARD COMPANY MAKES NO WARRANTIES, EXPRESSED OR IMPLIED,
* AS TO THE USEFULNESS OR CORRECTNESS OF THIS CODE OR ITS
* FITNESS FOR ANY PARTICULAR PURPOSE.
*
* Many thanks to Alessandro Rubini and Jonathan Corbet!
*
* Author: Andrew Christian
* 28 May 2002
*/
#include <linux/moduleparam.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/hdreg.h>
#include <linux/kdev_t.h>
#include <linux/blkdev.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/mmc/card.h>
#include <linux/mmc/protocol.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include "mmc_queue.h"
/*
* max 8 partitions per card
*/
#define MMC_SHIFT 3
static int major;
/*
* There is one mmc_blk_data per slot.
*/
struct mmc_blk_data {
spinlock_t lock;
struct gendisk *disk;
struct mmc_queue queue;
unsigned int usage;
unsigned int block_bits;
};
static DECLARE_MUTEX(open_lock);
static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
{
struct mmc_blk_data *md;
down(&open_lock);
md = disk->private_data;
if (md && md->usage == 0)
md = NULL;
if (md)
md->usage++;
up(&open_lock);
return md;
}
static void mmc_blk_put(struct mmc_blk_data *md)
{
down(&open_lock);
md->usage--;
if (md->usage == 0) {
put_disk(md->disk);
mmc_cleanup_queue(&md->queue);
kfree(md);
}
up(&open_lock);
}
static int mmc_blk_open(struct inode *inode, struct file *filp)
{
struct mmc_blk_data *md;
int ret = -ENXIO;
md = mmc_blk_get(inode->i_bdev->bd_disk);
if (md) {
if (md->usage == 2)
check_disk_change(inode->i_bdev);
ret = 0;
}
return ret;
}
static int mmc_blk_release(struct inode *inode, struct file *filp)
{
struct mmc_blk_data *md = inode->i_bdev->bd_disk->private_data;
mmc_blk_put(md);
return 0;
}
static int
mmc_blk_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg)
{
struct block_device *bdev = inode->i_bdev;
if (cmd == HDIO_GETGEO) {
struct hd_geometry geo;
memset(&geo, 0, sizeof(struct hd_geometry));
geo.cylinders = get_capacity(bdev->bd_disk) / (4 * 16);
geo.heads = 4;
geo.sectors = 16;
geo.start = get_start_sect(bdev);
return copy_to_user((void __user *)arg, &geo, sizeof(geo))
? -EFAULT : 0;
}
return -ENOTTY;
}
static struct block_device_operations mmc_bdops = {
.open = mmc_blk_open,
.release = mmc_blk_release,
.ioctl = mmc_blk_ioctl,
.owner = THIS_MODULE,
};
struct mmc_blk_request {
struct mmc_request mrq;
struct mmc_command cmd;
struct mmc_command stop;
struct mmc_data data;
};
static int mmc_blk_prep_rq(struct mmc_queue *mq, struct request *req)
{
struct mmc_blk_data *md = mq->data;
int stat = BLKPREP_OK;
/*
* If we have no device, we haven't finished initialising.
*/
if (!md || !mq->card) {
printk(KERN_ERR "%s: killing request - no device/host\n",
req->rq_disk->disk_name);
stat = BLKPREP_KILL;
}
return stat;
}
static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
{
struct mmc_blk_data *md = mq->data;
struct mmc_card *card = md->queue.card;
int ret;
if (mmc_card_claim_host(card))
goto cmd_err;
do {
struct mmc_blk_request brq;
struct mmc_command cmd;
memset(&brq, 0, sizeof(struct mmc_blk_request));
brq.mrq.cmd = &brq.cmd;
brq.mrq.data = &brq.data;
brq.cmd.arg = req->sector << 9;
brq.cmd.flags = MMC_RSP_R1;
brq.data.timeout_ns = card->csd.tacc_ns * 10;
brq.data.timeout_clks = card->csd.tacc_clks * 10;
brq.data.blksz_bits = md->block_bits;
brq.data.blocks = req->nr_sectors >> (md->block_bits - 9);
brq.stop.opcode = MMC_STOP_TRANSMISSION;
brq.stop.arg = 0;
brq.stop.flags = MMC_RSP_R1B;
if (rq_data_dir(req) == READ) {
brq.cmd.opcode = brq.data.blocks > 1 ? MMC_READ_MULTIPLE_BLOCK : MMC_READ_SINGLE_BLOCK;
brq.data.flags |= MMC_DATA_READ;
} else {
brq.cmd.opcode = MMC_WRITE_BLOCK;
brq.cmd.flags = MMC_RSP_R1B;
brq.data.flags |= MMC_DATA_WRITE;
brq.data.blocks = 1;
}
brq.mrq.stop = brq.data.blocks > 1 ? &brq.stop : NULL;
brq.data.sg = mq->sg;
brq.data.sg_len = blk_rq_map_sg(req->q, req, brq.data.sg);
mmc_wait_for_req(card->host, &brq.mrq);
if (brq.cmd.error) {
printk(KERN_ERR "%s: error %d sending read/write command\n",
req->rq_disk->disk_name, brq.cmd.error);
goto cmd_err;
}
if (brq.data.error) {
printk(KERN_ERR "%s: error %d transferring data\n",
req->rq_disk->disk_name, brq.data.error);
goto cmd_err;
}
if (brq.stop.error) {
printk(KERN_ERR "%s: error %d sending stop command\n",
req->rq_disk->disk_name, brq.stop.error);
goto cmd_err;
}
do {
int err;
cmd.opcode = MMC_SEND_STATUS;
cmd.arg = card->rca << 16;
cmd.flags = MMC_RSP_R1;
err = mmc_wait_for_cmd(card->host, &cmd, 5);
if (err) {
printk(KERN_ERR "%s: error %d requesting status\n",
req->rq_disk->disk_name, err);
goto cmd_err;
}
} while (!(cmd.resp[0] & R1_READY_FOR_DATA));
#if 0
if (cmd.resp[0] & ~0x00000900)
printk(KERN_ERR "%s: status = %08x\n",
req->rq_disk->disk_name, cmd.resp[0]);
if (mmc_decode_status(cmd.resp))
goto cmd_err;
#endif
/*
* A block was successfully transferred.
*/
spin_lock_irq(&md->lock);
ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
if (!ret) {
/*
* The whole request completed successfully.
*/
add_disk_randomness(req->rq_disk);
blkdev_dequeue_request(req);
end_that_request_last(req);
}
spin_unlock_irq(&md->lock);
} while (ret);
mmc_card_release_host(card);
return 1;
cmd_err:
mmc_card_release_host(card);
/*
* This is a little draconian, but until we get proper
* error handling sorted out here, its the best we can
* do - especially as some hosts have no idea how much
* data was transferred before the error occurred.
*/
spin_lock_irq(&md->lock);
do {
ret = end_that_request_chunk(req, 0,
req->current_nr_sectors << 9);
} while (ret);
add_disk_randomness(req->rq_disk);
blkdev_dequeue_request(req);
end_that_request_last(req);
spin_unlock_irq(&md->lock);
return 0;
}
#define MMC_NUM_MINORS (256 >> MMC_SHIFT)
static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))];
static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
{
struct mmc_blk_data *md;
int devidx, ret;
devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
if (devidx >= MMC_NUM_MINORS)
return ERR_PTR(-ENOSPC);
__set_bit(devidx, dev_use);
md = kmalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
if (md) {
memset(md, 0, sizeof(struct mmc_blk_data));
md->disk = alloc_disk(1 << MMC_SHIFT);
if (md->disk == NULL) {
kfree(md);
md = ERR_PTR(-ENOMEM);
goto out;
}
spin_lock_init(&md->lock);
md->usage = 1;
ret = mmc_init_queue(&md->queue, card, &md->lock);
if (ret) {
put_disk(md->disk);
kfree(md);
md = ERR_PTR(ret);
goto out;
}
md->queue.prep_fn = mmc_blk_prep_rq;
md->queue.issue_fn = mmc_blk_issue_rq;
md->queue.data = md;
md->disk->major = major;
md->disk->first_minor = devidx << MMC_SHIFT;
md->disk->fops = &mmc_bdops;
md->disk->private_data = md;
md->disk->queue = md->queue.queue;
md->disk->driverfs_dev = &card->dev;
/*
* As discussed on lkml, GENHD_FL_REMOVABLE should:
*
* - be set for removable media with permanent block devices
* - be unset for removable block devices with permanent media
*
* Since MMC block devices clearly fall under the second
* case, we do not set GENHD_FL_REMOVABLE. Userspace
* should use the block device creation/destruction hotplug
* messages to tell when the card is present.
*/
sprintf(md->disk->disk_name, "mmcblk%d", devidx);
sprintf(md->disk->devfs_name, "mmc/blk%d", devidx);
md->block_bits = card->csd.read_blkbits;
blk_queue_hardsect_size(md->queue.queue, 1 << md->block_bits);
set_capacity(md->disk, card->csd.capacity);
}
out:
return md;
}
static int
mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
{
struct mmc_command cmd;
int err;
mmc_card_claim_host(card);
cmd.opcode = MMC_SET_BLOCKLEN;
cmd.arg = 1 << card->csd.read_blkbits;
cmd.flags = MMC_RSP_R1;
err = mmc_wait_for_cmd(card->host, &cmd, 5);
mmc_card_release_host(card);
if (err) {
printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
md->disk->disk_name, cmd.arg, err);
return -EINVAL;
}
return 0;
}
static int mmc_blk_probe(struct mmc_card *card)
{
struct mmc_blk_data *md;
int err;
if (card->csd.cmdclass & ~0x1ff)
return -ENODEV;
if (card->csd.read_blkbits < 9) {
printk(KERN_WARNING "%s: read blocksize too small (%u)\n",
mmc_card_id(card), 1 << card->csd.read_blkbits);
return -ENODEV;
}
md = mmc_blk_alloc(card);
if (IS_ERR(md))
return PTR_ERR(md);
err = mmc_blk_set_blksize(md, card);
if (err)
goto out;
printk(KERN_INFO "%s: %s %s %dKiB\n",
md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
(card->csd.capacity << card->csd.read_blkbits) / 1024);
mmc_set_drvdata(card, md);
add_disk(md->disk);
return 0;
out:
mmc_blk_put(md);
return err;
}
static void mmc_blk_remove(struct mmc_card *card)
{
struct mmc_blk_data *md = mmc_get_drvdata(card);
if (md) {
int devidx;
del_gendisk(md->disk);
/*
* I think this is needed.
*/
md->disk->queue = NULL;
devidx = md->disk->first_minor >> MMC_SHIFT;
__clear_bit(devidx, dev_use);
mmc_blk_put(md);
}
mmc_set_drvdata(card, NULL);
}
#ifdef CONFIG_PM
static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
{
struct mmc_blk_data *md = mmc_get_drvdata(card);
if (md) {
mmc_queue_suspend(&md->queue);
}
return 0;
}
static int mmc_blk_resume(struct mmc_card *card)
{
struct mmc_blk_data *md = mmc_get_drvdata(card);
if (md) {
mmc_blk_set_blksize(md, card);
mmc_queue_resume(&md->queue);
}
return 0;
}
#else
#define mmc_blk_suspend NULL
#define mmc_blk_resume NULL
#endif
static struct mmc_driver mmc_driver = {
.drv = {
.name = "mmcblk",
},
.probe = mmc_blk_probe,
.remove = mmc_blk_remove,
.suspend = mmc_blk_suspend,
.resume = mmc_blk_resume,
};
static int __init mmc_blk_init(void)
{
int res = -ENOMEM;
res = register_blkdev(major, "mmc");
if (res < 0) {
printk(KERN_WARNING "Unable to get major %d for MMC media: %d\n",
major, res);
goto out;
}
if (major == 0)
major = res;
devfs_mk_dir("mmc");
return mmc_register_driver(&mmc_driver);
out:
return res;
}
static void __exit mmc_blk_exit(void)
{
mmc_unregister_driver(&mmc_driver);
devfs_remove("mmc");
unregister_blkdev(major, "mmc");
}
module_init(mmc_blk_init);
module_exit(mmc_blk_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
module_param(major, int, 0444);
MODULE_PARM_DESC(major, "specify the major device number for MMC block driver");
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