linux/drivers/mmc/mmci.c
David Howells 7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00

690 lines
15 KiB
C

/*
* linux/drivers/mmc/mmci.c - ARM PrimeCell MMCI PL180/1 driver
*
* Copyright (C) 2003 Deep Blue Solutions, Ltd, All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/highmem.h>
#include <linux/mmc/host.h>
#include <linux/mmc/protocol.h>
#include <linux/amba/bus.h>
#include <linux/clk.h>
#include <asm/cacheflush.h>
#include <asm/div64.h>
#include <asm/io.h>
#include <asm/scatterlist.h>
#include <asm/sizes.h>
#include <asm/mach/mmc.h>
#include "mmci.h"
#define DRIVER_NAME "mmci-pl18x"
#define DBG(host,fmt,args...) \
pr_debug("%s: %s: " fmt, mmc_hostname(host->mmc), __func__ , args)
static unsigned int fmax = 515633;
static void
mmci_request_end(struct mmci_host *host, struct mmc_request *mrq)
{
writel(0, host->base + MMCICOMMAND);
host->mrq = NULL;
host->cmd = NULL;
if (mrq->data)
mrq->data->bytes_xfered = host->data_xfered;
/*
* Need to drop the host lock here; mmc_request_done may call
* back into the driver...
*/
spin_unlock(&host->lock);
mmc_request_done(host->mmc, mrq);
spin_lock(&host->lock);
}
static void mmci_stop_data(struct mmci_host *host)
{
writel(0, host->base + MMCIDATACTRL);
writel(0, host->base + MMCIMASK1);
host->data = NULL;
}
static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
{
unsigned int datactrl, timeout, irqmask;
unsigned long long clks;
void __iomem *base;
int blksz_bits;
DBG(host, "blksz %04x blks %04x flags %08x\n",
data->blksz, data->blocks, data->flags);
host->data = data;
host->size = data->blksz;
host->data_xfered = 0;
mmci_init_sg(host, data);
clks = (unsigned long long)data->timeout_ns * host->cclk;
do_div(clks, 1000000000UL);
timeout = data->timeout_clks + (unsigned int)clks;
base = host->base;
writel(timeout, base + MMCIDATATIMER);
writel(host->size, base + MMCIDATALENGTH);
blksz_bits = ffs(data->blksz) - 1;
BUG_ON(1 << blksz_bits != data->blksz);
datactrl = MCI_DPSM_ENABLE | blksz_bits << 4;
if (data->flags & MMC_DATA_READ) {
datactrl |= MCI_DPSM_DIRECTION;
irqmask = MCI_RXFIFOHALFFULLMASK;
/*
* If we have less than a FIFOSIZE of bytes to transfer,
* trigger a PIO interrupt as soon as any data is available.
*/
if (host->size < MCI_FIFOSIZE)
irqmask |= MCI_RXDATAAVLBLMASK;
} else {
/*
* We don't actually need to include "FIFO empty" here
* since its implicit in "FIFO half empty".
*/
irqmask = MCI_TXFIFOHALFEMPTYMASK;
}
writel(datactrl, base + MMCIDATACTRL);
writel(readl(base + MMCIMASK0) & ~MCI_DATAENDMASK, base + MMCIMASK0);
writel(irqmask, base + MMCIMASK1);
}
static void
mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
{
void __iomem *base = host->base;
DBG(host, "op %02x arg %08x flags %08x\n",
cmd->opcode, cmd->arg, cmd->flags);
if (readl(base + MMCICOMMAND) & MCI_CPSM_ENABLE) {
writel(0, base + MMCICOMMAND);
udelay(1);
}
c |= cmd->opcode | MCI_CPSM_ENABLE;
if (cmd->flags & MMC_RSP_PRESENT) {
if (cmd->flags & MMC_RSP_136)
c |= MCI_CPSM_LONGRSP;
c |= MCI_CPSM_RESPONSE;
}
if (/*interrupt*/0)
c |= MCI_CPSM_INTERRUPT;
host->cmd = cmd;
writel(cmd->arg, base + MMCIARGUMENT);
writel(c, base + MMCICOMMAND);
}
static void
mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
unsigned int status)
{
if (status & MCI_DATABLOCKEND) {
host->data_xfered += data->blksz;
}
if (status & (MCI_DATACRCFAIL|MCI_DATATIMEOUT|MCI_TXUNDERRUN|MCI_RXOVERRUN)) {
if (status & MCI_DATACRCFAIL)
data->error = MMC_ERR_BADCRC;
else if (status & MCI_DATATIMEOUT)
data->error = MMC_ERR_TIMEOUT;
else if (status & (MCI_TXUNDERRUN|MCI_RXOVERRUN))
data->error = MMC_ERR_FIFO;
status |= MCI_DATAEND;
/*
* We hit an error condition. Ensure that any data
* partially written to a page is properly coherent.
*/
if (host->sg_len && data->flags & MMC_DATA_READ)
flush_dcache_page(host->sg_ptr->page);
}
if (status & MCI_DATAEND) {
mmci_stop_data(host);
if (!data->stop) {
mmci_request_end(host, data->mrq);
} else {
mmci_start_command(host, data->stop, 0);
}
}
}
static void
mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
unsigned int status)
{
void __iomem *base = host->base;
host->cmd = NULL;
cmd->resp[0] = readl(base + MMCIRESPONSE0);
cmd->resp[1] = readl(base + MMCIRESPONSE1);
cmd->resp[2] = readl(base + MMCIRESPONSE2);
cmd->resp[3] = readl(base + MMCIRESPONSE3);
if (status & MCI_CMDTIMEOUT) {
cmd->error = MMC_ERR_TIMEOUT;
} else if (status & MCI_CMDCRCFAIL && cmd->flags & MMC_RSP_CRC) {
cmd->error = MMC_ERR_BADCRC;
}
if (!cmd->data || cmd->error != MMC_ERR_NONE) {
mmci_request_end(host, cmd->mrq);
} else if (!(cmd->data->flags & MMC_DATA_READ)) {
mmci_start_data(host, cmd->data);
}
}
static int mmci_pio_read(struct mmci_host *host, char *buffer, unsigned int remain)
{
void __iomem *base = host->base;
char *ptr = buffer;
u32 status;
do {
int count = host->size - (readl(base + MMCIFIFOCNT) << 2);
if (count > remain)
count = remain;
if (count <= 0)
break;
readsl(base + MMCIFIFO, ptr, count >> 2);
ptr += count;
remain -= count;
if (remain == 0)
break;
status = readl(base + MMCISTATUS);
} while (status & MCI_RXDATAAVLBL);
return ptr - buffer;
}
static int mmci_pio_write(struct mmci_host *host, char *buffer, unsigned int remain, u32 status)
{
void __iomem *base = host->base;
char *ptr = buffer;
do {
unsigned int count, maxcnt;
maxcnt = status & MCI_TXFIFOEMPTY ? MCI_FIFOSIZE : MCI_FIFOHALFSIZE;
count = min(remain, maxcnt);
writesl(base + MMCIFIFO, ptr, count >> 2);
ptr += count;
remain -= count;
if (remain == 0)
break;
status = readl(base + MMCISTATUS);
} while (status & MCI_TXFIFOHALFEMPTY);
return ptr - buffer;
}
/*
* PIO data transfer IRQ handler.
*/
static irqreturn_t mmci_pio_irq(int irq, void *dev_id)
{
struct mmci_host *host = dev_id;
void __iomem *base = host->base;
u32 status;
status = readl(base + MMCISTATUS);
DBG(host, "irq1 %08x\n", status);
do {
unsigned long flags;
unsigned int remain, len;
char *buffer;
/*
* For write, we only need to test the half-empty flag
* here - if the FIFO is completely empty, then by
* definition it is more than half empty.
*
* For read, check for data available.
*/
if (!(status & (MCI_TXFIFOHALFEMPTY|MCI_RXDATAAVLBL)))
break;
/*
* Map the current scatter buffer.
*/
buffer = mmci_kmap_atomic(host, &flags) + host->sg_off;
remain = host->sg_ptr->length - host->sg_off;
len = 0;
if (status & MCI_RXACTIVE)
len = mmci_pio_read(host, buffer, remain);
if (status & MCI_TXACTIVE)
len = mmci_pio_write(host, buffer, remain, status);
/*
* Unmap the buffer.
*/
mmci_kunmap_atomic(host, buffer, &flags);
host->sg_off += len;
host->size -= len;
remain -= len;
if (remain)
break;
/*
* If we were reading, and we have completed this
* page, ensure that the data cache is coherent.
*/
if (status & MCI_RXACTIVE)
flush_dcache_page(host->sg_ptr->page);
if (!mmci_next_sg(host))
break;
status = readl(base + MMCISTATUS);
} while (1);
/*
* If we're nearing the end of the read, switch to
* "any data available" mode.
*/
if (status & MCI_RXACTIVE && host->size < MCI_FIFOSIZE)
writel(MCI_RXDATAAVLBLMASK, base + MMCIMASK1);
/*
* If we run out of data, disable the data IRQs; this
* prevents a race where the FIFO becomes empty before
* the chip itself has disabled the data path, and
* stops us racing with our data end IRQ.
*/
if (host->size == 0) {
writel(0, base + MMCIMASK1);
writel(readl(base + MMCIMASK0) | MCI_DATAENDMASK, base + MMCIMASK0);
}
return IRQ_HANDLED;
}
/*
* Handle completion of command and data transfers.
*/
static irqreturn_t mmci_irq(int irq, void *dev_id)
{
struct mmci_host *host = dev_id;
u32 status;
int ret = 0;
spin_lock(&host->lock);
do {
struct mmc_command *cmd;
struct mmc_data *data;
status = readl(host->base + MMCISTATUS);
status &= readl(host->base + MMCIMASK0);
writel(status, host->base + MMCICLEAR);
DBG(host, "irq0 %08x\n", status);
data = host->data;
if (status & (MCI_DATACRCFAIL|MCI_DATATIMEOUT|MCI_TXUNDERRUN|
MCI_RXOVERRUN|MCI_DATAEND|MCI_DATABLOCKEND) && data)
mmci_data_irq(host, data, status);
cmd = host->cmd;
if (status & (MCI_CMDCRCFAIL|MCI_CMDTIMEOUT|MCI_CMDSENT|MCI_CMDRESPEND) && cmd)
mmci_cmd_irq(host, cmd, status);
ret = 1;
} while (status);
spin_unlock(&host->lock);
return IRQ_RETVAL(ret);
}
static void mmci_request(struct mmc_host *mmc, struct mmc_request *mrq)
{
struct mmci_host *host = mmc_priv(mmc);
WARN_ON(host->mrq != NULL);
spin_lock_irq(&host->lock);
host->mrq = mrq;
if (mrq->data && mrq->data->flags & MMC_DATA_READ)
mmci_start_data(host, mrq->data);
mmci_start_command(host, mrq->cmd, 0);
spin_unlock_irq(&host->lock);
}
static void mmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
{
struct mmci_host *host = mmc_priv(mmc);
u32 clk = 0, pwr = 0;
if (ios->clock) {
if (ios->clock >= host->mclk) {
clk = MCI_CLK_BYPASS;
host->cclk = host->mclk;
} else {
clk = host->mclk / (2 * ios->clock) - 1;
if (clk > 256)
clk = 255;
host->cclk = host->mclk / (2 * (clk + 1));
}
clk |= MCI_CLK_ENABLE;
}
if (host->plat->translate_vdd)
pwr |= host->plat->translate_vdd(mmc_dev(mmc), ios->vdd);
switch (ios->power_mode) {
case MMC_POWER_OFF:
break;
case MMC_POWER_UP:
pwr |= MCI_PWR_UP;
break;
case MMC_POWER_ON:
pwr |= MCI_PWR_ON;
break;
}
if (ios->bus_mode == MMC_BUSMODE_OPENDRAIN)
pwr |= MCI_ROD;
writel(clk, host->base + MMCICLOCK);
if (host->pwr != pwr) {
host->pwr = pwr;
writel(pwr, host->base + MMCIPOWER);
}
}
static struct mmc_host_ops mmci_ops = {
.request = mmci_request,
.set_ios = mmci_set_ios,
};
static void mmci_check_status(unsigned long data)
{
struct mmci_host *host = (struct mmci_host *)data;
unsigned int status;
status = host->plat->status(mmc_dev(host->mmc));
if (status ^ host->oldstat)
mmc_detect_change(host->mmc, 0);
host->oldstat = status;
mod_timer(&host->timer, jiffies + HZ);
}
static int mmci_probe(struct amba_device *dev, void *id)
{
struct mmc_platform_data *plat = dev->dev.platform_data;
struct mmci_host *host;
struct mmc_host *mmc;
int ret;
/* must have platform data */
if (!plat) {
ret = -EINVAL;
goto out;
}
ret = amba_request_regions(dev, DRIVER_NAME);
if (ret)
goto out;
mmc = mmc_alloc_host(sizeof(struct mmci_host), &dev->dev);
if (!mmc) {
ret = -ENOMEM;
goto rel_regions;
}
host = mmc_priv(mmc);
host->clk = clk_get(&dev->dev, "MCLK");
if (IS_ERR(host->clk)) {
ret = PTR_ERR(host->clk);
host->clk = NULL;
goto host_free;
}
ret = clk_enable(host->clk);
if (ret)
goto clk_free;
host->plat = plat;
host->mclk = clk_get_rate(host->clk);
host->mmc = mmc;
host->base = ioremap(dev->res.start, SZ_4K);
if (!host->base) {
ret = -ENOMEM;
goto clk_disable;
}
mmc->ops = &mmci_ops;
mmc->f_min = (host->mclk + 511) / 512;
mmc->f_max = min(host->mclk, fmax);
mmc->ocr_avail = plat->ocr_mask;
mmc->caps = MMC_CAP_MULTIWRITE;
/*
* We can do SGIO
*/
mmc->max_hw_segs = 16;
mmc->max_phys_segs = NR_SG;
/*
* Since we only have a 16-bit data length register, we must
* ensure that we don't exceed 2^16-1 bytes in a single request.
* Choose 64 (512-byte) sectors as the limit.
*/
mmc->max_sectors = 64;
/*
* Set the maximum segment size. Since we aren't doing DMA
* (yet) we are only limited by the data length register.
*/
mmc->max_seg_size = mmc->max_sectors << 9;
spin_lock_init(&host->lock);
writel(0, host->base + MMCIMASK0);
writel(0, host->base + MMCIMASK1);
writel(0xfff, host->base + MMCICLEAR);
ret = request_irq(dev->irq[0], mmci_irq, IRQF_SHARED, DRIVER_NAME " (cmd)", host);
if (ret)
goto unmap;
ret = request_irq(dev->irq[1], mmci_pio_irq, IRQF_SHARED, DRIVER_NAME " (pio)", host);
if (ret)
goto irq0_free;
writel(MCI_IRQENABLE, host->base + MMCIMASK0);
amba_set_drvdata(dev, mmc);
mmc_add_host(mmc);
printk(KERN_INFO "%s: MMCI rev %x cfg %02x at 0x%016llx irq %d,%d\n",
mmc_hostname(mmc), amba_rev(dev), amba_config(dev),
(unsigned long long)dev->res.start, dev->irq[0], dev->irq[1]);
init_timer(&host->timer);
host->timer.data = (unsigned long)host;
host->timer.function = mmci_check_status;
host->timer.expires = jiffies + HZ;
add_timer(&host->timer);
return 0;
irq0_free:
free_irq(dev->irq[0], host);
unmap:
iounmap(host->base);
clk_disable:
clk_disable(host->clk);
clk_free:
clk_put(host->clk);
host_free:
mmc_free_host(mmc);
rel_regions:
amba_release_regions(dev);
out:
return ret;
}
static int mmci_remove(struct amba_device *dev)
{
struct mmc_host *mmc = amba_get_drvdata(dev);
amba_set_drvdata(dev, NULL);
if (mmc) {
struct mmci_host *host = mmc_priv(mmc);
del_timer_sync(&host->timer);
mmc_remove_host(mmc);
writel(0, host->base + MMCIMASK0);
writel(0, host->base + MMCIMASK1);
writel(0, host->base + MMCICOMMAND);
writel(0, host->base + MMCIDATACTRL);
free_irq(dev->irq[0], host);
free_irq(dev->irq[1], host);
iounmap(host->base);
clk_disable(host->clk);
clk_put(host->clk);
mmc_free_host(mmc);
amba_release_regions(dev);
}
return 0;
}
#ifdef CONFIG_PM
static int mmci_suspend(struct amba_device *dev, pm_message_t state)
{
struct mmc_host *mmc = amba_get_drvdata(dev);
int ret = 0;
if (mmc) {
struct mmci_host *host = mmc_priv(mmc);
ret = mmc_suspend_host(mmc, state);
if (ret == 0)
writel(0, host->base + MMCIMASK0);
}
return ret;
}
static int mmci_resume(struct amba_device *dev)
{
struct mmc_host *mmc = amba_get_drvdata(dev);
int ret = 0;
if (mmc) {
struct mmci_host *host = mmc_priv(mmc);
writel(MCI_IRQENABLE, host->base + MMCIMASK0);
ret = mmc_resume_host(mmc);
}
return ret;
}
#else
#define mmci_suspend NULL
#define mmci_resume NULL
#endif
static struct amba_id mmci_ids[] = {
{
.id = 0x00041180,
.mask = 0x000fffff,
},
{
.id = 0x00041181,
.mask = 0x000fffff,
},
{ 0, 0 },
};
static struct amba_driver mmci_driver = {
.drv = {
.name = DRIVER_NAME,
},
.probe = mmci_probe,
.remove = mmci_remove,
.suspend = mmci_suspend,
.resume = mmci_resume,
.id_table = mmci_ids,
};
static int __init mmci_init(void)
{
return amba_driver_register(&mmci_driver);
}
static void __exit mmci_exit(void)
{
amba_driver_unregister(&mmci_driver);
}
module_init(mmci_init);
module_exit(mmci_exit);
module_param(fmax, uint, 0444);
MODULE_DESCRIPTION("ARM PrimeCell PL180/181 Multimedia Card Interface driver");
MODULE_LICENSE("GPL");