linux/drivers/ata/sata_vsc.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

478 lines
13 KiB
C

/*
* sata_vsc.c - Vitesse VSC7174 4 port DPA SATA
*
* Maintained by: Jeremy Higdon @ SGI
* Please ALWAYS copy linux-ide@vger.kernel.org
* on emails.
*
* Copyright 2004 SGI
*
* Bits from Jeff Garzik, Copyright RedHat, Inc.
*
*
* 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; see the file COPYING. If not, write to
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*
*
* libata documentation is available via 'make {ps|pdf}docs',
* as Documentation/DocBook/libata.*
*
* Vitesse hardware documentation presumably available under NDA.
* Intel 31244 (same hardware interface) documentation presumably
* available from http://developer.intel.com/
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/dma-mapping.h>
#include <linux/device.h>
#include <scsi/scsi_host.h>
#include <linux/libata.h>
#define DRV_NAME "sata_vsc"
#define DRV_VERSION "2.0"
enum {
/* Interrupt register offsets (from chip base address) */
VSC_SATA_INT_STAT_OFFSET = 0x00,
VSC_SATA_INT_MASK_OFFSET = 0x04,
/* Taskfile registers offsets */
VSC_SATA_TF_CMD_OFFSET = 0x00,
VSC_SATA_TF_DATA_OFFSET = 0x00,
VSC_SATA_TF_ERROR_OFFSET = 0x04,
VSC_SATA_TF_FEATURE_OFFSET = 0x06,
VSC_SATA_TF_NSECT_OFFSET = 0x08,
VSC_SATA_TF_LBAL_OFFSET = 0x0c,
VSC_SATA_TF_LBAM_OFFSET = 0x10,
VSC_SATA_TF_LBAH_OFFSET = 0x14,
VSC_SATA_TF_DEVICE_OFFSET = 0x18,
VSC_SATA_TF_STATUS_OFFSET = 0x1c,
VSC_SATA_TF_COMMAND_OFFSET = 0x1d,
VSC_SATA_TF_ALTSTATUS_OFFSET = 0x28,
VSC_SATA_TF_CTL_OFFSET = 0x29,
/* DMA base */
VSC_SATA_UP_DESCRIPTOR_OFFSET = 0x64,
VSC_SATA_UP_DATA_BUFFER_OFFSET = 0x6C,
VSC_SATA_DMA_CMD_OFFSET = 0x70,
/* SCRs base */
VSC_SATA_SCR_STATUS_OFFSET = 0x100,
VSC_SATA_SCR_ERROR_OFFSET = 0x104,
VSC_SATA_SCR_CONTROL_OFFSET = 0x108,
/* Port stride */
VSC_SATA_PORT_OFFSET = 0x200,
/* Error interrupt status bit offsets */
VSC_SATA_INT_ERROR_CRC = 0x40,
VSC_SATA_INT_ERROR_T = 0x20,
VSC_SATA_INT_ERROR_P = 0x10,
VSC_SATA_INT_ERROR_R = 0x8,
VSC_SATA_INT_ERROR_E = 0x4,
VSC_SATA_INT_ERROR_M = 0x2,
VSC_SATA_INT_PHY_CHANGE = 0x1,
VSC_SATA_INT_ERROR = (VSC_SATA_INT_ERROR_CRC | VSC_SATA_INT_ERROR_T | \
VSC_SATA_INT_ERROR_P | VSC_SATA_INT_ERROR_R | \
VSC_SATA_INT_ERROR_E | VSC_SATA_INT_ERROR_M | \
VSC_SATA_INT_PHY_CHANGE),
};
#define is_vsc_sata_int_err(port_idx, int_status) \
(int_status & (VSC_SATA_INT_ERROR << (8 * port_idx)))
static u32 vsc_sata_scr_read (struct ata_port *ap, unsigned int sc_reg)
{
if (sc_reg > SCR_CONTROL)
return 0xffffffffU;
return readl((void __iomem *) ap->ioaddr.scr_addr + (sc_reg * 4));
}
static void vsc_sata_scr_write (struct ata_port *ap, unsigned int sc_reg,
u32 val)
{
if (sc_reg > SCR_CONTROL)
return;
writel(val, (void __iomem *) ap->ioaddr.scr_addr + (sc_reg * 4));
}
static void vsc_intr_mask_update(struct ata_port *ap, u8 ctl)
{
void __iomem *mask_addr;
u8 mask;
mask_addr = ap->host->mmio_base +
VSC_SATA_INT_MASK_OFFSET + ap->port_no;
mask = readb(mask_addr);
if (ctl & ATA_NIEN)
mask |= 0x80;
else
mask &= 0x7F;
writeb(mask, mask_addr);
}
static void vsc_sata_tf_load(struct ata_port *ap, const struct ata_taskfile *tf)
{
struct ata_ioports *ioaddr = &ap->ioaddr;
unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;
/*
* The only thing the ctl register is used for is SRST.
* That is not enabled or disabled via tf_load.
* However, if ATA_NIEN is changed, then we need to change the interrupt register.
*/
if ((tf->ctl & ATA_NIEN) != (ap->last_ctl & ATA_NIEN)) {
ap->last_ctl = tf->ctl;
vsc_intr_mask_update(ap, tf->ctl & ATA_NIEN);
}
if (is_addr && (tf->flags & ATA_TFLAG_LBA48)) {
writew(tf->feature | (((u16)tf->hob_feature) << 8), ioaddr->feature_addr);
writew(tf->nsect | (((u16)tf->hob_nsect) << 8), ioaddr->nsect_addr);
writew(tf->lbal | (((u16)tf->hob_lbal) << 8), ioaddr->lbal_addr);
writew(tf->lbam | (((u16)tf->hob_lbam) << 8), ioaddr->lbam_addr);
writew(tf->lbah | (((u16)tf->hob_lbah) << 8), ioaddr->lbah_addr);
} else if (is_addr) {
writew(tf->feature, ioaddr->feature_addr);
writew(tf->nsect, ioaddr->nsect_addr);
writew(tf->lbal, ioaddr->lbal_addr);
writew(tf->lbam, ioaddr->lbam_addr);
writew(tf->lbah, ioaddr->lbah_addr);
}
if (tf->flags & ATA_TFLAG_DEVICE)
writeb(tf->device, ioaddr->device_addr);
ata_wait_idle(ap);
}
static void vsc_sata_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
{
struct ata_ioports *ioaddr = &ap->ioaddr;
u16 nsect, lbal, lbam, lbah, feature;
tf->command = ata_check_status(ap);
tf->device = readw(ioaddr->device_addr);
feature = readw(ioaddr->error_addr);
nsect = readw(ioaddr->nsect_addr);
lbal = readw(ioaddr->lbal_addr);
lbam = readw(ioaddr->lbam_addr);
lbah = readw(ioaddr->lbah_addr);
tf->feature = feature;
tf->nsect = nsect;
tf->lbal = lbal;
tf->lbam = lbam;
tf->lbah = lbah;
if (tf->flags & ATA_TFLAG_LBA48) {
tf->hob_feature = feature >> 8;
tf->hob_nsect = nsect >> 8;
tf->hob_lbal = lbal >> 8;
tf->hob_lbam = lbam >> 8;
tf->hob_lbah = lbah >> 8;
}
}
/*
* vsc_sata_interrupt
*
* Read the interrupt register and process for the devices that have them pending.
*/
static irqreturn_t vsc_sata_interrupt (int irq, void *dev_instance)
{
struct ata_host *host = dev_instance;
unsigned int i;
unsigned int handled = 0;
u32 int_status;
spin_lock(&host->lock);
int_status = readl(host->mmio_base + VSC_SATA_INT_STAT_OFFSET);
for (i = 0; i < host->n_ports; i++) {
if (int_status & ((u32) 0xFF << (8 * i))) {
struct ata_port *ap;
ap = host->ports[i];
if (is_vsc_sata_int_err(i, int_status)) {
u32 err_status;
printk(KERN_DEBUG "%s: ignoring interrupt(s)\n", __FUNCTION__);
err_status = ap ? vsc_sata_scr_read(ap, SCR_ERROR) : 0;
vsc_sata_scr_write(ap, SCR_ERROR, err_status);
handled++;
}
if (ap && !(ap->flags & ATA_FLAG_DISABLED)) {
struct ata_queued_cmd *qc;
qc = ata_qc_from_tag(ap, ap->active_tag);
if (qc && (!(qc->tf.flags & ATA_TFLAG_POLLING)))
handled += ata_host_intr(ap, qc);
else if (is_vsc_sata_int_err(i, int_status)) {
/*
* On some chips (i.e. Intel 31244), an error
* interrupt will sneak in at initialization
* time (phy state changes). Clearing the SCR
* error register is not required, but it prevents
* the phy state change interrupts from recurring
* later.
*/
u32 err_status;
err_status = vsc_sata_scr_read(ap, SCR_ERROR);
printk(KERN_DEBUG "%s: clearing interrupt, "
"status %x; sata err status %x\n",
__FUNCTION__,
int_status, err_status);
vsc_sata_scr_write(ap, SCR_ERROR, err_status);
/* Clear interrupt status */
ata_chk_status(ap);
handled++;
}
}
}
}
spin_unlock(&host->lock);
return IRQ_RETVAL(handled);
}
static struct scsi_host_template vsc_sata_sht = {
.module = THIS_MODULE,
.name = DRV_NAME,
.ioctl = ata_scsi_ioctl,
.queuecommand = ata_scsi_queuecmd,
.can_queue = ATA_DEF_QUEUE,
.this_id = ATA_SHT_THIS_ID,
.sg_tablesize = LIBATA_MAX_PRD,
.cmd_per_lun = ATA_SHT_CMD_PER_LUN,
.emulated = ATA_SHT_EMULATED,
.use_clustering = ATA_SHT_USE_CLUSTERING,
.proc_name = DRV_NAME,
.dma_boundary = ATA_DMA_BOUNDARY,
.slave_configure = ata_scsi_slave_config,
.slave_destroy = ata_scsi_slave_destroy,
.bios_param = ata_std_bios_param,
};
static const struct ata_port_operations vsc_sata_ops = {
.port_disable = ata_port_disable,
.tf_load = vsc_sata_tf_load,
.tf_read = vsc_sata_tf_read,
.exec_command = ata_exec_command,
.check_status = ata_check_status,
.dev_select = ata_std_dev_select,
.bmdma_setup = ata_bmdma_setup,
.bmdma_start = ata_bmdma_start,
.bmdma_stop = ata_bmdma_stop,
.bmdma_status = ata_bmdma_status,
.qc_prep = ata_qc_prep,
.qc_issue = ata_qc_issue_prot,
.data_xfer = ata_mmio_data_xfer,
.freeze = ata_bmdma_freeze,
.thaw = ata_bmdma_thaw,
.error_handler = ata_bmdma_error_handler,
.post_internal_cmd = ata_bmdma_post_internal_cmd,
.irq_handler = vsc_sata_interrupt,
.irq_clear = ata_bmdma_irq_clear,
.scr_read = vsc_sata_scr_read,
.scr_write = vsc_sata_scr_write,
.port_start = ata_port_start,
.port_stop = ata_port_stop,
.host_stop = ata_pci_host_stop,
};
static void __devinit vsc_sata_setup_port(struct ata_ioports *port, unsigned long base)
{
port->cmd_addr = base + VSC_SATA_TF_CMD_OFFSET;
port->data_addr = base + VSC_SATA_TF_DATA_OFFSET;
port->error_addr = base + VSC_SATA_TF_ERROR_OFFSET;
port->feature_addr = base + VSC_SATA_TF_FEATURE_OFFSET;
port->nsect_addr = base + VSC_SATA_TF_NSECT_OFFSET;
port->lbal_addr = base + VSC_SATA_TF_LBAL_OFFSET;
port->lbam_addr = base + VSC_SATA_TF_LBAM_OFFSET;
port->lbah_addr = base + VSC_SATA_TF_LBAH_OFFSET;
port->device_addr = base + VSC_SATA_TF_DEVICE_OFFSET;
port->status_addr = base + VSC_SATA_TF_STATUS_OFFSET;
port->command_addr = base + VSC_SATA_TF_COMMAND_OFFSET;
port->altstatus_addr = base + VSC_SATA_TF_ALTSTATUS_OFFSET;
port->ctl_addr = base + VSC_SATA_TF_CTL_OFFSET;
port->bmdma_addr = base + VSC_SATA_DMA_CMD_OFFSET;
port->scr_addr = base + VSC_SATA_SCR_STATUS_OFFSET;
writel(0, base + VSC_SATA_UP_DESCRIPTOR_OFFSET);
writel(0, base + VSC_SATA_UP_DATA_BUFFER_OFFSET);
}
static int __devinit vsc_sata_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
{
static int printed_version;
struct ata_probe_ent *probe_ent = NULL;
unsigned long base;
int pci_dev_busy = 0;
void __iomem *mmio_base;
int rc;
if (!printed_version++)
dev_printk(KERN_DEBUG, &pdev->dev, "version " DRV_VERSION "\n");
rc = pci_enable_device(pdev);
if (rc)
return rc;
/*
* Check if we have needed resource mapped.
*/
if (pci_resource_len(pdev, 0) == 0) {
rc = -ENODEV;
goto err_out;
}
rc = pci_request_regions(pdev, DRV_NAME);
if (rc) {
pci_dev_busy = 1;
goto err_out;
}
/*
* Use 32 bit DMA mask, because 64 bit address support is poor.
*/
rc = pci_set_dma_mask(pdev, DMA_32BIT_MASK);
if (rc)
goto err_out_regions;
rc = pci_set_consistent_dma_mask(pdev, DMA_32BIT_MASK);
if (rc)
goto err_out_regions;
probe_ent = kmalloc(sizeof(*probe_ent), GFP_KERNEL);
if (probe_ent == NULL) {
rc = -ENOMEM;
goto err_out_regions;
}
memset(probe_ent, 0, sizeof(*probe_ent));
probe_ent->dev = pci_dev_to_dev(pdev);
INIT_LIST_HEAD(&probe_ent->node);
mmio_base = pci_iomap(pdev, 0, 0);
if (mmio_base == NULL) {
rc = -ENOMEM;
goto err_out_free_ent;
}
base = (unsigned long) mmio_base;
/*
* Due to a bug in the chip, the default cache line size can't be used
*/
pci_write_config_byte(pdev, PCI_CACHE_LINE_SIZE, 0x80);
probe_ent->sht = &vsc_sata_sht;
probe_ent->port_flags = ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
ATA_FLAG_MMIO;
probe_ent->port_ops = &vsc_sata_ops;
probe_ent->n_ports = 4;
probe_ent->irq = pdev->irq;
probe_ent->irq_flags = IRQF_SHARED;
probe_ent->mmio_base = mmio_base;
/* We don't care much about the PIO/UDMA masks, but the core won't like us
* if we don't fill these
*/
probe_ent->pio_mask = 0x1f;
probe_ent->mwdma_mask = 0x07;
probe_ent->udma_mask = 0x7f;
/* We have 4 ports per PCI function */
vsc_sata_setup_port(&probe_ent->port[0], base + 1 * VSC_SATA_PORT_OFFSET);
vsc_sata_setup_port(&probe_ent->port[1], base + 2 * VSC_SATA_PORT_OFFSET);
vsc_sata_setup_port(&probe_ent->port[2], base + 3 * VSC_SATA_PORT_OFFSET);
vsc_sata_setup_port(&probe_ent->port[3], base + 4 * VSC_SATA_PORT_OFFSET);
pci_set_master(pdev);
/*
* Config offset 0x98 is "Extended Control and Status Register 0"
* Default value is (1 << 28). All bits except bit 28 are reserved in
* DPA mode. If bit 28 is set, LED 0 reflects all ports' activity.
* If bit 28 is clear, each port has its own LED.
*/
pci_write_config_dword(pdev, 0x98, 0);
/* FIXME: check ata_device_add return value */
ata_device_add(probe_ent);
kfree(probe_ent);
return 0;
err_out_free_ent:
kfree(probe_ent);
err_out_regions:
pci_release_regions(pdev);
err_out:
if (!pci_dev_busy)
pci_disable_device(pdev);
return rc;
}
static const struct pci_device_id vsc_sata_pci_tbl[] = {
{ PCI_VENDOR_ID_VITESSE, 0x7174,
PCI_ANY_ID, PCI_ANY_ID, 0x10600, 0xFFFFFF, 0 },
{ PCI_VENDOR_ID_INTEL, 0x3200,
PCI_ANY_ID, PCI_ANY_ID, 0x10600, 0xFFFFFF, 0 },
{ } /* terminate list */
};
static struct pci_driver vsc_sata_pci_driver = {
.name = DRV_NAME,
.id_table = vsc_sata_pci_tbl,
.probe = vsc_sata_init_one,
.remove = ata_pci_remove_one,
};
static int __init vsc_sata_init(void)
{
return pci_register_driver(&vsc_sata_pci_driver);
}
static void __exit vsc_sata_exit(void)
{
pci_unregister_driver(&vsc_sata_pci_driver);
}
MODULE_AUTHOR("Jeremy Higdon");
MODULE_DESCRIPTION("low-level driver for Vitesse VSC7174 SATA controller");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, vsc_sata_pci_tbl);
MODULE_VERSION(DRV_VERSION);
module_init(vsc_sata_init);
module_exit(vsc_sata_exit);