Import 2.3.13pre7

[davej-history.git] / drivers / block / ide-dma.c

/*
 *  linux/drivers/block/ide-dma.c       Version 4.09    April 23, 1999
 *
 *  Copyright (c) 1999  Andre Hedrick
 *  May be copied or modified under the terms of the GNU General Public License
 */

/*
 *  Special Thanks to Mark for his Six years of work.
 *
 *  Copyright (c) 1995-1998  Mark Lord
 *  May be copied or modified under the terms of the GNU General Public License
 */

/*
 * This module provides support for the bus-master IDE DMA functions
 * of various PCI chipsets, including the Intel PIIX (i82371FB for
 * the 430 FX chipset), the PIIX3 (i82371SB for the 430 HX/VX and 
 * 440 chipsets), and the PIIX4 (i82371AB for the 430 TX chipset)
 * ("PIIX" stands for "PCI ISA IDE Xcellerator").
 *
 * Pretty much the same code works for other IDE PCI bus-mastering chipsets.
 *
 * DMA is supported for all IDE devices (disk drives, cdroms, tapes, floppies).
 *
 * By default, DMA support is prepared for use, but is currently enabled only
 * for drives which already have DMA enabled (UltraDMA or mode 2 multi/single),
 * or which are recognized as "good" (see table below).  Drives with only mode0
 * or mode1 (multi/single) DMA should also work with this chipset/driver
 * (eg. MC2112A) but are not enabled by default.
 *
 * Use "hdparm -i" to view modes supported by a given drive.
 *
 * The hdparm-3.5 (or later) utility can be used for manually enabling/disabling
 * DMA support, but must be (re-)compiled against this kernel version or later.
 *
 * To enable DMA, use "hdparm -d1 /dev/hd?" on a per-drive basis after booting.
 * If problems arise, ide.c will disable DMA operation after a few retries.
 * This error recovery mechanism works and has been extremely well exercised.
 *
 * IDE drives, depending on their vintage, may support several different modes
 * of DMA operation.  The boot-time modes are indicated with a "*" in
 * the "hdparm -i" listing, and can be changed with *knowledgeable* use of
 * the "hdparm -X" feature.  There is seldom a need to do this, as drives
 * normally power-up with their "best" PIO/DMA modes enabled.
 *
 * Testing has been done with a rather extensive number of drives,
 * with Quantum & Western Digital models generally outperforming the pack,
 * and Fujitsu & Conner (and some Seagate which are really Conner) drives
 * showing more lackluster throughput.
 *
 * Keep an eye on /var/adm/messages for "DMA disabled" messages.
 *
 * Some people have reported trouble with Intel Zappa motherboards.
 * This can be fixed by upgrading the AMI BIOS to version 1.00.04.BS0,
 * available from ftp://ftp.intel.com/pub/bios/10004bs0.exe
 * (thanks to Glen Morrell <glen@spin.Stanford.edu> for researching this).
 *
 * Thanks to "Christopher J. Reimer" <reimer@doe.carleton.ca> for
 * fixing the problem with the BIOS on some Acer motherboards.
 *
 * Thanks to "Benoit Poulot-Cazajous" <poulot@chorus.fr> for testing
 * "TX" chipset compatibility and for providing patches for the "TX" chipset.
 *
 * Thanks to Christian Brunner <chb@muc.de> for taking a good first crack
 * at generic DMA -- his patches were referred to when preparing this code.
 *
 * Most importantly, thanks to Robert Bringman <rob@mars.trion.com>
 * for supplying a Promise UDMA board & WD UDMA drive for this work!
 *
 * And, yes, Intel Zappa boards really *do* use both PIIX IDE ports.
 *
 * ACARD ATP850UF Chipset "Modified SCSI Class" with other names
 *       AEC6210 U/UF
 *       SIIG's UltraIDE Pro CN-2449
 * TTI   HPT343 Chipset "Modified SCSI Class" but reports as an
 *       unknown storage device.
 * NEW   check_drive_lists(ide_drive_t *drive, int good_bad)
 */

#include <linux/config.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/ide.h>

#include <asm/io.h>
#include <asm/irq.h>

#ifdef IDEDMA_NEW_DRIVE_LISTINGS

struct drive_list_entry {
        char * id_model;
        char * id_firmware;
};

struct drive_list_entry drive_whitelist [] = {

        { "Micropolis 2112A"    ,       "ALL"           },
        { "CONNER CTMA 4000"    ,       "ALL"           },
        { "CONNER CTT8000-A"    ,       "ALL"           },
        { "ST34342A"            ,       "ALL"           },
        { 0                     ,       0               }
};

struct drive_list_entry drive_blacklist [] = {

        { "WDC AC11000H"        ,       "ALL"           },
        { "WDC AC22100H"        ,       "ALL"           },
        { "WDC AC32500H"        ,       "ALL"           },
        { "WDC AC33100H"        ,       "ALL"           },
        { "WDC AC31600H"        ,       "ALL"           },
        { "WDC AC32100H"        ,       "24.09P07"      },
        { "WDC AC23200L"        ,       "21.10N21"      },
        { 0                     ,       0               }

};

int in_drive_list(struct hd_driveid *id, struct drive_list_entry * drive_table)
{
        for ( ; drive_table->id_model ; drive_table++)
                if ((!strcmp(drive_table->id_model, id->model)) &&
                    ((!strstr(drive_table->id_firmware, id->fw_rev)) ||
                     (!strcmp(drive_table->id_firmware, "ALL"))))
                        return 1;
        return 0;
}

#else /* !IDEDMA_NEW_DRIVE_LISTINGS */

/*
 * good_dma_drives() lists the model names (from "hdparm -i")
 * of drives which do not support mode2 DMA but which are
 * known to work fine with this interface under Linux.
 */
const char *good_dma_drives[] = {"Micropolis 2112A",
                                 "CONNER CTMA 4000",
                                 "CONNER CTT8000-A",
                                 "ST34342A",    /* for Sun Ultra */
                                 NULL};

/*
 * bad_dma_drives() lists the model names (from "hdparm -i")
 * of drives which supposedly support (U)DMA but which are
 * known to corrupt data with this interface under Linux.
 *
 * This is an empirical list. Its generated from bug reports. That means
 * while it reflects actual problem distributions it doesn't answer whether
 * the drive or the controller, or cabling, or software, or some combination
 * thereof is the fault. If you don't happen to agree with the kernel's 
 * opinion of your drive - use hdparm to turn DMA on.
 */
const char *bad_dma_drives[] = {"WDC AC11000H",
                                "WDC AC22100H",
                                "WDC AC32100H",
                                "WDC AC32500H",
                                "WDC AC33100H",
                                "WDC AC31600H",
                                NULL};

#endif /* IDEDMA_NEW_DRIVE_LISTINGS */

/*
 * Our Physical Region Descriptor (PRD) table should be large enough
 * to handle the biggest I/O request we are likely to see.  Since requests
 * can have no more than 256 sectors, and since the typical blocksize is
 * two or more sectors, we could get by with a limit of 128 entries here for
 * the usual worst case.  Most requests seem to include some contiguous blocks,
 * further reducing the number of table entries required.
 *
 * The driver reverts to PIO mode for individual requests that exceed
 * this limit (possible with 512 byte blocksizes, eg. MSDOS f/s), so handling
 * 100% of all crazy scenarios here is not necessary.
 *
 * As it turns out though, we must allocate a full 4KB page for this,
 * so the two PRD tables (ide0 & ide1) will each get half of that,
 * allowing each to have about 256 entries (8 bytes each) from this.
 */
#define PRD_BYTES       8
#define PRD_ENTRIES     (PAGE_SIZE / (2 * PRD_BYTES))

/*
 * dma_intr() is the handler for disk read/write DMA interrupts
 */
void ide_dma_intr (ide_drive_t *drive)
{
        int i;
        byte stat, dma_stat;

        dma_stat = HWIF(drive)->dmaproc(ide_dma_end, drive);
        stat = GET_STAT();                      /* get drive status */
        if (OK_STAT(stat,DRIVE_READY,drive->bad_wstat|DRQ_STAT)) {
                if (!dma_stat) {
                        struct request *rq = HWGROUP(drive)->rq;
                        rq = HWGROUP(drive)->rq;
                        for (i = rq->nr_sectors; i > 0;) {
                                i -= rq->current_nr_sectors;
                                ide_end_request(1, HWGROUP(drive));
                        }
                        return;
                }
                printk("%s: dma_intr: bad DMA status\n", drive->name);
        }
        ide__sti();     /* local CPU only */
        ide_error(drive, "dma_intr", stat);
}

/*
 * ide_build_dmatable() prepares a dma request.
 * Returns 0 if all went okay, returns 1 otherwise.
 * May also be invoked from trm290.c
 */
int ide_build_dmatable (ide_drive_t *drive, ide_dma_action_t func)
{
        struct request *rq = HWGROUP(drive)->rq;
        struct buffer_head *bh = rq->bh;
        unsigned int size, addr, *table = (unsigned int *)HWIF(drive)->dmatable;
        unsigned char *virt_addr;
#ifdef CONFIG_BLK_DEV_TRM290
        unsigned int is_trm290_chipset = (HWIF(drive)->chipset == ide_trm290);
#else
        const int is_trm290_chipset = 0;
#endif
        unsigned int count = 0;

        do {
                /*
                 * Determine addr and size of next buffer area.  We assume that
                 * individual virtual buffers are always composed linearly in
                 * physical memory.  For example, we assume that any 8kB buffer
                 * is always composed of two adjacent physical 4kB pages rather
                 * than two possibly non-adjacent physical 4kB pages.
                 */
                if (bh == NULL) {  /* paging requests have (rq->bh == NULL) */
                        virt_addr = rq->buffer;
                        addr = virt_to_bus (virt_addr);
                        size = rq->nr_sectors << 9;
                } else {
                        /* group sequential buffers into one large buffer */
                        virt_addr = bh->b_data;
                        addr = virt_to_bus (virt_addr);
                        size = bh->b_size;
                        while ((bh = bh->b_reqnext) != NULL) {
                                if ((addr + size) != virt_to_bus (bh->b_data))
                                        break;
                                size += bh->b_size;
                        }
                }
                /*
                 * Fill in the dma table, without crossing any 64kB boundaries.
                 * Most hardware requires 16-bit alignment of all blocks,
                 * but the trm290 requires 32-bit alignment.
                 */
                if ((addr & 3)) {
                        printk("%s: misaligned DMA buffer\n", drive->name);
                        return 0;
                }

                /*
                 * Some CPUs without cache snooping need to invalidate/write
                 * back their caches before DMA transfers to guarantee correct
                 * data.        -- rmk
                 */
                if (size) {
                        if (func == ide_dma_read) {
                                dma_cache_inv((unsigned int)virt_addr, size);
                        } else {
                                dma_cache_wback((unsigned int)virt_addr, size);
                        }
                }

                while (size) {
                        if (++count >= PRD_ENTRIES) {
                                printk("%s: DMA table too small\n", drive->name);
                                return 0; /* revert to PIO for this request */
                        } else {
                                unsigned int xcount, bcount = 0x10000 - (addr & 0xffff);
                                if (bcount > size)
                                        bcount = size;
                                *table++ = cpu_to_le32(addr);
                                xcount = bcount & 0xffff;
                                if (is_trm290_chipset)
                                        xcount = ((xcount >> 2) - 1) << 16;
                                *table++ = cpu_to_le32(xcount);
                                addr += bcount;
                                size -= bcount;
                        }
                }
        } while (bh != NULL);
        if (!count) {
                printk("%s: empty DMA table?\n", drive->name);
        } else {
                if (!is_trm290_chipset)
                        *--table |= cpu_to_le32(0x80000000);    /* set End-Of-Table (EOT) bit */
                /*
                 * Some CPUs need to flush the DMA table to physical RAM
                 * before DMA can start.        -- rmk
                 */
                dma_cache_wback((unsigned long)HWIF(drive)->dmatable, count * sizeof(unsigned int) * 2);
        }
        return count;
}

/*
 *  For both Blacklisted and Whitelisted drives.
 *  This is setup to be called as an extern for future support
 *  to other special driver code.
 */
int check_drive_lists (ide_drive_t *drive, int good_bad)
{
        struct hd_driveid *id = drive->id;

#ifdef IDEDMA_NEW_DRIVE_LISTINGS
        if (good_bad) {
                return in_drive_list(id, drive_whitelist);
        } else {
                int blacklist = in_drive_list(id, drive_blacklist);
                if (blacklist)
                        printk("%s: Disabling (U)DMA for %s\n", drive->name, id->model);
                return(blacklist);
        }
#else /* !IDEDMA_NEW_DRIVE_LISTINGS */
        const char **list;

        if (good_bad) {
                /* Consult the list of known "good" drives */
                list = good_dma_drives;
                while (*list) {
                        if (!strcmp(*list++,id->model))
                                return 1;
                }
        } else {
                /* Consult the list of known "bad" drives */
                list = bad_dma_drives;
                while (*list) {
                        if (!strcmp(*list++,id->model)) {
                                printk("%s: Disabling (U)DMA for %s\n",
                                        drive->name, id->model);
                                return 1;
                        }
                }
        }
#endif /* IDEDMA_NEW_DRIVE_LISTINGS */
        return 0;
}

static int config_drive_for_dma (ide_drive_t *drive)
{
        struct hd_driveid *id = drive->id;
        ide_hwif_t *hwif = HWIF(drive);

        if (id && (id->capability & 1) && hwif->autodma) {
                /* Consult the list of known "bad" drives */
                if (ide_dmaproc(ide_dma_bad_drive, drive))
                        return hwif->dmaproc(ide_dma_off, drive);

                /* Enable DMA on any drive that has UltraDMA (mode 3/4) enabled */
                if ((id->field_valid & 4) && (hwif->udma_four) && (id->word93 & 0x2000))
                        if ((id->dma_ultra & (id->dma_ultra >> 11) & 3))
                                return hwif->dmaproc(ide_dma_on, drive);
                /* Enable DMA on any drive that has UltraDMA (mode 0/1/2) enabled */
                if (id->field_valid & 4)        /* UltraDMA */
                        if ((id->dma_ultra & (id->dma_ultra >> 8) & 7))
                                return hwif->dmaproc(ide_dma_on, drive);
                /* Enable DMA on any drive that has mode2 DMA (multi or single) enabled */
                if (id->field_valid & 2)        /* regular DMA */
                        if ((id->dma_mword & 0x404) == 0x404 || (id->dma_1word & 0x404) == 0x404)
                                return hwif->dmaproc(ide_dma_on, drive);
                /* Consult the list of known "good" drives */
                if (ide_dmaproc(ide_dma_good_drive, drive))
                        return hwif->dmaproc(ide_dma_on, drive);
        }
        return hwif->dmaproc(ide_dma_off_quietly, drive);
}

/*
 * ide_dmaproc() initiates/aborts DMA read/write operations on a drive.
 *
 * The caller is assumed to have selected the drive and programmed the drive's
 * sector address using CHS or LBA.  All that remains is to prepare for DMA
 * and then issue the actual read/write DMA/PIO command to the drive.
 *
 * For ATAPI devices, we just prepare for DMA and return. The caller should
 * then issue the packet command to the drive and call us again with
 * ide_dma_begin afterwards.
 *
 * Returns 0 if all went well.
 * Returns 1 if DMA read/write could not be started, in which case
 * the caller should revert to PIO for the current request.
 * May also be invoked from trm290.c
 */
int ide_dmaproc (ide_dma_action_t func, ide_drive_t *drive)
{
        ide_hwif_t *hwif = HWIF(drive);
        unsigned long dma_base = hwif->dma_base;
        unsigned int count, reading = 0;
        byte dma_stat;

        switch (func) {
                case ide_dma_off:
                        printk("%s: DMA disabled\n", drive->name);
                case ide_dma_off_quietly:
                case ide_dma_on:
                        drive->using_dma = (func == ide_dma_on);
                        return 0;
                case ide_dma_check:
                        return config_drive_for_dma (drive);
                case ide_dma_read:
                        reading = 1 << 3;
                case ide_dma_write:
                        if (!(count = ide_build_dmatable(drive, func)))
                                return 1;       /* try PIO instead of DMA */
                        outl(virt_to_bus(hwif->dmatable), dma_base + 4); /* PRD table */
                        outb(reading, dma_base);                        /* specify r/w */
                        outb(inb(dma_base+2)|6, dma_base+2);            /* clear INTR & ERROR flags */
                        drive->waiting_for_dma = 1;
                        if (drive->media != ide_disk)
                                return 0;
                        ide_set_handler(drive, &ide_dma_intr, WAIT_CMD);/* issue cmd to drive */
                        OUT_BYTE(reading ? WIN_READDMA : WIN_WRITEDMA, IDE_COMMAND_REG);
                case ide_dma_begin:
                        /* Note that this is done *after* the cmd has
                         * been issued to the drive, as per the BM-IDE spec.
                         * The Promise Ultra33 doesn't work correctly when
                         * we do this part before issuing the drive cmd.
                         */
                        outb(inb(dma_base)|1, dma_base);                /* start DMA */
                        return 0;
                case ide_dma_end: /* returns 1 on error, 0 otherwise */
                        drive->waiting_for_dma = 0;
                        outb(inb(dma_base)&~1, dma_base);       /* stop DMA */
                        dma_stat = inb(dma_base+2);             /* get DMA status */
                        outb(dma_stat|6, dma_base+2);   /* clear the INTR & ERROR bits */
                        return (dma_stat & 7) != 4;     /* verify good DMA status */
                case ide_dma_test_irq: /* returns 1 if dma irq issued, 0 otherwise */
                        dma_stat = inb(dma_base+2);
                        return (dma_stat & 4) == 4;     /* return 1 if INTR asserted */
                case ide_dma_bad_drive:
                case ide_dma_good_drive:
                        return check_drive_lists(drive, (func == ide_dma_good_drive));
                case ide_dma_lostirq:
                case ide_dma_timeout:
                        /*
                         * printk("ide_dmaproc: chipset supported func only: %d\n", func);
                         */
                        return 1;
                default:
                        printk("ide_dmaproc: unsupported func: %d\n", func);
                        return 1;
        }
}

/*
 * Needed for allowing full modular support of ide-driver
 */
int ide_release_dma (ide_hwif_t *hwif)
{
        if (hwif->dmatable) {
                clear_page((unsigned long)hwif->dmatable);      /* clear PRD 1st */
                free_page((unsigned long)hwif->dmatable);       /* free PRD 2nd */
        }
        if ((hwif->dma_extra) && (hwif->channel == 0))
                release_region((hwif->dma_base + 16), hwif->dma_extra);
        release_region(hwif->dma_base, 8);
        return 1;
}

/*
 *      This can be called for a dynamically installed interface. Don't initfunc it
 */
 
void ide_setup_dma (ide_hwif_t *hwif, unsigned long dma_base, unsigned int num_ports)
{
        static unsigned long dmatable = 0;
        static unsigned leftover = 0;

        printk("    %s: BM-DMA at 0x%04lx-0x%04lx", hwif->name, dma_base, dma_base + num_ports - 1);
        if (check_region(dma_base, num_ports)) {
                printk(" -- ERROR, PORT ADDRESSES ALREADY IN USE\n");
                return;
        }
        request_region(dma_base, num_ports, hwif->name);
        hwif->dma_base = dma_base;
        if (leftover < (PRD_ENTRIES * PRD_BYTES)) {
                /*
                 * The BM-DMA uses full 32bit addr, so we can
                 * safely use __get_free_page() here instead
                 * of __get_dma_pages() -- no ISA limitations.
                 */
                dmatable = __get_free_pages(GFP_KERNEL,1);
                leftover = dmatable ? PAGE_SIZE : 0;
        }
        if (!dmatable) {
                printk(" -- ERROR, UNABLE TO ALLOCATE PRD TABLE\n");
        } else {
                hwif->dmatable = (unsigned long *) dmatable;
                dmatable += (PRD_ENTRIES * PRD_BYTES);
                leftover -= (PRD_ENTRIES * PRD_BYTES);
                hwif->dmaproc = &ide_dmaproc;

                if (hwif->chipset != ide_trm290) {
                        byte dma_stat = inb(dma_base+2);
                        printk(", BIOS settings: %s:%s, %s:%s",
                               hwif->drives[0].name, (dma_stat & 0x20) ? "DMA" : "pio",
                               hwif->drives[1].name, (dma_stat & 0x40) ? "DMA" : "pio");
                }
                printk("\n");
        }
}

/*
 * Fetch the DMA Bus-Master-I/O-Base-Address (BMIBA) from PCI space:
 */
unsigned long __init ide_get_or_set_dma_base (ide_hwif_t *hwif, int extra, const char *name)
{
        unsigned long   dma_base = 0;
        struct pci_dev  *dev = hwif->pci_dev;

        if (hwif->mate && hwif->mate->dma_base) {
                dma_base = hwif->mate->dma_base - (hwif->channel ? 0 : 8);
        } else {
                dma_base = dev->resource[4].start;
                if (!dma_base || dma_base == PCI_BASE_ADDRESS_IO_MASK) {
                        printk("%s: dma_base is invalid (0x%04lx)\n", name, dma_base);
                        dma_base = 0;
                }
        }
        if (dma_base) {
                if (extra) /* PDC20246, PDC20262, & HPT343 */
                        request_region(dma_base+16, extra, name);
                dma_base += hwif->channel ? 8 : 0;
                hwif->dma_extra = extra;

                switch(dev->device) {
                        case PCI_DEVICE_ID_CMD_643:
#ifdef CONFIG_BLK_DEV_ALI15X3
                        case PCI_DEVICE_ID_AL_M5219:
                        case PCI_DEVICE_ID_AL_M5229:
                                /*
                                 * Ali 15x3 chipsets know as ALI IV and V report
                                 * this as simplex, skip this test for them.
                                 */
#endif /* CONFIG_BLK_DEV_ALI15X3 */
                                outb(inb(dma_base+2) & 0x60, dma_base+2);
                                if (inb(dma_base+2) & 0x80) {
                                        printk("%s: simplex device: DMA forced\n", name);
                                }
                                break;
                        default:
                                /*
                                 * If the device claims "simplex" DMA,
                                 * this means only one of the two interfaces
                                 * can be trusted with DMA at any point in time.
                                 * So we should enable DMA only on one of the
                                 * two interfaces.
                                 */
                                if ((inb(dma_base+2) & 0x80)) { /* simplex device? */
                                        if ((!hwif->drives[0].present && !hwif->drives[1].present) ||
                                            (hwif->mate && hwif->mate->dma_base)) {
                                                printk("%s: simplex device:  DMA disabled\n", name);
                                                dma_base = 0;
                                        }
                                }
                }
        }
        return dma_base;
}