diff options
Diffstat (limited to 'drivers/ide/ide-dma-sff.c')
| -rw-r--r-- | drivers/ide/ide-dma-sff.c | 336 |
1 files changed, 336 insertions, 0 deletions
diff --git a/drivers/ide/ide-dma-sff.c b/drivers/ide/ide-dma-sff.c new file mode 100644 index 000000000..b7c2c0bd1 --- /dev/null +++ b/drivers/ide/ide-dma-sff.c @@ -0,0 +1,336 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/export.h> +#include <linux/ide.h> +#include <linux/scatterlist.h> +#include <linux/dma-mapping.h> +#include <linux/io.h> + +/** + * config_drive_for_dma - attempt to activate IDE DMA + * @drive: the drive to place in DMA mode + * + * If the drive supports at least mode 2 DMA or UDMA of any kind + * then attempt to place it into DMA mode. Drives that are known to + * support DMA but predate the DMA properties or that are known + * to have DMA handling bugs are also set up appropriately based + * on the good/bad drive lists. + */ + +int config_drive_for_dma(ide_drive_t *drive) +{ + ide_hwif_t *hwif = drive->hwif; + u16 *id = drive->id; + + if (drive->media != ide_disk) { + if (hwif->host_flags & IDE_HFLAG_NO_ATAPI_DMA) + return 0; + } + + /* + * Enable DMA on any drive that has + * UltraDMA (mode 0/1/2/3/4/5/6) enabled + */ + if ((id[ATA_ID_FIELD_VALID] & 4) && + ((id[ATA_ID_UDMA_MODES] >> 8) & 0x7f)) + return 1; + + /* + * Enable DMA on any drive that has mode2 DMA + * (multi or single) enabled + */ + if ((id[ATA_ID_MWDMA_MODES] & 0x404) == 0x404 || + (id[ATA_ID_SWDMA_MODES] & 0x404) == 0x404) + return 1; + + /* Consult the list of known "good" drives */ + if (ide_dma_good_drive(drive)) + return 1; + + return 0; +} + +u8 ide_dma_sff_read_status(ide_hwif_t *hwif) +{ + unsigned long addr = hwif->dma_base + ATA_DMA_STATUS; + + if (hwif->host_flags & IDE_HFLAG_MMIO) + return readb((void __iomem *)addr); + else + return inb(addr); +} +EXPORT_SYMBOL_GPL(ide_dma_sff_read_status); + +static void ide_dma_sff_write_status(ide_hwif_t *hwif, u8 val) +{ + unsigned long addr = hwif->dma_base + ATA_DMA_STATUS; + + if (hwif->host_flags & IDE_HFLAG_MMIO) + writeb(val, (void __iomem *)addr); + else + outb(val, addr); +} + +/** + * ide_dma_host_set - Enable/disable DMA on a host + * @drive: drive to control + * + * Enable/disable DMA on an IDE controller following generic + * bus-mastering IDE controller behaviour. + */ + +void ide_dma_host_set(ide_drive_t *drive, int on) +{ + ide_hwif_t *hwif = drive->hwif; + u8 unit = drive->dn & 1; + u8 dma_stat = hwif->dma_ops->dma_sff_read_status(hwif); + + if (on) + dma_stat |= (1 << (5 + unit)); + else + dma_stat &= ~(1 << (5 + unit)); + + ide_dma_sff_write_status(hwif, dma_stat); +} +EXPORT_SYMBOL_GPL(ide_dma_host_set); + +/** + * ide_build_dmatable - build IDE DMA table + * + * ide_build_dmatable() prepares a dma request. We map the command + * to get the pci bus addresses of the buffers and then build up + * the PRD table that the IDE layer wants to be fed. + * + * Most chipsets correctly interpret a length of 0x0000 as 64KB, + * but at least one (e.g. CS5530) misinterprets it as zero (!). + * So we break the 64KB entry into two 32KB entries instead. + * + * Returns the number of built PRD entries if all went okay, + * returns 0 otherwise. + * + * May also be invoked from trm290.c + */ + +int ide_build_dmatable(ide_drive_t *drive, struct ide_cmd *cmd) +{ + ide_hwif_t *hwif = drive->hwif; + __le32 *table = (__le32 *)hwif->dmatable_cpu; + unsigned int count = 0; + int i; + struct scatterlist *sg; + u8 is_trm290 = !!(hwif->host_flags & IDE_HFLAG_TRM290); + + for_each_sg(hwif->sg_table, sg, cmd->sg_nents, i) { + u32 cur_addr, cur_len, xcount, bcount; + + cur_addr = sg_dma_address(sg); + cur_len = sg_dma_len(sg); + + /* + * 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. + */ + + while (cur_len) { + if (count++ >= PRD_ENTRIES) + goto use_pio_instead; + + bcount = 0x10000 - (cur_addr & 0xffff); + if (bcount > cur_len) + bcount = cur_len; + *table++ = cpu_to_le32(cur_addr); + xcount = bcount & 0xffff; + if (is_trm290) + xcount = ((xcount >> 2) - 1) << 16; + else if (xcount == 0x0000) { + if (count++ >= PRD_ENTRIES) + goto use_pio_instead; + *table++ = cpu_to_le32(0x8000); + *table++ = cpu_to_le32(cur_addr + 0x8000); + xcount = 0x8000; + } + *table++ = cpu_to_le32(xcount); + cur_addr += bcount; + cur_len -= bcount; + } + } + + if (count) { + if (!is_trm290) + *--table |= cpu_to_le32(0x80000000); + return count; + } + +use_pio_instead: + printk(KERN_ERR "%s: %s\n", drive->name, + count ? "DMA table too small" : "empty DMA table?"); + + return 0; /* revert to PIO for this request */ +} +EXPORT_SYMBOL_GPL(ide_build_dmatable); + +/** + * ide_dma_setup - begin a DMA phase + * @drive: target device + * @cmd: command + * + * Build an IDE DMA PRD (IDE speak for scatter gather table) + * and then set up the DMA transfer registers for a device + * that follows generic IDE PCI DMA behaviour. Controllers can + * override this function if they need to + * + * Returns 0 on success. If a PIO fallback is required then 1 + * is returned. + */ + +int ide_dma_setup(ide_drive_t *drive, struct ide_cmd *cmd) +{ + ide_hwif_t *hwif = drive->hwif; + u8 mmio = (hwif->host_flags & IDE_HFLAG_MMIO) ? 1 : 0; + u8 rw = (cmd->tf_flags & IDE_TFLAG_WRITE) ? 0 : ATA_DMA_WR; + u8 dma_stat; + + /* fall back to pio! */ + if (ide_build_dmatable(drive, cmd) == 0) { + ide_map_sg(drive, cmd); + return 1; + } + + /* PRD table */ + if (mmio) + writel(hwif->dmatable_dma, + (void __iomem *)(hwif->dma_base + ATA_DMA_TABLE_OFS)); + else + outl(hwif->dmatable_dma, hwif->dma_base + ATA_DMA_TABLE_OFS); + + /* specify r/w */ + if (mmio) + writeb(rw, (void __iomem *)(hwif->dma_base + ATA_DMA_CMD)); + else + outb(rw, hwif->dma_base + ATA_DMA_CMD); + + /* read DMA status for INTR & ERROR flags */ + dma_stat = hwif->dma_ops->dma_sff_read_status(hwif); + + /* clear INTR & ERROR flags */ + ide_dma_sff_write_status(hwif, dma_stat | ATA_DMA_ERR | ATA_DMA_INTR); + + return 0; +} +EXPORT_SYMBOL_GPL(ide_dma_setup); + +/** + * ide_dma_sff_timer_expiry - handle a DMA timeout + * @drive: Drive that timed out + * + * An IDE DMA transfer timed out. In the event of an error we ask + * the driver to resolve the problem, if a DMA transfer is still + * in progress we continue to wait (arguably we need to add a + * secondary 'I don't care what the drive thinks' timeout here) + * Finally if we have an interrupt we let it complete the I/O. + * But only one time - we clear expiry and if it's still not + * completed after WAIT_CMD, we error and retry in PIO. + * This can occur if an interrupt is lost or due to hang or bugs. + */ + +int ide_dma_sff_timer_expiry(ide_drive_t *drive) +{ + ide_hwif_t *hwif = drive->hwif; + u8 dma_stat = hwif->dma_ops->dma_sff_read_status(hwif); + + printk(KERN_WARNING "%s: %s: DMA status (0x%02x)\n", + drive->name, __func__, dma_stat); + + if ((dma_stat & 0x18) == 0x18) /* BUSY Stupid Early Timer !! */ + return WAIT_CMD; + + hwif->expiry = NULL; /* one free ride for now */ + + if (dma_stat & ATA_DMA_ERR) /* ERROR */ + return -1; + + if (dma_stat & ATA_DMA_ACTIVE) /* DMAing */ + return WAIT_CMD; + + if (dma_stat & ATA_DMA_INTR) /* Got an Interrupt */ + return WAIT_CMD; + + return 0; /* Status is unknown -- reset the bus */ +} +EXPORT_SYMBOL_GPL(ide_dma_sff_timer_expiry); + +void ide_dma_start(ide_drive_t *drive) +{ + ide_hwif_t *hwif = drive->hwif; + u8 dma_cmd; + + /* 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. + */ + if (hwif->host_flags & IDE_HFLAG_MMIO) { + dma_cmd = readb((void __iomem *)(hwif->dma_base + ATA_DMA_CMD)); + writeb(dma_cmd | ATA_DMA_START, + (void __iomem *)(hwif->dma_base + ATA_DMA_CMD)); + } else { + dma_cmd = inb(hwif->dma_base + ATA_DMA_CMD); + outb(dma_cmd | ATA_DMA_START, hwif->dma_base + ATA_DMA_CMD); + } +} +EXPORT_SYMBOL_GPL(ide_dma_start); + +/* returns 1 on error, 0 otherwise */ +int ide_dma_end(ide_drive_t *drive) +{ + ide_hwif_t *hwif = drive->hwif; + u8 dma_stat = 0, dma_cmd = 0; + + /* stop DMA */ + if (hwif->host_flags & IDE_HFLAG_MMIO) { + dma_cmd = readb((void __iomem *)(hwif->dma_base + ATA_DMA_CMD)); + writeb(dma_cmd & ~ATA_DMA_START, + (void __iomem *)(hwif->dma_base + ATA_DMA_CMD)); + } else { + dma_cmd = inb(hwif->dma_base + ATA_DMA_CMD); + outb(dma_cmd & ~ATA_DMA_START, hwif->dma_base + ATA_DMA_CMD); + } + + /* get DMA status */ + dma_stat = hwif->dma_ops->dma_sff_read_status(hwif); + + /* clear INTR & ERROR bits */ + ide_dma_sff_write_status(hwif, dma_stat | ATA_DMA_ERR | ATA_DMA_INTR); + +#define CHECK_DMA_MASK (ATA_DMA_ACTIVE | ATA_DMA_ERR | ATA_DMA_INTR) + + /* verify good DMA status */ + if ((dma_stat & CHECK_DMA_MASK) != ATA_DMA_INTR) + return 0x10 | dma_stat; + return 0; +} +EXPORT_SYMBOL_GPL(ide_dma_end); + +/* returns 1 if dma irq issued, 0 otherwise */ +int ide_dma_test_irq(ide_drive_t *drive) +{ + ide_hwif_t *hwif = drive->hwif; + u8 dma_stat = hwif->dma_ops->dma_sff_read_status(hwif); + + return (dma_stat & ATA_DMA_INTR) ? 1 : 0; +} +EXPORT_SYMBOL_GPL(ide_dma_test_irq); + +const struct ide_dma_ops sff_dma_ops = { + .dma_host_set = ide_dma_host_set, + .dma_setup = ide_dma_setup, + .dma_start = ide_dma_start, + .dma_end = ide_dma_end, + .dma_test_irq = ide_dma_test_irq, + .dma_lost_irq = ide_dma_lost_irq, + .dma_timer_expiry = ide_dma_sff_timer_expiry, + .dma_sff_read_status = ide_dma_sff_read_status, +}; +EXPORT_SYMBOL_GPL(sff_dma_ops); |