Commit b19b2c2e authored by Jeff Garzik's avatar Jeff Garzik

[libata] Guarantee that S/G entries do not straddle IDE DMA 64k boundary

parent 61e7d4eb
/* /*
libata-core.c - helper library for ATA libata-core.c - helper library for ATA
Copyright 2003 Red Hat, Inc. All rights reserved. Copyright 2003-2004 Red Hat, Inc. All rights reserved.
Copyright 2003 Jeff Garzik Copyright 2003-2004 Jeff Garzik
The contents of this file are subject to the Open The contents of this file are subject to the Open
Software License version 1.1 that can be found at Software License version 1.1 that can be found at
...@@ -1653,18 +1653,60 @@ void ata_fill_sg(struct ata_queued_cmd *qc) ...@@ -1653,18 +1653,60 @@ void ata_fill_sg(struct ata_queued_cmd *qc)
{ {
struct scatterlist *sg = qc->sg; struct scatterlist *sg = qc->sg;
struct ata_port *ap = qc->ap; struct ata_port *ap = qc->ap;
unsigned int i; unsigned int i, idx;
assert(sg != NULL); assert(sg != NULL);
assert(qc->n_elem > 0); assert(qc->n_elem > 0);
idx = 0;
for (i = 0; i < qc->n_elem; i++) { for (i = 0; i < qc->n_elem; i++) {
ap->prd[i].addr = cpu_to_le32(sg_dma_address(&sg[i])); u32 addr, boundary;
ap->prd[i].flags_len = cpu_to_le32(sg_dma_len(&sg[i])); u32 sg_len, sg1len, sg2len;
VPRINTK("PRD[%u] = (0x%X, 0x%X)\n",
i, le32_to_cpu(ap->prd[i].addr), le32_to_cpu(ap->prd[i].flags_len)); /* determine if physical DMA addr spans 64K boundary.
* Note h/w doesn't support 64-bit, so we unconditionally
* truncate dma_addr_t to u32.
*/
addr = (u32) sg_dma_address(&sg[i]);
sg_len = sg_dma_len(&sg[i]);
boundary = (addr & ~0xffff) + (0xffff + 1);
if ((addr + sg_len) > boundary) {
/* straddles boundary, need two s/g entries */
sg2len = (addr + sg_len) - boundary;
sg1len = sg_len - sg2len;
} else {
/* no split, just one s/g entry */
sg2len = 0;
sg1len = sg_len;
} }
ap->prd[qc->n_elem - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
/* fill first S/G list entry */
ap->prd[idx].addr = cpu_to_le32(addr);
if (sg1len == 65536)
ap->prd[idx].flags_len = 0;
else
ap->prd[idx].flags_len = cpu_to_le32(sg1len);
VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", idx, addr, sg1len);
idx++;
/* if we had to break S/G entry across segment boundary,
* due to iommu merging, fill second S/G list entry
*/
if (sg2len) {
addr += sg1len;
ap->prd[idx].addr = cpu_to_le32(addr);
if (sg2len == 65536)
ap->prd[idx].flags_len = 0;
else
ap->prd[idx].flags_len = cpu_to_le32(sg2len);
VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", idx, addr, sg2len);
idx++;
}
}
if (idx)
ap->prd[idx - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
} }
/** /**
...@@ -2385,41 +2427,6 @@ static inline unsigned int ata_host_intr (struct ata_port *ap, ...@@ -2385,41 +2427,6 @@ static inline unsigned int ata_host_intr (struct ata_port *ap,
return handled; return handled;
} }
/**
* ata_chk_spurious_int - Check for spurious interrupts
* @ap: port to which command is being issued
*
* Examines the DMA status registers and clears
* unexpected interrupts. Created to work around
* hardware bug on Intel ICH5, but is applied to all
* chipsets using the standard irq handler, just for safety.
* If the bug is not present, this is simply a single
* PIO or MMIO read addition to the irq handler.
*
* LOCKING:
*/
static inline void ata_chk_spurious_int(struct ata_port *ap) {
int host_stat;
if (ap->flags & ATA_FLAG_MMIO) {
void *mmio = (void *) ap->ioaddr.bmdma_addr;
host_stat = readb(mmio + ATA_DMA_STATUS);
} else
host_stat = inb(ap->ioaddr.bmdma_addr + ATA_DMA_STATUS);
if ((host_stat & (ATA_DMA_INTR | ATA_DMA_ERR | ATA_DMA_ACTIVE)) == ATA_DMA_INTR) {
if (ap->flags & ATA_FLAG_MMIO) {
void *mmio = (void *) ap->ioaddr.bmdma_addr;
writeb(host_stat & ~ATA_DMA_ERR, mmio + ATA_DMA_STATUS);
} else
outb(host_stat & ~ATA_DMA_ERR, ap->ioaddr.bmdma_addr + ATA_DMA_STATUS);
DPRINTK("ata%u: Caught spurious interrupt, status 0x%X\n", ap->id, host_stat);
udelay(1);
}
}
/** /**
* ata_interrupt - * ata_interrupt -
* @irq: * @irq:
...@@ -2452,7 +2459,6 @@ irqreturn_t ata_interrupt (int irq, void *dev_instance, struct pt_regs *regs) ...@@ -2452,7 +2459,6 @@ irqreturn_t ata_interrupt (int irq, void *dev_instance, struct pt_regs *regs)
qc = ata_qc_from_tag(ap, ap->active_tag); qc = ata_qc_from_tag(ap, ap->active_tag);
if (qc && ((qc->flags & ATA_QCFLAG_POLL) == 0)) if (qc && ((qc->flags & ATA_QCFLAG_POLL) == 0))
handled += ata_host_intr(ap, qc); handled += ata_host_intr(ap, qc);
ata_chk_spurious_int(ap);
} }
} }
......
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