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libata: Support chips with 64K PRD quirk

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Add ata_dumb_qc_prep and supporting logic so that a driver can just
specify it needs to be helped in this area. 64K entries are split
as with drivers/ide.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This commit is contained in:
Alan Cox
2007-07-06 19:13:52 -04:00
committed by Jeff Garzik
parent c1e6f28cc5
commit d26fc9551a
6 changed files with 89 additions and 7 deletions
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80
drivers/ata/libata-core.c
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@@ -4102,6 +4102,68 @@ static void ata_fill_sg(struct ata_queued_cmd *qc)
ap->prd[idx - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
}
/**
* ata_fill_sg_dumb - Fill PCI IDE PRD table
* @qc: Metadata associated with taskfile to be transferred
*
* Fill PCI IDE PRD (scatter-gather) table with segments
* associated with the current disk command. Perform the fill
* so that we avoid writing any length 64K records for
* controllers that don't follow the spec.
*
* LOCKING:
* spin_lock_irqsave(host lock)
*
*/
static void ata_fill_sg_dumb(struct ata_queued_cmd *qc)
{
struct ata_port *ap = qc->ap;
struct scatterlist *sg;
unsigned int idx;
WARN_ON(qc->__sg == NULL);
WARN_ON(qc->n_elem == 0 && qc->pad_len == 0);
idx = 0;
ata_for_each_sg(sg, qc) {
u32 addr, offset;
u32 sg_len, len, blen;
/* 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);
sg_len = sg_dma_len(sg);
while (sg_len) {
offset = addr & 0xffff;
len = sg_len;
if ((offset + sg_len) > 0x10000)
len = 0x10000 - offset;
blen = len & 0xffff;
ap->prd[idx].addr = cpu_to_le32(addr);
if (blen == 0) {
/* Some PATA chipsets like the CS5530 can't
cope with 0x0000 meaning 64K as the spec says */
ap->prd[idx].flags_len = cpu_to_le32(0x8000);
blen = 0x8000;
ap->prd[++idx].addr = cpu_to_le32(addr + 0x8000);
}
ap->prd[idx].flags_len = cpu_to_le32(blen);
VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", idx, addr, len);
idx++;
sg_len -= len;
addr += len;
}
}
if (idx)
ap->prd[idx - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
}
/**
* ata_check_atapi_dma - Check whether ATAPI DMA can be supported
* @qc: Metadata associated with taskfile to check
@@ -4149,6 +4211,23 @@ void ata_qc_prep(struct ata_queued_cmd *qc)
ata_fill_sg(qc);
}
/**
* ata_dumb_qc_prep - Prepare taskfile for submission
* @qc: Metadata associated with taskfile to be prepared
*
* Prepare ATA taskfile for submission.
*
* LOCKING:
* spin_lock_irqsave(host lock)
*/
void ata_dumb_qc_prep(struct ata_queued_cmd *qc)
{
if (!(qc->flags & ATA_QCFLAG_DMAMAP))
return;
ata_fill_sg_dumb(qc);
}
void ata_noop_qc_prep(struct ata_queued_cmd *qc) { }
/**
@@ -6821,6 +6900,7 @@ EXPORT_SYMBOL_GPL(ata_do_set_mode);
EXPORT_SYMBOL_GPL(ata_data_xfer);
EXPORT_SYMBOL_GPL(ata_data_xfer_noirq);
EXPORT_SYMBOL_GPL(ata_qc_prep);
EXPORT_SYMBOL_GPL(ata_dumb_qc_prep);
EXPORT_SYMBOL_GPL(ata_noop_qc_prep);
EXPORT_SYMBOL_GPL(ata_bmdma_setup);
EXPORT_SYMBOL_GPL(ata_bmdma_start);