Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit c01e8a23 authored by Mark Lord's avatar Mark Lord Committed by Jeff Garzik
Browse files

[libata] sata_mv: Enable use of (basic) DMA for ATAPI on GEN_IIE chips 



This also gets rid of any need for mv_mode_filter().

Using basic DMA on GEN_IIE requires setting an undocumented
bit in an undocumented register.  For safety, we clear that
bit again when switching back to EDMA mode.

To avoid a performance penalty when switching modes,
we cache the register in port_priv, as already done for other regs.

Signed-off-by: default avatarMark Lord <mlord@pobox.com>
Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
parent 08da1759

drivers/ata/sata_mv.c

+28 −24
Original line number Diff line number Diff line
@@ -345,7 +345,7 @@ enum { 
	EDMA_ARB_CFG_OFS	= 0x38,



	EDMA_HALTCOND_OFS	= 0x60,		/* GenIIe halt conditions */



	EDMA_UNKNOWN_RSVD_OFS	= 0x6C,		/* GenIIe unknown/reserved */



	BMDMA_CMD_OFS		= 0x224,	/* bmdma command register */

	BMDMA_STATUS_OFS	= 0x228,	/* bmdma status register */
@@ -447,6 +447,7 @@ struct mv_cached_regs { 
	u32			fiscfg;

	u32			ltmode;

	u32			haltcond;

	u32			unknown_rsvd;

};



struct mv_port_priv {
@@ -563,8 +564,6 @@ static void mv_pmp_error_handler(struct ata_port *ap); 
static void mv_process_crpb_entries(struct ata_port *ap,

					struct mv_port_priv *pp);



static unsigned long mv_mode_filter(struct ata_device *dev,

				    unsigned long xfer_mask);

static void mv_sff_irq_clear(struct ata_port *ap);

static int mv_check_atapi_dma(struct ata_queued_cmd *qc);

static void mv_bmdma_setup(struct ata_queued_cmd *qc);
@@ -626,7 +625,6 @@ static struct ata_port_operations mv6_ops = { 
	.bmdma_start		= mv_bmdma_start,

	.bmdma_stop		= mv_bmdma_stop,

	.bmdma_status		= mv_bmdma_status,

	.mode_filter		= mv_mode_filter,

};



static struct ata_port_operations mv_iie_ops = {
@@ -842,6 +840,7 @@ static void mv_save_cached_regs(struct ata_port *ap) 
	pp->cached.fiscfg = readl(port_mmio + FISCFG_OFS);

	pp->cached.ltmode = readl(port_mmio + LTMODE_OFS);

	pp->cached.haltcond = readl(port_mmio + EDMA_HALTCOND_OFS);

	pp->cached.unknown_rsvd = readl(port_mmio + EDMA_UNKNOWN_RSVD_OFS);

}



/**
@@ -1252,6 +1251,30 @@ static void mv_60x1_errata_sata25(struct ata_port *ap, int want_ncq) 
		writel(new, hpriv->base + MV_GPIO_PORT_CTL_OFS);

}



/**

 * 	mv_bmdma_enable - set a magic bit on GEN_IIE to allow bmdma

 * 	@ap: Port being initialized

 *

 *	There are two DMA modes on these chips:  basic DMA, and EDMA.

 *

 *	Bit-0 of the "EDMA RESERVED" register enables/disables use

 *	of basic DMA on the GEN_IIE versions of the chips.

 *

 *	This bit survives EDMA resets, and must be set for basic DMA

 *	to function, and should be cleared when EDMA is active.

 */

static void mv_bmdma_enable_iie(struct ata_port *ap, int enable_bmdma)

{

	struct mv_port_priv *pp = ap->private_data;

	u32 new, *old = &pp->cached.unknown_rsvd;



	if (enable_bmdma)

		new = *old | 1;

	else

		new = *old & ~1;

	mv_write_cached_reg(mv_ap_base(ap) + EDMA_UNKNOWN_RSVD_OFS, old, new);

}



static void mv_edma_cfg(struct ata_port *ap, int want_ncq, int want_edma)

{

	u32 cfg;
@@ -1297,6 +1320,7 @@ static void mv_edma_cfg(struct ata_port *ap, int want_ncq, int want_edma) 
		}

		if (hpriv->hp_flags & MV_HP_CUT_THROUGH)

			cfg |= (1 << 17); /* enab cut-thru (dis stor&forwrd) */

		mv_bmdma_enable_iie(ap, !want_edma);

	}



	if (want_ncq) {
@@ -1464,26 +1488,6 @@ static void mv_crqb_pack_cmd(__le16 *cmdw, u8 data, u8 addr, unsigned last) 
	*cmdw = cpu_to_le16(tmp);

}



/**

 *	mv_mode_filter - Allow ATAPI DMA only on GenII chips.

 *	@dev: device whose xfer modes are being configured.

 *

 *	Only the GenII hardware can use DMA with ATAPI drives.

 */

static unsigned long mv_mode_filter(struct ata_device *adev,

				    unsigned long xfer_mask)

{

	if (adev->class == ATA_DEV_ATAPI) {

		struct mv_host_priv *hpriv = adev->link->ap->host->private_data;

		if (!IS_GEN_II(hpriv)) {

			xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);

			ata_dev_printk(adev, KERN_INFO,

				"ATAPI DMA not supported on this chipset\n");

		}

	}

	return xfer_mask;

}



/**

 *	mv_sff_irq_clear - Clear hardware interrupt after DMA.

 *	@ap: Port associated with this ATA transaction.