Merge branch 'master'

1 files changed, 51 insertions, 1 deletions

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 457bdc44e4b1..4b4cf6cf4acc 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -156,6 +156,10 @@ enum {
 	ATA_SHIFT_UDMA		= 0,
 	ATA_SHIFT_MWDMA		= 8,
 	ATA_SHIFT_PIO		= 11,
+
+	/* size of buffer to pad xfers ending on unaligned boundaries */
+	ATA_DMA_PAD_SZ		= 4,
+	ATA_DMA_PAD_BUF_SZ	= ATA_DMA_PAD_SZ * ATA_MAX_QUEUE,
 	
 	/* Masks for port functions */
 	ATA_PORT_PRIMARY	= (1 << 0),
@@ -252,9 +256,12 @@ struct ata_queued_cmd {
 	unsigned long		flags;		/* ATA_QCFLAG_xxx */
 	unsigned int		tag;
 	unsigned int		n_elem;
+	unsigned int		orig_n_elem;
 
 	int			dma_dir;
 
+	unsigned int		pad_len;
+
 	unsigned int		nsect;
 	unsigned int		cursect;
 
@@ -265,9 +272,11 @@ struct ata_queued_cmd {
 	unsigned int		cursg_ofs;
 
 	struct scatterlist	sgent;
+	struct scatterlist	pad_sgent;
 	void			*buf_virt;
 
-	struct scatterlist	*sg;
+	/* DO NOT iterate over __sg manually, use ata_for_each_sg() */
+	struct scatterlist	*__sg;
 
 	ata_qc_cb_t		complete_fn;
 
@@ -313,6 +322,9 @@ struct ata_port {
 	struct ata_prd		*prd;	 /* our SG list */
 	dma_addr_t		prd_dma; /* and its DMA mapping */
 
+	void			*pad;	/* array of DMA pad buffers */
+	dma_addr_t		pad_dma;
+
 	struct ata_ioports	ioaddr;	/* ATA cmd/ctl/dma register blocks */
 
 	u8			ctl;	/* cache of ATA control register */
@@ -515,6 +527,31 @@ extern int pci_test_config_bits(struct pci_dev *pdev, const struct pci_bits *bit
 #endif /* CONFIG_PCI */
 
 
+static inline int
+ata_sg_is_last(struct scatterlist *sg, struct ata_queued_cmd *qc)
+{
+	if (sg == &qc->pad_sgent)
+		return 1;
+	if (qc->pad_len)
+		return 0;
+	if (((sg - qc->__sg) + 1) == qc->n_elem)
+		return 1;
+	return 0;
+}
+
+static inline struct scatterlist *
+ata_qc_next_sg(struct scatterlist *sg, struct ata_queued_cmd *qc)
+{
+	if (sg == &qc->pad_sgent)
+		return NULL;
+	if (++sg - qc->__sg < qc->n_elem)
+		return sg;
+	return qc->pad_len ? &qc->pad_sgent : NULL;
+}
+
+#define ata_for_each_sg(sg, qc) \
+	for (sg = qc->__sg; sg; sg = ata_qc_next_sg(sg, qc))
+
 static inline unsigned int ata_tag_valid(unsigned int tag)
 {
 	return (tag < ATA_MAX_QUEUE) ? 1 : 0;
@@ -743,4 +780,17 @@ static inline unsigned int __ac_err_mask(u8 status)
 	return mask;
 }
 
+static inline int ata_pad_alloc(struct ata_port *ap, struct device *dev)
+{
+	ap->pad_dma = 0;
+	ap->pad = dma_alloc_coherent(dev, ATA_DMA_PAD_BUF_SZ,
+				     &ap->pad_dma, GFP_KERNEL);
+	return (ap->pad == NULL) ? -ENOMEM : 0;
+}
+
+static inline void ata_pad_free(struct ata_port *ap, struct device *dev)
+{
+	dma_free_coherent(dev, ATA_DMA_PAD_BUF_SZ, ap->pad, ap->pad_dma);
+}
+
 #endif /* __LINUX_LIBATA_H__ */