1 files changed, 77 insertions, 5 deletions

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 00a8a5738858..dcd17e7458ab 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -155,6 +155,10 @@ 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),
@@ -172,6 +176,13 @@ enum hsm_task_states {
         HSM_ST_ERR,
 };
 
+enum ata_completion_errors {
+        AC_ERR_OTHER            = (1 << 0),
+        AC_ERR_DEV              = (1 << 1),
+        AC_ERR_ATA_BUS          = (1 << 2),
+        AC_ERR_HOST_BUS         = (1 << 3),
+};
+
 /* forward declarations */
 struct scsi_device;
 struct ata_port_operations;
@@ -179,7 +190,7 @@ struct ata_port;
 struct ata_queued_cmd;
 
 /* typedefs */
-typedef int (*ata_qc_cb_t) (struct ata_queued_cmd *qc, u8 drv_stat);
+typedef int (*ata_qc_cb_t) (struct ata_queued_cmd *qc, unsigned int err_mask);
 
 struct ata_ioports {
         unsigned long           cmd_addr;
@@ -242,9 +253,12 @@ 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;
 
@@ -255,9 +269,11 @@ 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;
 
@@ -303,6 +319,9 @@ 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 */
@@ -347,7 +366,6 @@ struct ata_port_operations {
         void (*exec_command)(struct ata_port *ap, const struct ata_taskfile *tf);
         u8   (*check_status)(struct ata_port *ap);
         u8   (*check_altstatus)(struct ata_port *ap);
-        u8   (*check_err)(struct ata_port *ap);
         void (*dev_select)(struct ata_port *ap, unsigned int device);
 
         void (*phy_reset) (struct ata_port *ap);
@@ -434,7 +452,6 @@ extern void ata_noop_dev_select (struct ata_port *ap, unsigned int device);
 extern void ata_std_dev_select (struct ata_port *ap, unsigned int device);
 extern u8 ata_check_status(struct ata_port *ap);
 extern u8 ata_altstatus(struct ata_port *ap);
-extern u8 ata_chk_err(struct ata_port *ap);
 extern void ata_exec_command(struct ata_port *ap, const struct ata_taskfile *tf);
 extern int ata_port_start (struct ata_port *ap);
 extern void ata_port_stop (struct ata_port *ap);
@@ -455,7 +472,7 @@ extern void ata_bmdma_start (struct ata_queued_cmd *qc);
 extern void ata_bmdma_stop(struct ata_queued_cmd *qc);
 extern u8   ata_bmdma_status(struct ata_port *ap);
 extern void ata_bmdma_irq_clear(struct ata_port *ap);
-extern void ata_qc_complete(struct ata_queued_cmd *qc, u8 drv_stat);
+extern void ata_qc_complete(struct ata_queued_cmd *qc, unsigned int err_mask);
 extern void ata_eng_timeout(struct ata_port *ap);
 extern void ata_scsi_simulate(u16 *id, struct scsi_cmnd *cmd,
                               void (*done)(struct scsi_cmnd *));
@@ -507,6 +524,31 @@ 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;
@@ -718,4 +760,34 @@ static inline int ata_try_flush_cache(const struct ata_device *dev)
                ata_id_has_flush_ext(dev->id);
 }
 
+static inline unsigned int ac_err_mask(u8 status)
+{
+        if (status & ATA_BUSY)
+                return AC_ERR_ATA_BUS;
+        if (status & (ATA_ERR | ATA_DF))
+                return AC_ERR_DEV;
+        return 0;
+}
+
+static inline unsigned int __ac_err_mask(u8 status)
+{
+        unsigned int mask = ac_err_mask(status);
+        if (mask == 0)
+                return AC_ERR_OTHER;
+        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__ */