1 files changed, 207 insertions, 40 deletions

diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 4154e5b6bad8..dee4b12b0342 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -1314,12 +1314,12 @@ static inline u8 ata_dev_knobble(struct ata_port *ap)
 /**
  *      ata_dev_config - Run device specific handlers and check for
  *                       SATA->PATA bridges
- *      @ap: Bus 
+ *      @ap: Bus
  *      @i:  Device
  *
  *      LOCKING:
  */
- 
+
 void ata_dev_config(struct ata_port *ap, unsigned int i)
 {
         /* limit bridge transfers to udma5, 200 sectors */
@@ -2387,6 +2387,27 @@ static int ata_sg_setup(struct ata_queued_cmd *qc)
 }
 
 /**
+ *      ata_poll_qc_complete - turn irq back on and finish qc
+ *      @qc: Command to complete
+ *      @drv_stat: ATA status register content
+ *
+ *      LOCKING:
+ *      None.  (grabs host lock)
+ */
+
+void ata_poll_qc_complete(struct ata_queued_cmd *qc, u8 drv_stat)
+{
+        struct ata_port *ap = qc->ap;
+        unsigned long flags;
+
+        spin_lock_irqsave(&ap->host_set->lock, flags);
+        ap->flags &= ~ATA_FLAG_NOINTR;
+        ata_irq_on(ap);
+        ata_qc_complete(qc, drv_stat);
+        spin_unlock_irqrestore(&ap->host_set->lock, flags);
+}
+
+/**
  *      ata_pio_poll -
  *      @ap:
  *
@@ -2448,11 +2469,10 @@ static void ata_pio_complete (struct ata_port *ap)
         u8 drv_stat;
 
         /*
-         * This is purely hueristic.  This is a fast path.
-         * Sometimes when we enter, BSY will be cleared in
-         * a chk-status or two.  If not, the drive is probably seeking
-         * or something.  Snooze for a couple msecs, then
-         * chk-status again.  If still busy, fall back to
+         * This is purely heuristic.  This is a fast path.  Sometimes when
+         * we enter, BSY will be cleared in a chk-status or two.  If not,
+         * the drive is probably seeking or something.  Snooze for a couple
+         * msecs, then chk-status again.  If still busy, fall back to
          * PIO_ST_POLL state.
          */
         drv_stat = ata_busy_wait(ap, ATA_BUSY | ATA_DRQ, 10);
@@ -2477,9 +2497,7 @@ static void ata_pio_complete (struct ata_port *ap)
 
         ap->pio_task_state = PIO_ST_IDLE;
 
-        ata_irq_on(ap);
-
-        ata_qc_complete(qc, drv_stat);
+        ata_poll_qc_complete(qc, drv_stat);
 }
 
 
@@ -2504,6 +2522,20 @@ void swap_buf_le16(u16 *buf, unsigned int buf_words)
 #endif /* __BIG_ENDIAN */
 }
 
+/**
+ *      ata_mmio_data_xfer - Transfer data by MMIO
+ *      @ap: port to read/write
+ *      @buf: data buffer
+ *      @buflen: buffer length
+ *      @do_write: read/write
+ *
+ *      Transfer data from/to the device data register by MMIO.
+ *
+ *      LOCKING:
+ *      Inherited from caller.
+ *
+ */
+
 static void ata_mmio_data_xfer(struct ata_port *ap, unsigned char *buf,
                                unsigned int buflen, int write_data)
 {
@@ -2512,6 +2544,7 @@ static void ata_mmio_data_xfer(struct ata_port *ap, unsigned char *buf,
         u16 *buf16 = (u16 *) buf;
         void __iomem *mmio = (void __iomem *)ap->ioaddr.data_addr;
 
+        /* Transfer multiple of 2 bytes */
         if (write_data) {
                 for (i = 0; i < words; i++)
                         writew(le16_to_cpu(buf16[i]), mmio);
@@ -2519,19 +2552,76 @@ static void ata_mmio_data_xfer(struct ata_port *ap, unsigned char *buf,
                 for (i = 0; i < words; i++)
                         buf16[i] = cpu_to_le16(readw(mmio));
         }
+
+        /* Transfer trailing 1 byte, if any. */
+        if (unlikely(buflen & 0x01)) {
+                u16 align_buf[1] = { 0 };
+                unsigned char *trailing_buf = buf + buflen - 1;
+
+                if (write_data) {
+                        memcpy(align_buf, trailing_buf, 1);
+                        writew(le16_to_cpu(align_buf[0]), mmio);
+                } else {
+                        align_buf[0] = cpu_to_le16(readw(mmio));
+                        memcpy(trailing_buf, align_buf, 1);
+                }
+        }
 }
 
+/**
+ *      ata_pio_data_xfer - Transfer data by PIO
+ *      @ap: port to read/write
+ *      @buf: data buffer
+ *      @buflen: buffer length
+ *      @do_write: read/write
+ *
+ *      Transfer data from/to the device data register by PIO.
+ *
+ *      LOCKING:
+ *      Inherited from caller.
+ *
+ */
+
 static void ata_pio_data_xfer(struct ata_port *ap, unsigned char *buf,
                               unsigned int buflen, int write_data)
 {
-        unsigned int dwords = buflen >> 1;
+        unsigned int words = buflen >> 1;
 
+        /* Transfer multiple of 2 bytes */
         if (write_data)
-                outsw(ap->ioaddr.data_addr, buf, dwords);
+                outsw(ap->ioaddr.data_addr, buf, words);
         else
-                insw(ap->ioaddr.data_addr, buf, dwords);
+                insw(ap->ioaddr.data_addr, buf, words);
+
+        /* Transfer trailing 1 byte, if any. */
+        if (unlikely(buflen & 0x01)) {
+                u16 align_buf[1] = { 0 };
+                unsigned char *trailing_buf = buf + buflen - 1;
+
+                if (write_data) {
+                        memcpy(align_buf, trailing_buf, 1);
+                        outw(le16_to_cpu(align_buf[0]), ap->ioaddr.data_addr);
+                } else {
+                        align_buf[0] = cpu_to_le16(inw(ap->ioaddr.data_addr));
+                        memcpy(trailing_buf, align_buf, 1);
+                }
+        }
 }
 
+/**
+ *      ata_data_xfer - Transfer data from/to the data register.
+ *      @ap: port to read/write
+ *      @buf: data buffer
+ *      @buflen: buffer length
+ *      @do_write: read/write
+ *
+ *      Transfer data from/to the device data register.
+ *
+ *      LOCKING:
+ *      Inherited from caller.
+ *
+ */
+
 static void ata_data_xfer(struct ata_port *ap, unsigned char *buf,
                           unsigned int buflen, int do_write)
 {
@@ -2541,6 +2631,16 @@ static void ata_data_xfer(struct ata_port *ap, unsigned char *buf,
                 ata_pio_data_xfer(ap, buf, buflen, do_write);
 }
 
+/**
+ *      ata_pio_sector - Transfer ATA_SECT_SIZE (512 bytes) of data.
+ *      @qc: Command on going
+ *
+ *      Transfer ATA_SECT_SIZE of data from/to the ATA device.
+ *
+ *      LOCKING:
+ *      Inherited from caller.
+ */
+
 static void ata_pio_sector(struct ata_queued_cmd *qc)
 {
         int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
@@ -2579,6 +2679,18 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)
         kunmap(page);
 }
 
+/**
+ *      __atapi_pio_bytes - Transfer data from/to the ATAPI device.
+ *      @qc: Command on going
+ *      @bytes: number of bytes
+ *
+ *      Transfer Transfer data from/to the ATAPI device.
+ *
+ *      LOCKING:
+ *      Inherited from caller.
+ *
+ */
+
 static void __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
 {
         int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
@@ -2588,10 +2700,33 @@ static void __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
         unsigned char *buf;
         unsigned int offset, count;
 
-        if (qc->curbytes == qc->nbytes - bytes)
+        if (qc->curbytes + bytes >= qc->nbytes)
                 ap->pio_task_state = PIO_ST_LAST;
 
 next_sg:
+        if (unlikely(qc->cursg >= qc->n_elem)) {
+                /* 
+                 * The end of qc->sg is reached and the device expects
+                 * more data to transfer. In order not to overrun qc->sg
+                 * and fulfill length specified in the byte count register,
+                 *    - for read case, discard trailing data from the device
+                 *    - for write case, padding zero data to the device
+                 */
+                u16 pad_buf[1] = { 0 };
+                unsigned int words = bytes >> 1;
+                unsigned int i;
+
+                if (words) /* warning if bytes > 1 */
+                        printk(KERN_WARNING "ata%u: %u bytes trailing data\n", 
+                               ap->id, bytes);
+
+                for (i = 0; i < words; i++)
+                        ata_data_xfer(ap, (unsigned char*)pad_buf, 2, do_write);
+
+                ap->pio_task_state = PIO_ST_LAST;
+                return;
+        }
+
         sg = &qc->sg[qc->cursg];
 
         page = sg->page;
@@ -2625,11 +2760,21 @@ next_sg:
 
         kunmap(page);
 
-        if (bytes) {
+        if (bytes)
                 goto next_sg;
-        }
 }
 
+/**
+ *      atapi_pio_bytes - Transfer data from/to the ATAPI device.
+ *      @qc: Command on going
+ *
+ *      Transfer Transfer data from/to the ATAPI device.
+ *
+ *      LOCKING:
+ *      Inherited from caller.
+ *
+ */
+
 static void atapi_pio_bytes(struct ata_queued_cmd *qc)
 {
         struct ata_port *ap = qc->ap;
@@ -2702,9 +2847,7 @@ static void ata_pio_block(struct ata_port *ap)
                 if ((status & ATA_DRQ) == 0) {
                         ap->pio_task_state = PIO_ST_IDLE;
 
-                        ata_irq_on(ap);
-
-                        ata_qc_complete(qc, status);
+                        ata_poll_qc_complete(qc, status);
                         return;
                 }
 
@@ -2734,9 +2877,7 @@ static void ata_pio_error(struct ata_port *ap)
 
         ap->pio_task_state = PIO_ST_IDLE;
 
-        ata_irq_on(ap);
-
-        ata_qc_complete(qc, drv_stat | ATA_ERR);
+        ata_poll_qc_complete(qc, drv_stat | ATA_ERR);
 }
 
 static void ata_pio_task(void *_data)
@@ -2842,8 +2983,10 @@ static void atapi_request_sense(struct ata_port *ap, struct ata_device *dev,
 static void ata_qc_timeout(struct ata_queued_cmd *qc)
 {
         struct ata_port *ap = qc->ap;
+        struct ata_host_set *host_set = ap->host_set;
         struct ata_device *dev = qc->dev;
         u8 host_stat = 0, drv_stat;
+        unsigned long flags;
 
         DPRINTK("ENTER\n");
 
@@ -2854,7 +2997,9 @@ static void ata_qc_timeout(struct ata_queued_cmd *qc)
                 if (!(cmd->eh_eflags & SCSI_EH_CANCEL_CMD)) {
 
                         /* finish completing original command */
+                        spin_lock_irqsave(&host_set->lock, flags);
                         __ata_qc_complete(qc);
+                        spin_unlock_irqrestore(&host_set->lock, flags);
 
                         atapi_request_sense(ap, dev, cmd);
 
@@ -2865,6 +3010,8 @@ static void ata_qc_timeout(struct ata_queued_cmd *qc)
                 }
         }
 
+        spin_lock_irqsave(&host_set->lock, flags);
+
         /* hack alert!  We cannot use the supplied completion
          * function from inside the ->eh_strategy_handler() thread.
          * libata is the only user of ->eh_strategy_handler() in
@@ -2880,7 +3027,7 @@ static void ata_qc_timeout(struct ata_queued_cmd *qc)
                 host_stat = ap->ops->bmdma_status(ap);
 
                 /* before we do anything else, clear DMA-Start bit */
-                ap->ops->bmdma_stop(ap);
+                ap->ops->bmdma_stop(qc);
 
                 /* fall through */
 
@@ -2898,6 +3045,9 @@ static void ata_qc_timeout(struct ata_queued_cmd *qc)
                 ata_qc_complete(qc, drv_stat);
                 break;
         }
+
+        spin_unlock_irqrestore(&host_set->lock, flags);
+
 out:
         DPRINTK("EXIT\n");
 }
@@ -3071,9 +3221,14 @@ void ata_qc_complete(struct ata_queued_cmd *qc, u8 drv_stat)
         if (likely(qc->flags & ATA_QCFLAG_DMAMAP))
                 ata_sg_clean(qc);
 
+        /* atapi: mark qc as inactive to prevent the interrupt handler
+         * from completing the command twice later, before the error handler
+         * is called. (when rc != 0 and atapi request sense is needed)
+         */
+        qc->flags &= ~ATA_QCFLAG_ACTIVE;
+
         /* call completion callback */
         rc = qc->complete_fn(qc, drv_stat);
-        qc->flags &= ~ATA_QCFLAG_ACTIVE;
 
         /* if callback indicates not to complete command (non-zero),
          * return immediately
@@ -3203,11 +3358,13 @@ int ata_qc_issue_prot(struct ata_queued_cmd *qc)
                 break;
 
         case ATA_PROT_ATAPI_NODATA:
+                ap->flags |= ATA_FLAG_NOINTR;
                 ata_tf_to_host_nolock(ap, &qc->tf);
                 queue_work(ata_wq, &ap->packet_task);
                 break;
 
         case ATA_PROT_ATAPI_DMA:
+                ap->flags |= ATA_FLAG_NOINTR;
                 ap->ops->tf_load(ap, &qc->tf);   /* load tf registers */
                 ap->ops->bmdma_setup(qc);           /* set up bmdma */
                 queue_work(ata_wq, &ap->packet_task);
@@ -3252,7 +3409,7 @@ static void ata_bmdma_setup_mmio (struct ata_queued_cmd *qc)
 }
 
 /**
- *      ata_bmdma_start - Start a PCI IDE BMDMA transaction
+ *      ata_bmdma_start_mmio - Start a PCI IDE BMDMA transaction
  *      @qc: Info associated with this ATA transaction.
  *
  *      LOCKING:
@@ -3423,7 +3580,7 @@ u8 ata_bmdma_status(struct ata_port *ap)
 
 /**
  *      ata_bmdma_stop - Stop PCI IDE BMDMA transfer
- *      @ap: Port associated with this ATA transaction.
+ *      @qc: Command we are ending DMA for
  *
  *      Clears the ATA_DMA_START flag in the dma control register
  *
@@ -3433,8 +3590,9 @@ u8 ata_bmdma_status(struct ata_port *ap)
  *      spin_lock_irqsave(host_set lock)
  */
 
-void ata_bmdma_stop(struct ata_port *ap)
+void ata_bmdma_stop(struct ata_queued_cmd *qc)
 {
+        struct ata_port *ap = qc->ap;
         if (ap->flags & ATA_FLAG_MMIO) {
                 void __iomem *mmio = (void __iomem *) ap->ioaddr.bmdma_addr;
 
@@ -3486,7 +3644,7 @@ inline unsigned int ata_host_intr (struct ata_port *ap,
                         goto idle_irq;
 
                 /* before we do anything else, clear DMA-Start bit */
-                ap->ops->bmdma_stop(ap);
+                ap->ops->bmdma_stop(qc);
 
                 /* fall through */
 
@@ -3561,7 +3719,8 @@ irqreturn_t ata_interrupt (int irq, void *dev_instance, struct pt_regs *regs)
                 struct ata_port *ap;
 
                 ap = host_set->ports[i];
-                if (ap && (!(ap->flags & ATA_FLAG_PORT_DISABLED))) {
+                if (ap &&
+                    !(ap->flags & (ATA_FLAG_PORT_DISABLED | ATA_FLAG_NOINTR))) {
                         struct ata_queued_cmd *qc;
 
                         qc = ata_qc_from_tag(ap, ap->active_tag);
@@ -3613,19 +3772,27 @@ static void atapi_packet_task(void *_data)
         /* send SCSI cdb */
         DPRINTK("send cdb\n");
         assert(ap->cdb_len >= 12);
-        ata_data_xfer(ap, qc->cdb, ap->cdb_len, 1);
 
-        /* if we are DMA'ing, irq handler takes over from here */
-        if (qc->tf.protocol == ATA_PROT_ATAPI_DMA)
-                ap->ops->bmdma_start(qc);           /* initiate bmdma */
+        if (qc->tf.protocol == ATA_PROT_ATAPI_DMA ||
+            qc->tf.protocol == ATA_PROT_ATAPI_NODATA) {
+                unsigned long flags;
 
-        /* non-data commands are also handled via irq */
-        else if (qc->tf.protocol == ATA_PROT_ATAPI_NODATA) {
-                /* do nothing */
-        }
+                /* Once we're done issuing command and kicking bmdma,
+                 * irq handler takes over.  To not lose irq, we need
+                 * to clear NOINTR flag before sending cdb, but
+                 * interrupt handler shouldn't be invoked before we're
+                 * finished.  Hence, the following locking.
+                 */
+                spin_lock_irqsave(&ap->host_set->lock, flags);
+                ap->flags &= ~ATA_FLAG_NOINTR;
+                ata_data_xfer(ap, qc->cdb, ap->cdb_len, 1);
+                if (qc->tf.protocol == ATA_PROT_ATAPI_DMA)
+                        ap->ops->bmdma_start(qc);       /* initiate bmdma */
+                spin_unlock_irqrestore(&ap->host_set->lock, flags);
+        } else {
+                ata_data_xfer(ap, qc->cdb, ap->cdb_len, 1);
 
-        /* PIO commands are handled by polling */
-        else {
+                /* PIO commands are handled by polling */
                 ap->pio_task_state = PIO_ST;
                 queue_work(ata_wq, &ap->pio_task);
         }
@@ -3633,7 +3800,7 @@ static void atapi_packet_task(void *_data)
         return;
 
 err_out:
-        ata_qc_complete(qc, ATA_ERR);
+        ata_poll_qc_complete(qc, ATA_ERR);
 }