1 files changed, 107 insertions, 4 deletions

diff --git a/drivers/ata/sata_fsl.c b/drivers/ata/sata_fsl.c
index 0120b0d1e9a5..d6577b93bee3 100644
--- a/drivers/ata/sata_fsl.c
+++ b/drivers/ata/sata_fsl.c
@@ -6,7 +6,7 @@
  * Author: Ashish Kalra <ashish.kalra@freescale.com>
  * Li Yang <leoli@freescale.com>
  *
- * Copyright (c) 2006-2007, 2011 Freescale Semiconductor, Inc.
+ * Copyright (c) 2006-2007, 2011-2012 Freescale Semiconductor, Inc.
  *
  * This program is free software; you can redistribute  it and/or modify it
  * under  the terms of  the GNU General  Public License as published by the
@@ -26,6 +26,15 @@
 #include <asm/io.h>
 #include <linux/of_platform.h>
 
+static unsigned int intr_coalescing_count;
+module_param(intr_coalescing_count, int, S_IRUGO);
+MODULE_PARM_DESC(intr_coalescing_count,
+                                 "INT coalescing count threshold (1..31)");
+
+static unsigned int intr_coalescing_ticks;
+module_param(intr_coalescing_ticks, int, S_IRUGO);
+MODULE_PARM_DESC(intr_coalescing_ticks,
+                                 "INT coalescing timer threshold in AHB ticks");
 /* Controller information */
 enum {
         SATA_FSL_QUEUE_DEPTH    = 16,
@@ -83,6 +92,16 @@ enum {
 };
 
 /*
+ * Interrupt Coalescing Control Register bitdefs  */
+enum {
+        ICC_MIN_INT_COUNT_THRESHOLD     = 1,
+        ICC_MAX_INT_COUNT_THRESHOLD     = ((1 << 5) - 1),
+        ICC_MIN_INT_TICKS_THRESHOLD     = 0,
+        ICC_MAX_INT_TICKS_THRESHOLD     = ((1 << 19) - 1),
+        ICC_SAFE_INT_TICKS              = 1,
+};
+
+/*
 * Host Controller command register set - per port
 */
 enum {
@@ -263,8 +282,65 @@ struct sata_fsl_host_priv {
         void __iomem *csr_base;
         int irq;
         int data_snoop;
+        struct device_attribute intr_coalescing;
 };
 
+static void fsl_sata_set_irq_coalescing(struct ata_host *host,
+                unsigned int count, unsigned int ticks)
+{
+        struct sata_fsl_host_priv *host_priv = host->private_data;
+        void __iomem *hcr_base = host_priv->hcr_base;
+
+        if (count > ICC_MAX_INT_COUNT_THRESHOLD)
+                count = ICC_MAX_INT_COUNT_THRESHOLD;
+        else if (count < ICC_MIN_INT_COUNT_THRESHOLD)
+                count = ICC_MIN_INT_COUNT_THRESHOLD;
+
+        if (ticks > ICC_MAX_INT_TICKS_THRESHOLD)
+                ticks = ICC_MAX_INT_TICKS_THRESHOLD;
+        else if ((ICC_MIN_INT_TICKS_THRESHOLD == ticks) &&
+                        (count > ICC_MIN_INT_COUNT_THRESHOLD))
+                ticks = ICC_SAFE_INT_TICKS;
+
+        spin_lock(&host->lock);
+        iowrite32((count << 24 | ticks), hcr_base + ICC);
+
+        intr_coalescing_count = count;
+        intr_coalescing_ticks = ticks;
+        spin_unlock(&host->lock);
+
+        DPRINTK("intrrupt coalescing, count = 0x%x, ticks = %x\n",
+                        intr_coalescing_count, intr_coalescing_ticks);
+        DPRINTK("ICC register status: (hcr base: 0x%x) = 0x%x\n",
+                        hcr_base, ioread32(hcr_base + ICC));
+}
+
+static ssize_t fsl_sata_intr_coalescing_show(struct device *dev,
+                struct device_attribute *attr, char *buf)
+{
+        return sprintf(buf, "%d %d\n",
+                        intr_coalescing_count, intr_coalescing_ticks);
+}
+
+static ssize_t fsl_sata_intr_coalescing_store(struct device *dev,
+                struct device_attribute *attr,
+                const char *buf, size_t count)
+{
+        unsigned int coalescing_count,  coalescing_ticks;
+
+        if (sscanf(buf, "%d%d",
+                                &coalescing_count,
+                                &coalescing_ticks) != 2) {
+                printk(KERN_ERR "fsl-sata: wrong parameter format.\n");
+                return -EINVAL;
+        }
+
+        fsl_sata_set_irq_coalescing(dev_get_drvdata(dev),
+                        coalescing_count, coalescing_ticks);
+
+        return strlen(buf);
+}
+
 static inline unsigned int sata_fsl_tag(unsigned int tag,
                                         void __iomem *hcr_base)
 {
@@ -346,10 +422,10 @@ static unsigned int sata_fsl_fill_sg(struct ata_queued_cmd *qc, void *cmd_desc,
                         (unsigned long long)sg_addr, sg_len);
 
                 /* warn if each s/g element is not dword aligned */
-                if (sg_addr & 0x03)
+                if (unlikely(sg_addr & 0x03))
                         ata_port_err(qc->ap, "s/g addr unaligned : 0x%llx\n",
                                      (unsigned long long)sg_addr);
-                if (sg_len & 0x03)
+                if (unlikely(sg_len & 0x03))
                         ata_port_err(qc->ap, "s/g len unaligned : 0x%x\n",
                                      sg_len);
 
@@ -1245,6 +1321,13 @@ static int sata_fsl_init_controller(struct ata_host *host)
         iowrite32(0x00000FFFF, hcr_base + CE);
         iowrite32(0x00000FFFF, hcr_base + DE);
 
+        /*
+         * reset the number of command complete bits which will cause the
+         * interrupt to be signaled
+         */
+        fsl_sata_set_irq_coalescing(host, intr_coalescing_count,
+                        intr_coalescing_ticks);
+
         /*
          * host controller will be brought on-line, during xx_port_start()
          * callback, that should also initiate the OOB, COMINIT sequence
@@ -1309,7 +1392,7 @@ static int sata_fsl_probe(struct platform_device *ofdev)
         void __iomem *csr_base = NULL;
         struct sata_fsl_host_priv *host_priv = NULL;
         int irq;
-        struct ata_host *host;
+        struct ata_host *host = NULL;
         u32 temp;
 
         struct ata_port_info pi = sata_fsl_port_info[0];
@@ -1356,6 +1439,10 @@ static int sata_fsl_probe(struct platform_device *ofdev)
 
         /* allocate host structure */
         host = ata_host_alloc_pinfo(&ofdev->dev, ppi, SATA_FSL_MAX_PORTS);
+        if (!host) {
+                retval = -ENOMEM;
+                goto error_exit_with_cleanup;
+        }
 
         /* host->iomap is not used currently */
         host->private_data = host_priv;
@@ -1373,10 +1460,24 @@ static int sata_fsl_probe(struct platform_device *ofdev)
 
         dev_set_drvdata(&ofdev->dev, host);
 
+        host_priv->intr_coalescing.show = fsl_sata_intr_coalescing_show;
+        host_priv->intr_coalescing.store = fsl_sata_intr_coalescing_store;
+        sysfs_attr_init(&host_priv->intr_coalescing.attr);
+        host_priv->intr_coalescing.attr.name = "intr_coalescing";
+        host_priv->intr_coalescing.attr.mode = S_IRUGO | S_IWUSR;
+        retval = device_create_file(host->dev, &host_priv->intr_coalescing);
+        if (retval)
+                goto error_exit_with_cleanup;
+
         return 0;
 
 error_exit_with_cleanup:
 
+        if (host) {
+                dev_set_drvdata(&ofdev->dev, NULL);
+                ata_host_detach(host);
+        }
+
         if (hcr_base)
                 iounmap(hcr_base);
         if (host_priv)
@@ -1390,6 +1491,8 @@ static int sata_fsl_remove(struct platform_device *ofdev)
         struct ata_host *host = dev_get_drvdata(&ofdev->dev);
         struct sata_fsl_host_priv *host_priv = host->private_data;
 
+        device_remove_file(&ofdev->dev, &host_priv->intr_coalescing);
+
         ata_host_detach(host);
 
         dev_set_drvdata(&ofdev->dev, NULL);