4 files changed, 114 insertions, 92 deletions

diff --git a/drivers/dma/ioat_dma.c b/drivers/dma/ioat_dma.c
index 43b8cefad2c6..b0438c4f0c30 100644
--- a/drivers/dma/ioat_dma.c
+++ b/drivers/dma/ioat_dma.c
@@ -33,6 +33,7 @@
 #include <linux/delay.h>
 #include <linux/dma-mapping.h>
 #include <linux/workqueue.h>
+#include <linux/i7300_idle.h>
 #include "ioatdma.h"
 #include "ioatdma_registers.h"
 #include "ioatdma_hw.h"
@@ -171,8 +172,10 @@ static int ioat_dma_enumerate_channels(struct ioatdma_device *device)
         xfercap_scale = readb(device->reg_base + IOAT_XFERCAP_OFFSET);
         xfercap = (xfercap_scale == 0 ? -1 : (1UL << xfercap_scale));
 
-#if CONFIG_I7300_IDLE_IOAT_CHANNEL
-        device->common.chancnt--;
+#ifdef  CONFIG_I7300_IDLE_IOAT_CHANNEL
+        if (i7300_idle_platform_probe(NULL, NULL) == 0) {
+                device->common.chancnt--;
+        }
 #endif
         for (i = 0; i < device->common.chancnt; i++) {
                 ioat_chan = kzalloc(sizeof(*ioat_chan), GFP_KERNEL);
diff --git a/drivers/idle/Kconfig b/drivers/idle/Kconfig
index f5b26dd579e4..108264de0ac9 100644
--- a/drivers/idle/Kconfig
+++ b/drivers/idle/Kconfig
@@ -5,12 +5,13 @@ config I7300_IDLE_IOAT_CHANNEL
         bool
 
 config I7300_IDLE
-        tristate "Intel chipset idle power saving driver"
+        tristate "Intel chipset idle memory power saving driver"
         select I7300_IDLE_IOAT_CHANNEL
-        depends on X86_64
+        depends on X86_64 && EXPERIMENTAL
         help
-          Enable idle power savings with certain Intel server chipsets.
-          The chipset must have I/O AT support, such as the Intel 7300.
-          The power savings depends on the type and quantity of DRAM devices.
+          Enable memory power savings when idle with certain Intel server
+          chipsets. The chipset must have I/O AT support, such as the
+          Intel 7300. The power savings depends on the type and quantity of
+          DRAM devices.
 
 endmenu
diff --git a/drivers/idle/i7300_idle.c b/drivers/idle/i7300_idle.c
index 59d1bbc3cd3c..fb176f6ef9f8 100644
--- a/drivers/idle/i7300_idle.c
+++ b/drivers/idle/i7300_idle.c
@@ -25,6 +25,7 @@
 #include <linux/delay.h>
 #include <linux/debugfs.h>
 #include <linux/stop_machine.h>
+#include <linux/i7300_idle.h>
 
 #include <asm/idle.h>
 
@@ -34,6 +35,8 @@
 #define I7300_IDLE_DRIVER_VERSION       "1.55"
 #define I7300_PRINT                     "i7300_idle:"
 
+#define MAX_STOP_RETRIES        10
+
 static int debug;
 module_param_named(debug, debug, uint, 0644);
 MODULE_PARM_DESC(debug, "Enable debug printks in this driver");
@@ -46,12 +49,12 @@ MODULE_PARM_DESC(debug, "Enable debug printks in this driver");
  *  0 = No throttling
  *  1 = Throttle when > 4 activations per eval window (Maximum throttling)
  *  2 = Throttle when > 8 activations
- *  168 = Throttle when > 168 activations (Minimum throttling)
+ *  168 = Throttle when > 672 activations (Minimum throttling)
  */
-#define MAX_THRTLWLIMIT         168
-static uint i7300_idle_thrtlowlm = 1;
-module_param_named(thrtlwlimit, i7300_idle_thrtlowlm, uint, 0644);
-MODULE_PARM_DESC(thrtlwlimit,
+#define MAX_THROTTLE_LOW_LIMIT          168
+static uint throttle_low_limit = 1;
+module_param_named(throttle_low_limit, throttle_low_limit, uint, 0644);
+MODULE_PARM_DESC(throttle_low_limit,
                 "Value for THRTLOWLM activation field "
                 "(0 = disable throttle, 1 = Max throttle, 168 = Min throttle)");
 
@@ -110,9 +113,9 @@ static int i7300_idle_ioat_start(void)
 static void i7300_idle_ioat_stop(void)
 {
         int i;
-        u8 sts;
+        u64 sts;
 
-        for (i = 0; i < 5; i++) {
+        for (i = 0; i < MAX_STOP_RETRIES; i++) {
                 writeb(IOAT_CHANCMD_RESET,
                         ioat_chanbase + IOAT1_CHANCMD_OFFSET);
 
@@ -126,9 +129,10 @@ static void i7300_idle_ioat_stop(void)
 
         }
 
-        if (i == 5)
-                dprintk("failed to suspend+reset I/O AT after 5 retries\n");
-
+        if (i == MAX_STOP_RETRIES) {
+                dprintk("failed to stop I/O AT after %d retries\n",
+                        MAX_STOP_RETRIES);
+        }
 }
 
 /* Test I/O AT by copying 1024 byte from 2k to 1k */
@@ -275,7 +279,7 @@ static void __exit i7300_idle_ioat_exit(void)
         i7300_idle_ioat_stop();
 
         /* Wait for a while for the channel to halt before releasing */
-        for (i = 0; i < 10; i++) {
+        for (i = 0; i < MAX_STOP_RETRIES; i++) {
                 writeb(IOAT_CHANCMD_RESET,
                        ioat_chanbase + IOAT1_CHANCMD_OFFSET);
 
@@ -389,9 +393,9 @@ static void i7300_idle_start(void)
         new_ctl = i7300_idle_thrtctl_saved & ~DIMM_THRTCTL_THRMHUNT;
         pci_write_config_byte(fbd_dev, DIMM_THRTCTL, new_ctl);
 
-        limit = i7300_idle_thrtlowlm;
-        if (unlikely(limit > MAX_THRTLWLIMIT))
-                limit = MAX_THRTLWLIMIT;
+        limit = throttle_low_limit;
+        if (unlikely(limit > MAX_THROTTLE_LOW_LIMIT))
+                limit = MAX_THROTTLE_LOW_LIMIT;
 
         pci_write_config_byte(fbd_dev, DIMM_THRTLOW, limit);
 
@@ -440,7 +444,7 @@ static int i7300_idle_notifier(struct notifier_block *nb, unsigned long val,
         static ktime_t idle_begin_time;
         static int time_init = 1;
 
-        if (!i7300_idle_thrtlowlm)
+        if (!throttle_low_limit)
                 return 0;
 
         if (unlikely(time_init)) {
@@ -505,77 +509,8 @@ static struct notifier_block i7300_idle_nb = {
         .notifier_call = i7300_idle_notifier,
 };
 
-/*
- * I/O AT controls (PCI bus 0 device 8 function 0)
- * DIMM controls (PCI bus 0 device 16 function 1)
- */
-#define IOAT_BUS 0
-#define IOAT_DEVFN PCI_DEVFN(8, 0)
-#define MEMCTL_BUS 0
-#define MEMCTL_DEVFN PCI_DEVFN(16, 1)
-
-struct fbd_ioat {
-        unsigned int vendor;
-        unsigned int ioat_dev;
-};
-
-/*
- * The i5000 chip-set has the same hooks as the i7300
- * but support is disabled by default because this driver
- * has not been validated on that platform.
- */
-#define SUPPORT_I5000 0
-
-static const struct fbd_ioat fbd_ioat_list[] = {
-        {PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT_CNB},
-#if SUPPORT_I5000
-        {PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT},
-#endif
-        {0, 0}
-};
-
-/* table of devices that work with this driver */
-static const struct pci_device_id pci_tbl[] = {
-        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_FBD_CNB) },
-#if SUPPORT_I5000
-        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_5000_ERR) },
-#endif
-        { } /* Terminating entry */
-};
-
 MODULE_DEVICE_TABLE(pci, pci_tbl);
 
-/* Check for known platforms with I/O-AT */
-static int __init i7300_idle_platform_probe(void)
-{
-        int i;
-
-        fbd_dev = pci_get_bus_and_slot(MEMCTL_BUS, MEMCTL_DEVFN);
-        if (!fbd_dev)
-                return -ENODEV;
-
-        for (i = 0; pci_tbl[i].vendor != 0; i++) {
-                if (fbd_dev->vendor == pci_tbl[i].vendor &&
-                    fbd_dev->device == pci_tbl[i].device) {
-                        break;
-                }
-        }
-        if (pci_tbl[i].vendor == 0)
-                return -ENODEV;
-
-        ioat_dev = pci_get_bus_and_slot(IOAT_BUS, IOAT_DEVFN);
-        if (!ioat_dev)
-                return -ENODEV;
-
-        for (i = 0; fbd_ioat_list[i].vendor != 0; i++) {
-                if (ioat_dev->vendor == fbd_ioat_list[i].vendor &&
-                    ioat_dev->device == fbd_ioat_list[i].ioat_dev) {
-                        return 0;
-                }
-        }
-        return -ENODEV;
-}
-
 int stats_open_generic(struct inode *inode, struct file *fp)
 {
         fp->private_data = inode->i_private;
@@ -617,7 +552,7 @@ static int __init i7300_idle_init(void)
         cpus_clear(idle_cpumask);
         total_us = 0;
 
-        if (i7300_idle_platform_probe())
+        if (i7300_idle_platform_probe(&fbd_dev, &ioat_dev))
                 return -ENODEV;
 
         if (i7300_idle_thrt_save())
diff --git a/include/linux/i7300_idle.h b/include/linux/i7300_idle.h
new file mode 100644
index 000000000000..05a80c44513c
--- /dev/null
+++ b/include/linux/i7300_idle.h
@@ -0,0 +1,83 @@
+
+#ifndef I7300_IDLE_H
+#define I7300_IDLE_H
+
+#include <linux/pci.h>
+
+/*
+ * I/O AT controls (PCI bus 0 device 8 function 0)
+ * DIMM controls (PCI bus 0 device 16 function 1)
+ */
+#define IOAT_BUS 0
+#define IOAT_DEVFN PCI_DEVFN(8, 0)
+#define MEMCTL_BUS 0
+#define MEMCTL_DEVFN PCI_DEVFN(16, 1)
+
+struct fbd_ioat {
+        unsigned int vendor;
+        unsigned int ioat_dev;
+};
+
+/*
+ * The i5000 chip-set has the same hooks as the i7300
+ * but support is disabled by default because this driver
+ * has not been validated on that platform.
+ */
+#define SUPPORT_I5000 0
+
+static const struct fbd_ioat fbd_ioat_list[] = {
+        {PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT_CNB},
+#if SUPPORT_I5000
+        {PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT},
+#endif
+        {0, 0}
+};
+
+/* table of devices that work with this driver */
+static const struct pci_device_id pci_tbl[] = {
+        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_FBD_CNB) },
+#if SUPPORT_I5000
+        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_5000_ERR) },
+#endif
+        { } /* Terminating entry */
+};
+
+/* Check for known platforms with I/O-AT */
+static inline int i7300_idle_platform_probe(struct pci_dev **fbd_dev,
+                                                struct pci_dev **ioat_dev)
+{
+        int i;
+        struct pci_dev *memdev, *dmadev;
+
+        memdev = pci_get_bus_and_slot(MEMCTL_BUS, MEMCTL_DEVFN);
+        if (!memdev)
+                return -ENODEV;
+
+        for (i = 0; pci_tbl[i].vendor != 0; i++) {
+                if (memdev->vendor == pci_tbl[i].vendor &&
+                    memdev->device == pci_tbl[i].device) {
+                        break;
+                }
+        }
+        if (pci_tbl[i].vendor == 0)
+                return -ENODEV;
+
+        dmadev = pci_get_bus_and_slot(IOAT_BUS, IOAT_DEVFN);
+        if (!dmadev)
+                return -ENODEV;
+
+        for (i = 0; fbd_ioat_list[i].vendor != 0; i++) {
+                if (dmadev->vendor == fbd_ioat_list[i].vendor &&
+                    dmadev->device == fbd_ioat_list[i].ioat_dev) {
+                        if (fbd_dev)
+                                *fbd_dev = memdev;
+                        if (ioat_dev)
+                                *ioat_dev = dmadev;
+
+                        return 0;
+                }
+        }
+        return -ENODEV;
+}
+
+#endif