[PATCH] Disable ioat channel only on platforms where ile driver can load

From: Venki Pallipadi
Date: Wed Oct 22 2008 - 19:35:11 EST


On Wed, Oct 22, 2008 at 12:19:22AM -0700, Andi Kleen wrote:
> Pallipadi, Venkatesh wrote:
> >
> >>> +#if CONFIG_I7300_IDLE_IOAT_CHANNEL
> >>> + device->common.chancnt--;
> >>> +#endif
> >> I still think this lone decrement looks fishy. Can there please be some
> >> explanation how it exactly relates to the i7300 idle driver, where the
> >> matching increment is, etc.?
> >
> > No. This is not a increment/decrement thing. It is basically telling other
> > Users of IOAT that they have one IOAT channel less that they can use.
> > The last IOAT channel is used by i7300 idle driver to get the throttling to
> > work.
>
> Ok then it should be made conditional on the i7300 actually be available
> in the system? It looks like you do it always no matter what chipset is in there.

Does the patch below look OK?

Thanks,
Venki

Based on input from Andi Kleen:
share the platform detection code with ioat_dma and disable the channel in
dma engine only for specific platforms.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@xxxxxxxxx>

---
drivers/dma/ioat_dma.c | 5 ++
drivers/idle/i7300_idle.c | 72 +--------------------------------------
include/linux/i7300_idle.h | 83 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 89 insertions(+), 71 deletions(-)

Index: linux-acpi-2.6/drivers/idle/i7300_idle.c
===================================================================
--- linux-acpi-2.6.orig/drivers/idle/i7300_idle.c 2008-10-22 11:42:04.000000000 -0700
+++ linux-acpi-2.6/drivers/idle/i7300_idle.c 2008-10-22 11:42:46.000000000 -0700
@@ -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>

@@ -505,77 +506,8 @@ static struct notifier_block i7300_idle_
.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 +549,7 @@ 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())
Index: linux-acpi-2.6/include/linux/i7300_idle.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-acpi-2.6/include/linux/i7300_idle.h 2008-10-22 11:42:46.000000000 -0700
@@ -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
Index: linux-acpi-2.6/drivers/dma/ioat_dma.c
===================================================================
--- linux-acpi-2.6.orig/drivers/dma/ioat_dma.c 2008-10-22 11:42:04.000000000 -0700
+++ linux-acpi-2.6/drivers/dma/ioat_dma.c 2008-10-22 11:42:46.000000000 -0700
@@ -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"
@@ -172,7 +173,9 @@ static int ioat_dma_enumerate_channels(s
xfercap = (xfercap_scale == 0 ? -1 : (1UL << xfercap_scale));

#if CONFIG_I7300_IDLE_IOAT_CHANNEL
- device->common.chancnt--;
+ 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);
--
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