[PATCH 1/4] Changes to generic pci code

Kenji Kaneshige
2006-06-07T03:15:51Z

This patch adds the following changes into generic PCI code especially
for PCI legacy I/O port free drivers.

- Moved the following two things from pci_enable_device() into
pci_enable_device_bars(). By this change, we can use
pci_enable_device_bars() to enable only the specific regions.

o Call pci_fixup_device() on the device
o Set dev->is_enabled

- Added new field 'bars_enabled' into struct pci_device to
remember which BARs already enabled. This new field is
initialized at pci_enable_device_bars() time and cleared
at pci_disable_device() time. This is needed for
pci_default_resume() to enable appropriate BARs.

- Added new pci_request_selected_regions() and
pci_release_selected_regions() for PCI legacy I/O port free
drivers in order to request/release only the selected regions.

- Added helper routine pci_select_bars() which makes proper mask
of BARs from the specified resource type. This would be very
helpful for users of pci_enable_device_bars().

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>

---
drivers/pci/pci-driver.c | 3 +
drivers/pci/pci.c | 86 ++++++++++++++++++++++++++++++++++++-----------
include/linux/pci.h | 4 ++
3 files changed, 73 insertions(+), 20 deletions(-)

Index: linux-2.6.17-rc6/drivers/pci/pci-driver.c
===================================================================
--- linux-2.6.17-rc6.orig/drivers/pci/pci-driver.c 2006-06-06 21:39:11.000000000 +0900
+++ linux-2.6.17-rc6/drivers/pci/pci-driver.c 2006-06-06 21:40:26.000000000 +0900
@@ -293,7 +293,8 @@
pci_restore_state(pci_dev);
/* if the device was enabled before suspend, reenable */
if (pci_dev->is_enabled)
- retval = pci_enable_device(pci_dev);
+ retval = pci_enable_device_bars(pci_dev,
+ pci_dev->bars_enabled);
/* if the device was busmaster before the suspend, make it busmaster again */
if (pci_dev->is_busmaster)
pci_set_master(pci_dev);
Index: linux-2.6.17-rc6/drivers/pci/pci.c
===================================================================
--- linux-2.6.17-rc6.orig/drivers/pci/pci.c 2006-06-06 21:39:11.000000000 +0900
+++ linux-2.6.17-rc6/drivers/pci/pci.c 2006-06-06 21:55:46.000000000 +0900
@@ -490,6 +490,9 @@
err = pcibios_enable_device(dev, bars);
if (err < 0)
return err;
+ pci_fixup_device(pci_fixup_enable, dev);
+ dev->is_enabled = 1;
+ dev->bars_enabled = bars;
return 0;
}

@@ -507,8 +510,6 @@
int err = pci_enable_device_bars(dev, (1 << PCI_NUM_RESOURCES) - 1);
if (err)
return err;
- pci_fixup_device(pci_fixup_enable, dev);
- dev->is_enabled = 1;
return 0;
}

@@ -543,6 +544,7 @@

pcibios_disable_device(dev);
dev->is_enabled = 0;
+ dev->bars_enabled = 0;
}

/**
@@ -651,7 +653,7 @@
{
if (pci_resource_len(pdev, bar) == 0)
return 0;
-
+
if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) {
if (!request_region(pci_resource_start(pdev, bar),
pci_resource_len(pdev, bar), res_name))
@@ -674,6 +676,47 @@
return -EBUSY;
}

+/**
+ * pci_release_selected_regions - Release selected PCI I/O and memory resources
+ * @pdev: PCI device whose resources were previously reserved
+ * @bars: Bitmask of BARs to be released
+ *
+ * Release selected PCI I/O and memory resources previously reserved.
+ * Call this function only after all use of the PCI regions has ceased.
+ */
+void pci_release_selected_regions(struct pci_dev *pdev, int bars)
+{
+ int i;
+
+ for (i = 0; i < 6; i++)
+ if (bars & (1 << i))
+ pci_release_region(pdev, i);
+}
+
+/**
+ * pci_request_selected_regions - Reserve selected PCI I/O and memory resources
+ * @pdev: PCI device whose resources are to be reserved
+ * @bars: Bitmask of BARs to be requested
+ * @res_name: Name to be associated with resource
+ */
+int pci_request_selected_regions(struct pci_dev *pdev, int bars,
+ const char *res_name)
+{
+ int i;
+
+ for (i = 0; i < 6; i++)
+ if (bars & (1 << i))
+ if(pci_request_region(pdev, i, res_name))
+ goto err_out;
+ return 0;
+
+err_out:
+ while(--i >= 0)
+ if (bars & (1 << i))
+ pci_release_region(pdev, i);
+
+ return -EBUSY;
+}

/**
* pci_release_regions - Release reserved PCI I/O and memory resources
@@ -686,10 +729,7 @@

void pci_release_regions(struct pci_dev *pdev)
{
- int i;
-
- for (i = 0; i < 6; i++)
- pci_release_region(pdev, i);
+ pci_release_selected_regions(pdev, (1 << 6) - 1);
}

/**
@@ -707,18 +747,7 @@
*/
int pci_request_regions(struct pci_dev *pdev, const char *res_name)
{
- int i;
-
- for (i = 0; i < 6; i++)
- if(pci_request_region(pdev, i, res_name))
- goto err_out;
- return 0;
-
-err_out:
- while(--i >= 0)
- pci_release_region(pdev, i);
-
- return -EBUSY;
+ return pci_request_selected_regions(pdev, ((1 << 6) - 1), res_name);
}

/**
@@ -891,6 +920,22 @@
}
#endif

+/**
+ * pci_select_bars - Make BAR mask from the type of resource
+ * @pdev: the PCI device for which BAR mask is made
+ * @flags: resource type mask to be selected
+ *
+ * This helper routine makes bar mask from the type of resource.
+ */
+int pci_select_bars(struct pci_dev *dev, unsigned long flags)
+{
+ int i, bars = 0;
+ for (i = 0; i < PCI_NUM_RESOURCES; i++)
+ if (pci_resource_flags(dev, i) & flags)
+ bars |= (1 << i);
+ return bars;
+}
+
static int __devinit pci_init(void)
{
struct pci_dev *dev = NULL;
@@ -940,6 +985,8 @@
EXPORT_SYMBOL(pci_request_regions);
EXPORT_SYMBOL(pci_release_region);
EXPORT_SYMBOL(pci_request_region);
+EXPORT_SYMBOL(pci_release_selected_regions);
+EXPORT_SYMBOL(pci_request_selected_regions);
EXPORT_SYMBOL(pci_set_master);
EXPORT_SYMBOL(pci_set_mwi);
EXPORT_SYMBOL(pci_clear_mwi);
@@ -948,6 +995,7 @@
EXPORT_SYMBOL(pci_set_consistent_dma_mask);
EXPORT_SYMBOL(pci_assign_resource);
EXPORT_SYMBOL(pci_find_parent_resource);
+EXPORT_SYMBOL(pci_select_bars);

EXPORT_SYMBOL(pci_set_power_state);
EXPORT_SYMBOL(pci_save_state);
Index: linux-2.6.17-rc6/include/linux/pci.h
===================================================================
--- linux-2.6.17-rc6.orig/include/linux/pci.h 2006-06-06 21:39:11.000000000 +0900
+++ linux-2.6.17-rc6/include/linux/pci.h 2006-06-06 21:40:26.000000000 +0900
@@ -169,6 +169,7 @@
struct bin_attribute *rom_attr; /* attribute descriptor for sysfs ROM entry */
int rom_attr_enabled; /* has display of the rom attribute been enabled? */
struct bin_attribute *res_attr[DEVICE_COUNT_RESOURCE]; /* sysfs file for resources */
+ int bars_enabled; /* BARs enabled */
};

#define pci_dev_g(n) list_entry(n, struct pci_dev, global_list)
@@ -497,6 +498,7 @@
void pci_update_resource(struct pci_dev *dev, struct resource *res, int resno);
int pci_assign_resource(struct pci_dev *dev, int i);
void pci_restore_bars(struct pci_dev *dev);
+int pci_select_bars(struct pci_dev *dev, unsigned long flags);

/* ROM control related routines */
void __iomem __must_check *pci_map_rom(struct pci_dev *pdev, size_t *size);
@@ -525,6 +527,8 @@
void pci_release_regions(struct pci_dev *);
int pci_request_region(struct pci_dev *, int, const char *);
void pci_release_region(struct pci_dev *, int);
+int pci_request_selected_regions(struct pci_dev *, int, const char *);
+void pci_release_selected_regions(struct pci_dev *, int);

/* drivers/pci/bus.c */
int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,