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Subject[PATCH 1/3] PCI: Add support in pci_walk_bus() to invoke callback matching RID
Date
Add two arguments to pci_walk_bus() [requestorID and mask], and add
support in pci_walk_bus() to invoke the *callback* only for devices
whose RequestorID after applying *mask* matches with *requestorID*
passed as argument.

This is done in preparation for calculating the total number of
interrupt vectors that has to be supported by a specific GIC ITS device ID,
specifically when "msi-map-mask" is populated in device tree.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
drivers/pci/bus.c | 13 +++++++++----
include/linux/pci.h | 7 +++++--
2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index 3cef835b375f..e381e639ceaa 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -358,10 +358,12 @@ void pci_bus_add_devices(const struct pci_bus *bus)
}
EXPORT_SYMBOL(pci_bus_add_devices);

-/** pci_walk_bus - walk devices on/under bus, calling callback.
+/** __pci_walk_bus - walk devices on/under bus matching requestor ID, calling callback.
* @top bus whose devices should be walked
* @cb callback to be called for each device found
* @userdata arbitrary pointer to be passed to callback.
+ * @rid Requestor ID that has to be matched for the callback to be invoked
+ * @mask Mask that has to be applied to pci_dev_id(), before compating it with @rid
*
* Walk the given bus, including any bridged devices
* on buses under this bus. Call the provided callback
@@ -371,8 +373,8 @@ EXPORT_SYMBOL(pci_bus_add_devices);
* other than 0, we break out.
*
*/
-void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
- void *userdata)
+void __pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
+ void *userdata, u32 rid, u32 mask)
{
struct pci_dev *dev;
struct pci_bus *bus;
@@ -399,13 +401,16 @@ void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
} else
next = dev->bus_list.next;

+ if (mask != 0xffff && ((pci_dev_id(dev) & mask) != rid))
+ continue;
+
retval = cb(dev, userdata);
if (retval)
break;
}
up_read(&pci_bus_sem);
}
-EXPORT_SYMBOL_GPL(pci_walk_bus);
+EXPORT_SYMBOL_GPL(__pci_walk_bus);

struct pci_bus *pci_bus_get(struct pci_bus *bus)
{
diff --git a/include/linux/pci.h b/include/linux/pci.h
index cd8aa6fce204..8500fec56e50 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1473,14 +1473,17 @@ const struct pci_device_id *pci_match_id(const struct pci_device_id *ids,
int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max,
int pass);

-void pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
- void *userdata);
+void __pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void *),
+ void *userdata, u32 rid, u32 mask);
int pci_cfg_space_size(struct pci_dev *dev);
unsigned char pci_bus_max_busnr(struct pci_bus *bus);
void pci_setup_bridge(struct pci_bus *bus);
resource_size_t pcibios_window_alignment(struct pci_bus *bus,
unsigned long type);

+#define pci_walk_bus(top, cb, userdata) \
+ __pci_walk_bus((top), (cb), (userdata), 0x0, 0xffff)
+
#define PCI_VGA_STATE_CHANGE_BRIDGE (1 << 0)
#define PCI_VGA_STATE_CHANGE_DECODES (1 << 1)

--
2.17.1
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