[PATCH 03/20] ACPI: PCI: simplify buffer management for evaluating _PRT

Bjorn Helgaas
2008-12-09T04:30:16Z

Previously, acpi_pci_irq_add_prt() did all its own buffer management.
But now that we have ACPI_ALLOCATE_BUFFER, we no longer need to do
that management. And we don't have to call acpi_get_irq_routing_table()
twice (once to learn the size of the buffer needed, and again to
actually get the table).

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
---
drivers/acpi/pci_irq.c | 52 +++++++++++-------------------------------------
1 files changed, 12 insertions(+), 40 deletions(-)

diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c
index 8250c55..0a31527 100644
--- a/drivers/acpi/pci_irq.c
+++ b/drivers/acpi/pci_irq.c
@@ -245,55 +245,29 @@ acpi_pci_irq_del_entry(int segment, int bus, struct acpi_prt_entry *entry)

int acpi_pci_irq_add_prt(acpi_handle handle, int segment, int bus)
{
- acpi_status status = AE_OK;
- char *pathname = NULL;
- struct acpi_buffer buffer = { 0, NULL };
- struct acpi_pci_routing_table *prt = NULL;
- struct acpi_pci_routing_table *entry = NULL;
+ acpi_status status;
+ struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+ struct acpi_pci_routing_table *entry;
static int first_time = 1;

-
- pathname = kzalloc(ACPI_PATHNAME_MAX, GFP_KERNEL);
- if (!pathname)
- return -ENOMEM;
-
if (first_time) {
acpi_prt.count = 0;
INIT_LIST_HEAD(&acpi_prt.entries);
first_time = 0;
}

- /*
- * NOTE: We're given a 'handle' to the _PRT object's parent device
- * (either a PCI root bridge or PCI-PCI bridge).
- */
-
- buffer.length = ACPI_PATHNAME_MAX;
- buffer.pointer = pathname;
- acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
+ /* 'handle' is the _PRT's parent (root bridge or PCI-PCI bridge) */
+ status = acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
+ if (ACPI_FAILURE(status))
+ return -ENODEV;

printk(KERN_DEBUG "ACPI: PCI Interrupt Routing Table [%s._PRT]\n",
- pathname);
+ (char *) buffer.pointer);

- /*
- * Evaluate this _PRT and add its entries to our global list (acpi_prt).
- */
+ kfree(buffer.pointer);

- buffer.length = 0;
+ buffer.length = ACPI_ALLOCATE_BUFFER;
buffer.pointer = NULL;
- kfree(pathname);
- status = acpi_get_irq_routing_table(handle, &buffer);
- if (status != AE_BUFFER_OVERFLOW) {
- ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRT [%s]",
- acpi_format_exception(status)));
- return -ENODEV;
- }
-
- prt = kzalloc(buffer.length, GFP_KERNEL);
- if (!prt) {
- return -ENOMEM;
- }
- buffer.pointer = prt;

status = acpi_get_irq_routing_table(handle, &buffer);
if (ACPI_FAILURE(status)) {
@@ -303,16 +277,14 @@ int acpi_pci_irq_add_prt(acpi_handle handle, int segment, int bus)
return -ENODEV;
}

- entry = prt;
-
+ entry = buffer.pointer;
while (entry && (entry->length > 0)) {
acpi_pci_irq_add_entry(handle, segment, bus, entry);
entry = (struct acpi_pci_routing_table *)
((unsigned long)entry + entry->length);
}

- kfree(prt);
-
+ kfree(buffer.pointer);
return 0;
}