From: AMEET M. PARANJAPE <aparanja@redhat.com>
Date: Tue, 31 Mar 2009 11:05:09 -0400
Subject: [ppc] add support for ibm,req#msi-x
Message-id: 20090331150256.14954.64480.sendpatchset@squad5-lp1.lab.bos.redhat.com
O-Subject: [PATCH RHEL5.4 BZ492580 3/8]
Bugzilla: 492580
RH-Acked-by: David Howells <dhowells@redhat.com>
RH-Acked-by: David Howells <dhowells@redhat.com>

RHBZ#:
======
https://bugzilla.redhat.com/show_bug.cgi?id=492580

Description:
===========
Firmware encodes the number of MSI-X requested by a device in a
different property than for MSI. Pull the property name out as a
parameter and share the logic for both cases.

RHEL Version Found:
================
RHEL 5.3

kABI Status:
============
No symbols were harmed.

Brew:
=====
Built on all platforms.
http://brewweb.devel.redhat.com/brew/taskinfo?taskID=1744271

Upstream Status:
================
http://git.kernel.org/?p=linux/kernel/git/benh/powerpc.git;a=commit;h=3a51c0cbea947dc9194e18f11661eaa4dbfc5c13

Test Status:
============
There is a testcase provided in the Bugzilla.  A 'cat /proc/interrupts' should
show the device drivers has two interrupt entries for each port.  Run I/O
tests.  Then 'lspci -vv' should display the correct pci capabilities for the
installed adapter and show the adapter is using MSI-X interrupts opposed to MSO
or LSI interrupts.

===============================================================
Ameet Paranjape 978-392-3903 ext 23903
IBM on-site partner

Proposed Patch:
===============

diff --git a/arch/powerpc/kernel/msi-rtas.c b/arch/powerpc/kernel/msi-rtas.c
index 11408d4..afdbe6a 100644
--- a/arch/powerpc/kernel/msi-rtas.c
+++ b/arch/powerpc/kernel/msi-rtas.c
@@ -126,7 +126,7 @@ static void rtas_teardown_msi_irqs(struct pci_dev *pdev)
 	rtas_disable_msi(pdev);
 }
 
-static int check_req_msi(struct pci_dev *pdev, int nvec)
+static int check_req(struct pci_dev *pdev, int nvec, char *prop_name)
 {
 	struct device_node *dn;
 	struct pci_dn *pdn;
@@ -138,24 +138,34 @@ static int check_req_msi(struct pci_dev *pdev, int nvec)
 
 	dn = pdn->node;
 
-	req_msi = get_property(dn, "ibm,req#msi", NULL);
+	req_msi = get_property(dn, prop_name, NULL);
 	if (!req_msi) {
-		pr_debug("rtas_msi: No ibm,req#msi on %s\n", dn->full_name);
+		pr_debug("rtas_msi: No %s on %s\n", prop_name, dn->full_name);
 		return -ENOENT;
 	}
 
 	if (*req_msi < nvec) {
-		pr_debug("rtas_msi: ibm,req#msi requests < %d MSIs\n", nvec);
+		pr_debug("rtas_msi: %s requests < %d MSIs\n", prop_name, nvec);
 		return -ENOSPC;
 	}
 
 	return 0;
 }
 
+static int check_req_msi(struct pci_dev *pdev, int nvec)
+{
+	return check_req(pdev, nvec, "ibm,req#msi");
+}
+
+static int check_req_msix(struct pci_dev *pdev, int nvec)
+{
+	return check_req(pdev, nvec, "ibm,req#msi-x");
+}
+
 static int rtas_msi_check_device(struct pci_dev *pdev, int nvec, int type)
 {
 	if (type == PCI_CAP_ID_MSIX)
-		pr_debug("rtas_msi: MSI-X untested, trying anyway.\n");
+		return check_req_msix(pdev, nvec);
 
 	return check_req_msi(pdev, nvec);
 }