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authorAnton Blanchard <anton@samba.org>2012-06-04 16:47:03 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2012-09-07 10:45:31 +1000
commit752f5216f1eaabb0cfa84eaecd0ce17d79c7d2cf (patch)
tree3c580a585976bac22f248f2f74a7c3c34b6f4536 /arch/powerpc/platforms/pseries/msi.c
parentcf1a4cf8754afb248e498815c7957aeb4faca79f (diff)
downloadvexpress-lsk-752f5216f1eaabb0cfa84eaecd0ce17d79c7d2cf.tar.gz
powerpc/pseries: Round up MSI-X requests
The pseries firmware currently refuses any non power of two MSI-X request. Unfortunately most network drivers end up asking for that because they want a power of two for RX queues and one or two extra for everything else. This patch rounds up the firmware request to the next power of two if the quota allows it. If this fails we fall back to using the original request size. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/platforms/pseries/msi.c')
-rw-r--r--arch/powerpc/platforms/pseries/msi.c20
1 files changed, 19 insertions, 1 deletions
diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c
index 109fdb75578..8bc89e4ecb5 100644
--- a/arch/powerpc/platforms/pseries/msi.c
+++ b/arch/powerpc/platforms/pseries/msi.c
@@ -387,12 +387,13 @@ static int check_msix_entries(struct pci_dev *pdev)
return 0;
}
-static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
+static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type)
{
struct pci_dn *pdn;
int hwirq, virq, i, rc;
struct msi_desc *entry;
struct msi_msg msg;
+ int nvec = nvec_in;
pdn = get_pdn(pdev);
if (!pdn)
@@ -402,10 +403,23 @@ static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
return -EINVAL;
/*
+ * Firmware currently refuse any non power of two allocation
+ * so we round up if the quota will allow it.
+ */
+ if (type == PCI_CAP_ID_MSIX) {
+ int m = roundup_pow_of_two(nvec);
+ int quota = msi_quota_for_device(pdev, m);
+
+ if (quota >= m)
+ nvec = m;
+ }
+
+ /*
* Try the new more explicit firmware interface, if that fails fall
* back to the old interface. The old interface is known to never
* return MSI-Xs.
*/
+again:
if (type == PCI_CAP_ID_MSI) {
rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec);
@@ -417,6 +431,10 @@ static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec);
if (rc != nvec) {
+ if (nvec != nvec_in) {
+ nvec = nvec_in;
+ goto again;
+ }
pr_debug("rtas_msi: rtas_change_msi() failed\n");
return rc;
}