[PATCH] powerpc: Enable support for 32 bit MSI-X vectors

[Brian King]

Some devices are not capable of addressing 64 bits
via DMA, which includes MSI-X vectors. This allows
us to ensure these devices use MSI-X vectors in
32 bit space.

Signed-off-by: Brian King <brk...@linux.vnet.ibm.com>
---
 arch/powerpc/platforms/pseries/msi.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/msi.c 
b/arch/powerpc/platforms/pseries/msi.c
index 423ee1d5bd94..6dfb55b52d36 100644
--- a/arch/powerpc/platforms/pseries/msi.c
+++ b/arch/powerpc/platforms/pseries/msi.c
@@ -26,6 +26,7 @@ static int query_token, change_token;
 #define RTAS_CHANGE_MSI_FN     3
 #define RTAS_CHANGE_MSIX_FN    4
 #define RTAS_CHANGE_32MSI_FN   5
+#define RTAS_CHANGE_32MSIX_FN  6
 
 /* RTAS Helpers */
 
@@ -41,7 +42,7 @@ static int rtas_change_msi(struct pci_dn *pdn, u32 func, u32 
num_irqs)
        seq_num = 1;
        do {
                if (func == RTAS_CHANGE_MSI_FN || func == RTAS_CHANGE_MSIX_FN ||
-                   func == RTAS_CHANGE_32MSI_FN)
+                   func == RTAS_CHANGE_32MSI_FN || func == 
RTAS_CHANGE_32MSIX_FN)
                        rc = rtas_call(change_token, 6, 4, rtas_ret, addr,
                                        BUID_HI(buid), BUID_LO(buid),
                                        func, num_irqs, seq_num);
@@ -406,8 +407,12 @@ static int rtas_prepare_msi_irqs(struct pci_dev *pdev, int 
nvec_in, int type,
 
                if (use_32bit_msi_hack && rc > 0)
                        rtas_hack_32bit_msi_gen2(pdev);
-       } else
-               rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec);
+       } else {
+               if (pdev->no_64bit_msi)
+                       rc = rtas_change_msi(pdn, RTAS_CHANGE_32MSIX_FN, nvec);
+               else
+                       rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec);
+       }
 
        if (rc != nvec) {
                if (nvec != nvec_in) {
-- 
2.39.3