powerpc/pseries: Force 32 bit MSIs for devices that require it
The following patch implements a new PAPR change which allows
the OS to force the use of 32 bit MSIs, regardless of what
the PCI capabilities indicate. This is required for some
devices that advertise support for 64 bit MSIs but don't
actually support them.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c
index e5b0847..420524e 100644
--- a/arch/powerpc/platforms/pseries/msi.c
+++ b/arch/powerpc/platforms/pseries/msi.c
@@ -24,6 +24,7 @@
#define RTAS_RESET_FN 2
#define RTAS_CHANGE_MSI_FN 3
#define RTAS_CHANGE_MSIX_FN 4
+#define RTAS_CHANGE_32MSI_FN 5
static struct pci_dn *get_pdn(struct pci_dev *pdev)
{
@@ -58,7 +59,8 @@
seq_num = 1;
do {
- if (func == RTAS_CHANGE_MSI_FN || func == RTAS_CHANGE_MSIX_FN)
+ if (func == RTAS_CHANGE_MSI_FN || func == RTAS_CHANGE_MSIX_FN ||
+ func == RTAS_CHANGE_32MSI_FN)
rc = rtas_call(change_token, 6, 4, rtas_ret, addr,
BUID_HI(buid), BUID_LO(buid),
func, num_irqs, seq_num);
@@ -426,9 +428,12 @@
*/
again:
if (type == PCI_CAP_ID_MSI) {
- rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec);
+ if (pdn->force_32bit_msi)
+ rc = rtas_change_msi(pdn, RTAS_CHANGE_32MSI_FN, nvec);
+ else
+ rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec);
- if (rc < 0) {
+ if (rc < 0 && !pdn->force_32bit_msi) {
pr_debug("rtas_msi: trying the old firmware call.\n");
rc = rtas_change_msi(pdn, RTAS_CHANGE_FN, nvec);
}
@@ -512,3 +517,13 @@
return 0;
}
arch_initcall(rtas_msi_init);
+
+static void quirk_radeon(struct pci_dev *dev)
+{
+ struct pci_dn *pdn = get_pdn(dev);
+
+ if (pdn)
+ pdn->force_32bit_msi = 1;
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x68f2, quirk_radeon);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0xaa68, quirk_radeon);