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authorBrian King <brking@linux.vnet.ibm.com>2013-05-22 11:07:46 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2013-05-24 18:16:54 +1000
commitf1dd153121dcb872ae6cba8d52bec97519eb7d97 (patch)
tree83b710801b175faceba94b063d686e293e880f86 /arch/powerpc
parent83920c498ebb51cbd62f26f72e87c04a2a46dec9 (diff)
downloadvexpress-lsk-f1dd153121dcb872ae6cba8d52bec97519eb7d97.tar.gz
powerpc/pseries: Make 32-bit MSI quirk work on systems lacking firmware support
Recent commit e61133dda480062d221f09e4fc18f66763f8ecd0 added support for a new firmware feature to force an adapter to use 32 bit MSIs. However, this firmware is not available for all systems. The hack below allows devices needing 32 bit MSIs to work on these systems as well. It is careful to only enable this on Gen2 slots, which should limit this to configurations where this hack is needed and tested to work. [Small change to factor out the hack into a separate function -- BenH] Signed-off-by: Brian King <brking@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/platforms/pseries/msi.c40
1 files changed, 37 insertions, 3 deletions
diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c
index d34f4ffdb79..6d2f0abce6f 100644
--- a/arch/powerpc/platforms/pseries/msi.c
+++ b/arch/powerpc/platforms/pseries/msi.c
@@ -374,6 +374,23 @@ static int check_msix_entries(struct pci_dev *pdev)
return 0;
}
+static void rtas_hack_32bit_msi_gen2(struct pci_dev *pdev)
+{
+ u32 addr_hi, addr_lo;
+
+ /*
+ * We should only get in here for IODA1 configs. This is based on the
+ * fact that we using RTAS for MSIs, we don't have the 32 bit MSI RTAS
+ * support, and we are in a PCIe Gen2 slot.
+ */
+ dev_info(&pdev->dev,
+ "rtas_msi: No 32 bit MSI firmware support, forcing 32 bit MSI\n");
+ pci_read_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, &addr_hi);
+ addr_lo = 0xffff0000 | ((addr_hi >> (48 - 32)) << 4);
+ pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_LO, addr_lo);
+ pci_write_config_dword(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI, 0);
+}
+
static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type)
{
struct pci_dn *pdn;
@@ -381,6 +398,7 @@ static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type)
struct msi_desc *entry;
struct msi_msg msg;
int nvec = nvec_in;
+ int use_32bit_msi_hack = 0;
pdn = pci_get_pdn(pdev);
if (!pdn)
@@ -408,15 +426,31 @@ static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type)
*/
again:
if (type == PCI_CAP_ID_MSI) {
- if (pdn->force_32bit_msi)
+ if (pdn->force_32bit_msi) {
rc = rtas_change_msi(pdn, RTAS_CHANGE_32MSI_FN, nvec);
- else
+ if (rc < 0) {
+ /*
+ * We only want to run the 32 bit MSI hack below if
+ * the max bus speed is Gen2 speed
+ */
+ if (pdev->bus->max_bus_speed != PCIE_SPEED_5_0GT)
+ return rc;
+
+ use_32bit_msi_hack = 1;
+ }
+ } else
+ rc = -1;
+
+ if (rc < 0)
rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec);
- if (rc < 0 && !pdn->force_32bit_msi) {
+ if (rc < 0) {
pr_debug("rtas_msi: trying the old firmware call.\n");
rc = rtas_change_msi(pdn, RTAS_CHANGE_FN, nvec);
}
+
+ if (use_32bit_msi_hack && rc > 0)
+ rtas_hack_32bit_msi_gen2(pdev);
} else
rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec);