[PATCH 4.14 151/190] PCI: Add ACS quirk for iProc PAXB

Greg Kroah-Hartman
2020-06-19T14:51:37Z

From: Abhinav Ratna <abhinav.ratna@broadcom.com>

[ Upstream commit 46b2c32df7a462d0e64b68c513e5c4c1b2a399a7 ]

iProc PAXB Root Ports don't advertise an ACS capability, but they do not
allow peer-to-peer transactions between Root Ports. Add an ACS quirk so
each Root Port can be in a separate IOMMU group.

[bhelgaas: commit log, comment, use common implementation style]
Link: https://lore.kernel.org/r/1566275985-25670-1-git-send-email-srinath.mannam@broadcom.com
Signed-off-by: Abhinav Ratna <abhinav.ratna@broadcom.com>
Signed-off-by: Srinath Mannam <srinath.mannam@broadcom.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Scott Branden <scott.branden@broadcom.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/pci/quirks.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 1bc7d4bcfea4..f6e88d5b1c4f 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -4515,6 +4515,19 @@ static int pci_quirk_mf_endpoint_acs(struct pci_dev *dev, u16 acs_flags)
return acs_flags ? 0 : 1;
}

+static int pci_quirk_brcm_acs(struct pci_dev *dev, u16 acs_flags)
+{
+ /*
+ * iProc PAXB Root Ports don't advertise an ACS capability, but
+ * they do not allow peer-to-peer transactions between Root Ports.
+ * Allow each Root Port to be in a separate IOMMU group by masking
+ * SV/RR/CR/UF bits.
+ */
+ acs_flags &= ~(PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
+
+ return acs_flags ? 0 : 1;
+}
+
static const struct pci_dev_acs_enabled {
u16 vendor;
u16 device;
@@ -4597,6 +4610,7 @@ static const struct pci_dev_acs_enabled {
{ PCI_VENDOR_ID_CAVIUM, PCI_ANY_ID, pci_quirk_cavium_acs },
/* APM X-Gene */
{ PCI_VENDOR_ID_AMCC, 0xE004, pci_quirk_xgene_acs },
+ { PCI_VENDOR_ID_BROADCOM, 0xD714, pci_quirk_brcm_acs },
{ 0 }
};

--
2.25.1