From: Ali Saidi <alisaidi@amazon.com>
Date: Thu, 12 Sep 2019 16:00:40 +0300
Subject: PCI: Add ACS quirk for Amazon Annapurna Labs root ports
Git-commit: 76e67e9e0f0f2debf9df192502a759bdd0cb4dab
Patch-mainline: v5.4-rc1
References: bsc#1152187,bsc#1152525
The Amazon's Annapurna Labs root ports don't advertise an ACS
capability, but they don't allow peer-to-peer transactions and do
validate bus numbers through the SMMU. Additionally, it's not possible
for one RP to pass traffic to another RP.
Signed-off-by: Ali Saidi <alisaidi@amazon.com>
Signed-off-by: Jonathan Chocron <jonnyc@amazon.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>
---
drivers/pci/quirks.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -4494,6 +4494,24 @@ static int pci_quirk_qcom_rp_acs(struct
return ret;
}
+static int pci_quirk_al_acs(struct pci_dev *dev, u16 acs_flags)
+{
+ if (pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT)
+ return -ENOTTY;
+
+ /*
+ * Amazon's Annapurna Labs root ports don't include an ACS capability,
+ * but do include ACS-like functionality. The hardware doesn't support
+ * peer-to-peer transactions via the root port and each has a unique
+ * segment number.
+ *
+ * Additionally, the root ports cannot send traffic to each other.
+ */
+ acs_flags &= ~(PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);
+
+ return acs_flags ? 0 : 1;
+}
+
/*
* Sunrise Point PCH root ports implement ACS, but unfortunately as shown in
* the datasheet (Intel 100 Series Chipset Family PCH Datasheet, Vol. 2,
@@ -4699,6 +4717,8 @@ static const struct pci_dev_acs_enabled
{ PCI_VENDOR_ID_AMPERE, 0xE00B, pci_quirk_xgene_acs },
{ PCI_VENDOR_ID_AMPERE, 0xE00C, pci_quirk_xgene_acs },
{ PCI_VENDOR_ID_BROADCOM, 0xD714, pci_quirk_brcm_acs },
+ /* Amazon Annapurna Labs */
+ { PCI_VENDOR_ID_AMAZON_ANNAPURNA_LABS, 0x0031, pci_quirk_al_acs },
{ 0 }
};