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PCI: Add ACS quirk for Amazon Annapurna Labs root ports 

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>
alistair/sunxi64-5.4-dsi
Ali Saidi 2019-09-12 16:00:40 +03:00 committed by Lorenzo Pieralisi
parent 4a36a60c34
commit 76e67e9e0f
1 changed files with 20 additions and 0 deletions
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20
drivers/pci/quirks.c
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@ -4366,6 +4366,24 @@ static int pci_quirk_qcom_rp_acs(struct pci_dev *dev, u16 acs_flags)
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,
@ -4559,6 +4577,8 @@ static const struct pci_dev_acs_enabled {
{ PCI_VENDOR_ID_AMPERE, 0xE00A, pci_quirk_xgene_acs },
{ PCI_VENDOR_ID_AMPERE, 0xE00B, pci_quirk_xgene_acs },
{ PCI_VENDOR_ID_AMPERE, 0xE00C, pci_quirk_xgene_acs },
/* Amazon Annapurna Labs */
{ PCI_VENDOR_ID_AMAZON_ANNAPURNA_LABS, 0x0031, pci_quirk_al_acs },
{ 0 }
};