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Commit 76e67e9e authored by Ali Saidi's avatar Ali Saidi Committed by Lorenzo Pieralisi
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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: default avatarAli Saidi <alisaidi@amazon.com>
Signed-off-by: default avatarJonathan Chocron <jonnyc@amazon.com>
Signed-off-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: default avatarGustavo Pimentel <gustavo.pimentel@synopsys.com>
Reviewed-by: default avatarAndrew Murray <andrew.murray@arm.com>
Acked-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 4a36a60c

drivers/pci/quirks.c

+20 −0
Original line number Diff line number Diff line
@@ -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 }

};