commit 7f342678634f16795892677204366e835e450dda
author Vadim Lomovtsev <Vadim.Lomovtsev@cavium.com> Tue Oct 17 05:47:38 2017 -0700
committer Bjorn Helgaas <bhelgaas@google.com> Thu Oct 19 04:59:53 2017 -0500
tree 842b44e63982ace3ab8a7c92d6a88cae22844ccc
parent ff26449e415a5601c8bb5b67ac4ae801f7165696

PCI: Set Cavium ACS capability quirk flags to assert RR/CR/SV/UF

The Cavium ThunderX (CN8XXX) family of PCIe Root Ports does not advertise
an ACS capability.  However, the RTL internally implements similar
protection as if ACS had Request Redirection, Completion Redirection,
Source Validation, and Upstream Forwarding features enabled.

Change Cavium ACS capabilities quirk flags accordingly.

Fixes: b404bcfbf035 ("PCI: Add ACS quirk for all Cavium devices")
Signed-off-by: Vadim Lomovtsev <Vadim.Lomovtsev@cavium.com>
[bhelgaas: tidy changelog, comment, stable tag]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org	# v4.6+: b77d537d00d0: PCI: Apply Cavium ACS quirk only to CN81xx/CN83xx/CN88xx devices

drivers/pci/quirks.c

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index a4d3361..c23650c 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -4214,12 +4214,14 @@
 static int pci_quirk_cavium_acs(struct pci_dev *dev, u16 acs_flags)
 {
 	/*
-	 * Cavium devices matching this quirk do not perform peer-to-peer
-	 * with other functions, allowing masking out these bits as if they
-	 * were unimplemented in the ACS capability.
+	 * Cavium root ports don't advertise an ACS capability.  However,
+	 * the RTL internally implements similar protection as if ACS had
+	 * Request Redirection, Completion Redirection, Source Validation,
+	 * and Upstream Forwarding features enabled.  Assert that the
+	 * hardware implements and enables equivalent ACS functionality for
+	 * these flags.
 	 */
-	acs_flags &= ~(PCI_ACS_SV | PCI_ACS_TB | PCI_ACS_RR |
-		       PCI_ACS_CR | PCI_ACS_UF | PCI_ACS_DT);
+	acs_flags &= ~(PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_SV | PCI_ACS_UF);
 
 	if (!((dev->device >= 0xa000) && (dev->device <= 0xa0ff)))
 		return -ENOTTY;