A PASID-like feature is implemented on AMBA without using TLP prefixes
and these devices have PASID capability though not supporting TLP.
Adding a pasid_no_tlp bit for "PASID works without TLP prefixes" and
pci_enable_pasid() checks pasid_no_tlp as well as eetlp_prefix_path.

Suggested-by: Bjorn Helgaas <helg...@kernel.org>
Signed-off-by: Zhangfei Gao <zhangfei....@linaro.org>
---
 drivers/pci/ats.c   | 2 +-
 include/linux/pci.h | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index 793d381..88f981b 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -380,7 +380,7 @@ int pci_enable_pasid(struct pci_dev *pdev, int features)
        if (WARN_ON(pdev->pasid_enabled))
                return -EBUSY;
 
-       if (!pdev->eetlp_prefix_path)
+       if (!pdev->eetlp_prefix_path && !pdev->pasid_no_tlp)
                return -EINVAL;
 
        if (!pasid)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 86c799c..1daa943 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -388,6 +388,7 @@ struct pci_dev {
                                           supported from root to here */
        u16             l1ss;           /* L1SS Capability pointer */
 #endif
+       unsigned int    pasid_no_tlp:1;         /* PASID works without TLP 
Prefix */
        unsigned int    eetlp_prefix_path:1;    /* End-to-End TLP Prefix */
 
        pci_channel_state_t error_state;        /* Current connectivity state */
-- 
2.9.5

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