[PATCH v2 07/19] pcie: Helper function to check if ATS is enabled

[CLEMENT MATHIEU--DRIF]

From: Clement Mathieu--Drif <clement.mathieu--drif@eviden.com>

ats_enabled checks whether the capability is
present or not. If so, we read the configuration space to get
the status of the feature (enabled or not).

Signed-off-by: Clement Mathieu--Drif <clement.mathieu--drif@eviden.com>
---
 hw/pci/pcie.c         | 9 +++++++++
 include/hw/pci/pcie.h | 1 +
 2 files changed, 10 insertions(+)

diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index 8186d64234..3b8fd6f33c 100644
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -1247,3 +1247,12 @@ bool pcie_pasid_enabled(const PCIDevice *dev)
     return (pci_get_word(dev->config + dev->exp.pasid_cap + PCI_PASID_CTRL) &
                 PCI_PASID_CTRL_ENABLE) != 0;
 }
+
+bool pcie_ats_enabled(const PCIDevice *dev)
+{
+    if (!pci_is_express(dev) || !dev->exp.ats_cap) {
+        return false;
+    }
+    return (pci_get_word(dev->config + dev->exp.ats_cap + PCI_ATS_CTRL) &
+                PCI_ATS_CTRL_ENABLE) != 0;
+}
diff --git a/include/hw/pci/pcie.h b/include/hw/pci/pcie.h
index 63604ccc6e..7e7b8baa6e 100644
--- a/include/hw/pci/pcie.h
+++ b/include/hw/pci/pcie.h
@@ -158,4 +158,5 @@ void pcie_pasid_init(PCIDevice *dev, uint16_t offset, 
uint8_t pasid_width,
                      bool exec_perm, bool priv_mod);
 
 bool pcie_pasid_enabled(const PCIDevice *dev);
+bool pcie_ats_enabled(const PCIDevice *dev);
 #endif /* QEMU_PCIE_H */
-- 
2.47.1