[PATCH v5 21/23] iommu/vt-d: add intel iommu page response function

[Jacob Pan]

This patch adds page response support for Intel VT-d.
Generic response data is taken from the IOMMU API
then parsed into VT-d specific response descriptor format.

Signed-off-by: Jacob Pan <jacob.jun....@linux.intel.com>
---
 drivers/iommu/intel-iommu.c | 47 +++++++++++++++++++++++++++++++++++++++++++++
 include/linux/intel-iommu.h |  3 +++
 2 files changed, 50 insertions(+)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 3949b3cf..c261639 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5101,6 +5101,52 @@ static int intel_iommu_sva_invalidate(struct 
iommu_domain *domain,
        return ret;
 }
 
+static int intel_iommu_page_response(struct device *dev, struct 
page_response_msg *msg)
+{
+       struct qi_desc resp;
+       struct intel_iommu *iommu;
+       struct pci_dev *pdev;
+       u8 bus, devfn;
+       u16 rid;
+       u64 desc;
+
+       pdev = to_pci_dev(dev);
+       iommu = device_to_iommu(dev, &bus, &devfn);
+       if (!iommu) {
+               dev_err(dev, "No IOMMU for device to unbind PASID table\n");
+               return -ENODEV;
+       }
+
+       pci_dev_get(pdev);
+       rid = ((u16)bus << 8) | devfn;
+       /* Iommu private data contains  preserved page request descriptor, so we
+        * inspect the SRR bit for response type then queue response with only
+        * the private data [54:32].
+        */
+       desc = msg->private_data;
+       if (desc & QI_PRQ_SRR) {
+               /* Page Stream Response */
+               resp.low = QI_PSTRM_IDX(msg->page_req_group_id) |
+                       (desc & QI_PRQ_PRIV) | 
QI_PSTRM_BUS(PCI_BUS_NUM(pdev->bus->number)) |
+                       QI_PSTRM_PASID(msg->pasid) | QI_PSTRM_RESP_TYPE;
+               resp.high = QI_PSTRM_ADDR(msg->addr) | 
QI_PSTRM_DEVFN(pdev->devfn & 0xff) |
+                       QI_PSTRM_RESP_CODE(msg->resp_code);
+       } else {
+               /* Page Group Response */
+               resp.low = QI_PGRP_PASID(msg->pasid) |
+                       QI_PGRP_DID(rid) |
+                       QI_PGRP_PASID_P(msg->pasid_present) |
+                       QI_PGRP_RESP_TYPE;
+               resp.high = QI_PGRP_IDX(msg->page_req_group_id) |
+                       (desc & QI_PRQ_PRIV) | 
QI_PGRP_RESP_CODE(msg->resp_code);
+
+       }
+       qi_submit_sync(&resp, iommu);
+       pci_dev_put(pdev);
+
+       return 0;
+}
+
 static int intel_iommu_map(struct iommu_domain *domain,
                           unsigned long iova, phys_addr_t hpa,
                           size_t size, int iommu_prot)
@@ -5530,6 +5576,7 @@ const struct iommu_ops intel_iommu_ops = {
        .bind_pasid_table       = intel_iommu_bind_pasid_table,
        .unbind_pasid_table     = intel_iommu_unbind_pasid_table,
        .sva_invalidate         = intel_iommu_sva_invalidate,
+       .page_response          = intel_iommu_page_response,
 #endif
        .map                    = intel_iommu_map,
        .unmap                  = intel_iommu_unmap,
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index b3a26c7..94366d9 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -337,6 +337,9 @@ enum {
 #define QI_PSTRM_BUS(bus)      (((u64)(bus)) << 24)
 #define QI_PSTRM_PASID(pasid)  (((u64)(pasid)) << 4)
 
+#define QI_PRQ_SRR     BIT_ULL(0)
+#define QI_PRQ_PRIV    GENMASK_ULL(54, 32)
+
 #define QI_RESP_SUCCESS                0x0
 #define QI_RESP_INVALID                0x1
 #define QI_RESP_FAILURE                0xf
-- 
2.7.4