[PATCH v2 12/20] system/physmem: Add ats_do_translate helper

[Ruslan Ruslichenko <ruslichenko.r@gmail.com>]

From: Ruslan Ruslichenko <Ruslan_Ruslichenko@epam.com>

Add 'ats_do_translate' method to enable manual IOMMU address
translation.

This allows the Remote Port subsystem to resolve guest virtual
addresses to physical addresses by querying the QEMU IOMMU
translation pipeline. This is required for the Remote Port
subsystem to support translation  requests from external masters
in a co-simulation environment.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Signed-off-by: Takahiro Nakata <takahiro.nakata.wr@renesas.com>
Signed-off-by: Ruslan Ruslichenko <Ruslan_Ruslichenko@epam.com>
---
 include/system/memory.h |  8 +++++++
 system/physmem.c        | 53 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 61 insertions(+)

diff --git a/include/system/memory.h b/include/system/memory.h
index a7e03fc3e7..2032d3028d 100644
--- a/include/system/memory.h
+++ b/include/system/memory.h
@@ -2583,6 +2583,14 @@ static inline MemoryRegion *address_space_translate(AddressSpace *as,
                               addr, xlat, len, is_write, attrs);
 }
 
+MemoryRegion *ats_do_translate(AddressSpace *as,
+    hwaddr addr,
+    hwaddr *xlat,
+    hwaddr *plen_out,
+    AddressSpace **target_as,
+    int *prot,
+    MemTxAttrs attrs);
+
 /* address_space_access_valid: check for validity of accessing an address
  * space range
  *
diff --git a/system/physmem.c b/system/physmem.c
index a4a6a4710c..1acda22ede 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -525,6 +525,59 @@ static MemoryRegionSection flatview_do_translate(FlatView *fv,
     return *section;
 }
 
+/* This function is called from RCU critical section */
+MemoryRegion *ats_do_translate(AddressSpace *as,
+                               hwaddr addr,
+                               hwaddr *xlat,
+                               hwaddr *plen_out,
+                               AddressSpace **target_as,
+                               int *prot,
+                               MemTxAttrs attrs)
+{
+    MemoryRegionSection *section;
+    IOMMUMemoryRegion *iommu_mr;
+    hwaddr plen = (hwaddr)(-1);
+    FlatView *fv = address_space_to_flatview(as);
+    IOMMUMemoryRegionClass *imrc;
+    IOMMUTLBEntry iotlb;
+    int iommu_idx = 0;
+
+    if (!plen_out) {
+        plen_out = &plen;
+    }
+
+    /* This can be MMIO, so setup MMIO bit. */
+    section = address_space_translate_internal(
+            flatview_to_dispatch(fv), addr, xlat,
+            plen_out, true);
+
+    /* Illegal translation */
+    if (section->mr == &io_mem_unassigned) {
+        return NULL;
+    }
+
+    iommu_mr = memory_region_get_iommu(section->mr);
+    if (!iommu_mr) {
+        return NULL;
+    }
+
+    imrc = memory_region_get_iommu_class_nocheck(iommu_mr);
+
+    if (imrc->attrs_to_index) {
+        iommu_idx = imrc->attrs_to_index(iommu_mr, attrs);
+    }
+
+    iotlb = imrc->translate(iommu_mr, addr, IOMMU_RO, iommu_idx);
+
+    *xlat = ((iotlb.translated_addr & ~iotlb.addr_mask)
+            | (addr & iotlb.addr_mask));
+    *plen_out = MIN(*plen_out, (addr | iotlb.addr_mask) - addr + 1);
+    *prot = iotlb.perm;
+    *target_as = iotlb.target_as;
+
+    return section->mr;
+}
+
 /* Called from RCU critical section */
 IOMMUTLBEntry address_space_get_iotlb_entry(AddressSpace *as, hwaddr addr,
                                             bool is_write, MemTxAttrs attrs)
-- 
2.43.0