memory: Define API for MemoryRegionOps to take attrs and return status

Define an API so that devices can register MemoryRegionOps whose read
and write callback functions are passed an arbitrary pointer to some
transaction attributes and can return a success-or-failure status code.
This will allow us to model devices which:
 * behave differently for ARM Secure/NonSecure memory accesses
 * behave differently for privileged/unprivileged accesses
 * may return a transaction failure (causing a guest exception)
   for erroneous accesses

This patch defines the new API and plumbs the attributes parameter through
to the memory.c public level functions io_mem_read() and io_mem_write(),
where it is currently dummied out.

The success/failure response indication is also propagated out to
io_mem_read() and io_mem_write(), which retain the old-style
boolean true-for-error return.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

1 files changed, 140 insertions, 67 deletions

diff --git a/memory.c b/memory.c
index ee3f2a8..9bb5674 100644
--- a/memory.c
+++ b/memory.c
@@ -368,57 +368,84 @@ static void adjust_endianness(MemoryRegion *mr, uint64_t *data, unsigned size)
     }
 }
 
-static void memory_region_oldmmio_read_accessor(MemoryRegion *mr,
+static MemTxResult memory_region_oldmmio_read_accessor(MemoryRegion *mr,
+                                                       hwaddr addr,
+                                                       uint64_t *value,
+                                                       unsigned size,
+                                                       unsigned shift,
+                                                       uint64_t mask,
+                                                       MemTxAttrs attrs)
+{
+    uint64_t tmp;
+
+    tmp = mr->ops->old_mmio.read[ctz32(size)](mr->opaque, addr);
+    trace_memory_region_ops_read(mr, addr, tmp, size);
+    *value |= (tmp & mask) << shift;
+    return MEMTX_OK;
+}
+
+static MemTxResult  memory_region_read_accessor(MemoryRegion *mr,
                                                 hwaddr addr,
                                                 uint64_t *value,
                                                 unsigned size,
                                                 unsigned shift,
-                                                uint64_t mask)
+                                                uint64_t mask,
+                                                MemTxAttrs attrs)
 {
     uint64_t tmp;
 
-    tmp = mr->ops->old_mmio.read[ctz32(size)](mr->opaque, addr);
+    if (mr->flush_coalesced_mmio) {
+        qemu_flush_coalesced_mmio_buffer();
+    }
+    tmp = mr->ops->read(mr->opaque, addr, size);
     trace_memory_region_ops_read(mr, addr, tmp, size);
     *value |= (tmp & mask) << shift;
+    return MEMTX_OK;
 }
 
-static void memory_region_read_accessor(MemoryRegion *mr,
-                                        hwaddr addr,
-                                        uint64_t *value,
-                                        unsigned size,
-                                        unsigned shift,
-                                        uint64_t mask)
+static MemTxResult memory_region_read_with_attrs_accessor(MemoryRegion *mr,
+                                                          hwaddr addr,
+                                                          uint64_t *value,
+                                                          unsigned size,
+                                                          unsigned shift,
+                                                          uint64_t mask,
+                                                          MemTxAttrs attrs)
 {
-    uint64_t tmp;
+    uint64_t tmp = 0;
+    MemTxResult r;
 
     if (mr->flush_coalesced_mmio) {
         qemu_flush_coalesced_mmio_buffer();
     }
-    tmp = mr->ops->read(mr->opaque, addr, size);
+    r = mr->ops->read_with_attrs(mr->opaque, addr, &tmp, size, attrs);
     trace_memory_region_ops_read(mr, addr, tmp, size);
     *value |= (tmp & mask) << shift;
+    return r;
 }
 
-static void memory_region_oldmmio_write_accessor(MemoryRegion *mr,
-                                                 hwaddr addr,
-                                                 uint64_t *value,
-                                                 unsigned size,
-                                                 unsigned shift,
-                                                 uint64_t mask)
+static MemTxResult memory_region_oldmmio_write_accessor(MemoryRegion *mr,
+                                                        hwaddr addr,
+                                                        uint64_t *value,
+                                                        unsigned size,
+                                                        unsigned shift,
+                                                        uint64_t mask,
+                                                        MemTxAttrs attrs)
 {
     uint64_t tmp;
 
     tmp = (*value >> shift) & mask;
     trace_memory_region_ops_write(mr, addr, tmp, size);
     mr->ops->old_mmio.write[ctz32(size)](mr->opaque, addr, tmp);
+    return MEMTX_OK;
 }
 
-static void memory_region_write_accessor(MemoryRegion *mr,
-                                         hwaddr addr,
-                                         uint64_t *value,
-                                         unsigned size,
-                                         unsigned shift,
-                                         uint64_t mask)
+static MemTxResult memory_region_write_accessor(MemoryRegion *mr,
+                                                hwaddr addr,
+                                                uint64_t *value,
+                                                unsigned size,
+                                                unsigned shift,
+                                                uint64_t mask,
+                                                MemTxAttrs attrs)
 {
     uint64_t tmp;
 
@@ -428,24 +455,46 @@ static void memory_region_write_accessor(MemoryRegion *mr,
     tmp = (*value >> shift) & mask;
     trace_memory_region_ops_write(mr, addr, tmp, size);
     mr->ops->write(mr->opaque, addr, tmp, size);
+    return MEMTX_OK;
 }
 
-static void access_with_adjusted_size(hwaddr addr,
+static MemTxResult memory_region_write_with_attrs_accessor(MemoryRegion *mr,
+                                                           hwaddr addr,
+                                                           uint64_t *value,
+                                                           unsigned size,
+                                                           unsigned shift,
+                                                           uint64_t mask,
+                                                           MemTxAttrs attrs)
+{
+    uint64_t tmp;
+
+    if (mr->flush_coalesced_mmio) {
+        qemu_flush_coalesced_mmio_buffer();
+    }
+    tmp = (*value >> shift) & mask;
+    trace_memory_region_ops_write(mr, addr, tmp, size);
+    return mr->ops->write_with_attrs(mr->opaque, addr, tmp, size, attrs);
+}
+
+static MemTxResult access_with_adjusted_size(hwaddr addr,
                                       uint64_t *value,
                                       unsigned size,
                                       unsigned access_size_min,
                                       unsigned access_size_max,
-                                      void (*access)(MemoryRegion *mr,
-                                                     hwaddr addr,
-                                                     uint64_t *value,
-                                                     unsigned size,
-                                                     unsigned shift,
-                                                     uint64_t mask),
-                                      MemoryRegion *mr)
+                                      MemTxResult (*access)(MemoryRegion *mr,
+                                                            hwaddr addr,
+                                                            uint64_t *value,
+                                                            unsigned size,
+                                                            unsigned shift,
+                                                            uint64_t mask,
+                                                            MemTxAttrs attrs),
+                                      MemoryRegion *mr,
+                                      MemTxAttrs attrs)
 {
     uint64_t access_mask;
     unsigned access_size;
     unsigned i;
+    MemTxResult r = MEMTX_OK;
 
     if (!access_size_min) {
         access_size_min = 1;
@@ -459,14 +508,16 @@ static void access_with_adjusted_size(hwaddr addr,
     access_mask = -1ULL >> (64 - access_size * 8);
     if (memory_region_big_endian(mr)) {
         for (i = 0; i < size; i += access_size) {
-            access(mr, addr + i, value, access_size,
-                   (size - access_size - i) * 8, access_mask);
+            r |= access(mr, addr + i, value, access_size,
+                        (size - access_size - i) * 8, access_mask, attrs);
         }
     } else {
         for (i = 0; i < size; i += access_size) {
-            access(mr, addr + i, value, access_size, i * 8, access_mask);
+            r |= access(mr, addr + i, value, access_size, i * 8,
+                        access_mask, attrs);
         }
     }
+    return r;
 }
 
 static AddressSpace *memory_region_to_address_space(MemoryRegion *mr)
@@ -1053,62 +1104,82 @@ bool memory_region_access_valid(MemoryRegion *mr,
     return true;
 }
 
-static uint64_t memory_region_dispatch_read1(MemoryRegion *mr,
-                                             hwaddr addr,
-                                             unsigned size)
+static MemTxResult memory_region_dispatch_read1(MemoryRegion *mr,
+                                                hwaddr addr,
+                                                uint64_t *pval,
+                                                unsigned size,
+                                                MemTxAttrs attrs)
 {
-    uint64_t data = 0;
+    *pval = 0;
 
     if (mr->ops->read) {
-        access_with_adjusted_size(addr, &data, size,
-                                  mr->ops->impl.min_access_size,
-                                  mr->ops->impl.max_access_size,
-                                  memory_region_read_accessor, mr);
+        return access_with_adjusted_size(addr, pval, size,
+                                         mr->ops->impl.min_access_size,
+                                         mr->ops->impl.max_access_size,
+                                         memory_region_read_accessor,
+                                         mr, attrs);
+    } else if (mr->ops->read_with_attrs) {
+        return access_with_adjusted_size(addr, pval, size,
+                                         mr->ops->impl.min_access_size,
+                                         mr->ops->impl.max_access_size,
+                                         memory_region_read_with_attrs_accessor,
+                                         mr, attrs);
     } else {
-        access_with_adjusted_size(addr, &data, size, 1, 4,
-                                  memory_region_oldmmio_read_accessor, mr);
+        return access_with_adjusted_size(addr, pval, size, 1, 4,
+                                         memory_region_oldmmio_read_accessor,
+                                         mr, attrs);
     }
-
-    return data;
 }
 
-static bool memory_region_dispatch_read(MemoryRegion *mr,
-                                        hwaddr addr,
-                                        uint64_t *pval,
-                                        unsigned size)
+static MemTxResult memory_region_dispatch_read(MemoryRegion *mr,
+                                               hwaddr addr,
+                                               uint64_t *pval,
+                                               unsigned size,
+                                               MemTxAttrs attrs)
 {
+    MemTxResult r;
+
     if (!memory_region_access_valid(mr, addr, size, false)) {
         *pval = unassigned_mem_read(mr, addr, size);
-        return true;
+        return MEMTX_DECODE_ERROR;
     }
 
-    *pval = memory_region_dispatch_read1(mr, addr, size);
+    r = memory_region_dispatch_read1(mr, addr, pval, size, attrs);
     adjust_endianness(mr, pval, size);
-    return false;
+    return r;
 }
 
-static bool memory_region_dispatch_write(MemoryRegion *mr,
-                                         hwaddr addr,
-                                         uint64_t data,
-                                         unsigned size)
+static MemTxResult memory_region_dispatch_write(MemoryRegion *mr,
+                                                hwaddr addr,
+                                                uint64_t data,
+                                                unsigned size,
+                                                MemTxAttrs attrs)
 {
     if (!memory_region_access_valid(mr, addr, size, true)) {
         unassigned_mem_write(mr, addr, data, size);
-        return true;
+        return MEMTX_DECODE_ERROR;
     }
 
     adjust_endianness(mr, &data, size);
 
     if (mr->ops->write) {
-        access_with_adjusted_size(addr, &data, size,
-                                  mr->ops->impl.min_access_size,
-                                  mr->ops->impl.max_access_size,
-                                  memory_region_write_accessor, mr);
+        return access_with_adjusted_size(addr, &data, size,
+                                         mr->ops->impl.min_access_size,
+                                         mr->ops->impl.max_access_size,
+                                         memory_region_write_accessor, mr,
+                                         attrs);
+    } else if (mr->ops->write_with_attrs) {
+        return
+            access_with_adjusted_size(addr, &data, size,
+                                      mr->ops->impl.min_access_size,
+                                      mr->ops->impl.max_access_size,
+                                      memory_region_write_with_attrs_accessor,
+                                      mr, attrs);
     } else {
-        access_with_adjusted_size(addr, &data, size, 1, 4,
-                                  memory_region_oldmmio_write_accessor, mr);
+        return access_with_adjusted_size(addr, &data, size, 1, 4,
+                                         memory_region_oldmmio_write_accessor,
+                                         mr, attrs);
     }
-    return false;
 }
 
 void memory_region_init_io(MemoryRegion *mr,
@@ -1994,13 +2065,15 @@ void address_space_destroy(AddressSpace *as)
 
 bool io_mem_read(MemoryRegion *mr, hwaddr addr, uint64_t *pval, unsigned size)
 {
-    return memory_region_dispatch_read(mr, addr, pval, size);
+    return memory_region_dispatch_read(mr, addr, pval, size,
+                                       MEMTXATTRS_UNSPECIFIED);
 }
 
 bool io_mem_write(MemoryRegion *mr, hwaddr addr,
                   uint64_t val, unsigned size)
 {
-    return memory_region_dispatch_write(mr, addr, val, size);
+    return memory_region_dispatch_write(mr, addr, val, size,
+                                        MEMTXATTRS_UNSPECIFIED);
 }
 
 typedef struct MemoryRegionList MemoryRegionList;