[PATCH-for-11.1 0/8] system/memory: Constify various AddressSpace/MemoryRegionCache arguments

[PATCH-for-11.1 0/8] system/memory: Constify various AddressSpace/MemoryRegionCache arguments

[Philippe Mathieu-Daudé]

When structures are only accessed read-only, it is safer to mark
them const to protect against invalid API (ab)uses. This is also
an useful hint to compilers.

Philippe Mathieu-Daudé (8):
  system/memory: Constify various AddressSpace arguments (flatview)
  system/memory: Constify various AddressSpace arguments (checks)
  system/memory: Constify various AddressSpace arguments (xlat)
  system/memory: Constify various AddressSpace arguments (flat-range)
  system/memory: Constify various AddressSpace arguments (notify)
  system/memory: Constify various AddressSpace arguments (cache)
  system/memory: Constify various AddressSpace arguments (access)
  system/memory: Constify various MemoryRegionCache arguments

 include/system/memory.h                 | 32 +++++++++---------
 include/system/memory_cached.h          | 20 +++++------
 system/memory-internal.h                |  5 +--
 include/system/memory_ldst_cached.h.inc | 15 +++++----
 system/memory.c                         | 18 +++++-----
 system/physmem.c                        | 44 ++++++++++++++-----------
 6 files changed, 73 insertions(+), 61 deletions(-)

-- 
2.53.0

[PATCH-for-11.1 1/8] system/memory: Constify various AddressSpace arguments (flatview)

[Philippe Mathieu-Daudé]

Mark the AddressSpace structure const when it is only accessed read-only.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/system/memory.h  | 2 +-
 system/memory-internal.h | 5 +++--
 system/memory.c          | 2 +-
 3 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/include/system/memory.h b/include/system/memory.h
index d7b18b632d5..1417132f6d9 100644
--- a/include/system/memory.h
+++ b/include/system/memory.h
@@ -1201,7 +1201,7 @@ struct FlatView {
     MemoryRegion *root;
 };
 
-static inline FlatView *address_space_to_flatview(AddressSpace *as)
+static inline FlatView *address_space_to_flatview(const AddressSpace *as)
 {
     return qatomic_rcu_read(&as->current_map);
 }
diff --git a/system/memory-internal.h b/system/memory-internal.h
index 5f0524756eb..0066ffdffb6 100644
--- a/system/memory-internal.h
+++ b/system/memory-internal.h
@@ -20,12 +20,13 @@ static inline AddressSpaceDispatch *flatview_to_dispatch(FlatView *fv)
     return fv->dispatch;
 }
 
-static inline AddressSpaceDispatch *address_space_to_dispatch(AddressSpace *as)
+static inline
+AddressSpaceDispatch *address_space_to_dispatch(const AddressSpace *as)
 {
     return flatview_to_dispatch(address_space_to_flatview(as));
 }
 
-FlatView *address_space_get_flatview(AddressSpace *as);
+FlatView *address_space_get_flatview(const AddressSpace *as);
 void flatview_unref(FlatView *view);
 
 extern const MemoryRegionOps unassigned_mem_ops;
diff --git a/system/memory.c b/system/memory.c
index 17a7bcd9af7..bd12184a879 100644
--- a/system/memory.c
+++ b/system/memory.c
@@ -819,7 +819,7 @@ static void address_space_add_del_ioeventfds(AddressSpace *as,
     }
 }
 
-FlatView *address_space_get_flatview(AddressSpace *as)
+FlatView *address_space_get_flatview(const AddressSpace *as)
 {
     FlatView *view;
 
-- 
2.53.0

[PATCH-for-11.1 2/8] system/memory: Constify various AddressSpace arguments (checks)

[Philippe Mathieu-Daudé]

Mark the AddressSpace structure const when it is only accessed read-only.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/system/memory.h | 5 +++--
 system/physmem.c        | 4 ++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/include/system/memory.h b/include/system/memory.h
index 1417132f6d9..858dc40dc5f 100644
--- a/include/system/memory.h
+++ b/include/system/memory.h
@@ -2829,7 +2829,8 @@ static inline MemoryRegion *address_space_translate(AddressSpace *as,
  * @is_write: indicates the transfer direction
  * @attrs: memory attributes
  */
-bool address_space_access_valid(AddressSpace *as, hwaddr addr, hwaddr len,
+bool address_space_access_valid(const AddressSpace *as,
+                                hwaddr addr, hwaddr len,
                                 bool is_write, MemTxAttrs attrs);
 
 /**
@@ -2839,7 +2840,7 @@ bool address_space_access_valid(AddressSpace *as, hwaddr addr, hwaddr len,
  * @as: #AddressSpace to be accessed
  * @addr: address within that address space
  */
-bool address_space_is_io(AddressSpace *as, hwaddr addr);
+bool address_space_is_io(const AddressSpace *as, hwaddr addr);
 
 /* address_space_map: map a physical memory region into a host virtual address
  *
diff --git a/system/physmem.c b/system/physmem.c
index 4e26f1a1d42..23ea6b69255 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -3652,7 +3652,7 @@ static bool flatview_access_valid(FlatView *fv, hwaddr addr, hwaddr len,
     return true;
 }
 
-bool address_space_access_valid(AddressSpace *as, hwaddr addr,
+bool address_space_access_valid(const AddressSpace *as, hwaddr addr,
                                 hwaddr len, bool is_write,
                                 MemTxAttrs attrs)
 {
@@ -3663,7 +3663,7 @@ bool address_space_access_valid(AddressSpace *as, hwaddr addr,
     return flatview_access_valid(fv, addr, len, is_write, attrs);
 }
 
-bool address_space_is_io(AddressSpace *as, hwaddr addr)
+bool address_space_is_io(const AddressSpace *as, hwaddr addr)
 {
     MemoryRegion *mr;
 
-- 
2.53.0

[PATCH-for-11.1 3/8] system/memory: Constify various AddressSpace arguments (xlat)

[Philippe Mathieu-Daudé]

Mark the AddressSpace structure const when it is only accessed read-only.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/system/memory.h |  4 ++--
 system/physmem.c        | 10 ++++++----
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/include/system/memory.h b/include/system/memory.h
index 858dc40dc5f..38e4f7b25e5 100644
--- a/include/system/memory.h
+++ b/include/system/memory.h
@@ -2783,7 +2783,7 @@ void address_space_flush_icache_range(AddressSpace *as, hwaddr addr, hwaddr len)
 /* address_space_get_iotlb_entry: translate an address into an IOTLB
  * entry. Should be called from an RCU critical section.
  */
-IOMMUTLBEntry address_space_get_iotlb_entry(AddressSpace *as, hwaddr addr,
+IOMMUTLBEntry address_space_get_iotlb_entry(const AddressSpace *as, hwaddr addr,
                                             bool is_write, MemTxAttrs attrs);
 
 /* address_space_translate: translate an address range into an address space
@@ -2804,7 +2804,7 @@ MemoryRegion *flatview_translate(FlatView *fv,
                                  hwaddr *len, bool is_write,
                                  MemTxAttrs attrs);
 
-static inline MemoryRegion *address_space_translate(AddressSpace *as,
+static inline MemoryRegion *address_space_translate(const AddressSpace *as,
                                                     hwaddr addr, hwaddr *xlat,
                                                     hwaddr *len, bool is_write,
                                                     MemTxAttrs attrs)
diff --git a/system/physmem.c b/system/physmem.c
index 23ea6b69255..bbcbcedda15 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -528,19 +528,21 @@ static MemoryRegionSection flatview_do_translate(FlatView *fv,
 }
 
 /* Called from RCU critical section */
-IOMMUTLBEntry address_space_get_iotlb_entry(AddressSpace *as, hwaddr addr,
+IOMMUTLBEntry address_space_get_iotlb_entry(const AddressSpace *as, hwaddr addr,
                                             bool is_write, MemTxAttrs attrs)
 {
     MemoryRegionSection section;
     hwaddr xlat, page_mask;
+    AddressSpace target_as = *as;
+    AddressSpace *ptarget_as = &target_as;
 
     /*
      * This can never be MMIO, and we don't really care about plen,
      * but page mask.
      */
     section = flatview_do_translate(address_space_to_flatview(as), addr, &xlat,
-                                    NULL, &page_mask, is_write, false, &as,
-                                    attrs);
+                                    NULL, &page_mask, is_write, false,
+                                    &ptarget_as, attrs);
 
     /* Illegal translation */
     if (section.mr == &io_mem_unassigned) {
@@ -552,7 +554,7 @@ IOMMUTLBEntry address_space_get_iotlb_entry(AddressSpace *as, hwaddr addr,
         section.offset_within_region;
 
     return (IOMMUTLBEntry) {
-        .target_as = as,
+        .target_as = &target_as,
         .iova = addr & ~page_mask,
         .translated_addr = xlat & ~page_mask,
         .addr_mask = page_mask,
-- 
2.53.0

[PATCH-for-11.1 4/8] system/memory: Constify various AddressSpace arguments (flat-range)

[Philippe Mathieu-Daudé]

Mark the AddressSpace structure const when it is only accessed read-only.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 system/memory.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/system/memory.c b/system/memory.c
index bd12184a879..87ebeb93458 100644
--- a/system/memory.c
+++ b/system/memory.c
@@ -888,7 +888,8 @@ static void address_space_update_ioeventfds(AddressSpace *as)
  * range `cmr'.  Only the part that has intersection of the specified
  * FlatRange will be sent.
  */
-static void flat_range_coalesced_io_notify(FlatRange *fr, AddressSpace *as,
+static void flat_range_coalesced_io_notify(FlatRange *fr,
+                                           const AddressSpace *as,
                                            CoalescedMemoryRange *cmr, bool add)
 {
     AddrRange tmp;
@@ -912,7 +913,7 @@ static void flat_range_coalesced_io_notify(FlatRange *fr, AddressSpace *as,
     }
 }
 
-static void flat_range_coalesced_io_del(FlatRange *fr, AddressSpace *as)
+static void flat_range_coalesced_io_del(FlatRange *fr, const AddressSpace *as)
 {
     CoalescedMemoryRange *cmr;
 
@@ -921,7 +922,7 @@ static void flat_range_coalesced_io_del(FlatRange *fr, AddressSpace *as)
     }
 }
 
-static void flat_range_coalesced_io_add(FlatRange *fr, AddressSpace *as)
+static void flat_range_coalesced_io_add(FlatRange *fr, const AddressSpace *as)
 {
     MemoryRegion *mr = fr->mr;
     CoalescedMemoryRange *cmr;
@@ -939,7 +940,8 @@ static void
 flat_range_coalesced_io_notify_listener_add_del(FlatRange *fr,
                                                 MemoryRegionSection *mrs,
                                                 MemoryListener *listener,
-                                                AddressSpace *as, bool add)
+                                                const AddressSpace *as,
+                                                bool add)
 {
     CoalescedMemoryRange *cmr;
     MemoryRegion *mr = fr->mr;
-- 
2.53.0

[PATCH-for-11.1 5/8] system/memory: Constify various AddressSpace arguments (notify)

[Philippe Mathieu-Daudé]

Mark the AddressSpace structure const when it is only accessed read-only.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/system/memory.h | 2 +-
 system/memory.c         | 6 +++---
 system/physmem.c        | 2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/system/memory.h b/include/system/memory.h
index 38e4f7b25e5..4c013593cae 100644
--- a/include/system/memory.h
+++ b/include/system/memory.h
@@ -2682,7 +2682,7 @@ void address_space_destroy_free(AddressSpace *as);
  *
  * @as: an initialized #AddressSpace
  */
-void address_space_remove_listeners(AddressSpace *as);
+void address_space_remove_listeners(const AddressSpace *as);
 
 /**
  * address_space_rw: read from or write to an address space.
diff --git a/system/memory.c b/system/memory.c
index 87ebeb93458..40e17ed22c6 100644
--- a/system/memory.c
+++ b/system/memory.c
@@ -2978,7 +2978,7 @@ void memory_global_dirty_log_stop(unsigned int flags)
 }
 
 static void listener_add_address_space(MemoryListener *listener,
-                                       AddressSpace *as)
+                                       const AddressSpace *as)
 {
     unsigned i;
     FlatView *view;
@@ -3043,7 +3043,7 @@ static void listener_add_address_space(MemoryListener *listener,
 }
 
 static void listener_del_address_space(MemoryListener *listener,
-                                       AddressSpace *as)
+                                       const AddressSpace *as)
 {
     unsigned i;
     FlatView *view;
@@ -3148,7 +3148,7 @@ void memory_listener_unregister(MemoryListener *listener)
     listener->address_space = NULL;
 }
 
-void address_space_remove_listeners(AddressSpace *as)
+void address_space_remove_listeners(const AddressSpace *as)
 {
     while (!QTAILQ_EMPTY(&as->listeners)) {
         memory_listener_unregister(QTAILQ_FIRST(&as->listeners));
diff --git a/system/physmem.c b/system/physmem.c
index bbcbcedda15..c00f75bf591 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -3573,7 +3573,7 @@ address_space_unregister_map_client_do(AddressSpaceMapClient *client)
     g_free(client);
 }
 
-static void address_space_notify_map_clients_locked(AddressSpace *as)
+static void address_space_notify_map_clients_locked(const AddressSpace *as)
 {
     AddressSpaceMapClient *client;
 
-- 
2.53.0

[PATCH-for-11.1 6/8] system/memory: Constify various AddressSpace arguments (cache)

[Philippe Mathieu-Daudé]

Mark the AddressSpace structure const when it is only accessed read-only.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/system/memory_cached.h | 2 +-
 system/physmem.c               | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/system/memory_cached.h b/include/system/memory_cached.h
index 6eb6179140b..760ecb38c19 100644
--- a/include/system/memory_cached.h
+++ b/include/system/memory_cached.h
@@ -117,7 +117,7 @@ void address_space_stb_cached(MemoryRegionCache *cache,
  * are relative to @addr.
  */
 int64_t address_space_cache_init(MemoryRegionCache *cache,
-                                 AddressSpace *as,
+                                 const AddressSpace *as,
                                  hwaddr addr,
                                  hwaddr len,
                                  bool is_write);
diff --git a/system/physmem.c b/system/physmem.c
index c00f75bf591..b7280e74aa2 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -3837,7 +3837,7 @@ void cpu_physical_memory_unmap(void *buffer, hwaddr len,
 #include "memory_ldst.c.inc"
 
 int64_t address_space_cache_init(MemoryRegionCache *cache,
-                                 AddressSpace *as,
+                                 const AddressSpace *as,
                                  hwaddr addr,
                                  hwaddr len,
                                  bool is_write)
-- 
2.53.0

[PATCH-for-11.1 7/8] system/memory: Constify various AddressSpace arguments (access)

[Philippe Mathieu-Daudé]

Mark the AddressSpace structure const when it is only accessed read-only.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/system/memory.h | 19 ++++++++++---------
 system/physmem.c        | 16 +++++++++-------
 2 files changed, 19 insertions(+), 16 deletions(-)

diff --git a/include/system/memory.h b/include/system/memory.h
index 4c013593cae..564b94f1448 100644
--- a/include/system/memory.h
+++ b/include/system/memory.h
@@ -2698,7 +2698,7 @@ void address_space_remove_listeners(const AddressSpace *as);
  * @len: the number of bytes to read or write
  * @is_write: indicates the transfer direction
  */
-MemTxResult address_space_rw(AddressSpace *as, hwaddr addr,
+MemTxResult address_space_rw(const AddressSpace *as, hwaddr addr,
                              MemTxAttrs attrs, void *buf,
                              hwaddr len, bool is_write);
 
@@ -2715,7 +2715,7 @@ MemTxResult address_space_rw(AddressSpace *as, hwaddr addr,
  * @buf: buffer with the data transferred
  * @len: the number of bytes to write
  */
-MemTxResult address_space_write(AddressSpace *as, hwaddr addr,
+MemTxResult address_space_write(const AddressSpace *as, hwaddr addr,
                                 MemTxAttrs attrs,
                                 const void *buf, hwaddr len);
 
@@ -2741,7 +2741,7 @@ MemTxResult address_space_write(AddressSpace *as, hwaddr addr,
  * @buf: buffer with the data transferred
  * @len: the number of bytes to write
  */
-MemTxResult address_space_write_rom(AddressSpace *as, hwaddr addr,
+MemTxResult address_space_write_rom(const AddressSpace *as, hwaddr addr,
                                     MemTxAttrs attrs,
                                     const void *buf, hwaddr len);
 
@@ -2768,17 +2768,18 @@ MemTxResult address_space_write_rom(AddressSpace *as, hwaddr addr,
 
 #define SUFFIX
 #define ARG1         as
-#define ARG1_DECL    AddressSpace *as
+#define ARG1_DECL    const AddressSpace *as
 #include "system/memory_ldst.h.inc"
 
 #ifndef TARGET_NOT_USING_LEGACY_LDST_PHYS_API
 #define SUFFIX
 #define ARG1         as
-#define ARG1_DECL    AddressSpace *as
+#define ARG1_DECL    const AddressSpace *as
 #include "system/memory_ldst_phys.h.inc"
 #endif
 
-void address_space_flush_icache_range(AddressSpace *as, hwaddr addr, hwaddr len);
+void address_space_flush_icache_range(const AddressSpace *as,
+                                      hwaddr addr, hwaddr len);
 
 /* address_space_get_iotlb_entry: translate an address into an IOTLB
  * entry. Should be called from an RCU critical section.
@@ -2898,7 +2899,7 @@ void address_space_register_map_client(AddressSpace *as, QEMUBH *bh);
 void address_space_unregister_map_client(AddressSpace *as, QEMUBH *bh);
 
 /* Internal functions, part of the implementation of address_space_read.  */
-MemTxResult address_space_read_full(AddressSpace *as, hwaddr addr,
+MemTxResult address_space_read_full(const AddressSpace *as, hwaddr addr,
                                     MemTxAttrs attrs, void *buf, hwaddr len);
 MemTxResult flatview_read_continue(FlatView *fv, hwaddr addr,
                                    MemTxAttrs attrs, void *buf,
@@ -2953,7 +2954,7 @@ static inline bool memory_access_is_direct(const MemoryRegion *mr,
  * @len: length of the data transferred
  */
 static inline __attribute__((__always_inline__))
-MemTxResult address_space_read(AddressSpace *as, hwaddr addr,
+MemTxResult address_space_read(const AddressSpace *as, hwaddr addr,
                                MemTxAttrs attrs, void *buf,
                                hwaddr len)
 {
@@ -2996,7 +2997,7 @@ MemTxResult address_space_read(AddressSpace *as, hwaddr addr,
  * @len: the number of bytes to fill with the constant byte
  * @attrs: memory transaction attributes
  */
-MemTxResult address_space_set(AddressSpace *as, hwaddr addr,
+MemTxResult address_space_set(const AddressSpace *as, hwaddr addr,
                               uint8_t c, hwaddr len, MemTxAttrs attrs);
 
 /* Coalesced MMIO regions are areas where write operations can be reordered.
diff --git a/system/physmem.c b/system/physmem.c
index b7280e74aa2..8327b7c3de1 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -3424,7 +3424,7 @@ static MemTxResult flatview_read(FlatView *fv, hwaddr addr,
                                   mr_addr, l, mr);
 }
 
-MemTxResult address_space_read_full(AddressSpace *as, hwaddr addr,
+MemTxResult address_space_read_full(const AddressSpace *as, hwaddr addr,
                                     MemTxAttrs attrs, void *buf, hwaddr len)
 {
     MemTxResult result = MEMTX_OK;
@@ -3439,7 +3439,7 @@ MemTxResult address_space_read_full(AddressSpace *as, hwaddr addr,
     return result;
 }
 
-MemTxResult address_space_write(AddressSpace *as, hwaddr addr,
+MemTxResult address_space_write(const AddressSpace *as, hwaddr addr,
                                 MemTxAttrs attrs,
                                 const void *buf, hwaddr len)
 {
@@ -3455,7 +3455,8 @@ MemTxResult address_space_write(AddressSpace *as, hwaddr addr,
     return result;
 }
 
-MemTxResult address_space_rw(AddressSpace *as, hwaddr addr, MemTxAttrs attrs,
+MemTxResult address_space_rw(const AddressSpace *as,
+                             hwaddr addr, MemTxAttrs attrs,
                              void *buf, hwaddr len, bool is_write)
 {
     if (is_write) {
@@ -3465,7 +3466,7 @@ MemTxResult address_space_rw(AddressSpace *as, hwaddr addr, MemTxAttrs attrs,
     }
 }
 
-MemTxResult address_space_set(AddressSpace *as, hwaddr addr,
+MemTxResult address_space_set(const AddressSpace *as, hwaddr addr,
                               uint8_t c, hwaddr len, MemTxAttrs attrs)
 {
 #define FILLBUF_SIZE 512
@@ -3497,7 +3498,7 @@ void cpu_physical_memory_write(hwaddr addr, const void *buf, hwaddr len)
 }
 
 /* used for ROM loading : can write in RAM and ROM */
-MemTxResult address_space_write_rom(AddressSpace *as, hwaddr addr,
+MemTxResult address_space_write_rom(const AddressSpace *as, hwaddr addr,
                                     MemTxAttrs attrs,
                                     const void *buf, hwaddr len)
 {
@@ -3522,7 +3523,8 @@ MemTxResult address_space_write_rom(AddressSpace *as, hwaddr addr,
     return MEMTX_OK;
 }
 
-void address_space_flush_icache_range(AddressSpace *as, hwaddr addr, hwaddr len)
+void address_space_flush_icache_range(const AddressSpace *as,
+                                      hwaddr addr, hwaddr len)
 {
     /*
      * This function should do the same thing as an icache flush that was
@@ -3828,7 +3830,7 @@ void cpu_physical_memory_unmap(void *buffer, hwaddr len,
     return address_space_unmap(&address_space_memory, buffer, len, is_write, access_len);
 }
 
-#define ARG1_DECL                AddressSpace *as
+#define ARG1_DECL                const AddressSpace *as
 #define ARG1                     as
 #define SUFFIX
 #define TRANSLATE(...)           address_space_translate(as, __VA_ARGS__)
-- 
2.53.0

[PATCH-for-11.1 8/8] system/memory: Constify various MemoryRegionCache arguments

[Philippe Mathieu-Daudé]

Mark the MemoryRegionCache structure const when it is only
accessed read-only.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/system/memory_cached.h          | 18 +++++++++---------
 include/system/memory_ldst_cached.h.inc | 15 +++++++++------
 system/physmem.c                        | 10 +++++-----
 3 files changed, 23 insertions(+), 20 deletions(-)

diff --git a/include/system/memory_cached.h b/include/system/memory_cached.h
index 760ecb38c19..09d46821bec 100644
--- a/include/system/memory_cached.h
+++ b/include/system/memory_cached.h
@@ -51,12 +51,12 @@ struct MemoryRegionCache {
 
 #define SUFFIX       _cached_slow
 #define ARG1         cache
-#define ARG1_DECL    MemoryRegionCache *cache
+#define ARG1_DECL    const MemoryRegionCache *cache
 #include "system/memory_ldst.h.inc"
 
 /* Inline fast path for direct RAM access.  */
 static inline
-uint8_t address_space_ldub_cached(MemoryRegionCache *cache, hwaddr addr,
+uint8_t address_space_ldub_cached(const MemoryRegionCache *cache, hwaddr addr,
                                   MemTxAttrs attrs, MemTxResult *result)
 {
     assert(addr < cache->len);
@@ -68,7 +68,7 @@ uint8_t address_space_ldub_cached(MemoryRegionCache *cache, hwaddr addr,
 }
 
 static inline
-void address_space_stb_cached(MemoryRegionCache *cache,
+void address_space_stb_cached(const MemoryRegionCache *cache,
                               hwaddr addr, uint8_t val,
                               MemTxAttrs attrs, MemTxResult *result)
 {
@@ -93,7 +93,7 @@ void address_space_stb_cached(MemoryRegionCache *cache,
 
 #define SUFFIX       _cached
 #define ARG1         cache
-#define ARG1_DECL    MemoryRegionCache *cache
+#define ARG1_DECL    const MemoryRegionCache *cache
 #include "system/memory_ldst_phys.h.inc"
 
 /**
@@ -145,7 +145,7 @@ static inline void address_space_cache_init_empty(MemoryRegionCache *cache)
  * address that was passed to @address_space_cache_init.
  * @access_len: The number of bytes that were written starting at @addr.
  */
-void address_space_cache_invalidate(MemoryRegionCache *cache,
+void address_space_cache_invalidate(const MemoryRegionCache *cache,
                                     hwaddr addr,
                                     hwaddr access_len);
 
@@ -160,9 +160,9 @@ void address_space_cache_destroy(MemoryRegionCache *cache);
  * Internal functions, part of the implementation of address_space_read_cached
  * and address_space_write_cached.
  */
-MemTxResult address_space_read_cached_slow(MemoryRegionCache *cache,
+MemTxResult address_space_read_cached_slow(const MemoryRegionCache *cache,
                                            hwaddr addr, void *buf, hwaddr len);
-MemTxResult address_space_write_cached_slow(MemoryRegionCache *cache,
+MemTxResult address_space_write_cached_slow(const MemoryRegionCache *cache,
                                             hwaddr addr, const void *buf,
                                             hwaddr len);
 
@@ -175,7 +175,7 @@ MemTxResult address_space_write_cached_slow(MemoryRegionCache *cache,
  * @len: length of the data transferred
  */
 static inline MemTxResult
-address_space_read_cached(MemoryRegionCache *cache, hwaddr addr,
+address_space_read_cached(const MemoryRegionCache *cache, hwaddr addr,
                           void *buf, hwaddr len)
 {
     assert(addr < cache->len && len <= cache->len - addr);
@@ -197,7 +197,7 @@ address_space_read_cached(MemoryRegionCache *cache, hwaddr addr,
  * @len: length of the data transferred
  */
 static inline MemTxResult
-address_space_write_cached(MemoryRegionCache *cache, hwaddr addr,
+address_space_write_cached(const MemoryRegionCache *cache, hwaddr addr,
                            const void *buf, hwaddr len)
 {
     assert(addr < cache->len && len <= cache->len - addr);
diff --git a/include/system/memory_ldst_cached.h.inc b/include/system/memory_ldst_cached.h.inc
index d7834f852c4..b4c696bff1f 100644
--- a/include/system/memory_ldst_cached.h.inc
+++ b/include/system/memory_ldst_cached.h.inc
@@ -24,7 +24,8 @@
 #define LD_P(size) \
     glue(glue(ld, size), glue(ENDIANNESS, _p))
 
-static inline uint16_t ADDRESS_SPACE_LD_CACHED(uw)(MemoryRegionCache *cache,
+static inline
+uint16_t ADDRESS_SPACE_LD_CACHED(uw)(const MemoryRegionCache *cache,
     hwaddr addr, MemTxAttrs attrs, MemTxResult *result)
 {
     assert(addr < cache->len && 2 <= cache->len - addr);
@@ -36,7 +37,8 @@ static inline uint16_t ADDRESS_SPACE_LD_CACHED(uw)(MemoryRegionCache *cache,
     }
 }
 
-static inline uint32_t ADDRESS_SPACE_LD_CACHED(l)(MemoryRegionCache *cache,
+static inline
+uint32_t ADDRESS_SPACE_LD_CACHED(l)(const MemoryRegionCache *cache,
     hwaddr addr, MemTxAttrs attrs, MemTxResult *result)
 {
     assert(addr < cache->len && 4 <= cache->len - addr);
@@ -48,7 +50,8 @@ static inline uint32_t ADDRESS_SPACE_LD_CACHED(l)(MemoryRegionCache *cache,
     }
 }
 
-static inline uint64_t ADDRESS_SPACE_LD_CACHED(q)(MemoryRegionCache *cache,
+static inline
+uint64_t ADDRESS_SPACE_LD_CACHED(q)(const MemoryRegionCache *cache,
     hwaddr addr, MemTxAttrs attrs, MemTxResult *result)
 {
     assert(addr < cache->len && 8 <= cache->len - addr);
@@ -71,7 +74,7 @@ static inline uint64_t ADDRESS_SPACE_LD_CACHED(q)(MemoryRegionCache *cache,
 #define ST_P(size) \
     glue(glue(st, size), glue(ENDIANNESS, _p))
 
-static inline void ADDRESS_SPACE_ST_CACHED(w)(MemoryRegionCache *cache,
+static inline void ADDRESS_SPACE_ST_CACHED(w)(const MemoryRegionCache *cache,
     hwaddr addr, uint16_t val, MemTxAttrs attrs, MemTxResult *result)
 {
     assert(addr < cache->len && 2 <= cache->len - addr);
@@ -82,7 +85,7 @@ static inline void ADDRESS_SPACE_ST_CACHED(w)(MemoryRegionCache *cache,
     }
 }
 
-static inline void ADDRESS_SPACE_ST_CACHED(l)(MemoryRegionCache *cache,
+static inline void ADDRESS_SPACE_ST_CACHED(l)(const MemoryRegionCache *cache,
     hwaddr addr, uint32_t val, MemTxAttrs attrs, MemTxResult *result)
 {
     assert(addr < cache->len && 4 <= cache->len - addr);
@@ -93,7 +96,7 @@ static inline void ADDRESS_SPACE_ST_CACHED(l)(MemoryRegionCache *cache,
     }
 }
 
-static inline void ADDRESS_SPACE_ST_CACHED(q)(MemoryRegionCache *cache,
+static inline void ADDRESS_SPACE_ST_CACHED(q)(const MemoryRegionCache *cache,
     hwaddr addr, uint64_t val, MemTxAttrs attrs, MemTxResult *result)
 {
     assert(addr < cache->len && 8 <= cache->len - addr);
diff --git a/system/physmem.c b/system/physmem.c
index 8327b7c3de1..5f1be89649e 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -3886,7 +3886,7 @@ int64_t address_space_cache_init(MemoryRegionCache *cache,
     return l;
 }
 
-void address_space_cache_invalidate(MemoryRegionCache *cache,
+void address_space_cache_invalidate(const MemoryRegionCache *cache,
                                     hwaddr addr,
                                     hwaddr access_len)
 {
@@ -3917,7 +3917,7 @@ void address_space_cache_destroy(MemoryRegionCache *cache)
  * address_space_cache_init.
  */
 static inline MemoryRegion *address_space_translate_cached(
-    MemoryRegionCache *cache, hwaddr addr, hwaddr *xlat,
+    const MemoryRegionCache *cache, hwaddr addr, hwaddr *xlat,
     hwaddr *plen, bool is_write, MemTxAttrs attrs)
 {
     MemoryRegionSection section;
@@ -3998,7 +3998,7 @@ static MemTxResult address_space_read_continue_cached(MemTxAttrs attrs,
  * out of line function when the target is an MMIO or IOMMU region.
  */
 MemTxResult
-address_space_read_cached_slow(MemoryRegionCache *cache, hwaddr addr,
+address_space_read_cached_slow(const MemoryRegionCache *cache, hwaddr addr,
                                    void *buf, hwaddr len)
 {
     hwaddr mr_addr, l;
@@ -4015,7 +4015,7 @@ address_space_read_cached_slow(MemoryRegionCache *cache, hwaddr addr,
  * out of line function when the target is an MMIO or IOMMU region.
  */
 MemTxResult
-address_space_write_cached_slow(MemoryRegionCache *cache, hwaddr addr,
+address_space_write_cached_slow(const MemoryRegionCache *cache, hwaddr addr,
                                     const void *buf, hwaddr len)
 {
     hwaddr mr_addr, l;
@@ -4028,7 +4028,7 @@ address_space_write_cached_slow(MemoryRegionCache *cache, hwaddr addr,
                                                buf, len, mr_addr, l, mr);
 }
 
-#define ARG1_DECL                MemoryRegionCache *cache
+#define ARG1_DECL                const MemoryRegionCache *cache
 #define ARG1                     cache
 #define SUFFIX                   _cached_slow
 #define TRANSLATE(...)           address_space_translate_cached(cache, __VA_ARGS__)
-- 
2.53.0

Re: [PATCH-for-11.1 0/8] system/memory: Constify various AddressSpace/MemoryRegionCache arguments

[Pierrick Bouvier]

On 3/19/26 12:10 PM, Philippe Mathieu-Daudé wrote:
> When structures are only accessed read-only, it is safer to mark
> them const to protect against invalid API (ab)uses. This is also
> an useful hint to compilers.
> 
> Philippe Mathieu-Daudé (8):
>    system/memory: Constify various AddressSpace arguments (flatview)
>    system/memory: Constify various AddressSpace arguments (checks)
>    system/memory: Constify various AddressSpace arguments (xlat)
>    system/memory: Constify various AddressSpace arguments (flat-range)
>    system/memory: Constify various AddressSpace arguments (notify)
>    system/memory: Constify various AddressSpace arguments (cache)
>    system/memory: Constify various AddressSpace arguments (access)
>    system/memory: Constify various MemoryRegionCache arguments
> 
>   include/system/memory.h                 | 32 +++++++++---------
>   include/system/memory_cached.h          | 20 +++++------
>   system/memory-internal.h                |  5 +--
>   include/system/memory_ldst_cached.h.inc | 15 +++++----
>   system/memory.c                         | 18 +++++-----
>   system/physmem.c                        | 44 ++++++++++++++-----------
>   6 files changed, 73 insertions(+), 61 deletions(-)
> 

Series:
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>

Re: [PATCH-for-11.1 3/8] system/memory: Constify various AddressSpace arguments (xlat)

[Peter Xu]

On Thu, Mar 19, 2026 at 08:10:12PM +0100, Philippe Mathieu-Daudé wrote:
> Mark the AddressSpace structure const when it is only accessed read-only.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>  include/system/memory.h |  4 ++--
>  system/physmem.c        | 10 ++++++----
>  2 files changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/include/system/memory.h b/include/system/memory.h
> index 858dc40dc5f..38e4f7b25e5 100644
> --- a/include/system/memory.h
> +++ b/include/system/memory.h
> @@ -2783,7 +2783,7 @@ void address_space_flush_icache_range(AddressSpace *as, hwaddr addr, hwaddr len)
>  /* address_space_get_iotlb_entry: translate an address into an IOTLB
>   * entry. Should be called from an RCU critical section.
>   */
> -IOMMUTLBEntry address_space_get_iotlb_entry(AddressSpace *as, hwaddr addr,
> +IOMMUTLBEntry address_space_get_iotlb_entry(const AddressSpace *as, hwaddr addr,
>                                              bool is_write, MemTxAttrs attrs);
>  
>  /* address_space_translate: translate an address range into an address space
> @@ -2804,7 +2804,7 @@ MemoryRegion *flatview_translate(FlatView *fv,
>                                   hwaddr *len, bool is_write,
>                                   MemTxAttrs attrs);
>  
> -static inline MemoryRegion *address_space_translate(AddressSpace *as,
> +static inline MemoryRegion *address_space_translate(const AddressSpace *as,
>                                                      hwaddr addr, hwaddr *xlat,
>                                                      hwaddr *len, bool is_write,
>                                                      MemTxAttrs attrs)
> diff --git a/system/physmem.c b/system/physmem.c
> index 23ea6b69255..bbcbcedda15 100644
> --- a/system/physmem.c
> +++ b/system/physmem.c
> @@ -528,19 +528,21 @@ static MemoryRegionSection flatview_do_translate(FlatView *fv,
>  }
>  
>  /* Called from RCU critical section */
> -IOMMUTLBEntry address_space_get_iotlb_entry(AddressSpace *as, hwaddr addr,
> +IOMMUTLBEntry address_space_get_iotlb_entry(const AddressSpace *as, hwaddr addr,
>                                              bool is_write, MemTxAttrs attrs)
>  {
>      MemoryRegionSection section;
>      hwaddr xlat, page_mask;
> +    AddressSpace target_as = *as;

Is this one an overkill?  It'll deep copy everything of AS..

> +    AddressSpace *ptarget_as = &target_as;
>  
>      /*
>       * This can never be MMIO, and we don't really care about plen,
>       * but page mask.
>       */
>      section = flatview_do_translate(address_space_to_flatview(as), addr, &xlat,
> -                                    NULL, &page_mask, is_write, false, &as,
> -                                    attrs);
> +                                    NULL, &page_mask, is_write, false,
> +                                    &ptarget_as, attrs);
>  
>      /* Illegal translation */
>      if (section.mr == &io_mem_unassigned) {
> @@ -552,7 +554,7 @@ IOMMUTLBEntry address_space_get_iotlb_entry(AddressSpace *as, hwaddr addr,
>          section.offset_within_region;
>  
>      return (IOMMUTLBEntry) {
> -        .target_as = as,
> +        .target_as = &target_as,
>          .iova = addr & ~page_mask,
>          .translated_addr = xlat & ~page_mask,
>          .addr_mask = page_mask,
> -- 
> 2.53.0
> 

-- 
Peter Xu