[Qemu-devel] [PATCH 3/3] exec: change iotlb APIs to take AddressSpaceDispatch

[Mike Day]

From: Paolo Bonzini <address@hidden>

This makes it possible to start following RCU rules, which require
not dereferencing as->dispatch more than once.  It is not covering
the whole of TCG, since the TLB data structures are not RCU-friendly,
but it is enough for exec.c.

Signed-off-by: Paolo Bonzini <address@hidden>
Reviewed-by: Mike Day <address@hidden>
---
 cputlb.c              | 7 ++++---
 exec.c                | 9 +++++----
 include/exec/cputlb.h | 9 ++++++---
 3 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/cputlb.c b/cputlb.c
index 977c0ca..1f74d08 100644
--- a/cputlb.c
+++ b/cputlb.c
@@ -255,6 +255,7 @@ void tlb_set_page(CPUArchState *env, target_ulong vaddr,
                   hwaddr paddr, int prot,
                   int mmu_idx, target_ulong size)
 {
+    AddressSpaceDispatch *d;
     MemoryRegionSection *section;
     unsigned int index;
     target_ulong address;
@@ -269,8 +270,8 @@ void tlb_set_page(CPUArchState *env, target_ulong vaddr,
     }
 
     sz = size;
-    section = address_space_translate_for_iotlb(&address_space_memory, paddr,
-                                                &xlat, &sz);
+    d = address_space_memory.dispatch;
+    section = address_space_translate_for_iotlb(d, paddr, &xlat, &sz);
     assert(sz >= TARGET_PAGE_SIZE);
 
 #if defined(DEBUG_TLB)
@@ -290,7 +291,7 @@ void tlb_set_page(CPUArchState *env, target_ulong vaddr,
     }
 
     code_address = address;
-    iotlb = memory_region_section_get_iotlb(env, section, vaddr, paddr, xlat,
+    iotlb = memory_region_section_get_iotlb(d, env, section, vaddr, paddr, 
xlat,
                                             prot, &address);
 
     index = (vaddr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
diff --git a/exec.c b/exec.c
index 52e7fd5..c194bad 100644
--- a/exec.c
+++ b/exec.c
@@ -301,11 +301,11 @@ MemoryRegion *address_space_translate(AddressSpace *as, 
hwaddr addr,
 }
 
 MemoryRegionSection *
-address_space_translate_for_iotlb(AddressSpace *as, hwaddr addr, hwaddr *xlat,
+address_space_translate_for_iotlb(AddressSpaceDispatch *d, hwaddr addr, hwaddr 
*xlat,
                                   hwaddr *plen)
 {
     MemoryRegionSection *section;
-    section = address_space_translate_internal(as->dispatch, addr, xlat, plen, 
false);
+    section = address_space_translate_internal(d, addr, xlat, plen, false);
 
     assert(!section->mr->iommu_ops);
     return section;
@@ -719,7 +719,8 @@ static int cpu_physical_memory_set_dirty_tracking(int 
enable)
     return ret;
 }
 
-hwaddr memory_region_section_get_iotlb(CPUArchState *env,
+hwaddr memory_region_section_get_iotlb(AddressSpaceDispatch *d,
+                                       CPUArchState *env,
                                        MemoryRegionSection *section,
                                        target_ulong vaddr,
                                        hwaddr paddr, hwaddr xlat,
@@ -739,7 +740,7 @@ hwaddr memory_region_section_get_iotlb(CPUArchState *env,
             iotlb |= PHYS_SECTION_ROM;
         }
     } else {
-        iotlb = section - address_space_memory.dispatch->sections;
+        iotlb = section - d->sections;
         iotlb += xlat;
     }
 
diff --git a/include/exec/cputlb.h b/include/exec/cputlb.h
index e21cb60..bd7ff2f 100644
--- a/include/exec/cputlb.h
+++ b/include/exec/cputlb.h
@@ -19,6 +19,8 @@
 #ifndef CPUTLB_H
 #define CPUTLB_H
 
+#include <exec/memory-internal.h>
+
 #if !defined(CONFIG_USER_ONLY)
 /* cputlb.c */
 void tlb_protect_code(ram_addr_t ram_addr);
@@ -34,9 +36,10 @@ extern int tlb_flush_count;
 void tb_flush_jmp_cache(CPUArchState *env, target_ulong addr);
 
 MemoryRegionSection *
-address_space_translate_for_iotlb(AddressSpace *as, hwaddr addr, hwaddr *xlat,
-                                  hwaddr *plen);
-hwaddr memory_region_section_get_iotlb(CPUArchState *env,
+address_space_translate_for_iotlb(AddressSpaceDispatch *d, hwaddr addr,
+                                  hwaddr *xlat, hwaddr *plen);
+hwaddr memory_region_section_get_iotlb(AddressSpaceDispatch *d,
+                                       CPUArchState *env,
                                        MemoryRegionSection *section,
                                        target_ulong vaddr,
                                        hwaddr paddr, hwaddr xlat,
-- 
1.8.3.1