[Qemu-devel] [PATCH 2/5] memory: store section indices in iotlb instead of io indices

[Avi Kivity <avi@redhat.com>]

A step towards eliminating io indices.

Signed-off-by: Avi Kivity <avi@redhat.com>
---
 exec-all.h         |    1 +
 exec.c             |   23 +++++++++++++++++++----
 softmmu_template.h |    8 ++++----
 3 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/exec-all.h b/exec-all.h
index 51d01f2..3ffe9dd 100644
--- a/exec-all.h
+++ b/exec-all.h
@@ -299,6 +299,7 @@ extern void *tci_tb_ptr;
 
 #if !defined(CONFIG_USER_ONLY)
 
+target_phys_addr_t section_to_ioaddr(target_phys_addr_t section_io_addr);
 uint64_t io_mem_read(int index, target_phys_addr_t addr, unsigned size);
 void io_mem_write(int index, target_phys_addr_t addr, uint64_t value,
                   unsigned size);
diff --git a/exec.c b/exec.c
index 1fb0158..a35eb4f 100644
--- a/exec.c
+++ b/exec.c
@@ -191,6 +191,9 @@
 static MemoryRegionSection *phys_sections;
 static unsigned phys_sections_nb, phys_sections_nb_alloc;
 static uint16_t phys_section_unassigned;
+static uint16_t phys_section_notdirty;
+static uint16_t phys_section_rom;
+static uint16_t phys_section_watch;
 
 struct PhysPageEntry {
     uint16_t is_leaf : 1;
@@ -2214,9 +2217,9 @@ void tlb_set_page(CPUState *env, target_ulong vaddr,
         iotlb = (memory_region_get_ram_addr(section->mr) & TARGET_PAGE_MASK)
             + section_addr(section, paddr);
         if (!section->readonly)
-            iotlb |= io_mem_notdirty.ram_addr;
+            iotlb |= phys_section_notdirty;
         else
-            iotlb |= io_mem_rom.ram_addr;
+            iotlb |= phys_section_rom;
     } else {
         /* IO handlers are currently passed a physical address.
            It would be nice to pass an offset from the base address
@@ -2224,7 +2227,7 @@ void tlb_set_page(CPUState *env, target_ulong vaddr,
            and avoid full address decoding in every device.
            We can't use the high bits of pd for this because
            IO_MEM_ROMD uses these as a ram address.  */
-        iotlb = memory_region_get_ram_addr(section->mr) & ~TARGET_PAGE_MASK;
+        iotlb = section - phys_sections;
         iotlb += section_addr(section, paddr);
     }
 
@@ -2235,7 +2238,7 @@ void tlb_set_page(CPUState *env, target_ulong vaddr,
         if (vaddr == (wp->vaddr & TARGET_PAGE_MASK)) {
             /* Avoid trapping reads of pages with a write breakpoint. */
             if ((prot & PAGE_WRITE) || (wp->flags & BP_MEM_READ)) {
-                iotlb = io_mem_watch.ram_addr + paddr;
+                iotlb = phys_section_watch + paddr;
                 address |= TLB_MMIO;
                 break;
             }
@@ -3559,6 +3562,15 @@ static uint16_t dummy_section(MemoryRegion *mr)
     return phys_section_add(&section);
 }
 
+target_phys_addr_t section_to_ioaddr(target_phys_addr_t section_io_addr)
+{
+    MemoryRegionSection *section;
+
+    section = &phys_sections[section_io_addr & ~TARGET_PAGE_MASK];
+    return (section_io_addr & TARGET_PAGE_MASK)
+        | (section->mr->ram_addr & ~TARGET_PAGE_MASK);
+}
+
 static void io_mem_init(void)
 {
     int i;
@@ -3586,6 +3598,9 @@ static void core_begin(MemoryListener *listener)
     phys_sections_clear();
     phys_map.ptr = PHYS_MAP_NODE_NIL;
     phys_section_unassigned = dummy_section(&io_mem_unassigned);
+    phys_section_notdirty = dummy_section(&io_mem_notdirty);
+    phys_section_rom = dummy_section(&io_mem_rom);
+    phys_section_watch = dummy_section(&io_mem_watch);
 }
 
 static void core_commit(MemoryListener *listener)
diff --git a/softmmu_template.h b/softmmu_template.h
index 97020f8..7c7e15b 100644
--- a/softmmu_template.h
+++ b/softmmu_template.h
@@ -110,7 +110,7 @@ DATA_TYPE REGPARM glue(glue(__ld, SUFFIX), MMUSUFFIX)(target_ulong addr,
             if ((addr & (DATA_SIZE - 1)) != 0)
                 goto do_unaligned_access;
             retaddr = GETPC();
-            ioaddr = env->iotlb[mmu_idx][index];
+            ioaddr = section_to_ioaddr(env->iotlb[mmu_idx][index]);
             res = glue(io_read, SUFFIX)(ioaddr, addr, retaddr);
         } else if (((addr & ~TARGET_PAGE_MASK) + DATA_SIZE - 1) >= TARGET_PAGE_SIZE) {
             /* slow unaligned access (it spans two pages or IO) */
@@ -164,7 +164,7 @@ static DATA_TYPE glue(glue(slow_ld, SUFFIX), MMUSUFFIX)(target_ulong addr,
             /* IO access */
             if ((addr & (DATA_SIZE - 1)) != 0)
                 goto do_unaligned_access;
-            ioaddr = env->iotlb[mmu_idx][index];
+            ioaddr = section_to_ioaddr(env->iotlb[mmu_idx][index]);
             res = glue(io_read, SUFFIX)(ioaddr, addr, retaddr);
         } else if (((addr & ~TARGET_PAGE_MASK) + DATA_SIZE - 1) >= TARGET_PAGE_SIZE) {
         do_unaligned_access:
@@ -251,7 +251,7 @@ void REGPARM glue(glue(__st, SUFFIX), MMUSUFFIX)(target_ulong addr,
             if ((addr & (DATA_SIZE - 1)) != 0)
                 goto do_unaligned_access;
             retaddr = GETPC();
-            ioaddr = env->iotlb[mmu_idx][index];
+            ioaddr = section_to_ioaddr(env->iotlb[mmu_idx][index]);
             glue(io_write, SUFFIX)(ioaddr, val, addr, retaddr);
         } else if (((addr & ~TARGET_PAGE_MASK) + DATA_SIZE - 1) >= TARGET_PAGE_SIZE) {
         do_unaligned_access:
@@ -303,7 +303,7 @@ static void glue(glue(slow_st, SUFFIX), MMUSUFFIX)(target_ulong addr,
             /* IO access */
             if ((addr & (DATA_SIZE - 1)) != 0)
                 goto do_unaligned_access;
-            ioaddr = env->iotlb[mmu_idx][index];
+            ioaddr = section_to_ioaddr(env->iotlb[mmu_idx][index]);
             glue(io_write, SUFFIX)(ioaddr, val, addr, retaddr);
         } else if (((addr & ~TARGET_PAGE_MASK) + DATA_SIZE - 1) >= TARGET_PAGE_SIZE) {
         do_unaligned_access:
-- 
1.7.9