Move the DMA CHERI tag invalidation to invalidate_and_set_dirty().

This change moves the CHERI tag invalidation for I/O to the same
place that RAM is invalidated and marked dirty on writes or
invalidate_and_set_dirty().  Not all I/O that writes to memory uses
the previous place (dma_memory_rw) and this is more general.

exec.c

@@ -2344,6 +2344,9 @@ int cpu_memory_rw_debug(CPUState *cpu, target_ulong addr,
 
 #else
 
+/* XXX CHERI tag memory emulation needs to be moved to memory.c */
+void cheri_tag_phys_invalidate(hwaddr paddr, hwaddr len);
+
 static void invalidate_and_set_dirty(MemoryRegion *mr, hwaddr addr,
                                      hwaddr length)
 {
@@ -2361,6 +2364,9 @@ static void invalidate_and_set_dirty(MemoryRegion *mr, hwaddr addr,
         dirty_log_mask &= ~(1 << DIRTY_MEMORY_CODE);
     }
     cpu_physical_memory_set_dirty_range(addr, length, dirty_log_mask);
+
+    /* Invalidate the CHERI memory tags. */
+    cheri_tag_phys_invalidate(addr, length);
 }
 
 static int memory_access_size(MemoryRegion *mr, unsigned l, hwaddr addr)

include/sysemu/dma.h

@@ -84,26 +84,12 @@ static inline bool dma_memory_valid(AddressSpace *as,
                                       dir == DMA_DIRECTION_FROM_DEVICE);
 }
 
-/* XXX CHERI tag memory emulation needs to be moved to memory.c */
-void cheri_tag_dma_invalidate(uint64_t paddr, uint64_t len);
-
 static inline int dma_memory_rw_relaxed(AddressSpace *as, dma_addr_t addr,
                                         void *buf, dma_addr_t len,
                                         DMADirection dir)
 {
-    MemTxResult ret;
-
-    ret = address_space_rw(as, addr, MEMTXATTRS_UNSPECIFIED,
-                                  buf, len, dir == DMA_DIRECTION_FROM_DEVICE);
-
-    /*
-     * If successful and was a write to memory then invalidate
-     * the CHERI memory tag(s).
-     */
-    if (ret == MEMTX_OK && dir == DMA_DIRECTION_FROM_DEVICE)
-        cheri_tag_dma_invalidate(addr, len);
-
-    return (bool)ret;
+    return (bool)address_space_rw(as, addr, MEMTXATTRS_UNSPECIFIED,
+            buf, len, dir == DMA_DIRECTION_FROM_DEVICE);
 }
 
 static inline int dma_memory_read_relaxed(AddressSpace *as, dma_addr_t addr,

target-mips/cpu.h

@@ -1272,7 +1272,7 @@ static inline void cpu_mips_store_cause(CPUMIPSState *env, target_ulong val)
 
 void cheri_tag_init(uint64_t memory_size);
 void cheri_tag_invalidate(CPUMIPSState *env, target_ulong vaddr, int32_t size);
-void cheri_tag_dma_invalidate(uint64_t paddr, uint64_t len);
+void cheri_tag_phys_invalidate(hwaddr paddr, hwaddr len);
 int  cheri_tag_get(CPUMIPSState *env, target_ulong vaddr, int reg,
         hwaddr *ret_paddr);
 void cheri_tag_set(CPUMIPSState *env, target_ulong vaddr, int reg);

target-mips/helper.c

@@ -995,7 +995,7 @@ void r4k_invalidate_tlb (CPUMIPSState *env, int idx, int use_extra)
 #endif /* ! CHERI_MAGIC128 */
 
 uint8_t **cheri_tagmem = NULL;
-uint64_t cheri_ntagblks = 0;
+uint64_t cheri_ntagblks = 0ul;
 
 void cheri_tag_init(uint64_t memory_size)
 {
@@ -1060,16 +1060,19 @@ void cheri_tag_invalidate(CPUMIPSState *env, target_ulong vaddr, int32_t size)
     return;
 }
 
-void cheri_tag_dma_invalidate(uint64_t paddr, uint64_t len)
+void cheri_tag_phys_invalidate(hwaddr paddr, hwaddr len)
 {
-    uint64_t tag, addr, endaddr;
+    uint64_t tag, addr, endaddr, tagmem_idx;
     uint8_t *tagblk;
 
-    endaddr = paddr + len;
+    endaddr = (uint64_t)(paddr + len);
 
-    for(addr = paddr; addr < endaddr; addr += CAP_SIZE) {
+    for(addr = (uint64_t)paddr; addr < endaddr; addr += CAP_SIZE) {
         tag = addr >> CAP_TAG_SHFT;
-        tagblk = cheri_tagmem[tag >> CAP_TAGBLK_SHFT];
+        tagmem_idx = tag >> CAP_TAGBLK_SHFT;
+        if (tagmem_idx > cheri_ntagblks)
+            return;
+        tagblk = cheri_tagmem[tagmem_idx];
 
         if (tagblk != NULL)
             tagblk[CAP_TAGBLK_IDX(tag)] = 0;
@@ -1198,6 +1201,6 @@ int cheri_tag_get_m128(CPUMIPSState *env, target_ulong vaddr, int reg,
 
 #else /* ! TARGET_CHERI */
 
-void cheri_tag_dma_invalidate(uint64_t paddr, uint64_t len) { }
+void cheri_tag_phys_invalidate(hwaddr paddr, hwaddr len) { }
 
 #endif /* ! TARGET_CHERI */