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authorPaolo Bonzini <pbonzini@redhat.com>2016-11-22 12:04:52 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2016-12-22 16:00:23 +0100
commit1f4e496e1fc2eb6c8bf377a0f9695930c380bfd3 (patch)
tree20ae0a2b754332418a682b5a9361e54708d3b19b /include/exec/memory.h
parent715c31ec8e12107f47ac74b464c97e813c76f898 (diff)
exec: introduce MemoryRegionCache
Device models often have to perform multiple access to a single memory region that is known in advance, but would to use "DMA-style" functions instead of address_space_map/unmap. This can happen for example when the data has to undergo endianness conversion. Introduce a new data structure to cache the result of address_space_translate without forcing usage of a host address like address_space_map does. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'include/exec/memory.h')
-rw-r--r--include/exec/memory.h151
1 files changed, 151 insertions, 0 deletions
diff --git a/include/exec/memory.h b/include/exec/memory.h
index f35b6125ab..64560f61b4 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -1419,6 +1419,125 @@ void stl_be_phys(AddressSpace *as, hwaddr addr, uint32_t val);
void stq_le_phys(AddressSpace *as, hwaddr addr, uint64_t val);
void stq_be_phys(AddressSpace *as, hwaddr addr, uint64_t val);
+struct MemoryRegionCache {
+ hwaddr xlat;
+ void *ptr;
+ hwaddr len;
+ MemoryRegion *mr;
+ bool is_write;
+};
+
+/* address_space_cache_init: prepare for repeated access to a physical
+ * memory region
+ *
+ * @cache: #MemoryRegionCache to be filled
+ * @as: #AddressSpace to be accessed
+ * @addr: address within that address space
+ * @len: length of buffer
+ * @is_write: indicates the transfer direction
+ *
+ * Will only work with RAM, and may map a subset of the requested range by
+ * returning a value that is less than @len. On failure, return a negative
+ * errno value.
+ *
+ * Because it only works with RAM, this function can be used for
+ * read-modify-write operations. In this case, is_write should be %true.
+ *
+ * Note that addresses passed to the address_space_*_cached functions
+ * are relative to @addr.
+ */
+int64_t address_space_cache_init(MemoryRegionCache *cache,
+ AddressSpace *as,
+ hwaddr addr,
+ hwaddr len,
+ bool is_write);
+
+/**
+ * address_space_cache_invalidate: complete a write to a #MemoryRegionCache
+ *
+ * @cache: The #MemoryRegionCache to operate on.
+ * @addr: The first physical address that was written, relative to the
+ * 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,
+ hwaddr addr,
+ hwaddr access_len);
+
+/**
+ * address_space_cache_destroy: free a #MemoryRegionCache
+ *
+ * @cache: The #MemoryRegionCache whose memory should be released.
+ */
+void address_space_cache_destroy(MemoryRegionCache *cache);
+
+/* address_space_ld*_cached: load from a cached #MemoryRegion
+ * address_space_st*_cached: store into a cached #MemoryRegion
+ *
+ * These functions perform a load or store of the byte, word,
+ * longword or quad to the specified address. The address is
+ * a physical address in the AddressSpace, but it must lie within
+ * a #MemoryRegion that was mapped with address_space_cache_init.
+ *
+ * The _le suffixed functions treat the data as little endian;
+ * _be indicates big endian; no suffix indicates "same endianness
+ * as guest CPU".
+ *
+ * The "guest CPU endianness" accessors are deprecated for use outside
+ * target-* code; devices should be CPU-agnostic and use either the LE
+ * or the BE accessors.
+ *
+ * @cache: previously initialized #MemoryRegionCache to be accessed
+ * @addr: address within the address space
+ * @val: data value, for stores
+ * @attrs: memory transaction attributes
+ * @result: location to write the success/failure of the transaction;
+ * if NULL, this information is discarded
+ */
+uint32_t address_space_ldub_cached(MemoryRegionCache *cache, hwaddr addr,
+ MemTxAttrs attrs, MemTxResult *result);
+uint32_t address_space_lduw_le_cached(MemoryRegionCache *cache, hwaddr addr,
+ MemTxAttrs attrs, MemTxResult *result);
+uint32_t address_space_lduw_be_cached(MemoryRegionCache *cache, hwaddr addr,
+ MemTxAttrs attrs, MemTxResult *result);
+uint32_t address_space_ldl_le_cached(MemoryRegionCache *cache, hwaddr addr,
+ MemTxAttrs attrs, MemTxResult *result);
+uint32_t address_space_ldl_be_cached(MemoryRegionCache *cache, hwaddr addr,
+ MemTxAttrs attrs, MemTxResult *result);
+uint64_t address_space_ldq_le_cached(MemoryRegionCache *cache, hwaddr addr,
+ MemTxAttrs attrs, MemTxResult *result);
+uint64_t address_space_ldq_be_cached(MemoryRegionCache *cache, hwaddr addr,
+ MemTxAttrs attrs, MemTxResult *result);
+void address_space_stb_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val,
+ MemTxAttrs attrs, MemTxResult *result);
+void address_space_stw_le_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val,
+ MemTxAttrs attrs, MemTxResult *result);
+void address_space_stw_be_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val,
+ MemTxAttrs attrs, MemTxResult *result);
+void address_space_stl_le_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val,
+ MemTxAttrs attrs, MemTxResult *result);
+void address_space_stl_be_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val,
+ MemTxAttrs attrs, MemTxResult *result);
+void address_space_stq_le_cached(MemoryRegionCache *cache, hwaddr addr, uint64_t val,
+ MemTxAttrs attrs, MemTxResult *result);
+void address_space_stq_be_cached(MemoryRegionCache *cache, hwaddr addr, uint64_t val,
+ MemTxAttrs attrs, MemTxResult *result);
+
+uint32_t ldub_phys_cached(MemoryRegionCache *cache, hwaddr addr);
+uint32_t lduw_le_phys_cached(MemoryRegionCache *cache, hwaddr addr);
+uint32_t lduw_be_phys_cached(MemoryRegionCache *cache, hwaddr addr);
+uint32_t ldl_le_phys_cached(MemoryRegionCache *cache, hwaddr addr);
+uint32_t ldl_be_phys_cached(MemoryRegionCache *cache, hwaddr addr);
+uint64_t ldq_le_phys_cached(MemoryRegionCache *cache, hwaddr addr);
+uint64_t ldq_be_phys_cached(MemoryRegionCache *cache, hwaddr addr);
+void stb_phys_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val);
+void stw_le_phys_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val);
+void stw_be_phys_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val);
+void stl_le_phys_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val);
+void stl_be_phys_cached(MemoryRegionCache *cache, hwaddr addr, uint32_t val);
+void stq_le_phys_cached(MemoryRegionCache *cache, hwaddr addr, uint64_t val);
+void stq_be_phys_cached(MemoryRegionCache *cache, hwaddr addr, uint64_t val);
+
/* address_space_translate: translate an address range into an address space
* into a MemoryRegion and an address range into that section. Should be
* called from an RCU critical section, to avoid that the last reference
@@ -1544,6 +1663,38 @@ MemTxResult address_space_read(AddressSpace *as, hwaddr addr, MemTxAttrs attrs,
return result;
}
+/**
+ * address_space_read_cached: read from a cached RAM region
+ *
+ * @cache: Cached region to be addressed
+ * @addr: address relative to the base of the RAM region
+ * @buf: buffer with the data transferred
+ * @len: length of the data transferred
+ */
+static inline void
+address_space_read_cached(MemoryRegionCache *cache, hwaddr addr,
+ void *buf, int len)
+{
+ assert(addr < cache->len && len <= cache->len - addr);
+ memcpy(buf, cache->ptr + addr, len);
+}
+
+/**
+ * address_space_write_cached: write to a cached RAM region
+ *
+ * @cache: Cached region to be addressed
+ * @addr: address relative to the base of the RAM region
+ * @buf: buffer with the data transferred
+ * @len: length of the data transferred
+ */
+static inline void
+address_space_write_cached(MemoryRegionCache *cache, hwaddr addr,
+ void *buf, int len)
+{
+ assert(addr < cache->len && len <= cache->len - addr);
+ memcpy(cache->ptr + addr, buf, len);
+}
+
#endif
#endif