memory: add address_space_translate

Using phys_page_find to translate an AddressSpace to a MemoryRegionSection
is unwieldy.  It requires to pass the page index rather than the address,
and later memory_region_section_addr has to be called.  Replace
memory_region_section_addr with a function that does all of it: call
phys_page_find, compute the offset within the region, and check how
big the current mapping is.  This way, a large flat region can be written
with a single lookup rather than a page at a time.

address_space_translate will also provide a single point where IOMMU
forwarding is implemented.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini
2013-05-29 16:26:50 +02:00
parent b018ddf633
commit 149f54b53b
5 changed files with 131 additions and 130 deletions
+14 -17
View File
@@ -751,23 +751,6 @@ void memory_region_set_alias_offset(MemoryRegion *mr,
MemoryRegionSection memory_region_find(MemoryRegion *mr,
hwaddr addr, uint64_t size);
/**
* memory_region_section_addr: get offset within MemoryRegionSection
*
* Returns offset within MemoryRegionSection
*
* @section: the memory region section being queried
* @addr: address in address space
*/
static inline hwaddr
memory_region_section_addr(MemoryRegionSection *section,
hwaddr addr)
{
addr -= section->offset_within_address_space;
addr += section->offset_within_region;
return addr;
}
/**
* address_space_sync_dirty_bitmap: synchronize the dirty log for all memory
*
@@ -869,6 +852,20 @@ void address_space_write(AddressSpace *as, hwaddr addr,
*/
void address_space_read(AddressSpace *as, hwaddr addr, uint8_t *buf, int len);
/* address_space_translate: translate an address range into an address space
* into a MemoryRegionSection and an address range into that section
*
* @as: #AddressSpace to be accessed
* @addr: address within that address space
* @xlat: pointer to address within the returned memory region section's
* #MemoryRegion.
* @len: pointer to length
* @is_write: indicates the transfer direction
*/
MemoryRegionSection *address_space_translate(AddressSpace *as, hwaddr addr,
hwaddr *xlat, hwaddr *len,
bool is_write);
/* address_space_map: map a physical memory region into a host virtual address
*
* May map a subset of the requested range, given by and returned in @plen.