memory: simplify multipage/subpage registration

Instead of considering subpage on a per-page basis, split each section
into a subpage head, multipage body, and subpage tail, and register
each separately.  This simplifies the registration functions.

Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Avi Kivity 2012-02-13 17:14:32 +02:00
parent 31ab2b4a46
commit 0f0cb164cc

120
exec.c
View File

@ -2538,28 +2538,7 @@ typedef struct subpage_t {
static int subpage_register (subpage_t *mmio, uint32_t start, uint32_t end,
uint16_t section);
static subpage_t *subpage_init (target_phys_addr_t base, uint16_t *section,
uint16_t orig_section);
#define CHECK_SUBPAGE(addr, start_addr, start_addr2, end_addr, end_addr2, \
need_subpage) \
do { \
if (addr > start_addr) \
start_addr2 = 0; \
else { \
start_addr2 = start_addr & ~TARGET_PAGE_MASK; \
if (start_addr2 > 0) \
need_subpage = 1; \
} \
\
if ((start_addr + orig_size) - addr >= TARGET_PAGE_SIZE) \
end_addr2 = TARGET_PAGE_SIZE - 1; \
else { \
end_addr2 = (start_addr + orig_size - 1) & ~TARGET_PAGE_MASK; \
if (end_addr2 < TARGET_PAGE_SIZE - 1) \
need_subpage = 1; \
} \
} while (0)
static subpage_t *subpage_init(target_phys_addr_t base);
static void destroy_page_desc(uint16_t section_index)
{
MemoryRegionSection *section = &phys_sections[section_index];
@ -2622,47 +2601,85 @@ static void phys_sections_clear(void)
start_addr and region_offset are rounded down to a page boundary
before calculating this offset. This should not be a problem unless
the low bits of start_addr and region_offset differ. */
void cpu_register_physical_memory_log(MemoryRegionSection *section,
bool readonly)
static void register_subpage(MemoryRegionSection *section)
{
subpage_t *subpage;
target_phys_addr_t base = section->offset_within_address_space
& TARGET_PAGE_MASK;
MemoryRegionSection existing = phys_page_find(base >> TARGET_PAGE_BITS);
MemoryRegionSection subsection = {
.offset_within_address_space = base,
.size = TARGET_PAGE_SIZE,
};
uint16_t *ptr;
target_phys_addr_t start, end;
assert(existing.mr->subpage || existing.mr == &io_mem_unassigned);
if (!(existing.mr->subpage)) {
subpage = subpage_init(base);
subsection.mr = &subpage->iomem;
ptr = phys_page_find_alloc(base >> TARGET_PAGE_BITS, 1);
*ptr = phys_section_add(&subsection);
} else {
subpage = container_of(existing.mr, subpage_t, iomem);
}
start = section->offset_within_address_space & ~TARGET_PAGE_MASK;
end = start + section->size;
subpage_register(subpage, start, end, phys_section_add(section));
}
static void register_multipage(MemoryRegionSection *section)
{
target_phys_addr_t start_addr = section->offset_within_address_space;
ram_addr_t size = section->size;
target_phys_addr_t addr, end_addr;
ram_addr_t orig_size = size;
subpage_t *subpage;
uint16_t section_index = phys_section_add(section);
assert(size);
size = (size + TARGET_PAGE_SIZE - 1) & TARGET_PAGE_MASK;
end_addr = start_addr + (target_phys_addr_t)size;
addr = start_addr;
do {
uint16_t *p = phys_page_find_alloc(addr >> TARGET_PAGE_BITS, 1);
uint16_t orig_memory = *p;
target_phys_addr_t start_addr2, end_addr2;
int need_subpage = 0;
MemoryRegion *mr = phys_sections[orig_memory].mr;
CHECK_SUBPAGE(addr, start_addr, start_addr2, end_addr, end_addr2,
need_subpage);
if (need_subpage) {
if (!(mr->subpage)) {
subpage = subpage_init((addr & TARGET_PAGE_MASK),
p, orig_memory);
} else {
subpage = container_of(mr, subpage_t, iomem);
}
subpage_register(subpage, start_addr2, end_addr2,
section_index);
} else {
*p = section_index;
}
assert(*p == phys_section_unassigned);
*p = section_index;
addr += TARGET_PAGE_SIZE;
} while (addr != end_addr);
}
void cpu_register_physical_memory_log(MemoryRegionSection *section,
bool readonly)
{
MemoryRegionSection now = *section, remain = *section;
if ((now.offset_within_address_space & ~TARGET_PAGE_MASK)
|| (now.size < TARGET_PAGE_SIZE)) {
now.size = MIN(TARGET_PAGE_ALIGN(now.offset_within_address_space)
- now.offset_within_address_space,
now.size);
register_subpage(&now);
remain.size -= now.size;
remain.offset_within_address_space += now.size;
remain.offset_within_region += now.size;
}
now = remain;
now.size &= TARGET_PAGE_MASK;
if (now.size) {
register_multipage(&now);
remain.size -= now.size;
remain.offset_within_address_space += now.size;
remain.offset_within_region += now.size;
}
now = remain;
if (now.size) {
register_subpage(&now);
}
}
void qemu_register_coalesced_mmio(target_phys_addr_t addr, ram_addr_t size)
{
if (kvm_enabled())
@ -3442,14 +3459,9 @@ static int subpage_register (subpage_t *mmio, uint32_t start, uint32_t end,
return 0;
}
static subpage_t *subpage_init (target_phys_addr_t base, uint16_t *section_ind,
uint16_t orig_section)
static subpage_t *subpage_init(target_phys_addr_t base)
{
subpage_t *mmio;
MemoryRegionSection section = {
.offset_within_address_space = base,
.size = TARGET_PAGE_SIZE,
};
mmio = g_malloc0(sizeof(subpage_t));
@ -3457,13 +3469,11 @@ static subpage_t *subpage_init (target_phys_addr_t base, uint16_t *section_ind,
memory_region_init_io(&mmio->iomem, &subpage_ops, mmio,
"subpage", TARGET_PAGE_SIZE);
mmio->iomem.subpage = true;
section.mr = &mmio->iomem;
#if defined(DEBUG_SUBPAGE)
printf("%s: %p base " TARGET_FMT_plx " len %08x %d\n", __func__,
mmio, base, TARGET_PAGE_SIZE, subpage_memory);
#endif
*section_ind = phys_section_add(&section);
subpage_register(mmio, 0, TARGET_PAGE_SIZE-1, orig_section);
subpage_register(mmio, 0, TARGET_PAGE_SIZE-1, phys_section_unassigned);
return mmio;
}