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exec: Resolve subpages in one step except for IOTLB fills

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Except for the case of setting the IOTLB entry in TCG mode, we can avoid
the subpage dispatching handlers and do the resolution directly on
address_space_lookup_region. An IOTLB entry describes a full page, not
only the region that the first access to a sub-divided page may return.

This patch therefore introduces a special translation function,
address_space_translate_for_iotlb, that avoids the subpage resolutions.
In contrast, callers of the existing address_space_translate service
will now always receive the terminal memory region section. This will be
important for breaking the BQL and for enabling unaligned memory region.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Jan Kiszka 2013-05-26 21:46:51 +02:00 committed by Paolo Bonzini
parent f52cc46742
commit 90260c6c09
3 changed files with 42 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
cputlb.c
View File

@ -256,8 +256,8 @@ void tlb_set_page(CPUArchState *env, target_ulong vaddr,
}
sz = size;
section = address_space_translate(&address_space_memory, paddr, &xlat, &sz,
false);
section = address_space_translate_for_iotlb(&address_space_memory, paddr,
&xlat, &sz);
assert(sz >= TARGET_PAGE_SIZE);
#if defined(DEBUG_TLB)

49
exec.c
View File

@ -97,6 +97,13 @@ struct AddressSpaceDispatch {
MemoryListener listener;
};
#define SUBPAGE_IDX(addr) ((addr) & ~TARGET_PAGE_MASK)
typedef struct subpage_t {
MemoryRegion iomem;
hwaddr base;
uint16_t sub_section[TARGET_PAGE_SIZE];
} subpage_t;
static MemoryRegionSection *phys_sections;
static unsigned phys_sections_nb, phys_sections_nb_alloc;
static uint16_t phys_section_unassigned;
@ -220,19 +227,28 @@ bool memory_region_is_unassigned(MemoryRegion *mr)
}
static MemoryRegionSection *address_space_lookup_region(AddressSpace *as,
hwaddr addr)
hwaddr addr,
bool resolve_subpage)
{
return phys_page_find(as->dispatch, addr >> TARGET_PAGE_BITS);
MemoryRegionSection *section;
subpage_t *subpage;
section = phys_page_find(as->dispatch, addr >> TARGET_PAGE_BITS);
if (resolve_subpage && section->mr->subpage) {
subpage = container_of(section->mr, subpage_t, iomem);
section = &phys_sections[subpage->sub_section[SUBPAGE_IDX(addr)]];
}
return section;
}
MemoryRegionSection *address_space_translate(AddressSpace *as, hwaddr addr,
hwaddr *xlat, hwaddr *plen,
bool is_write)
static MemoryRegionSection *
address_space_translate_internal(AddressSpace *as, hwaddr addr, hwaddr *xlat,
hwaddr *plen, bool resolve_subpage)
{
MemoryRegionSection *section;
Int128 diff;
section = address_space_lookup_region(as, addr);
section = address_space_lookup_region(as, addr, resolve_subpage);
/* Compute offset within MemoryRegionSection */
addr -= section->offset_within_address_space;
@ -243,6 +259,20 @@ MemoryRegionSection *address_space_translate(AddressSpace *as, hwaddr addr,
*plen = int128_get64(int128_min(diff, int128_make64(*plen)));
return section;
}
MemoryRegionSection *address_space_translate(AddressSpace *as, hwaddr addr,
hwaddr *xlat, hwaddr *plen,
bool is_write)
{
return address_space_translate_internal(as, addr, xlat, plen, true);
}
MemoryRegionSection *
address_space_translate_for_iotlb(AddressSpace *as, hwaddr addr, hwaddr *xlat,
hwaddr *plen)
{
return address_space_translate_internal(as, addr, xlat, plen, false);
}
#endif
void cpu_exec_init_all(void)
@ -697,13 +727,6 @@ hwaddr memory_region_section_get_iotlb(CPUArchState *env,
#if !defined(CONFIG_USER_ONLY)
#define SUBPAGE_IDX(addr) ((addr) & ~TARGET_PAGE_MASK)
typedef struct subpage_t {
MemoryRegion iomem;
hwaddr base;
uint16_t sub_section[TARGET_PAGE_SIZE];
} subpage_t;
static int subpage_register (subpage_t *mmio, uint32_t start, uint32_t end,
uint16_t section);
static subpage_t *subpage_init(hwaddr base);

4
include/exec/cputlb.h
View File

@ -32,6 +32,10 @@ extern int tlb_flush_count;
/* exec.c */
void tb_flush_jmp_cache(CPUArchState *env, target_ulong addr);
MemoryRegionSection *
address_space_translate_for_iotlb(AddressSpace *as, hwaddr addr, hwaddr *xlat,
hwaddr *plen);
hwaddr memory_region_section_get_iotlb(CPUArchState *env,
MemoryRegionSection *section,
target_ulong vaddr,