Re: [Qemu-devel] [RFC][PATCH 09/15] memory: Introduce address_space_lookup_region

[Paolo Bonzini <pbonzini@redhat.com>]

Il 06/05/2013 16:26, Jan Kiszka ha scritto:
> This new service so far only replaces phys_page_find as public API. In a
> follow-up step, it will return the effective memory region for the
> specified address, i.e. after resolving what are currently sub-pages.
> Moreover, it will also once encapsulate locking and reference counting
> when we introduce BQL-free dispatching.

In my IOMMU rebase I have a similar function:

/* 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);

It wraps (actually, replaces) both phys_page_find and
memory_region_section_addr.

Paolo

> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
>  cputlb.c              |    2 +-
>  exec.c                |   46 +++++++++++++++++++++-------------------------
>  include/exec/cputlb.h |    2 --
>  include/exec/memory.h |    9 +++++++++
>  translate-all.c       |    3 +--
>  5 files changed, 32 insertions(+), 30 deletions(-)
> 
> diff --git a/cputlb.c b/cputlb.c
> index aba7e44..e2c95c1 100644
> --- a/cputlb.c
> +++ b/cputlb.c
> @@ -254,7 +254,7 @@ void tlb_set_page(CPUArchState *env, target_ulong vaddr,
>      if (size != TARGET_PAGE_SIZE) {
>          tlb_add_large_page(env, vaddr, size);
>      }
> -    section = phys_page_find(address_space_memory.dispatch, paddr >> TARGET_PAGE_BITS);
> +    section = address_space_lookup_region(&address_space_memory, paddr);
>  #if defined(DEBUG_TLB)
>      printf("tlb_set_page: vaddr=" TARGET_FMT_lx " paddr=0x" TARGET_FMT_plx
>             " prot=%x idx=%d pd=0x%08lx\n",
> diff --git a/exec.c b/exec.c
> index 19725db..53c2778 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -182,7 +182,8 @@ static void phys_page_set(AddressSpaceDispatch *d,
>      phys_page_set_level(&d->phys_map, &index, &nb, leaf, P_L2_LEVELS - 1);
>  }
>  
> -MemoryRegionSection *phys_page_find(AddressSpaceDispatch *d, hwaddr index)
> +static MemoryRegionSection *phys_page_find(AddressSpaceDispatch *d,
> +                                           hwaddr index)
>  {
>      PhysPageEntry lp = d->phys_map;
>      PhysPageEntry *p;
> @@ -1894,19 +1895,16 @@ static void invalidate_and_set_dirty(hwaddr addr,
>  void address_space_rw(AddressSpace *as, hwaddr addr, uint8_t *buf,
>                        int len, bool is_write)
>  {
> -    AddressSpaceDispatch *d = as->dispatch;
>      int l;
>      uint8_t *ptr;
>      uint32_t val;
> -    hwaddr page;
>      MemoryRegionSection *section;
>  
>      while (len > 0) {
> -        page = addr & TARGET_PAGE_MASK;
> -        l = (page + TARGET_PAGE_SIZE) - addr;
> +        l = ((addr & TARGET_PAGE_MASK) + TARGET_PAGE_SIZE) - addr;
>          if (l > len)
>              l = len;
> -        section = phys_page_find(d, page >> TARGET_PAGE_BITS);
> +        section = address_space_lookup_region(as, addr);
>  
>          if (is_write) {
>              if (!memory_region_is_ram(section->mr)) {
> @@ -2006,18 +2004,15 @@ void cpu_physical_memory_rw(hwaddr addr, uint8_t *buf,
>  void cpu_physical_memory_write_rom(hwaddr addr,
>                                     const uint8_t *buf, int len)
>  {
> -    AddressSpaceDispatch *d = address_space_memory.dispatch;
>      int l;
>      uint8_t *ptr;
> -    hwaddr page;
>      MemoryRegionSection *section;
>  
>      while (len > 0) {
> -        page = addr & TARGET_PAGE_MASK;
> -        l = (page + TARGET_PAGE_SIZE) - addr;
> +        l = ((addr & TARGET_PAGE_MASK) + TARGET_PAGE_SIZE) - addr;
>          if (l > len)
>              l = len;
> -        section = phys_page_find(d, page >> TARGET_PAGE_BITS);
> +        section = address_space_lookup_region(&address_space_memory, addr);
>  
>          if (!(memory_region_is_ram(section->mr) ||
>                memory_region_is_romd(section->mr))) {
> @@ -2096,22 +2091,19 @@ void *address_space_map(AddressSpace *as,
>                          hwaddr *plen,
>                          bool is_write)
>  {
> -    AddressSpaceDispatch *d = as->dispatch;
>      hwaddr len = *plen;
>      hwaddr todo = 0;
>      int l;
> -    hwaddr page;
>      MemoryRegionSection *section;
>      ram_addr_t raddr = RAM_ADDR_MAX;
>      ram_addr_t rlen;
>      void *ret;
>  
>      while (len > 0) {
> -        page = addr & TARGET_PAGE_MASK;
> -        l = (page + TARGET_PAGE_SIZE) - addr;
> +        l = ((addr & TARGET_PAGE_MASK) + TARGET_PAGE_SIZE) - addr;
>          if (l > len)
>              l = len;
> -        section = phys_page_find(d, page >> TARGET_PAGE_BITS);
> +        section = address_space_lookup_region(as, addr);
>  
>          if (!(memory_region_is_ram(section->mr) && !section->readonly)) {
>              if (todo || bounce.buffer) {
> @@ -2188,6 +2180,11 @@ void cpu_physical_memory_unmap(void *buffer, hwaddr len,
>      return address_space_unmap(&address_space_memory, buffer, len, is_write, access_len);
>  }
>  
> +MemoryRegionSection *address_space_lookup_region(AddressSpace *as, hwaddr addr)
> +{
> +    return phys_page_find(as->dispatch, addr >> TARGET_PAGE_BITS);
> +}
> +
>  /* warning: addr must be aligned */
>  static inline uint32_t ldl_phys_internal(hwaddr addr,
>                                           enum device_endian endian)
> @@ -2196,7 +2193,7 @@ static inline uint32_t ldl_phys_internal(hwaddr addr,
>      uint32_t val;
>      MemoryRegionSection *section;
>  
> -    section = phys_page_find(address_space_memory.dispatch, addr >> TARGET_PAGE_BITS);
> +    section = address_space_lookup_region(&address_space_memory, addr);
>  
>      if (!(memory_region_is_ram(section->mr) ||
>            memory_region_is_romd(section->mr))) {
> @@ -2255,7 +2252,7 @@ static inline uint64_t ldq_phys_internal(hwaddr addr,
>      uint64_t val;
>      MemoryRegionSection *section;
>  
> -    section = phys_page_find(address_space_memory.dispatch, addr >> TARGET_PAGE_BITS);
> +    section = address_space_lookup_region(&address_space_memory, addr);
>  
>      if (!(memory_region_is_ram(section->mr) ||
>            memory_region_is_romd(section->mr))) {
> @@ -2322,7 +2319,7 @@ static inline uint32_t lduw_phys_internal(hwaddr addr,
>      uint64_t val;
>      MemoryRegionSection *section;
>  
> -    section = phys_page_find(address_space_memory.dispatch, addr >> TARGET_PAGE_BITS);
> +    section = address_space_lookup_region(&address_space_memory, addr);
>  
>      if (!(memory_region_is_ram(section->mr) ||
>            memory_region_is_romd(section->mr))) {
> @@ -2381,7 +2378,7 @@ void stl_phys_notdirty(hwaddr addr, uint32_t val)
>      uint8_t *ptr;
>      MemoryRegionSection *section;
>  
> -    section = phys_page_find(address_space_memory.dispatch, addr >> TARGET_PAGE_BITS);
> +    section = address_space_lookup_region(&address_space_memory, addr);
>  
>      if (!memory_region_is_ram(section->mr) || section->readonly) {
>          addr = memory_region_section_addr(section, addr);
> @@ -2413,7 +2410,7 @@ void stq_phys_notdirty(hwaddr addr, uint64_t val)
>      uint8_t *ptr;
>      MemoryRegionSection *section;
>  
> -    section = phys_page_find(address_space_memory.dispatch, addr >> TARGET_PAGE_BITS);
> +    section = address_space_lookup_region(&address_space_memory, addr);
>  
>      if (!memory_region_is_ram(section->mr) || section->readonly) {
>          addr = memory_region_section_addr(section, addr);
> @@ -2442,7 +2439,7 @@ static inline void stl_phys_internal(hwaddr addr, uint32_t val,
>      uint8_t *ptr;
>      MemoryRegionSection *section;
>  
> -    section = phys_page_find(address_space_memory.dispatch, addr >> TARGET_PAGE_BITS);
> +    section = address_space_lookup_region(&address_space_memory, addr);
>  
>      if (!memory_region_is_ram(section->mr) || section->readonly) {
>          addr = memory_region_section_addr(section, addr);
> @@ -2509,7 +2506,7 @@ static inline void stw_phys_internal(hwaddr addr, uint32_t val,
>      uint8_t *ptr;
>      MemoryRegionSection *section;
>  
> -    section = phys_page_find(address_space_memory.dispatch, addr >> TARGET_PAGE_BITS);
> +    section = address_space_lookup_region(&address_space_memory, addr);
>  
>      if (!memory_region_is_ram(section->mr) || section->readonly) {
>          addr = memory_region_section_addr(section, addr);
> @@ -2634,8 +2631,7 @@ bool cpu_physical_memory_is_io(hwaddr phys_addr)
>  {
>      MemoryRegionSection *section;
>  
> -    section = phys_page_find(address_space_memory.dispatch,
> -                             phys_addr >> TARGET_PAGE_BITS);
> +    section = address_space_lookup_region(&address_space_memory, phys_addr);
>  
>      return !(memory_region_is_ram(section->mr) ||
>               memory_region_is_romd(section->mr));
> diff --git a/include/exec/cputlb.h b/include/exec/cputlb.h
> index 733c885..f144e6e 100644
> --- a/include/exec/cputlb.h
> +++ b/include/exec/cputlb.h
> @@ -26,8 +26,6 @@ void tlb_unprotect_code_phys(CPUArchState *env, ram_addr_t ram_addr,
>                               target_ulong vaddr);
>  void tlb_reset_dirty_range(CPUTLBEntry *tlb_entry, uintptr_t start,
>                             uintptr_t length);
> -MemoryRegionSection *phys_page_find(struct AddressSpaceDispatch *d,
> -                                    hwaddr index);
>  void cpu_tlb_reset_dirty_all(ram_addr_t start1, ram_addr_t length);
>  void tlb_set_dirty(CPUArchState *env, target_ulong vaddr);
>  extern int tlb_flush_count;
> diff --git a/include/exec/memory.h b/include/exec/memory.h
> index 9e88320..11ca4e2 100644
> --- a/include/exec/memory.h
> +++ b/include/exec/memory.h
> @@ -887,6 +887,15 @@ void *address_space_map(AddressSpace *as, hwaddr addr,
>  void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len,
>                           int is_write, hwaddr access_len);
>  
> +/**
> + * address_space_lookup_region: Looks up memory region corresponding to given
> + *                              access address
> + *
> + * @as: #AddressSpace to be accessed
> + * @addr: address within that address space
> + */
> +MemoryRegionSection *address_space_lookup_region(AddressSpace *as,
> +                                                 hwaddr addr);
>  
>  #endif
>  
> diff --git a/translate-all.c b/translate-all.c
> index da93608..078a657 100644
> --- a/translate-all.c
> +++ b/translate-all.c
> @@ -1356,8 +1356,7 @@ void tb_invalidate_phys_addr(hwaddr addr)
>      ram_addr_t ram_addr;
>      MemoryRegionSection *section;
>  
> -    section = phys_page_find(address_space_memory.dispatch,
> -                             addr >> TARGET_PAGE_BITS);
> +    section = address_space_lookup_region(&address_space_memory, addr);
>      if (!(memory_region_is_ram(section->mr)
>            || (section->mr->rom_device && section->mr->readable))) {
>          return;
>