Commit a203ac70 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

memory: extract first iteration of address_space_read and address_space_write 



We want to inline the case where there is only one iteration, because
then the compiler can also inline the memcpy.  As a start, extract
everything after the first address_space_translate call.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent eb7eeb88

exec.c

+65 −20
Original line number Diff line number Diff line
@@ -2468,22 +2468,19 @@ static bool prepare_mmio_access(MemoryRegion *mr) 
    return release_lock;

}



MemTxResult address_space_write(AddressSpace *as, hwaddr addr, MemTxAttrs attrs,

                                const uint8_t *buf, int len)

/* Called within RCU critical section.  */

static MemTxResult address_space_write_continue(AddressSpace *as, hwaddr addr,

                                                MemTxAttrs attrs,

                                                const uint8_t *buf,

                                                int len, hwaddr addr1,

                                                hwaddr l, MemoryRegion *mr)

{

    hwaddr l;

    uint8_t *ptr;

    uint64_t val;

    hwaddr addr1;

    MemoryRegion *mr;

    MemTxResult result = MEMTX_OK;

    bool release_lock = false;



    rcu_read_lock();

    while (len > 0) {

        l = len;

        mr = address_space_translate(as, addr, &addr1, &l, true);



    for (;;) {

        if (!memory_access_is_direct(mr, true)) {

            release_lock |= prepare_mmio_access(mr);

            l = memory_access_size(mr, l, addr1);
@@ -2533,28 +2530,50 @@ MemTxResult address_space_write(AddressSpace *as, hwaddr addr, MemTxAttrs attrs, 
        len -= l;

        buf += l;

        addr += l;



        if (!len) {

            break;

        }



        l = len;

        mr = address_space_translate(as, addr, &addr1, &l, true);

    }

    rcu_read_unlock();



    return result;

}



MemTxResult address_space_read(AddressSpace *as, hwaddr addr, MemTxAttrs attrs,

                               uint8_t *buf, int len)

MemTxResult address_space_write(AddressSpace *as, hwaddr addr, MemTxAttrs attrs,

                                const uint8_t *buf, int len)

{

    hwaddr l;

    uint8_t *ptr;

    uint64_t val;

    hwaddr addr1;

    MemoryRegion *mr;

    MemTxResult result = MEMTX_OK;

    bool release_lock = false;



    if (len > 0) {

        rcu_read_lock();

    while (len > 0) {

        l = len;

        mr = address_space_translate(as, addr, &addr1, &l, false);

        mr = address_space_translate(as, addr, &addr1, &l, true);

        result = address_space_write_continue(as, addr, attrs, buf, len,

                                              addr1, l, mr);

        rcu_read_unlock();

    }



    return result;

}



/* Called within RCU critical section.  */

MemTxResult address_space_read_continue(AddressSpace *as, hwaddr addr,

                                        MemTxAttrs attrs, uint8_t *buf,

                                        int len, hwaddr addr1, hwaddr l,

                                        MemoryRegion *mr)

{

    uint8_t *ptr;

    uint64_t val;

    MemTxResult result = MEMTX_OK;

    bool release_lock = false;



    for (;;) {

        if (!memory_access_is_direct(mr, false)) {

            /* I/O case */

            release_lock |= prepare_mmio_access(mr);
@@ -2601,8 +2620,34 @@ MemTxResult address_space_read(AddressSpace *as, hwaddr addr, MemTxAttrs attrs, 
        len -= l;

        buf += l;

        addr += l;



        if (!len) {

            break;

        }



        l = len;

        mr = address_space_translate(as, addr, &addr1, &l, false);

    }



    return result;

}



MemTxResult address_space_read(AddressSpace *as, hwaddr addr, MemTxAttrs attrs,

                               uint8_t *buf, int len)

{

    hwaddr l;

    hwaddr addr1;

    MemoryRegion *mr;

    MemTxResult result = MEMTX_OK;



    if (len > 0) {

        rcu_read_lock();

        l = len;

        mr = address_space_translate(as, addr, &addr1, &l, false);

        result = address_space_read_continue(as, addr, attrs, buf, len,

                                             addr1, l, mr);

        rcu_read_unlock();

    }



    return result;

}

include/exec/memory.h

+6 −0
Original line number Diff line number Diff line
@@ -1366,6 +1366,12 @@ void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len, 
                         int is_write, hwaddr access_len);





/* Internal functions, part of the implementation of address_space_read.  */

MemTxResult address_space_read_continue(AddressSpace *as, hwaddr addr,

                                        MemTxAttrs attrs, uint8_t *buf,

                                        int len, hwaddr addr1, hwaddr l,

					MemoryRegion *mr);



#endif



#endif