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physmem: Factor out body of flatview_read/write_continue() loop
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This code will be reused for the address_space_cached accessors
shortly.

Also reduce scope of result variable now we aren't directly
calling this in the loop.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20240307153710.30907-4-Jonathan.Cameron@huawei.com
Signed-off-by: Peter Xu <peterx@redhat.com>
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@jic23 @xzpeter
jic23 authored and xzpeter committed Mar 11, 2024
1 parent bcfd8ba commit e7927d3
Showing 1 changed file with 99 additions and 70 deletions.
169 changes: 99 additions & 70 deletions system/physmem.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2681,6 +2681,56 @@ static bool flatview_access_allowed(MemoryRegion *mr, MemTxAttrs attrs,
return false;
}

static MemTxResult flatview_write_continue_step(MemTxAttrs attrs,
const uint8_t *buf,
hwaddr len, hwaddr mr_addr,
hwaddr *l, MemoryRegion *mr)
{
if (!flatview_access_allowed(mr, attrs, mr_addr, *l)) {
return MEMTX_ACCESS_ERROR;
}

if (!memory_access_is_direct(mr, true)) {
uint64_t val;
MemTxResult result;
bool release_lock = prepare_mmio_access(mr);

*l = memory_access_size(mr, *l, mr_addr);
/*
* XXX: could force current_cpu to NULL to avoid
* potential bugs
*/

/*
* Assure Coverity (and ourselves) that we are not going to OVERRUN
* the buffer by following ldn_he_p().
*/
#ifdef QEMU_STATIC_ANALYSIS
assert((*l == 1 && len >= 1) ||
(*l == 2 && len >= 2) ||
(*l == 4 && len >= 4) ||
(*l == 8 && len >= 8));
#endif
val = ldn_he_p(buf, *l);
result = memory_region_dispatch_write(mr, mr_addr, val,
size_memop(*l), attrs);
if (release_lock) {
bql_unlock();
}

return result;
} else {
/* RAM case */
uint8_t *ram_ptr = qemu_ram_ptr_length(mr->ram_block, mr_addr, l,
false);

memmove(ram_ptr, buf, *l);
invalidate_and_set_dirty(mr, mr_addr, *l);

return MEMTX_OK;
}
}

/* Called within RCU critical section. */
static MemTxResult flatview_write_continue(FlatView *fv, hwaddr addr,
MemTxAttrs attrs,
Expand All @@ -2692,44 +2742,8 @@ static MemTxResult flatview_write_continue(FlatView *fv, hwaddr addr,
const uint8_t *buf = ptr;

for (;;) {
if (!flatview_access_allowed(mr, attrs, mr_addr, l)) {
result |= MEMTX_ACCESS_ERROR;
/* Keep going. */
} else if (!memory_access_is_direct(mr, true)) {
uint64_t val;
bool release_lock = prepare_mmio_access(mr);

l = memory_access_size(mr, l, mr_addr);
/* XXX: could force current_cpu to NULL to avoid
potential bugs */

/*
* Assure Coverity (and ourselves) that we are not going to OVERRUN
* the buffer by following ldn_he_p().
*/
#ifdef QEMU_STATIC_ANALYSIS
assert((l == 1 && len >= 1) ||
(l == 2 && len >= 2) ||
(l == 4 && len >= 4) ||
(l == 8 && len >= 8));
#endif
val = ldn_he_p(buf, l);
result |= memory_region_dispatch_write(mr, mr_addr, val,
size_memop(l), attrs);
if (release_lock) {
bql_unlock();
}


} else {
/* RAM case */

uint8_t *ram_ptr = qemu_ram_ptr_length(mr->ram_block, mr_addr, &l,
false);

memmove(ram_ptr, buf, l);
invalidate_and_set_dirty(mr, mr_addr, l);
}
result |= flatview_write_continue_step(attrs, buf, len, mr_addr, &l,
mr);

len -= l;
buf += l;
Expand Down Expand Up @@ -2763,6 +2777,52 @@ static MemTxResult flatview_write(FlatView *fv, hwaddr addr, MemTxAttrs attrs,
mr_addr, l, mr);
}

static MemTxResult flatview_read_continue_step(MemTxAttrs attrs, uint8_t *buf,
hwaddr len, hwaddr mr_addr,
hwaddr *l,
MemoryRegion *mr)
{
if (!flatview_access_allowed(mr, attrs, mr_addr, *l)) {
return MEMTX_ACCESS_ERROR;
}

if (!memory_access_is_direct(mr, false)) {
/* I/O case */
uint64_t val;
MemTxResult result;
bool release_lock = prepare_mmio_access(mr);

*l = memory_access_size(mr, *l, mr_addr);
result = memory_region_dispatch_read(mr, mr_addr, &val, size_memop(*l),
attrs);

/*
* Assure Coverity (and ourselves) that we are not going to OVERRUN
* the buffer by following stn_he_p().
*/
#ifdef QEMU_STATIC_ANALYSIS
assert((*l == 1 && len >= 1) ||
(*l == 2 && len >= 2) ||
(*l == 4 && len >= 4) ||
(*l == 8 && len >= 8));
#endif
stn_he_p(buf, *l, val);

if (release_lock) {
bql_unlock();
}
return result;
} else {
/* RAM case */
uint8_t *ram_ptr = qemu_ram_ptr_length(mr->ram_block, mr_addr, l,
false);

memcpy(buf, ram_ptr, *l);

return MEMTX_OK;
}
}

/* Called within RCU critical section. */
MemTxResult flatview_read_continue(FlatView *fv, hwaddr addr,
MemTxAttrs attrs, void *ptr,
Expand All @@ -2774,38 +2834,7 @@ MemTxResult flatview_read_continue(FlatView *fv, hwaddr addr,

fuzz_dma_read_cb(addr, len, mr);
for (;;) {
if (!flatview_access_allowed(mr, attrs, mr_addr, l)) {
result |= MEMTX_ACCESS_ERROR;
/* Keep going. */
} else if (!memory_access_is_direct(mr, false)) {
/* I/O case */
uint64_t val;
bool release_lock = prepare_mmio_access(mr);

l = memory_access_size(mr, l, mr_addr);
result |= memory_region_dispatch_read(mr, mr_addr, &val,
size_memop(l), attrs);

/*
* Assure Coverity (and ourselves) that we are not going to OVERRUN
* the buffer by following stn_he_p().
*/
#ifdef QEMU_STATIC_ANALYSIS
assert((l == 1 && len >= 1) ||
(l == 2 && len >= 2) ||
(l == 4 && len >= 4) ||
(l == 8 && len >= 8));
#endif
stn_he_p(buf, l, val);
if (release_lock) {
bql_unlock();
}
} else {
/* RAM case */
uint8_t *ram_ptr = qemu_ram_ptr_length(mr->ram_block, mr_addr, &l,
false);
memcpy(buf, ram_ptr, l);
}
result |= flatview_read_continue_step(attrs, buf, len, mr_addr, &l, mr);

len -= l;
buf += l;
Expand Down

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