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authorHanweidong <hanweidong@huawei.com>2013-04-02 13:22:41 +0000
committerStefano Stabellini <stefano.stabellini@eu.citrix.com>2013-04-03 11:51:53 +0000
commit044d4e1aae539bd4214175bd9591b3de7986cf18 (patch)
treeff7de919a19b2b71cccde39389bc881a31129bc7 /xen-mapcache.c
parente2deee3ea6136b6189e8cfd26379420b9a398d96 (diff)
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xen-mapcache: pass the right size argument to test_bits
Compute the correct size for test_bits(). qemu_get_ram_ptr() and qemu_safe_ram_ptr() will call xen_map_cache() with size is 0 if the requested address is in the RAM. Then xen_map_cache() will pass the size 0 to test_bits() for checking if the corresponding pfn was mapped in cache. But test_bits() will always return 1 when size is 0 without any bit testing. Actually, for this case, test_bits should check one bit. So this patch introduced a __test_bit_size which is greater than 0 and a multiple of XC_PAGE_SIZE, then test_bits can work correctly with __test_bit_size >> XC_PAGE_SHIFT as its size. Signed-off-by: Zhenguo Wang <wangzhenguo@huawei.com> Signed-off-by: Weidong Han <hanweidong@huawei.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Diffstat (limited to 'xen-mapcache.c')
-rw-r--r--xen-mapcache.c26
1 files changed, 22 insertions, 4 deletions
diff --git a/xen-mapcache.c b/xen-mapcache.c
index a80cbdb..5a626cd 100644
--- a/xen-mapcache.c
+++ b/xen-mapcache.c
@@ -200,6 +200,7 @@ uint8_t *xen_map_cache(hwaddr phys_addr, hwaddr size,
hwaddr address_index;
hwaddr address_offset;
hwaddr __size = size;
+ hwaddr __test_bit_size = size;
bool translated = false;
tryagain:
@@ -208,9 +209,23 @@ tryagain:
trace_xen_map_cache(phys_addr);
+ /* __test_bit_size is always a multiple of XC_PAGE_SIZE */
+ if (size) {
+ __test_bit_size = size + (phys_addr & (XC_PAGE_SIZE - 1));
+
+ if (__test_bit_size % XC_PAGE_SIZE) {
+ __test_bit_size += XC_PAGE_SIZE - (__test_bit_size % XC_PAGE_SIZE);
+ }
+ } else {
+ __test_bit_size = XC_PAGE_SIZE;
+ }
+
if (mapcache->last_entry != NULL &&
mapcache->last_entry->paddr_index == address_index &&
- !lock && !__size) {
+ !lock && !__size &&
+ test_bits(address_offset >> XC_PAGE_SHIFT,
+ __test_bit_size >> XC_PAGE_SHIFT,
+ mapcache->last_entry->valid_mapping)) {
trace_xen_map_cache_return(mapcache->last_entry->vaddr_base + address_offset);
return mapcache->last_entry->vaddr_base + address_offset;
}
@@ -229,7 +244,8 @@ tryagain:
while (entry && entry->lock && entry->vaddr_base &&
(entry->paddr_index != address_index || entry->size != __size ||
- !test_bits(address_offset >> XC_PAGE_SHIFT, size >> XC_PAGE_SHIFT,
+ !test_bits(address_offset >> XC_PAGE_SHIFT,
+ __test_bit_size >> XC_PAGE_SHIFT,
entry->valid_mapping))) {
pentry = entry;
entry = entry->next;
@@ -241,13 +257,15 @@ tryagain:
} else if (!entry->lock) {
if (!entry->vaddr_base || entry->paddr_index != address_index ||
entry->size != __size ||
- !test_bits(address_offset >> XC_PAGE_SHIFT, size >> XC_PAGE_SHIFT,
+ !test_bits(address_offset >> XC_PAGE_SHIFT,
+ __test_bit_size >> XC_PAGE_SHIFT,
entry->valid_mapping)) {
xen_remap_bucket(entry, __size, address_index);
}
}
- if(!test_bits(address_offset >> XC_PAGE_SHIFT, size >> XC_PAGE_SHIFT,
+ if(!test_bits(address_offset >> XC_PAGE_SHIFT,
+ __test_bit_size >> XC_PAGE_SHIFT,
entry->valid_mapping)) {
mapcache->last_entry = NULL;
if (!translated && mapcache->phys_offset_to_gaddr) {