On Wed, 14 Jan 2015, Paolo Bonzini wrote:
> Extend the existing dummy mapcache_lock/unlock macros to cover all of
> xen-mapcache.c. This prepares for unlocked memory access, when parts
> of exec.c will not be protected by the BQL.
>
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
Acked-by: Stefano Stabellini <stefano.stabell...@eu.citrix.com>
> xen-mapcache.c | 54 +++++++++++++++++++++++++++++++++++++++++++-----------
> 1 file changed, 43 insertions(+), 11 deletions(-)
>
> diff --git a/xen-mapcache.c b/xen-mapcache.c
> index 458069b..8cefd0c 100644
> --- a/xen-mapcache.c
> +++ b/xen-mapcache.c
> @@ -49,9 +49,6 @@
> */
> #define NON_MCACHE_MEMORY_SIZE (80 * 1024 * 1024)
>
> -#define mapcache_lock() ((void)0)
> -#define mapcache_unlock() ((void)0)
> -
> typedef struct MapCacheEntry {
> hwaddr paddr_index;
> uint8_t *vaddr_base;
> @@ -79,11 +76,22 @@ typedef struct MapCache {
> unsigned int mcache_bucket_shift;
>
> phys_offset_to_gaddr_t phys_offset_to_gaddr;
> + QemuMutex lock;
> void *opaque;
> } MapCache;
>
> static MapCache *mapcache;
>
> +static inline void mapcache_lock(void)
> +{
> + qemu_mutex_lock(&mapcache->lock);
> +}
> +
> +static inline void mapcache_unlock(void)
> +{
> + qemu_mutex_unlock(&mapcache->lock);
> +}
> +
> static inline int test_bits(int nr, int size, const unsigned long *addr)
> {
> unsigned long res = find_next_zero_bit(addr, size + nr, nr);
> @@ -102,6 +110,7 @@ void xen_map_cache_init(phys_offset_to_gaddr_t f, void
> *opaque)
>
> mapcache->phys_offset_to_gaddr = f;
> mapcache->opaque = opaque;
> + qemu_mutex_init(&mapcache->lock);
>
> QTAILQ_INIT(&mapcache->locked_entries);
>
> @@ -193,8 +202,8 @@ static void xen_remap_bucket(MapCacheEntry *entry,
> g_free(err);
> }
>
> -uint8_t *xen_map_cache(hwaddr phys_addr, hwaddr size,
> - uint8_t lock)
> +static uint8_t *xen_map_cache_unlocked(hwaddr phys_addr, hwaddr size,
> + uint8_t lock)
> {
> MapCacheEntry *entry, *pentry = NULL;
> hwaddr address_index;
> @@ -291,14 +300,27 @@ tryagain:
> return mapcache->last_entry->vaddr_base + address_offset;
> }
>
> +uint8_t *xen_map_cache(hwaddr phys_addr, hwaddr size,
> + uint8_t lock)
> +{
> + uint8_t *p;
> +
> + mapcache_lock();
> + p = xen_map_cache_unlocked(phys_addr, size, lock);
> + mapcache_unlock();
> + return p;
> +}
> +
> ram_addr_t xen_ram_addr_from_mapcache(void *ptr)
> {
> MapCacheEntry *entry = NULL;
> MapCacheRev *reventry;
> hwaddr paddr_index;
> hwaddr size;
> + ram_addr_t raddr;
> int found = 0;
>
> + mapcache_lock();
> QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) {
> if (reventry->vaddr_req == ptr) {
> paddr_index = reventry->paddr_index;
> @@ -323,13 +345,16 @@ ram_addr_t xen_ram_addr_from_mapcache(void *ptr)
> }
> if (!entry) {
> DPRINTF("Trying to find address %p that is not in the mapcache!\n",
> ptr);
> - return 0;
> + raddr = 0;
> + } else {
> + raddr = (reventry->paddr_index << MCACHE_BUCKET_SHIFT) +
> + ((unsigned long) ptr - (unsigned long) entry->vaddr_base);
> }
> - return (reventry->paddr_index << MCACHE_BUCKET_SHIFT) +
> - ((unsigned long) ptr - (unsigned long) entry->vaddr_base);
> + mapcache_unlock();
> + return raddr;
> }
>
> -void xen_invalidate_map_cache_entry(uint8_t *buffer)
> +static void xen_invalidate_map_cache_entry_unlocked(uint8_t *buffer)
> {
> MapCacheEntry *entry = NULL, *pentry = NULL;
> MapCacheRev *reventry;
> @@ -383,6 +408,13 @@ void xen_invalidate_map_cache_entry(uint8_t *buffer)
> g_free(entry);
> }
>
> +void xen_invalidate_map_cache_entry(uint8_t *buffer)
> +{
> + mapcache_lock();
> + xen_invalidate_map_cache_entry_unlocked(buffer);
> + mapcache_unlock();
> +}
> +
> void xen_invalidate_map_cache(void)
> {
> unsigned long i;
> @@ -391,14 +423,14 @@ void xen_invalidate_map_cache(void)
> /* Flush pending AIO before destroying the mapcache */
> bdrv_drain_all();
>
> + mapcache_lock();
> +
> QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) {
> DPRINTF("There should be no locked mappings at this time, "
> "but "TARGET_FMT_plx" -> %p is present\n",
> reventry->paddr_index, reventry->vaddr_req);
> }
>
> - mapcache_lock();
> -
> for (i = 0; i < mapcache->nr_buckets; i++) {
> MapCacheEntry *entry = &mapcache->entry[i];
>
> --
> 1.8.3.1
>
