landisk: bus_dma.c cleanup

[Tobias Ulmer]

Found while debugging cache problems on landisk

Remove mapstore and error, remnants of code logic long gone.
DMAMAP_RESET is only used on landisk, disrupts readability and the one
line saved per use doesn't really justify its existence to me

--- a/sys/arch/landisk/landisk/bus_dma.c
+++ b/sys/arch/landisk/landisk/bus_dma.c
@@ -67,11 +67,6 @@ struct _bus_dma_tag landisk_bus_dma = {
        ._dmamem_mmap = _bus_dmamem_mmap,
 };
 
-#define DMAMAP_RESET(_m) do { \
-       (_m)->dm_mapsize = 0; \
-       (_m)->dm_nsegs = 0; \
-} while (0)
-
 int    _bus_dmamap_load_vaddr(bus_dma_tag_t, bus_dmamap_t,
            void *, bus_size_t, pmap_t);
 int    _bus_dmamap_load_paddr(bus_dma_tag_t, bus_dmamap_t,
@@ -85,9 +80,7 @@ _bus_dmamap_create(bus_dma_tag_t t, bus_size_t size, int 
nsegments,
     bus_size_t maxsegsz, bus_size_t boundary, int flags, bus_dmamap_t *dmamp)
 {
        bus_dmamap_t map;
-       void *mapstore;
        size_t mapsize;
-       int error;
 
        DPRINTF(("bus_dmamap_create: t = %p, size = %ld, nsegments = %d, 
maxsegsz = %ld, boundary = %ld, flags = %x\n", t, size, nsegments, maxsegsz, 
boundary, flags));
 
@@ -103,23 +96,21 @@ _bus_dmamap_create(bus_dma_tag_t t, bus_size_t size, int 
nsegments,
         * The bus_dmamap_t includes one bus_dma_segment_t, hence
         * the (nsegments - 1).
         */
-       error = 0;
        mapsize = sizeof(struct _bus_dmamap) +
            (sizeof(bus_dma_segment_t) * (nsegments - 1));
-       if ((mapstore = malloc(mapsize, M_DEVBUF, (flags & BUS_DMA_NOWAIT) ?
+       if ((map = malloc(mapsize, M_DEVBUF, (flags & BUS_DMA_NOWAIT) ?
            (M_NOWAIT | M_ZERO) : (M_WAITOK | M_ZERO))) == NULL)
                return (ENOMEM);
 
-       DPRINTF(("bus_dmamap_create: dmamp = %p\n", mapstore));
+       DPRINTF(("bus_dmamap_create: dmamp = %p\n", map));
 
-       map = (bus_dmamap_t)mapstore;
        map->_dm_size = size;
        map->_dm_segcnt = nsegments;
        map->_dm_maxsegsz = maxsegsz;
        map->_dm_boundary = boundary;
        map->_dm_flags = flags & ~(BUS_DMA_WAITOK|BUS_DMA_NOWAIT);
-
-       DMAMAP_RESET(map); /* no valid mappings */
+       map->dm_mapsize = 0;    /* no valid mappings */
+       map->dm_nsegs = 0;
 
        *dmamp = map;
 
@@ -245,7 +236,8 @@ _bus_dmamap_load(bus_dma_tag_t t, bus_dmamap_t map, void 
*buf,
 
        DPRINTF(("bus_dmamap_load: t = %p, map = %p, buf = %p, buflen = %ld, p 
= %p, flags = %x\n", t, map, buf, buflen, p, flags));
 
-       DMAMAP_RESET(map);
+       map->dm_mapsize = 0;
+       map->dm_nsegs = 0;
 
        if (buflen > map->_dm_size)
                return (EINVAL);
@@ -253,7 +245,8 @@ _bus_dmamap_load(bus_dma_tag_t t, bus_dmamap_t map, void 
*buf,
        error = _bus_dmamap_load_vaddr(t, map, buf, buflen,
            p == NULL ? pmap_kernel() : p->p_vmspace->vm_map.pmap);
        if (error != 0) {
-               DMAMAP_RESET(map); /* no valid mappings */
+               map->dm_mapsize = 0; /* no valid mappings */
+               map->dm_nsegs = 0;
                return (error);
        }
 
@@ -272,7 +265,8 @@ _bus_dmamap_load_mbuf(bus_dma_tag_t t, bus_dmamap_t map, 
struct mbuf *m0,
        struct mbuf *m;
        int error;
 
-       DMAMAP_RESET(map);
+       map->dm_mapsize = 0;
+       map->dm_nsegs = 0;
 
 #ifdef DIAGNOSTIC
        if ((m0->m_flags & M_PKTHDR) == 0)
@@ -289,7 +283,8 @@ _bus_dmamap_load_mbuf(bus_dma_tag_t t, bus_dmamap_t map, 
struct mbuf *m0,
                error = _bus_dmamap_load_vaddr(t, map, m->m_data, m->m_len,
                    pmap_kernel());
                if (error != 0) {
-                       DMAMAP_RESET(map);
+                       map->dm_mapsize = 0;
+                       map->dm_nsegs = 0;
                        return (error);
                }
        }