Program window #2 to allow the second GB of low memory to use direct DMA;

adapted from a long gone FreeBSD.

diff --git a/sys/arch/alpha/pci/tsp_dma.c b/sys/arch/alpha/pci/tsp_dma.c
index e56f6b1..403a2df 100644 (file)
--- a/sys/arch/alpha/pci/tsp_dma.c
+++ b/sys/arch/alpha/pci/tsp_dma.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tsp_dma.c,v 1.8 2009/10/02 18:01:47 miod Exp $ */
+/* $OpenBSD: tsp_dma.c,v 1.9 2014/01/06 20:11:40 miod Exp $ */
 /* $NetBSD: tsp_dma.c,v 1.1 1999/06/29 06:46:47 ross Exp $ */
 
 /*-
@@ -105,37 +105,50 @@ tsp_dma_init(struct device *tsp, struct tsp_config *pcp)
        bus_dma_tag_t t;
        struct ts_pchip *pccsr = pcp->pc_csr;
        bus_addr_t dwbase, dwlen, sgwbase, sgwlen, tbase;
-       static struct map_expected {
-               u_int32_t base, mask, enables;
+       static const struct map_expected {
+               u_int32_t base, mask, physbase, enables;
        } premap[4] = {
-               { 0x00800000, 0x00700000, WSBA_ENA | WSBA_SG },
-               { 0x80000000, 0x3ff00000, WSBA_ENA           },
-               { 0, 0, 0 },
+               /* 0-8MB at 8MB with S/G DMA (isa space) */
+               { 0x00800000, 0x00700000, 0x00000000, WSBA_ENA | WSBA_SG },
+               /* 0-1GB at 2GB direct */
+               { 0x80000000, 0x3ff00000, 0x00000000, WSBA_ENA           },
+               /* 1-2GB at 3GB direct */
+               { 0xC0000000, 0x3ff00000, 0x40000000, WSBA_ENA           },
                { 0, 0, 0 }
        };
 
        alpha_mb();
        for(i = 0; i < 4; ++i) {
+#ifdef DEBUG
                if (EDIFF(pccsr->tsp_wsba[i].tsg_r, premap[i].base) ||
-                   EDIFF(pccsr->tsp_wsm[i].tsg_r, premap[i].mask))
+                   EDIFF(pccsr->tsp_wsm[i].tsg_r, premap[i].mask) ||
+                   ((premap[i].enables & WSBA_SG) == 0 &&
+                     pccsr->tsp_tba[i].tsg_r != premap[i].physbase))
                        printf("%s: window %d: %lx/base %lx/mask %lx"
                            " reinitialized\n",
                            tsp->dv_xname, i,
                            pccsr->tsp_wsba[i].tsg_r,
                            pccsr->tsp_wsm[i].tsg_r,
                            pccsr->tsp_tba[i].tsg_r);
+#endif
                pccsr->tsp_wsba[i].tsg_r = premap[i].base | premap[i].enables;
                pccsr->tsp_wsm[i].tsg_r = premap[i].mask;
+               if ((premap[i].enables & WSBA_SG) == 0)
+                       pccsr->tsp_tba[i].tsg_r = premap[i].physbase;
        }
        alpha_mb();
 
        /*
-        * Initialize the DMA tag used for direct-mapped DMA.
+        * Initialize the DMA tags used for direct-mapped DMA.
         */
        t = &pcp->pc_dmat_direct;
        t->_cookie = pcp;
        t->_wbase = dwbase = WSBA_ADDR(pccsr->tsp_wsba[1].tsg_r);
-       t->_wsize = dwlen = WSM_LEN(pccsr->tsp_wsm[1].tsg_r);
+       t->_wsize = dwlen = WSM_LEN(pccsr->tsp_wsm[1].tsg_r) +
+           WSM_LEN(pccsr->tsp_wsm[2].tsg_r);
+       KDASSERT(WSBA_ADDR(pccsr->tsp_wsba[2].tsg_r) ==
+           WSBA_ADDR(pccsr->tsp_wsba[1].tsg_r) +
+           WSM_LEN(pccsr->tsp_wsm[1].tsg_r));
        t->_next_window = &pcp->pc_dmat_sgmap;
        t->_boundary = 0;
        t->_sgmap = NULL;
@@ -188,21 +201,6 @@ tsp_dma_init(struct device *tsp, struct tsp_config *pcp)
        alpha_sgmap_init(t, &pcp->pc_sgmap, "tsp_sgmap",
            sgwbase, 0, sgwlen, sizeof(u_int64_t), NULL, (32*1024));
 
-       /*
-        * Enable window 0 and enable SG PTE mapping.
-        */
-       alpha_mb();
-       pccsr->tsp_wsba[0].tsg_r |= WSBA_SG | WSBA_ENA;
-       alpha_mb();
-
-       /*
-        * Enable window 1 in direct mode.
-        */
-       alpha_mb();
-       pccsr->tsp_wsba[1].tsg_r =
-           (pccsr->tsp_wsba[1].tsg_r & ~WSBA_SG) | WSBA_ENA;
-       alpha_mb();
-
        /*
         * Check windows for sanity, especially if we later decide to
         * use the firmware's initialization in some cases.