[src/riastradh-drm2]: src/sys/external/bsd/drm2/drm Add drm_pci_alloc/drm_pci...

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/76d3db047d6b
branches:  riastradh-drm2
changeset: 788195:76d3db047d6b
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Wed Jul 24 02:39:25 2013 +0000

description:
Add drm_pci_alloc/drm_pci_free to local drm_memory.c.

Moved here from upstream's drm_pci.c because they don't actually
depend on anything of PCI; they just invoke the bus-independent
bus_dma abstraction.

diffstat:

 sys/external/bsd/drm2/drm/drm_memory.c |  122 ++++++++++++++++++++++++++++++++-
 1 files changed, 120 insertions(+), 2 deletions(-)

diffs (140 lines):

diff -r af0465165406 -r 76d3db047d6b sys/external/bsd/drm2/drm/drm_memory.c
--- a/sys/external/bsd/drm2/drm/drm_memory.c    Wed Jul 24 02:39:11 2013 +0000
+++ b/sys/external/bsd/drm2/drm/drm_memory.c    Wed Jul 24 02:39:25 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: drm_memory.c,v 1.1.2.1 2013/07/24 02:23:06 riastradh Exp $     */
+/*     $NetBSD: drm_memory.c,v 1.1.2.2 2013/07/24 02:39:25 riastradh Exp $     */
 
 /*-
  * Copyright (c) 2013 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: drm_memory.c,v 1.1.2.1 2013/07/24 02:23:06 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: drm_memory.c,v 1.1.2.2 2013/07/24 02:39:25 riastradh Exp $");
 
 /* XXX Cargo-culted from the old drm_memory.c.  */
 
@@ -216,3 +216,121 @@
                        bus_space_unmap(bst, bm->bm_bsh, bm->bm_size);
        }
 }
+
+/*
+ * Allocate a drm dma handle, allocate memory fit for DMA, and map it.
+ *
+ * XXX This is called drm_pci_alloc for hysterical raisins; it is not
+ * specific to PCI.
+ *
+ * XXX For now, we use non-blocking allocations because this is called
+ * by ioctls with the drm global mutex held.
+ *
+ * XXX Error information is lost because this returns NULL on failure,
+ * not even an error embedded in a pointer.
+ */
+struct drm_dma_handle *
+drm_pci_alloc(struct drm_device *dev, size_t size, size_t align)
+{
+       int nsegs;
+       int error;
+
+       /*
+        * Allocate a drm_dma_handle record.
+        *
+        * XXX Must use kzalloc because callers pass this to kfree, not
+        * necessarily to drm_pci_free.  Whattakludge.
+        */
+       struct drm_dma_handle *const dmah = kzalloc(sizeof(*dmah), GFP_ATOMIC);
+       if (dmah == NULL) {
+               error = -ENOMEM;
+               goto out;
+       }
+       dmah->dmah_tag = dev->dmat;
+
+       /*
+        * Allocate the requested amount of DMA-safe memory.
+        */
+       /* XXX errno NetBSD->Linux */
+       error = -bus_dmamem_alloc(dmah->dmah_tag, size, align, 0,
+           &dmah->dmah_seg, 1, &nsegs, BUS_DMA_NOWAIT);
+       if (error)
+               goto fail0;
+       KASSERT(nsegs == 1);
+
+       /*
+        * XXX Old drm passed BUS_DMA_NOWAIT below but BUS_DMA_WAITOK
+        * above.  WTF?
+        */
+
+       /*
+        * Map the DMA-safe memory into kernel virtual address space.
+        */
+       /* XXX errno NetBSD->Linux */
+       error = -bus_dmamem_map(dmah->dmah_tag, &dmah->dmah_seg, 1, size,
+           &dmah->vaddr,
+           (BUS_DMA_NOWAIT | BUS_DMA_COHERENT | BUS_DMA_NOCACHE));
+       if (error)
+               goto fail1;
+       dmah->size = size;
+
+       /*
+        * Create a map for DMA transfers.
+        */
+       /* XXX errno NetBSD->Linux */
+       error = -bus_dmamap_create(dmah->dmah_tag, size, 1, size, 0,
+           BUS_DMA_NOWAIT, &dmah->dmah_map);
+       if (error)
+               goto fail2;
+
+       /*
+        * Load the kva buffer into the map for DMA transfers.
+        */
+       /* XXX errno NetBSD->Linux */
+       error = -bus_dmamap_load(dmah->dmah_tag, dmah->dmah_map, dmah->vaddr,
+           size, NULL, (BUS_DMA_NOWAIT | BUS_DMA_NOCACHE));
+       if (error)
+               goto fail3;
+
+       /* Record the bus address for convenient reference.  */
+       dmah->busaddr = dmah->dmah_map->dm_segs[0].ds_addr;
+
+       /* Zero the DMA buffer.  XXX Yikes!  Is this necessary?  */
+       memset(dmah->vaddr, 0, size);
+
+       /* Success!  */
+       return dmah;
+
+fail3: bus_dmamap_destroy(dmah->dmah_tag, dmah->dmah_map);
+fail2: bus_dmamem_unmap(dmah->dmah_tag, dmah->vaddr, dmah->size);
+fail1: bus_dmamem_free(dmah->dmah_tag, &dmah->dmah_seg, 1);
+fail0: dmah->dmah_tag = NULL;  /* XXX paranoia */
+       kfree(dmah);
+out:   DRM_DEBUG("drm_pci_alloc failed: %d\n", error);
+       return NULL;
+}
+
+/*
+ * Release the bus DMA mappings and memory in dmah.
+ */
+void
+__drm_pci_free(struct drm_device *dev, struct drm_dma_handle *dmah)
+{
+
+       bus_dmamap_unload(dmah->dmah_tag, dmah->dmah_map);
+       bus_dmamap_destroy(dmah->dmah_tag, dmah->dmah_map);
+       bus_dmamem_unmap(dmah->dmah_tag, dmah->vaddr, dmah->size);
+       bus_dmamem_free(dmah->dmah_tag, &dmah->dmah_seg, 1);
+       dmah->dmah_tag = NULL;  /* XXX paranoia */
+}
+
+/*
+ * Release the bus DMA mappings and memory in dmah, and deallocate it.
+ */
+void
+drm_pci_free(struct drm_device *dev, struct drm_dma_handle *dmah)
+{
+
+       __drm_pci_free(dev, dmah);
+       kfree(dmah);
+}