Add a DRM GEM CMA helper from NetBSD. Plenty of parts are still

under ifdef for us, so for now we don't support SG tables or the
GEM CMA ops, but at least it lets us create a simple framebuffer.

ok kettenis@

2 files changed, 323 insertions, 0 deletions

diff --git a/sys/dev/pci/drm/drm_gem_cma_helper.c b/sys/dev/pci/drm/drm_gem_cma_helper.c
new file mode 100644
index 00000000000..30bf992d263
--- /dev/null
+++ b/sys/dev/pci/drm/drm_gem_cma_helper.c
@@ -0,0 +1,297 @@
+/* $OpenBSD: drm_gem_cma_helper.c,v 1.1 2020/02/21 15:42:36 patrick Exp $ */
+/* $NetBSD: drm_gem_cma_helper.c,v 1.9 2019/11/05 23:29:28 jmcneill Exp $ */
+/*-
+ * Copyright (c) 2015-2017 Jared McNeill <jmcneill@invisible.ca>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/param.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_gem_cma_helper.h>
+
+#include <uvm/uvm.h>
+
+static struct drm_gem_cma_object *
+drm_gem_cma_create_internal(struct drm_device *ddev, size_t size,
+    struct sg_table *sgt)
+{
+	struct drm_gem_cma_object *obj;
+	int error, nsegs;
+
+	obj = malloc(sizeof(*obj), M_DRM, M_WAITOK | M_ZERO);
+	obj->dmat = ddev->dmat;
+	obj->dmasize = size;
+
+	if (sgt) {
+#ifdef notyet
+		error = -drm_prime_sg_to_bus_dmamem(obj->dmat, obj->dmasegs, 1,
+		    &nsegs, sgt);
+#endif
+		error = -ENOMEM;
+	} else {
+		error = bus_dmamem_alloc(obj->dmat, obj->dmasize,
+		    PAGE_SIZE, 0, obj->dmasegs, 1, &nsegs,
+		    BUS_DMA_WAITOK);
+	}
+	if (error)
+		goto failed;
+	error = bus_dmamem_map(obj->dmat, obj->dmasegs, nsegs,
+	    obj->dmasize, &obj->vaddr,
+	    BUS_DMA_WAITOK | BUS_DMA_NOCACHE);
+	if (error)
+		goto free;
+	error = bus_dmamap_create(obj->dmat, obj->dmasize, 1,
+	    obj->dmasize, 0, BUS_DMA_WAITOK, &obj->dmamap);
+	if (error)
+		goto unmap;
+	error = bus_dmamap_load(obj->dmat, obj->dmamap, obj->vaddr,
+	    obj->dmasize, NULL, BUS_DMA_WAITOK);
+	if (error)
+		goto destroy;
+
+#ifdef notyet
+	if (!sgt)
+#endif
+		memset(obj->vaddr, 0, obj->dmasize);
+
+	drm_gem_private_object_init(ddev, &obj->base, size);
+
+	return obj;
+
+destroy:
+	bus_dmamap_destroy(obj->dmat, obj->dmamap);
+unmap:
+	bus_dmamem_unmap(obj->dmat, obj->vaddr, obj->dmasize);
+free:
+#ifdef notyet
+	if (obj->sgt)
+		drm_prime_sg_free(obj->sgt);
+	else
+#endif
+		bus_dmamem_free(obj->dmat, obj->dmasegs, nsegs);
+failed:
+	free(obj, M_DRM, sizeof(*obj));
+
+	return NULL;
+}
+
+struct drm_gem_cma_object *
+drm_gem_cma_create(struct drm_device *ddev, size_t size)
+{
+
+	return drm_gem_cma_create_internal(ddev, size, NULL);
+}
+
+static void
+drm_gem_cma_obj_free(struct drm_gem_cma_object *obj)
+{
+
+	bus_dmamap_unload(obj->dmat, obj->dmamap);
+	bus_dmamap_destroy(obj->dmat, obj->dmamap);
+	bus_dmamem_unmap(obj->dmat, obj->vaddr, obj->dmasize);
+#ifdef notyet
+	if (obj->sgt)
+		drm_prime_sg_free(obj->sgt);
+	else
+#endif
+		bus_dmamem_free(obj->dmat, obj->dmasegs, 1);
+	free(obj, M_DRM, sizeof(*obj));
+}
+
+void
+drm_gem_cma_free_object(struct drm_gem_object *gem_obj)
+{
+	struct drm_gem_cma_object *obj = to_drm_gem_cma_obj(gem_obj);
+
+	drm_gem_free_mmap_offset(gem_obj);
+	drm_gem_object_release(gem_obj);
+	drm_gem_cma_obj_free(obj);
+}
+
+int
+drm_gem_cma_dumb_create(struct drm_file *file_priv, struct drm_device *ddev,
+    struct drm_mode_create_dumb *args)
+{
+	struct drm_gem_cma_object *obj;
+	uint32_t handle;
+	int error;
+
+	args->pitch = args->width * ((args->bpp + 7) / 8);
+	args->size = args->pitch * args->height;
+	args->size = roundup(args->size, PAGE_SIZE);
+	args->handle = 0;
+
+	obj = drm_gem_cma_create(ddev, args->size);
+	if (obj == NULL)
+		return -ENOMEM;
+
+	error = drm_gem_handle_create(file_priv, &obj->base, &handle);
+	drm_gem_object_unreference_unlocked(&obj->base);
+	if (error) {
+		drm_gem_cma_obj_free(obj);
+		return error;
+	}
+
+	args->handle = handle;
+
+	return 0;
+}
+
+int
+drm_gem_cma_dumb_map_offset(struct drm_file *file_priv, struct drm_device *ddev,
+    uint32_t handle, uint64_t *offset)
+{
+	struct drm_gem_object *gem_obj;
+	struct drm_gem_cma_object *obj;
+	int error;
+
+	gem_obj = drm_gem_object_lookup(file_priv, handle);
+	if (gem_obj == NULL)
+		return -ENOENT;
+
+	obj = to_drm_gem_cma_obj(gem_obj);
+
+	if (drm_vma_node_has_offset(&obj->base.vma_node) == 0) {
+		error = drm_gem_create_mmap_offset(&obj->base);
+		if (error)
+			goto done;
+	} else {
+		error = 0;
+	}
+
+	*offset = drm_vma_node_offset_addr(&obj->base.vma_node);
+
+done:
+	drm_gem_object_unreference_unlocked(&obj->base);
+
+	return error;
+}
+
+static int
+drm_gem_cma_fault(struct uvm_faultinfo *ufi, vaddr_t vaddr,
+    struct vm_page **pps, int npages, int centeridx, vm_prot_t access_type,
+    int flags)
+{
+	struct vm_map_entry *entry = ufi->entry;
+	struct uvm_object *uobj = entry->object.uvm_obj;
+	struct drm_gem_object *gem_obj =
+	    container_of(uobj, struct drm_gem_object, uobj);
+	struct drm_gem_cma_object *obj = to_drm_gem_cma_obj(gem_obj);
+	off_t curr_offset;
+	vaddr_t curr_va;
+	paddr_t paddr;
+	int lcv, retval;
+	vm_prot_t mapprot;
+
+	if (UVM_ET_ISCOPYONWRITE(entry))
+		return EIO;
+
+	curr_offset = entry->offset + (vaddr - entry->start);
+	curr_va = vaddr;
+
+	retval = 0;
+	for (lcv = 0; lcv < npages; lcv++, curr_offset += PAGE_SIZE,
+	    curr_va += PAGE_SIZE) {
+		if ((flags & PGO_ALLPAGES) == 0 && lcv != centeridx)
+			continue;
+		if (pps[lcv] == PGO_DONTCARE)
+			continue;
+
+		paddr = bus_dmamem_mmap(obj->dmat, obj->dmasegs, 1,
+		    curr_offset, access_type, 0);
+		if (paddr == -1) {
+			retval = EIO;
+			break;
+		}
+		mapprot = ufi->entry->protection;
+
+		if (pmap_enter(ufi->orig_map->pmap, curr_va, paddr, mapprot,
+		    PMAP_CANFAIL | mapprot) != 0) {
+			pmap_update(ufi->orig_map->pmap);
+			uvmfault_unlockall(ufi, ufi->entry->aref.ar_amap,
+			    uobj, NULL);
+			uvm_wait("drm_gem_cma_fault");
+			return ERESTART;
+		}
+	}
+
+	pmap_update(ufi->orig_map->pmap);
+	uvmfault_unlockall(ufi, ufi->entry->aref.ar_amap, uobj, NULL);
+
+	return retval;
+}
+
+#ifdef notyet
+const struct uvm_pagerops drm_gem_cma_uvm_ops = {
+	.pgo_reference = drm_gem_pager_reference,
+	.pgo_detach = drm_gem_pager_detach,
+	.pgo_fault = drm_gem_cma_fault,
+};
+#endif
+
+struct sg_table *
+drm_gem_cma_prime_get_sg_table(struct drm_gem_object *gem_obj)
+{
+	struct drm_gem_cma_object *obj = to_drm_gem_cma_obj(gem_obj);
+
+	return NULL;
+#ifdef notyet
+	return drm_prime_bus_dmamem_to_sg(obj->dmat, obj->dmasegs, 1);
+#endif
+}
+
+struct drm_gem_object *
+drm_gem_cma_prime_import_sg_table(struct drm_device *ddev,
+    struct dma_buf_attachment *attach, struct sg_table *sgt)
+{
+	return NULL;
+#ifdef notyet
+	size_t size = drm_prime_sg_size(sgt);
+	struct drm_gem_cma_object *obj;
+
+	obj = drm_gem_cma_create_internal(ddev, size, sgt);
+	if (obj == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	return &obj->base;
+#endif
+}
+
+void *
+drm_gem_cma_prime_vmap(struct drm_gem_object *gem_obj)
+{
+	struct drm_gem_cma_object *obj = to_drm_gem_cma_obj(gem_obj);
+
+	return obj->vaddr;
+}
+
+void
+drm_gem_cma_prime_vunmap(struct drm_gem_object *gem_obj, void *vaddr)
+{
+	struct drm_gem_cma_object *obj =
+	    to_drm_gem_cma_obj(gem_obj);
+
+	KASSERT(vaddr == obj->vaddr);
+}
diff --git a/sys/dev/pci/drm/include/drm/drm_gem_cma_helper.h b/sys/dev/pci/drm/include/drm/drm_gem_cma_helper.h
new file mode 100644
index 00000000000..df4e4de031a
--- /dev/null
+++ b/sys/dev/pci/drm/include/drm/drm_gem_cma_helper.h
@@ -0,0 +1,26 @@
+/* Public Domain */
+
+#include <drm/drmP.h>
+#include <drm/drm_gem.h>
+
+void drm_gem_cma_free_object(struct drm_gem_object *);
+int drm_gem_cma_dumb_create(struct drm_file *, struct drm_device *,
+    struct drm_mode_create_dumb *);
+int drm_gem_cma_dumb_map_offset(struct drm_file *, struct drm_device *,
+    uint32_t, uint64_t *);
+struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *,
+    size_t);
+
+extern const struct uvm_pagerops drm_gem_cma_uvm_ops;
+
+struct drm_gem_cma_object {
+	struct drm_gem_object	base;
+	bus_dma_tag_t		dmat;
+	bus_dmamap_t		dmamap;
+	bus_dma_segment_t	dmasegs[1];
+	size_t			dmasize;
+	caddr_t			vaddr;
+	struct sg_table		*sgt;
+};
+
+#define to_drm_gem_cma_obj(gem_obj) container_of(gem_obj, struct drm_gem_cma_object, base)