staging: vboxvideo: Add vboxvideo to drivers/staging

This commit adds the vboxvideo drm/kms driver for the virtual graphics
card used in Virtual Box virtual machines to drivers/staging.

Why drivers/staging? This driver is already being patched into the kernel
by several distros, thus it is good to get this driver upstream soon, so
that work on the driver can be easily shared.

At the same time we want to take our time to get this driver properly
cleaned up (mainly converted to the new atomic modesetting APIs) before
submitting it as a normal driver under drivers/gpu/drm, putting this
driver in staging for now allows both.

Note this driver has already been significantly cleaned up, when I started
working on this the files under /usr/src/vboxguest/vboxvideo as installed
by Virtual Box 5.1.18 Guest Additions had a total linecount of 52681
lines. The version in this commit has 4874 lines.

Cc: vbox-dev@virtualbox.org
Cc: Michael Thayer <michael.thayer@oracle.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Michael Thayer <michael.thayer@oracle.com>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 115 insertions, 0 deletions

diff --git a/drivers/staging/vboxvideo/vbox_hgsmi.c b/drivers/staging/vboxvideo/vbox_hgsmi.c
new file mode 100644
index 000000000000..822fd31121cb
--- /dev/null
+++ b/drivers/staging/vboxvideo/vbox_hgsmi.c
@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2017 Oracle Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * Authors: Hans de Goede <hdegoede@redhat.com>
+ */
+
+#include "vbox_drv.h"
+#include "vboxvideo_vbe.h"
+#include "hgsmi_defs.h"
+
+/* One-at-a-Time Hash from http://www.burtleburtle.net/bob/hash/doobs.html */
+static u32 hgsmi_hash_process(u32 hash, const u8 *data, int size)
+{
+	while (size--) {
+		hash += *data++;
+		hash += (hash << 10);
+		hash ^= (hash >> 6);
+	}
+
+	return hash;
+}
+
+static u32 hgsmi_hash_end(u32 hash)
+{
+	hash += (hash << 3);
+	hash ^= (hash >> 11);
+	hash += (hash << 15);
+
+	return hash;
+}
+
+/* Not really a checksum but that is the naming used in all vbox code */
+static u32 hgsmi_checksum(u32 offset,
+			  const struct hgsmi_buffer_header *header,
+			  const struct hgsmi_buffer_tail *tail)
+{
+	u32 checksum;
+
+	checksum = hgsmi_hash_process(0, (u8 *)&offset, sizeof(offset));
+	checksum = hgsmi_hash_process(checksum, (u8 *)header, sizeof(*header));
+	/* 4 -> Do not checksum the checksum itself */
+	checksum = hgsmi_hash_process(checksum, (u8 *)tail, 4);
+
+	return hgsmi_hash_end(checksum);
+}
+
+void *hgsmi_buffer_alloc(struct gen_pool *guest_pool, size_t size,
+			 u8 channel, u16 channel_info)
+{
+	struct hgsmi_buffer_header *h;
+	struct hgsmi_buffer_tail *t;
+	size_t total_size;
+	dma_addr_t offset;
+
+	total_size = size + sizeof(*h) + sizeof(*t);
+	h = gen_pool_dma_alloc(guest_pool, total_size, &offset);
+	if (!h)
+		return NULL;
+
+	t = (struct hgsmi_buffer_tail *)((u8 *)h + sizeof(*h) + size);
+
+	h->flags = HGSMI_BUFFER_HEADER_F_SEQ_SINGLE;
+	h->data_size = size;
+	h->channel = channel;
+	h->channel_info = channel_info;
+	memset(&h->u.header_data, 0, sizeof(h->u.header_data));
+
+	t->reserved = 0;
+	t->checksum = hgsmi_checksum(offset, h, t);
+
+	return (u8 *)h + sizeof(*h);
+}
+
+void hgsmi_buffer_free(struct gen_pool *guest_pool, void *buf)
+{
+	struct hgsmi_buffer_header *h =
+		(struct hgsmi_buffer_header *)((u8 *)buf - sizeof(*h));
+	size_t total_size = h->data_size + sizeof(*h) +
+					     sizeof(struct hgsmi_buffer_tail);
+
+	gen_pool_free(guest_pool, (unsigned long)h, total_size);
+}
+
+int hgsmi_buffer_submit(struct gen_pool *guest_pool, void *buf)
+{
+	phys_addr_t offset;
+
+	offset = gen_pool_virt_to_phys(guest_pool, (unsigned long)buf -
+				       sizeof(struct hgsmi_buffer_header));
+	outl(offset, VGA_PORT_HGSMI_GUEST);
+	/* Make the compiler aware that the host has changed memory. */
+	mb();
+
+	return 0;
+}