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path: root/drivers/gpu/drm/vboxvideo/vbva_base.c
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Diffstat (limited to 'drivers/gpu/drm/vboxvideo/vbva_base.c')
-rw-r--r--drivers/gpu/drm/vboxvideo/vbva_base.c214
1 files changed, 214 insertions, 0 deletions
diff --git a/drivers/gpu/drm/vboxvideo/vbva_base.c b/drivers/gpu/drm/vboxvideo/vbva_base.c
new file mode 100644
index 000000000000..36bc9824ec3f
--- /dev/null
+++ b/drivers/gpu/drm/vboxvideo/vbva_base.c
@@ -0,0 +1,214 @@
+// SPDX-License-Identifier: MIT
+/* Copyright (C) 2006-2017 Oracle Corporation */
+
+#include <linux/vbox_err.h>
+#include "vbox_drv.h"
+#include "vboxvideo_guest.h"
+#include "hgsmi_channels.h"
+
+/*
+ * There is a hardware ring buffer in the graphics device video RAM, formerly
+ * in the VBox VMMDev PCI memory space.
+ * All graphics commands go there serialized by vbva_buffer_begin_update.
+ * and vbva_buffer_end_update.
+ *
+ * free_offset is writing position. data_offset is reading position.
+ * free_offset == data_offset means buffer is empty.
+ * There must be always gap between data_offset and free_offset when data
+ * are in the buffer.
+ * Guest only changes free_offset, host changes data_offset.
+ */
+
+static u32 vbva_buffer_available(const struct vbva_buffer *vbva)
+{
+ s32 diff = vbva->data_offset - vbva->free_offset;
+
+ return diff > 0 ? diff : vbva->data_len + diff;
+}
+
+static void vbva_buffer_place_data_at(struct vbva_buf_ctx *vbva_ctx,
+ const void *p, u32 len, u32 offset)
+{
+ struct vbva_buffer *vbva = vbva_ctx->vbva;
+ u32 bytes_till_boundary = vbva->data_len - offset;
+ u8 *dst = &vbva->data[offset];
+ s32 diff = len - bytes_till_boundary;
+
+ if (diff <= 0) {
+ /* Chunk will not cross buffer boundary. */
+ memcpy(dst, p, len);
+ } else {
+ /* Chunk crosses buffer boundary. */
+ memcpy(dst, p, bytes_till_boundary);
+ memcpy(&vbva->data[0], (u8 *)p + bytes_till_boundary, diff);
+ }
+}
+
+static void vbva_buffer_flush(struct gen_pool *ctx)
+{
+ struct vbva_flush *p;
+
+ p = hgsmi_buffer_alloc(ctx, sizeof(*p), HGSMI_CH_VBVA, VBVA_FLUSH);
+ if (!p)
+ return;
+
+ p->reserved = 0;
+
+ hgsmi_buffer_submit(ctx, p);
+ hgsmi_buffer_free(ctx, p);
+}
+
+bool vbva_write(struct vbva_buf_ctx *vbva_ctx, struct gen_pool *ctx,
+ const void *p, u32 len)
+{
+ struct vbva_record *record;
+ struct vbva_buffer *vbva;
+ u32 available;
+
+ vbva = vbva_ctx->vbva;
+ record = vbva_ctx->record;
+
+ if (!vbva || vbva_ctx->buffer_overflow ||
+ !record || !(record->len_and_flags & VBVA_F_RECORD_PARTIAL))
+ return false;
+
+ available = vbva_buffer_available(vbva);
+
+ while (len > 0) {
+ u32 chunk = len;
+
+ if (chunk >= available) {
+ vbva_buffer_flush(ctx);
+ available = vbva_buffer_available(vbva);
+ }
+
+ if (chunk >= available) {
+ if (WARN_ON(available <= vbva->partial_write_tresh)) {
+ vbva_ctx->buffer_overflow = true;
+ return false;
+ }
+ chunk = available - vbva->partial_write_tresh;
+ }
+
+ vbva_buffer_place_data_at(vbva_ctx, p, chunk,
+ vbva->free_offset);
+
+ vbva->free_offset = (vbva->free_offset + chunk) %
+ vbva->data_len;
+ record->len_and_flags += chunk;
+ available -= chunk;
+ len -= chunk;
+ p += chunk;
+ }
+
+ return true;
+}
+
+static bool vbva_inform_host(struct vbva_buf_ctx *vbva_ctx,
+ struct gen_pool *ctx, s32 screen, bool enable)
+{
+ struct vbva_enable_ex *p;
+ bool ret;
+
+ p = hgsmi_buffer_alloc(ctx, sizeof(*p), HGSMI_CH_VBVA, VBVA_ENABLE);
+ if (!p)
+ return false;
+
+ p->base.flags = enable ? VBVA_F_ENABLE : VBVA_F_DISABLE;
+ p->base.offset = vbva_ctx->buffer_offset;
+ p->base.result = VERR_NOT_SUPPORTED;
+ if (screen >= 0) {
+ p->base.flags |= VBVA_F_EXTENDED | VBVA_F_ABSOFFSET;
+ p->screen_id = screen;
+ }
+
+ hgsmi_buffer_submit(ctx, p);
+
+ if (enable)
+ ret = p->base.result >= 0;
+ else
+ ret = true;
+
+ hgsmi_buffer_free(ctx, p);
+
+ return ret;
+}
+
+bool vbva_enable(struct vbva_buf_ctx *vbva_ctx, struct gen_pool *ctx,
+ struct vbva_buffer *vbva, s32 screen)
+{
+ bool ret = false;
+
+ memset(vbva, 0, sizeof(*vbva));
+ vbva->partial_write_tresh = 256;
+ vbva->data_len = vbva_ctx->buffer_length - sizeof(struct vbva_buffer);
+ vbva_ctx->vbva = vbva;
+
+ ret = vbva_inform_host(vbva_ctx, ctx, screen, true);
+ if (!ret)
+ vbva_disable(vbva_ctx, ctx, screen);
+
+ return ret;
+}
+
+void vbva_disable(struct vbva_buf_ctx *vbva_ctx, struct gen_pool *ctx,
+ s32 screen)
+{
+ vbva_ctx->buffer_overflow = false;
+ vbva_ctx->record = NULL;
+ vbva_ctx->vbva = NULL;
+
+ vbva_inform_host(vbva_ctx, ctx, screen, false);
+}
+
+bool vbva_buffer_begin_update(struct vbva_buf_ctx *vbva_ctx,
+ struct gen_pool *ctx)
+{
+ struct vbva_record *record;
+ u32 next;
+
+ if (!vbva_ctx->vbva ||
+ !(vbva_ctx->vbva->host_flags.host_events & VBVA_F_MODE_ENABLED))
+ return false;
+
+ WARN_ON(vbva_ctx->buffer_overflow || vbva_ctx->record);
+
+ next = (vbva_ctx->vbva->record_free_index + 1) % VBVA_MAX_RECORDS;
+
+ /* Flush if all slots in the records queue are used */
+ if (next == vbva_ctx->vbva->record_first_index)
+ vbva_buffer_flush(ctx);
+
+ /* If even after flush there is no place then fail the request */
+ if (next == vbva_ctx->vbva->record_first_index)
+ return false;
+
+ record = &vbva_ctx->vbva->records[vbva_ctx->vbva->record_free_index];
+ record->len_and_flags = VBVA_F_RECORD_PARTIAL;
+ vbva_ctx->vbva->record_free_index = next;
+ /* Remember which record we are using. */
+ vbva_ctx->record = record;
+
+ return true;
+}
+
+void vbva_buffer_end_update(struct vbva_buf_ctx *vbva_ctx)
+{
+ struct vbva_record *record = vbva_ctx->record;
+
+ WARN_ON(!vbva_ctx->vbva || !record ||
+ !(record->len_and_flags & VBVA_F_RECORD_PARTIAL));
+
+ /* Mark the record completed. */
+ record->len_and_flags &= ~VBVA_F_RECORD_PARTIAL;
+
+ vbva_ctx->buffer_overflow = false;
+ vbva_ctx->record = NULL;
+}
+
+void vbva_setup_buffer_context(struct vbva_buf_ctx *vbva_ctx,
+ u32 buffer_offset, u32 buffer_length)
+{
+ vbva_ctx->buffer_offset = buffer_offset;
+ vbva_ctx->buffer_length = buffer_length;
+}