diff options
Diffstat (limited to 'drivers/gpu/drm/vboxvideo/vbva_base.c')
| -rw-r--r-- | drivers/gpu/drm/vboxvideo/vbva_base.c | 214 |
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 000000000..36bc9824e --- /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; +} |