-static inline void vga_set_mem_top(struct vc_data *c)
-{
- write_vga(12, (c->vc_visible_origin - vga_vram_base) / 2);
-}
-
-#ifdef CONFIG_VGACON_SOFT_SCROLLBACK
-#include <linux/bootmem.h>
-/* software scrollback */
-static void *vgacon_scrollback;
-static int vgacon_scrollback_tail;
-static int vgacon_scrollback_size;
-static int vgacon_scrollback_rows;
-static int vgacon_scrollback_cnt;
-static int vgacon_scrollback_cur;
-static int vgacon_scrollback_save;
-static int vgacon_scrollback_restore;
-
-static void vgacon_scrollback_init(int pitch)
-{
- int rows = CONFIG_VGACON_SOFT_SCROLLBACK_SIZE * 1024/pitch;
-
- if (vgacon_scrollback) {
- vgacon_scrollback_cnt = 0;
- vgacon_scrollback_tail = 0;
- vgacon_scrollback_cur = 0;
- vgacon_scrollback_rows = rows - 1;
- vgacon_scrollback_size = rows * pitch;
- }
-}
-
-static void vgacon_scrollback_startup(void)
-{
- vgacon_scrollback = alloc_bootmem(CONFIG_VGACON_SOFT_SCROLLBACK_SIZE
- * 1024);
- vgacon_scrollback_init(vga_video_num_columns * 2);
-}
-
-static void vgacon_scrollback_update(struct vc_data *c, int t, int count)
-{
- void *p;
-
- if (!vgacon_scrollback_size || c->vc_num != fg_console)
- return;
-
- p = (void *) (c->vc_origin + t * c->vc_size_row);
-
- while (count--) {
- scr_memcpyw(vgacon_scrollback + vgacon_scrollback_tail,
- p, c->vc_size_row);
- vgacon_scrollback_cnt++;
- p += c->vc_size_row;
- vgacon_scrollback_tail += c->vc_size_row;
-
- if (vgacon_scrollback_tail >= vgacon_scrollback_size)
- vgacon_scrollback_tail = 0;
-
- if (vgacon_scrollback_cnt > vgacon_scrollback_rows)
- vgacon_scrollback_cnt = vgacon_scrollback_rows;
-
- vgacon_scrollback_cur = vgacon_scrollback_cnt;
- }
-}
-
-static void vgacon_restore_screen(struct vc_data *c)
-{
- vgacon_scrollback_save = 0;
-
- if (!vga_is_gfx && !vgacon_scrollback_restore) {
- scr_memcpyw((u16 *) c->vc_origin, (u16 *) c->vc_screenbuf,
- c->vc_screenbuf_size > vga_vram_size ?
- vga_vram_size : c->vc_screenbuf_size);
- vgacon_scrollback_restore = 1;
- vgacon_scrollback_cur = vgacon_scrollback_cnt;
- }
-}
-
-static int vgacon_scrolldelta(struct vc_data *c, int lines)
-{
- int start, end, count, soff, diff;
- void *d, *s;
-
- if (!lines) {
- c->vc_visible_origin = c->vc_origin;
- vga_set_mem_top(c);
- return 1;
- }
-
- if (!vgacon_scrollback)
- return 1;
-
- if (!vgacon_scrollback_save) {
- vgacon_cursor(c, CM_ERASE);
- vgacon_save_screen(c);
- vgacon_scrollback_save = 1;
- }
-
- vgacon_scrollback_restore = 0;
- start = vgacon_scrollback_cur + lines;
- end = start + abs(lines);
-
- if (start < 0)
- start = 0;
-
- if (start > vgacon_scrollback_cnt)
- start = vgacon_scrollback_cnt;
-
- if (end < 0)
- end = 0;
-
- if (end > vgacon_scrollback_cnt)
- end = vgacon_scrollback_cnt;
-
- vgacon_scrollback_cur = start;
- count = end - start;
- soff = vgacon_scrollback_tail - ((vgacon_scrollback_cnt - end) *
- c->vc_size_row);
- soff -= count * c->vc_size_row;
-
- if (soff < 0)
- soff += vgacon_scrollback_size;
-
- count = vgacon_scrollback_cnt - start;
-
- if (count > c->vc_rows)
- count = c->vc_rows;
-
- diff = c->vc_rows - count;
-
- d = (void *) c->vc_origin;
- s = (void *) c->vc_screenbuf;
-
- while (count--) {
- scr_memcpyw(d, vgacon_scrollback + soff, c->vc_size_row);
- d += c->vc_size_row;
- soff += c->vc_size_row;
-
- if (soff >= vgacon_scrollback_size)
- soff = 0;
- }
-
- if (diff == c->vc_rows) {
- vgacon_cursor(c, CM_MOVE);
- } else {
- while (diff--) {
- scr_memcpyw(d, s, c->vc_size_row);
- d += c->vc_size_row;
- s += c->vc_size_row;
- }
- }
-
- return 1;
-}
-#else
-#define vgacon_scrollback_startup(...) do { } while (0)
-#define vgacon_scrollback_init(...) do { } while (0)
-#define vgacon_scrollback_update(...) do { } while (0)
-
-static void vgacon_restore_screen(struct vc_data *c)
-{
- if (c->vc_origin != c->vc_visible_origin)
- vgacon_scrolldelta(c, 0);
-}
-
-static int vgacon_scrolldelta(struct vc_data *c, int lines)
-{
- if (!lines) /* Turn scrollback off */
- c->vc_visible_origin = c->vc_origin;
- else {
- int margin = c->vc_size_row * 4;
- int ul, we, p, st;
-
- if (vga_rolled_over >
- (c->vc_scr_end - vga_vram_base) + margin) {
- ul = c->vc_scr_end - vga_vram_base;
- we = vga_rolled_over + c->vc_size_row;
- } else {
- ul = 0;
- we = vga_vram_size;
- }
- p = (c->vc_visible_origin - vga_vram_base - ul + we) % we +
- lines * c->vc_size_row;
- st = (c->vc_origin - vga_vram_base - ul + we) % we;
- if (st < 2 * margin)
- margin = 0;
- if (p < margin)
- p = 0;
- if (p > st - margin)
- p = st;
- c->vc_visible_origin = vga_vram_base + (p + ul) % we;
- }
- vga_set_mem_top(c);
- return 1;
-}
-#endif /* CONFIG_VGACON_SOFT_SCROLLBACK */
-
-static const char *vgacon_startup(void)