[src/trunk]: src/sys/dev/wscons introduce a putchar() based implementation of...

[macallan <macallan%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a0be924b334d
branches:  trunk
changeset: 950235:a0be924b334d
user:      macallan <macallan%NetBSD.org@localhost>
date:      Thu Jan 21 21:45:42 2021 +0000

description:
introduce a putchar() based implementation of cursor() in order to avoid
framebuffer reads
quite a speedup on arm64 / genfb

diffstat:

 sys/dev/wscons/wsdisplay_vcons.c    |  75 ++++++++++++++++++++++++++++++++++--
 sys/dev/wscons/wsdisplay_vconsvar.h |   6 +-
 2 files changed, 73 insertions(+), 8 deletions(-)

diffs (146 lines):

diff -r 64f86aff723f -r a0be924b334d sys/dev/wscons/wsdisplay_vcons.c
--- a/sys/dev/wscons/wsdisplay_vcons.c  Thu Jan 21 20:48:33 2021 +0000
+++ b/sys/dev/wscons/wsdisplay_vcons.c  Thu Jan 21 21:45:42 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: wsdisplay_vcons.c,v 1.47 2021/01/17 19:03:32 jmcneill Exp $ */
+/*     $NetBSD: wsdisplay_vcons.c,v 1.48 2021/01/21 21:45:42 macallan Exp $ */
 
 /*-
  * Copyright (c) 2005, 2006 Michael Lorenz
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: wsdisplay_vcons.c,v 1.47 2021/01/17 19:03:32 jmcneill Exp $");
+__KERNEL_RCSID(0, "$NetBSD: wsdisplay_vcons.c,v 1.48 2021/01/21 21:45:42 macallan Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -103,6 +103,7 @@
 static void vcons_putchar_cached(void *, int, int, u_int, long);
 #endif
 static void vcons_cursor(void *, int, int, int);
+static void vcons_cursor_noread(void *, int, int, int);
 
 /*
  * methods that avoid framebuffer reads
@@ -352,7 +353,12 @@
        ri->ri_ops.eraserows = vcons_eraserows; 
        ri->ri_ops.erasecols = vcons_erasecols; 
        ri->ri_ops.putchar   = vcons_putchar;
-       ri->ri_ops.cursor    = vcons_cursor;
+       if (scr->scr_flags & VCONS_NO_CURSOR) {
+               ri->ri_ops.cursor    = vcons_cursor_noread;
+       } else {
+               ri->ri_ops.cursor    = vcons_cursor;
+       }
+
        ri->ri_ops.copycols  = vcons_copycols;
        ri->ri_ops.copyrows  = vcons_copyrows;
 
@@ -469,7 +475,10 @@
        ri->ri_ops.eraserows = vcons_eraserows; 
        ri->ri_ops.erasecols = vcons_erasecols; 
        ri->ri_ops.putchar   = vcons_putchar;
-       ri->ri_ops.cursor    = vcons_cursor;
+       if (scr->scr_flags & VCONS_NO_CURSOR) {
+               ri->ri_ops.cursor    = vcons_cursor_noread;
+       } else
+               ri->ri_ops.cursor    = vcons_cursor;
        ri->ri_ops.copycols  = vcons_copycols;
        ri->ri_ops.copyrows  = vcons_copyrows;
        vcons_unlock(vd->active);
@@ -609,8 +618,8 @@
                                if (c == ' ') {
                                        /*
                                         * if we already erased the background
-                                        * and this blank uses the same colour
-                                        * and flags we don't need to do
+                                        * and if this blank uses the same 
+                                        * colour and flags we don't need to do
                                         * anything here
                                         */
                                        if (acmp == cmp && start == -1)
@@ -1301,6 +1310,60 @@
        vcons_unlock(scr);
 }
 
+static void
+vcons_cursor_noread(void *cookie, int on, int row, int col)
+{
+       struct rasops_info *ri = cookie;
+       struct vcons_screen *scr = ri->ri_hw;
+       int offset = 0; 
+
+#if defined(VCONS_DRAW_INTR)
+       if (scr->scr_vd->use_intr) {
+               vcons_lock(scr);
+               if (scr->scr_ri.ri_crow != row || scr->scr_ri.ri_ccol != col) {
+                       scr->scr_ri.ri_crow = row;
+                       scr->scr_ri.ri_ccol = col;
+                       atomic_inc_uint(&scr->scr_dirty);
+               }
+               vcons_unlock(scr);
+               return;
+       }
+#endif
+
+       vcons_lock(scr);
+
+#ifdef WSDISPLAY_SCROLLSUPPORT
+       offset = scr->scr_current_offset;
+#endif
+       if (SCREEN_IS_VISIBLE(scr) && SCREEN_CAN_DRAW(scr)) {
+               int ofs = offset + ri->ri_crow * ri->ri_cols + ri->ri_ccol;
+               if (ri->ri_flg & RI_CURSOR) {
+                       scr->putchar(cookie, ri->ri_crow, ri->ri_ccol,
+                           scr->scr_chars[ofs], scr->scr_attrs[ofs]);
+                       ri->ri_flg &= ~RI_CURSOR;
+               }
+               ri->ri_crow = row;
+               ri->ri_ccol = col;
+               ofs = offset + ri->ri_crow * ri->ri_cols + ri->ri_ccol;
+               if (on) {
+                       scr->putchar(cookie, row, col, scr->scr_chars[ofs],
+#ifdef VCONS_DEBUG_CURSOR_NOREAD
+                       /* draw a red cursor so we can tell which cursor() 
+                        * implementation is being used */
+                           ((scr->scr_attrs[ofs] & 0xff00ffff) ^ 0x0f000000) |
+                             0x00010000);
+#else
+                           scr->scr_attrs[ofs] ^ 0x0f0f0000);
+#endif
+                       ri->ri_flg |= RI_CURSOR;
+               }
+       } else {
+               scr->scr_ri.ri_crow = row;
+               scr->scr_ri.ri_ccol = col;
+       }
+       vcons_unlock(scr);
+}
+
 /* methods to read/write characters via ioctl() */
 
 static int
diff -r 64f86aff723f -r a0be924b334d sys/dev/wscons/wsdisplay_vconsvar.h
--- a/sys/dev/wscons/wsdisplay_vconsvar.h       Thu Jan 21 20:48:33 2021 +0000
+++ b/sys/dev/wscons/wsdisplay_vconsvar.h       Thu Jan 21 21:45:42 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: wsdisplay_vconsvar.h,v 1.30 2021/01/17 19:03:32 jmcneill Exp $ */
+/*     $NetBSD: wsdisplay_vconsvar.h,v 1.31 2021/01/21 21:45:42 macallan Exp $ */
 
 /*-
  * Copyright (c) 2005, 2006 Michael Lorenz
@@ -65,9 +65,11 @@
  */
 #define VCONS_NO_COPYCOLS      0x10    /* use putchar() based copycols() */
 #define VCONS_NO_COPYROWS      0x20    /* use putchar() based copyrows() */
-#define VCONS_DONT_READ                (VCONS_NO_COPYCOLS|VCONS_NO_COPYROWS)
+#define VCONS_DONT_READ                (VCONS_NO_COPYCOLS|VCONS_NO_COPYROWS|VCONS_NO_CURSOR)
                                        /* avoid framebuffer reads */
 #define VCONS_LOADFONT         0x40    /* driver can load_font() */
+#define VCONS_NO_CURSOR                0x80    /* use putchar() based cursor(), to
+                                        * avoid fb reads */
        /* status flags used by vcons */
        uint32_t scr_status;
 #define VCONS_IS_VISIBLE       1       /* this screen is currently visible */