xen: introduce a generic framebuffer driver

Abstract away from vesa.c the funcions to handle a linear framebuffer
and print characters to it.
Make use of the new functions in vesa.c.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Jan Beulich <JBeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
[ ijc -- s/fbp/lfbp/ in two places to fix the build ]
Committed-by: Ian Campbell <ian.campbell@citrix.com>

4 files changed, 254 insertions, 153 deletions

diff --git a/xen/drivers/video/Makefile b/xen/drivers/video/Makefile
index 2993c39f25..77f9d5daa0 100644
--- a/xen/drivers/video/Makefile
+++ b/xen/drivers/video/Makefile
@@ -2,4 +2,5 @@ obj-$(HAS_VGA) := vga.o
 obj-$(HAS_VIDEO) += font_8x14.o
 obj-$(HAS_VIDEO) += font_8x16.o
 obj-$(HAS_VIDEO) += font_8x8.o
+obj-$(HAS_VIDEO) += lfb.o
 obj-$(HAS_VGA) += vesa.o
diff --git a/xen/drivers/video/lfb.c b/xen/drivers/video/lfb.c
new file mode 100644
index 0000000000..cc7f7ac169
--- /dev/null
+++ b/xen/drivers/video/lfb.c
@@ -0,0 +1,183 @@
+/******************************************************************************
+ * lfb.c
+ *
+ * linear frame buffer handling.
+ */
+
+#include <xen/config.h>
+#include <xen/kernel.h>
+#include <xen/lib.h>
+#include <xen/errno.h>
+#include "lfb.h"
+#include "font.h"
+
+#define MAX_XRES 1900
+#define MAX_YRES 1200
+#define MAX_BPP 4
+#define MAX_FONT_W 8
+#define MAX_FONT_H 16
+
+struct lfb_status {
+    struct lfb_prop lfbp;
+
+    unsigned char *lbuf, *text_buf;
+    unsigned int *line_len;
+    unsigned int xpos, ypos;
+};
+static struct lfb_status lfb;
+
+static void lfb_show_line(
+    const unsigned char *text_line,
+    unsigned char *video_line,
+    unsigned int nr_chars,
+    unsigned int nr_cells)
+{
+    unsigned int i, j, b, bpp, pixel;
+
+    bpp = (lfb.lfbp.bits_per_pixel + 7) >> 3;
+
+    for ( i = 0; i < lfb.lfbp.font->height; i++ )
+    {
+        unsigned char *ptr = lfb.lbuf;
+
+        for ( j = 0; j < nr_chars; j++ )
+        {
+            const unsigned char *bits = lfb.lfbp.font->data;
+            bits += ((text_line[j] * lfb.lfbp.font->height + i) *
+                     ((lfb.lfbp.font->width + 7) >> 3));
+            for ( b = lfb.lfbp.font->width; b--; )
+            {
+                pixel = (*bits & (1u<<b)) ? lfb.lfbp.pixel_on : 0;
+                memcpy(ptr, &pixel, bpp);
+                ptr += bpp;
+            }
+        }
+
+        memset(ptr, 0, (lfb.lfbp.width - nr_chars * lfb.lfbp.font->width) * bpp);
+        memcpy(video_line, lfb.lbuf, nr_cells * lfb.lfbp.font->width * bpp);
+        video_line += lfb.lfbp.bytes_per_line;
+    }
+}
+
+/* Fast mode which redraws all modified parts of a 2D text buffer. */
+void lfb_redraw_puts(const char *s)
+{
+    unsigned int i, min_redraw_y = lfb.ypos;
+    char c;
+
+    /* Paste characters into text buffer. */
+    while ( (c = *s++) != '\0' )
+    {
+        if ( (c == '\n') || (lfb.xpos >= lfb.lfbp.text_columns) )
+        {
+            if ( ++lfb.ypos >= lfb.lfbp.text_rows )
+            {
+                min_redraw_y = 0;
+                lfb.ypos = lfb.lfbp.text_rows - 1;
+                memmove(lfb.text_buf, lfb.text_buf + lfb.lfbp.text_columns,
+                        lfb.ypos * lfb.lfbp.text_columns);
+                memset(lfb.text_buf + lfb.ypos * lfb.lfbp.text_columns, 0, lfb.xpos);
+            }
+            lfb.xpos = 0;
+        }
+
+        if ( c != '\n' )
+            lfb.text_buf[lfb.xpos++ + lfb.ypos * lfb.lfbp.text_columns] = c;
+    }
+
+    /* Render modified section of text buffer to VESA linear framebuffer. */
+    for ( i = min_redraw_y; i <= lfb.ypos; i++ )
+    {
+        const unsigned char *line = lfb.text_buf + i * lfb.lfbp.text_columns;
+        unsigned int width;
+
+        for ( width = lfb.lfbp.text_columns; width; --width )
+            if ( line[width - 1] )
+                 break;
+        lfb_show_line(line,
+                       lfb.lfbp.lfb + i * lfb.lfbp.font->height * lfb.lfbp.bytes_per_line,
+                       width, max(lfb.line_len[i], width));
+        lfb.line_len[i] = width;
+    }
+
+    lfb.lfbp.flush();
+}
+
+/* Slower line-based scroll mode which interacts better with dom0. */
+void lfb_scroll_puts(const char *s)
+{
+    unsigned int i;
+    char c;
+
+    while ( (c = *s++) != '\0' )
+    {
+        if ( (c == '\n') || (lfb.xpos >= lfb.lfbp.text_columns) )
+        {
+            unsigned int bytes = (lfb.lfbp.width *
+                                  ((lfb.lfbp.bits_per_pixel + 7) >> 3));
+            unsigned char *src = lfb.lfbp.lfb + lfb.lfbp.font->height * lfb.lfbp.bytes_per_line;
+            unsigned char *dst = lfb.lfbp.lfb;
+
+            /* New line: scroll all previous rows up one line. */
+            for ( i = lfb.lfbp.font->height; i < lfb.lfbp.height; i++ )
+            {
+                memcpy(dst, src, bytes);
+                src += lfb.lfbp.bytes_per_line;
+                dst += lfb.lfbp.bytes_per_line;
+            }
+
+            /* Render new line. */
+            lfb_show_line(
+                lfb.text_buf,
+                lfb.lfbp.lfb + (lfb.lfbp.text_rows-1) * lfb.lfbp.font->height *
+                lfb.lfbp.bytes_per_line,
+                lfb.xpos, lfb.lfbp.text_columns);
+
+            lfb.xpos = 0;
+        }
+
+        if ( c != '\n' )
+            lfb.text_buf[lfb.xpos++] = c;
+    }
+
+    lfb.lfbp.flush();
+}
+
+void lfb_carriage_return(void)
+{
+    lfb.xpos = 0;
+}
+
+int __init lfb_init(struct lfb_prop *lfbp)
+{
+    if ( lfbp->width > MAX_XRES || lfbp->height > MAX_YRES )
+    {
+        printk(XENLOG_WARNING "Couldn't initialize a %ux%u framebuffer early.\n",
+               lfbp->width, lfbp->height);
+        return -EINVAL;
+    }
+
+    lfb.lfbp = *lfbp;
+
+    lfb.lbuf = xmalloc_bytes(lfb.lfbp.bytes_per_line);
+    lfb.text_buf = xzalloc_bytes(lfb.lfbp.text_columns * lfb.lfbp.text_rows);
+    lfb.line_len = xzalloc_array(unsigned int, lfb.lfbp.text_columns);
+
+    if ( !lfb.lbuf || !lfb.text_buf || !lfb.line_len )
+        goto fail;
+
+    return 0;
+
+fail:
+    printk(XENLOG_ERR "Couldn't allocate enough memory to drive the framebuffer\n");
+    lfb_free();
+
+    return -ENOMEM;
+}
+
+void lfb_free(void)
+{
+    xfree(lfb.lbuf);
+    xfree(lfb.text_buf);
+    xfree(lfb.line_len);
+}
diff --git a/xen/drivers/video/lfb.h b/xen/drivers/video/lfb.h
new file mode 100644
index 0000000000..ac40a66379
--- /dev/null
+++ b/xen/drivers/video/lfb.h
@@ -0,0 +1,46 @@
+/*
+ * xen/drivers/video/lfb.h
+ *
+ * Cross-platform framebuffer library
+ *
+ * Stefano Stabellini <stefano.stabellini@eu.citrix.com>
+ * Copyright (c) 2013 Citrix Systems.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _XEN_LFB_H
+#define _XEN_LFB_H
+
+#include <xen/init.h>
+
+struct lfb_prop {
+    const struct font_desc *font;
+    unsigned char *lfb;
+    unsigned int pixel_on;
+    uint16_t width, height;
+    uint16_t bytes_per_line;
+    uint16_t bits_per_pixel;
+    void (*flush)(void);
+
+    unsigned int text_columns;
+    unsigned int text_rows;
+};
+
+void lfb_redraw_puts(const char *s);
+void lfb_scroll_puts(const char *s);
+void lfb_carriage_return(void);
+void lfb_free(void);
+
+/* initialize the framebuffer */
+int lfb_init(struct lfb_prop *lfbp);
+
+#endif
diff --git a/xen/drivers/video/vesa.c b/xen/drivers/video/vesa.c
index aaf8b23404..575db620e5 100644
--- a/xen/drivers/video/vesa.c
+++ b/xen/drivers/video/vesa.c
@@ -13,20 +13,15 @@
 #include <asm/io.h>
 #include <asm/page.h>
 #include "font.h"
+#include "lfb.h"
 
 #define vlfb_info    vga_console_info.u.vesa_lfb
-#define text_columns (vlfb_info.width / font->width)
-#define text_rows    (vlfb_info.height / font->height)
 
-static void vesa_redraw_puts(const char *s);
-static void vesa_scroll_puts(const char *s);
+static void lfb_flush(void);
 
-static unsigned char *lfb, *lbuf, *text_buf;
-static unsigned int *__initdata line_len;
+static unsigned char *lfb;
 static const struct font_desc *font;
 static bool_t vga_compat;
-static unsigned int pixel_on;
-static unsigned int xpos, ypos;
 
 static unsigned int vram_total;
 integer_param("vesa-ram", vram_total);
@@ -87,29 +82,26 @@ void __init vesa_early_init(void)
 
 void __init vesa_init(void)
 {
-    if ( !font )
-        goto fail;
-
-    lbuf = xmalloc_bytes(vlfb_info.bytes_per_line);
-    if ( !lbuf )
-        goto fail;
+    struct lfb_prop lfbp;
 
-    text_buf = xzalloc_bytes(text_columns * text_rows);
-    if ( !text_buf )
-        goto fail;
+    if ( !font )
+        return;
 
-    line_len = xzalloc_array(unsigned int, text_columns);
-    if ( !line_len )
-        goto fail;
+    lfbp.font = font;
+    lfbp.bits_per_pixel = vlfb_info.bits_per_pixel;
+    lfbp.bytes_per_line = vlfb_info.bytes_per_line;
+    lfbp.width = vlfb_info.width;
+    lfbp.height = vlfb_info.height;
+    lfbp.flush = lfb_flush;
+    lfbp.text_columns = vlfb_info.width / font->width;
+    lfbp.text_rows = vlfb_info.height / font->height;
 
-    lfb = ioremap(vlfb_info.lfb_base, vram_remap);
+    lfbp.lfb = lfb = ioremap(vlfb_info.lfb_base, vram_remap);
     if ( !lfb )
-        goto fail;
+        return;
 
     memset(lfb, 0, vram_remap);
 
-    video_puts = vesa_redraw_puts;
-
     printk(XENLOG_INFO "vesafb: framebuffer at %#x, mapped to 0x%p, "
            "using %uk, total %uk\n",
            vlfb_info.lfb_base, lfb,
@@ -131,7 +123,7 @@ void __init vesa_init(void)
     {
         /* Light grey in truecolor. */
         unsigned int grey = 0xaaaaaaaa;
-        pixel_on = 
+        lfbp.pixel_on =
             ((grey >> (32 - vlfb_info.  red_size)) << vlfb_info.  red_pos) |
             ((grey >> (32 - vlfb_info.green_size)) << vlfb_info.green_pos) |
             ((grey >> (32 - vlfb_info. blue_size)) << vlfb_info. blue_pos);
@@ -139,15 +131,12 @@ void __init vesa_init(void)
     else
     {
         /* White(ish) in default pseudocolor palette. */
-        pixel_on = 7;
+        lfbp.pixel_on = 7;
     }
 
-    return;
-
- fail:
-    xfree(lbuf);
-    xfree(text_buf);
-    xfree(line_len);
+    if ( lfb_init(&lfbp) < 0 )
+        return;
+    video_puts = lfb_redraw_puts;
 }
 
 #include <asm/mtrr.h>
@@ -192,8 +181,8 @@ void __init vesa_endboot(bool_t keep)
 {
     if ( keep )
     {
-        xpos = 0;
-        video_puts = vesa_scroll_puts;
+        video_puts = lfb_scroll_puts;
+        lfb_carriage_return();
     }
     else
     {
@@ -202,124 +191,6 @@ void __init vesa_endboot(bool_t keep)
             memset(lfb + i * vlfb_info.bytes_per_line, 0,
                    vlfb_info.width * bpp);
         lfb_flush();
+        lfb_free();
     }
-
-    xfree(line_len);
-}
-
-/* Render one line of text to given linear framebuffer line. */
-static void vesa_show_line(
-    const unsigned char *text_line,
-    unsigned char *video_line,
-    unsigned int nr_chars,
-    unsigned int nr_cells)
-{
-    unsigned int i, j, b, bpp, pixel;
-
-    bpp = (vlfb_info.bits_per_pixel + 7) >> 3;
-
-    for ( i = 0; i < font->height; i++ )
-    {
-        unsigned char *ptr = lbuf;
-
-        for ( j = 0; j < nr_chars; j++ )
-        {
-            const unsigned char *bits = font->data;
-            bits += ((text_line[j] * font->height + i) *
-                     ((font->width + 7) >> 3));
-            for ( b = font->width; b--; )
-            {
-                pixel = (*bits & (1u<<b)) ? pixel_on : 0;
-                memcpy(ptr, &pixel, bpp);
-                ptr += bpp;
-            }
-        }
-
-        memset(ptr, 0, (vlfb_info.width - nr_chars * font->width) * bpp);
-        memcpy(video_line, lbuf, nr_cells * font->width * bpp);
-        video_line += vlfb_info.bytes_per_line;
-    }
-}
-
-/* Fast mode which redraws all modified parts of a 2D text buffer. */
-static void __init vesa_redraw_puts(const char *s)
-{
-    unsigned int i, min_redraw_y = ypos;
-    char c;
-
-    /* Paste characters into text buffer. */
-    while ( (c = *s++) != '\0' )
-    {
-        if ( (c == '\n') || (xpos >= text_columns) )
-        {
-            if ( ++ypos >= text_rows )
-            {
-                min_redraw_y = 0;
-                ypos = text_rows - 1;
-                memmove(text_buf, text_buf + text_columns,
-                        ypos * text_columns);
-                memset(text_buf + ypos * text_columns, 0, xpos);
-            }
-            xpos = 0;
-        }
-
-        if ( c != '\n' )
-            text_buf[xpos++ + ypos * text_columns] = c;
-    }
-
-    /* Render modified section of text buffer to VESA linear framebuffer. */
-    for ( i = min_redraw_y; i <= ypos; i++ )
-    {
-        const unsigned char *line = text_buf + i * text_columns;
-        unsigned int width;
-
-        for ( width = text_columns; width; --width )
-            if ( line[width - 1] )
-                 break;
-        vesa_show_line(line,
-                       lfb + i * font->height * vlfb_info.bytes_per_line,
-                       width, max(line_len[i], width));
-        line_len[i] = width;
-    }
-
-    lfb_flush();
-}
-
-/* Slower line-based scroll mode which interacts better with dom0. */
-static void vesa_scroll_puts(const char *s)
-{
-    unsigned int i;
-    char c;
-
-    while ( (c = *s++) != '\0' )
-    {
-        if ( (c == '\n') || (xpos >= text_columns) )
-        {
-            unsigned int bytes = (vlfb_info.width *
-                                  ((vlfb_info.bits_per_pixel + 7) >> 3));
-            unsigned char *src = lfb + font->height * vlfb_info.bytes_per_line;
-            unsigned char *dst = lfb;
-            
-            /* New line: scroll all previous rows up one line. */
-            for ( i = font->height; i < vlfb_info.height; i++ )
-            {
-                memcpy(dst, src, bytes);
-                src += vlfb_info.bytes_per_line;
-                dst += vlfb_info.bytes_per_line;
-            }
-
-            /* Render new line. */
-            vesa_show_line(
-                text_buf,
-                lfb + (text_rows-1) * font->height * vlfb_info.bytes_per_line,
-                xpos, text_columns);
-
-            xpos = 0;
-        }
-
-        if ( c != '\n' )
-            text_buf[xpos++] = c;
-    }
-
-    lfb_flush();
 }