linux/drivers/video/fbdev/vesafb.c
Thomas Zimmermann c2bc958b2b fbdev: vesafb: Detect VGA compatibility from screen info's VESA attributes
Test the vesa_attributes field in struct screen_info for compatibility
with VGA hardware. Vesafb currently tests bit 1 in screen_info's
capabilities field which indicates a 64-bit lfb address and is
unrelated to VGA compatibility.

Section 4.4 of the Vesa VBE 2.0 specifications defines that bit 5 in
the mode's attributes field signals VGA compatibility. The mode is
compatible with VGA hardware if the bit is clear. In that case, the
driver can access VGA state of the VBE's underlying hardware. The
vesafb driver uses this feature to program the color LUT in palette
modes. Without, colors might be incorrect.

The problem got introduced in commit 89ec4c238e ("[PATCH] vesafb: Fix
incorrect logo colors in x86_64"). It incorrectly stores the mode
attributes in the screen_info's capabilities field and updates vesafb
accordingly. Later, commit 5e8ddcbe86 ("Video mode probing support for
the new x86 setup code") fixed the screen_info, but did not update vesafb.
Color output still tends to work, because bit 1 in capabilities is
usually 0.

Besides fixing the bug in vesafb, this commit introduces a helper that
reads the correct bit from screen_info.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 5e8ddcbe86 ("Video mode probing support for the new x86 setup code")
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Cc: <stable@vger.kernel.org> # v2.6.23+
Signed-off-by: Helge Deller <deller@gmx.de>
2024-06-18 14:04:03 +02:00

523 lines
15 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* framebuffer driver for VBE 2.0 compliant graphic boards
*
* switching to graphics mode happens at boot time (while
* running in real mode, see arch/i386/boot/video.S).
*
* (c) 1998 Gerd Knorr <kraxel@goldbach.in-berlin.de>
*
*/
#include <linux/aperture.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/fb.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/screen_info.h>
#include <linux/io.h>
#include <video/vga.h>
#define dac_reg (0x3c8)
#define dac_val (0x3c9)
/* --------------------------------------------------------------------- */
struct vesafb_par {
u32 pseudo_palette[256];
resource_size_t base;
resource_size_t size;
int wc_cookie;
struct resource *region;
};
static struct fb_var_screeninfo vesafb_defined = {
.activate = FB_ACTIVATE_NOW,
.height = -1,
.width = -1,
.right_margin = 32,
.upper_margin = 16,
.lower_margin = 4,
.vsync_len = 4,
.vmode = FB_VMODE_NONINTERLACED,
};
static struct fb_fix_screeninfo vesafb_fix = {
.id = "VESA VGA",
.type = FB_TYPE_PACKED_PIXELS,
.accel = FB_ACCEL_NONE,
};
static int inverse __read_mostly;
static int mtrr __read_mostly; /* disable mtrr */
static int vram_remap; /* Set amount of memory to be used */
static int vram_total; /* Set total amount of memory */
static int pmi_setpal __read_mostly = 1; /* pmi for palette changes ??? */
static int ypan __read_mostly; /* 0..nothing, 1..ypan, 2..ywrap */
static void (*pmi_start)(void) __read_mostly;
static void (*pmi_pal) (void) __read_mostly;
static int depth __read_mostly;
static int vga_compat __read_mostly;
/* --------------------------------------------------------------------- */
static int vesafb_pan_display(struct fb_var_screeninfo *var,
struct fb_info *info)
{
#ifdef __i386__
int offset;
offset = (var->yoffset * info->fix.line_length + var->xoffset) / 4;
__asm__ __volatile__(
"call *(%%edi)"
: /* no return value */
: "a" (0x4f07), /* EAX */
"b" (0), /* EBX */
"c" (offset), /* ECX */
"d" (offset >> 16), /* EDX */
"D" (&pmi_start)); /* EDI */
#endif
return 0;
}
static int vesa_setpalette(int regno, unsigned red, unsigned green,
unsigned blue)
{
int shift = 16 - depth;
int err = -EINVAL;
/*
* Try VGA registers first...
*/
if (vga_compat) {
outb_p(regno, dac_reg);
outb_p(red >> shift, dac_val);
outb_p(green >> shift, dac_val);
outb_p(blue >> shift, dac_val);
err = 0;
}
#ifdef __i386__
/*
* Fallback to the PMI....
*/
if (err && pmi_setpal) {
struct { u_char blue, green, red, pad; } entry;
entry.red = red >> shift;
entry.green = green >> shift;
entry.blue = blue >> shift;
entry.pad = 0;
__asm__ __volatile__(
"call *(%%esi)"
: /* no return value */
: "a" (0x4f09), /* EAX */
"b" (0), /* EBX */
"c" (1), /* ECX */
"d" (regno), /* EDX */
"D" (&entry), /* EDI */
"S" (&pmi_pal)); /* ESI */
err = 0;
}
#endif
return err;
}
static int vesafb_setcolreg(unsigned regno, unsigned red, unsigned green,
unsigned blue, unsigned transp,
struct fb_info *info)
{
int err = 0;
/*
* Set a single color register. The values supplied are
* already rounded down to the hardware's capabilities
* (according to the entries in the `var' structure). Return
* != 0 for invalid regno.
*/
if (regno >= info->cmap.len)
return 1;
if (info->var.bits_per_pixel == 8)
err = vesa_setpalette(regno,red,green,blue);
else if (regno < 16) {
switch (info->var.bits_per_pixel) {
case 16:
if (info->var.red.offset == 10) {
/* 1:5:5:5 */
((u32*) (info->pseudo_palette))[regno] =
((red & 0xf800) >> 1) |
((green & 0xf800) >> 6) |
((blue & 0xf800) >> 11);
} else {
/* 0:5:6:5 */
((u32*) (info->pseudo_palette))[regno] =
((red & 0xf800) ) |
((green & 0xfc00) >> 5) |
((blue & 0xf800) >> 11);
}
break;
case 24:
case 32:
red >>= 8;
green >>= 8;
blue >>= 8;
((u32 *)(info->pseudo_palette))[regno] =
(red << info->var.red.offset) |
(green << info->var.green.offset) |
(blue << info->var.blue.offset);
break;
}
}
return err;
}
/*
* fb_ops.fb_destroy is called by the last put_fb_info() call at the end
* of unregister_framebuffer() or fb_release(). Do any cleanup here.
*/
static void vesafb_destroy(struct fb_info *info)
{
struct vesafb_par *par = info->par;
fb_dealloc_cmap(&info->cmap);
arch_phys_wc_del(par->wc_cookie);
if (info->screen_base)
iounmap(info->screen_base);
release_mem_region(par->base, par->size);
framebuffer_release(info);
}
static struct fb_ops vesafb_ops = {
.owner = THIS_MODULE,
FB_DEFAULT_IOMEM_OPS,
.fb_destroy = vesafb_destroy,
.fb_setcolreg = vesafb_setcolreg,
.fb_pan_display = vesafb_pan_display,
};
static int vesafb_setup(char *options)
{
char *this_opt;
if (!options || !*options)
return 0;
while ((this_opt = strsep(&options, ",")) != NULL) {
if (!*this_opt) continue;
if (! strcmp(this_opt, "inverse"))
inverse=1;
else if (! strcmp(this_opt, "redraw"))
ypan=0;
else if (! strcmp(this_opt, "ypan"))
ypan=1;
else if (! strcmp(this_opt, "ywrap"))
ypan=2;
else if (! strcmp(this_opt, "vgapal"))
pmi_setpal=0;
else if (! strcmp(this_opt, "pmipal"))
pmi_setpal=1;
else if (! strncmp(this_opt, "mtrr:", 5))
mtrr = simple_strtoul(this_opt+5, NULL, 0);
else if (! strcmp(this_opt, "nomtrr"))
mtrr=0;
else if (! strncmp(this_opt, "vtotal:", 7))
vram_total = simple_strtoul(this_opt+7, NULL, 0);
else if (! strncmp(this_opt, "vremap:", 7))
vram_remap = simple_strtoul(this_opt+7, NULL, 0);
}
return 0;
}
static int vesafb_probe(struct platform_device *dev)
{
struct screen_info *si;
struct fb_info *info;
struct vesafb_par *par;
int i, err;
unsigned int size_vmode;
unsigned int size_remap;
unsigned int size_total;
char *option = NULL;
/*
* If we fail probing the device, the kernel might try a different
* driver. We get a copy of the attached screen_info, so that we can
* modify its values without affecting later drivers.
*/
si = dev_get_platdata(&dev->dev);
if (!si)
return -ENODEV;
si = devm_kmemdup(&dev->dev, si, sizeof(*si), GFP_KERNEL);
if (!si)
return -ENOMEM;
/* ignore error return of fb_get_options */
fb_get_options("vesafb", &option);
vesafb_setup(option);
if (si->orig_video_isVGA != VIDEO_TYPE_VLFB)
return -ENODEV;
vga_compat = !__screen_info_vbe_mode_nonvga(si);
vesafb_fix.smem_start = si->lfb_base;
vesafb_defined.bits_per_pixel = si->lfb_depth;
if (15 == vesafb_defined.bits_per_pixel)
vesafb_defined.bits_per_pixel = 16;
vesafb_defined.xres = si->lfb_width;
vesafb_defined.yres = si->lfb_height;
vesafb_fix.line_length = si->lfb_linelength;
vesafb_fix.visual = (vesafb_defined.bits_per_pixel == 8) ?
FB_VISUAL_PSEUDOCOLOR : FB_VISUAL_TRUECOLOR;
/* size_vmode -- that is the amount of memory needed for the
* used video mode, i.e. the minimum amount of
* memory we need. */
size_vmode = vesafb_defined.yres * vesafb_fix.line_length;
/* size_total -- all video memory we have. Used for mtrr
* entries, resource allocation and bounds
* checking. */
size_total = si->lfb_size * 65536;
if (vram_total)
size_total = vram_total * 1024 * 1024;
if (size_total < size_vmode)
size_total = size_vmode;
/* size_remap -- the amount of video memory we are going to
* use for vesafb. With modern cards it is no
* option to simply use size_total as that
* wastes plenty of kernel address space. */
size_remap = size_vmode * 2;
if (vram_remap)
size_remap = vram_remap * 1024 * 1024;
if (size_remap < size_vmode)
size_remap = size_vmode;
if (size_remap > size_total)
size_remap = size_total;
vesafb_fix.smem_len = size_remap;
#ifndef __i386__
si->vesapm_seg = 0;
#endif
if (!request_mem_region(vesafb_fix.smem_start, size_total, "vesafb")) {
printk(KERN_WARNING
"vesafb: cannot reserve video memory at 0x%lx\n",
vesafb_fix.smem_start);
/* We cannot make this fatal. Sometimes this comes from magic
spaces our resource handlers simply don't know about */
}
info = framebuffer_alloc(sizeof(struct vesafb_par), &dev->dev);
if (!info) {
release_mem_region(vesafb_fix.smem_start, size_total);
return -ENOMEM;
}
platform_set_drvdata(dev, info);
par = info->par;
info->pseudo_palette = par->pseudo_palette;
par->base = si->lfb_base;
par->size = size_total;
printk(KERN_INFO "vesafb: mode is %dx%dx%d, linelength=%d, pages=%d\n",
vesafb_defined.xres, vesafb_defined.yres, vesafb_defined.bits_per_pixel,
vesafb_fix.line_length, si->pages);
if (si->vesapm_seg) {
printk(KERN_INFO "vesafb: protected mode interface info at %04x:%04x\n",
si->vesapm_seg, si->vesapm_off);
}
if (si->vesapm_seg < 0xc000)
ypan = pmi_setpal = 0; /* not available or some DOS TSR ... */
if (ypan || pmi_setpal) {
unsigned long pmi_phys;
unsigned short *pmi_base;
pmi_phys = ((unsigned long)si->vesapm_seg << 4) + si->vesapm_off;
pmi_base = (unsigned short *)phys_to_virt(pmi_phys);
pmi_start = (void*)((char*)pmi_base + pmi_base[1]);
pmi_pal = (void*)((char*)pmi_base + pmi_base[2]);
printk(KERN_INFO "vesafb: pmi: set display start = %p, set palette = %p\n",pmi_start,pmi_pal);
if (pmi_base[3]) {
printk(KERN_INFO "vesafb: pmi: ports = ");
for (i = pmi_base[3]/2; pmi_base[i] != 0xffff; i++)
printk("%x ", pmi_base[i]);
printk("\n");
if (pmi_base[i] != 0xffff) {
/*
* memory areas not supported (yet?)
*
* Rules are: we have to set up a descriptor for the requested
* memory area and pass it in the ES register to the BIOS function.
*/
printk(KERN_INFO "vesafb: can't handle memory requests, pmi disabled\n");
ypan = pmi_setpal = 0;
}
}
}
if (vesafb_defined.bits_per_pixel == 8 && !pmi_setpal && !vga_compat) {
printk(KERN_WARNING "vesafb: hardware palette is unchangeable,\n"
" colors may be incorrect\n");
vesafb_fix.visual = FB_VISUAL_STATIC_PSEUDOCOLOR;
}
vesafb_defined.xres_virtual = vesafb_defined.xres;
vesafb_defined.yres_virtual = vesafb_fix.smem_len / vesafb_fix.line_length;
if (ypan && vesafb_defined.yres_virtual > vesafb_defined.yres) {
printk(KERN_INFO "vesafb: scrolling: %s using protected mode interface, yres_virtual=%d\n",
(ypan > 1) ? "ywrap" : "ypan",vesafb_defined.yres_virtual);
} else {
printk(KERN_INFO "vesafb: scrolling: redraw\n");
vesafb_defined.yres_virtual = vesafb_defined.yres;
ypan = 0;
}
/* some dummy values for timing to make fbset happy */
vesafb_defined.pixclock = 10000000 / vesafb_defined.xres * 1000 / vesafb_defined.yres;
vesafb_defined.left_margin = (vesafb_defined.xres / 8) & 0xf8;
vesafb_defined.hsync_len = (vesafb_defined.xres / 8) & 0xf8;
vesafb_defined.red.offset = si->red_pos;
vesafb_defined.red.length = si->red_size;
vesafb_defined.green.offset = si->green_pos;
vesafb_defined.green.length = si->green_size;
vesafb_defined.blue.offset = si->blue_pos;
vesafb_defined.blue.length = si->blue_size;
vesafb_defined.transp.offset = si->rsvd_pos;
vesafb_defined.transp.length = si->rsvd_size;
if (vesafb_defined.bits_per_pixel <= 8) {
depth = vesafb_defined.green.length;
vesafb_defined.red.length =
vesafb_defined.green.length =
vesafb_defined.blue.length =
vesafb_defined.bits_per_pixel;
}
printk(KERN_INFO "vesafb: %s: "
"size=%d:%d:%d:%d, shift=%d:%d:%d:%d\n",
(vesafb_defined.bits_per_pixel > 8) ?
"Truecolor" : (vga_compat || pmi_setpal) ?
"Pseudocolor" : "Static Pseudocolor",
si->rsvd_size,
si->red_size,
si->green_size,
si->blue_size,
si->rsvd_pos,
si->red_pos,
si->green_pos,
si->blue_pos);
vesafb_fix.ypanstep = ypan ? 1 : 0;
vesafb_fix.ywrapstep = (ypan>1) ? 1 : 0;
/* request failure does not faze us, as vgacon probably has this
* region already (FIXME) */
par->region = request_region(0x3c0, 32, "vesafb");
if (mtrr == 3) {
unsigned int temp_size = size_total;
/* Find the largest power-of-two */
temp_size = roundup_pow_of_two(temp_size);
/* Try and find a power of two to add */
do {
par->wc_cookie =
arch_phys_wc_add(vesafb_fix.smem_start,
temp_size);
temp_size >>= 1;
} while (temp_size >= PAGE_SIZE && par->wc_cookie < 0);
info->screen_base = ioremap_wc(vesafb_fix.smem_start, vesafb_fix.smem_len);
} else {
if (mtrr && mtrr != 3)
WARN_ONCE(1, "Only MTRR_TYPE_WRCOMB (3) make sense\n");
info->screen_base = ioremap(vesafb_fix.smem_start, vesafb_fix.smem_len);
}
if (!info->screen_base) {
printk(KERN_ERR
"vesafb: abort, cannot ioremap video memory 0x%x @ 0x%lx\n",
vesafb_fix.smem_len, vesafb_fix.smem_start);
err = -EIO;
goto err_release_region;
}
printk(KERN_INFO "vesafb: framebuffer at 0x%lx, mapped to 0x%p, "
"using %dk, total %dk\n",
vesafb_fix.smem_start, info->screen_base,
size_remap/1024, size_total/1024);
if (!ypan)
vesafb_ops.fb_pan_display = NULL;
info->fbops = &vesafb_ops;
info->var = vesafb_defined;
info->fix = vesafb_fix;
info->flags = (ypan ? FBINFO_HWACCEL_YPAN : 0);
if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
err = -ENOMEM;
goto err_release_region;
}
err = devm_aperture_acquire_for_platform_device(dev, par->base, par->size);
if (err)
goto err_fb_dealloc_cmap;
if (register_framebuffer(info)<0) {
err = -EINVAL;
goto err_fb_dealloc_cmap;
}
fb_info(info, "%s frame buffer device\n", info->fix.id);
return 0;
err_fb_dealloc_cmap:
fb_dealloc_cmap(&info->cmap);
err_release_region:
arch_phys_wc_del(par->wc_cookie);
if (info->screen_base)
iounmap(info->screen_base);
if (par->region)
release_region(0x3c0, 32);
framebuffer_release(info);
release_mem_region(vesafb_fix.smem_start, size_total);
return err;
}
static void vesafb_remove(struct platform_device *pdev)
{
struct fb_info *info = platform_get_drvdata(pdev);
if (((struct vesafb_par *)(info->par))->region)
release_region(0x3c0, 32);
/* vesafb_destroy takes care of info cleanup */
unregister_framebuffer(info);
}
static struct platform_driver vesafb_driver = {
.driver = {
.name = "vesa-framebuffer",
},
.probe = vesafb_probe,
.remove_new = vesafb_remove,
};
module_platform_driver(vesafb_driver);
MODULE_LICENSE("GPL");