uvesafb: Clean up MTRR code
The old code allowed very strange memory types. Now it works like
all the other video drivers: ioremap_wc is used unconditionally,
and MTRRs are set if PAT is unavailable (unless MTRR is disabled
by a module parameter).
UC, WB, and WT support is gone. If there are MTRR conflicts that prevent
addition of a WC MTRR, adding a non-conflicting MTRR is pointless; it's
better to just turn off MTRR support entirely.
As an added bonus, any MTRR added is freed on unload.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/video/uvesafb.c b/drivers/video/uvesafb.c
index e328a61..296279b 100644
--- a/drivers/video/uvesafb.c
+++ b/drivers/video/uvesafb.c
@@ -24,9 +24,6 @@
#ifdef CONFIG_X86
#include <video/vga.h>
#endif
-#ifdef CONFIG_MTRR
-#include <asm/mtrr.h>
-#endif
#include "edid.h"
static struct cb_id uvesafb_cn_id = {
@@ -1540,67 +1537,30 @@
static void uvesafb_init_mtrr(struct fb_info *info)
{
-#ifdef CONFIG_MTRR
+ struct uvesafb_par *par = info->par;
+
if (mtrr && !(info->fix.smem_start & (PAGE_SIZE - 1))) {
int temp_size = info->fix.smem_len;
- unsigned int type = 0;
- switch (mtrr) {
- case 1:
- type = MTRR_TYPE_UNCACHABLE;
- break;
- case 2:
- type = MTRR_TYPE_WRBACK;
- break;
- case 3:
- type = MTRR_TYPE_WRCOMB;
- break;
- case 4:
- type = MTRR_TYPE_WRTHROUGH;
- break;
- default:
- type = 0;
- break;
- }
+ int rc;
- if (type) {
- int rc;
+ /* Find the largest power-of-two */
+ temp_size = roundup_pow_of_two(temp_size);
- /* Find the largest power-of-two */
- temp_size = roundup_pow_of_two(temp_size);
+ /* Try and find a power of two to add */
+ do {
+ rc = arch_phys_wc_add(info->fix.smem_start, temp_size);
+ temp_size >>= 1;
+ } while (temp_size >= PAGE_SIZE && rc == -EINVAL);
- /* Try and find a power of two to add */
- do {
- rc = mtrr_add(info->fix.smem_start,
- temp_size, type, 1);
- temp_size >>= 1;
- } while (temp_size >= PAGE_SIZE && rc == -EINVAL);
- }
+ if (rc >= 0)
+ par->mtrr_handle = rc;
}
-#endif /* CONFIG_MTRR */
}
static void uvesafb_ioremap(struct fb_info *info)
{
-#ifdef CONFIG_X86
- switch (mtrr) {
- case 1: /* uncachable */
- info->screen_base = ioremap_nocache(info->fix.smem_start, info->fix.smem_len);
- break;
- case 2: /* write-back */
- info->screen_base = ioremap_cache(info->fix.smem_start, info->fix.smem_len);
- break;
- case 3: /* write-combining */
- info->screen_base = ioremap_wc(info->fix.smem_start, info->fix.smem_len);
- break;
- case 4: /* write-through */
- default:
- info->screen_base = ioremap(info->fix.smem_start, info->fix.smem_len);
- break;
- }
-#else
- info->screen_base = ioremap(info->fix.smem_start, info->fix.smem_len);
-#endif /* CONFIG_X86 */
+ info->screen_base = ioremap_wc(info->fix.smem_start, info->fix.smem_len);
}
static ssize_t uvesafb_show_vbe_ver(struct device *dev,
@@ -1851,6 +1811,7 @@
unregister_framebuffer(info);
release_region(0x3c0, 32);
iounmap(info->screen_base);
+ arch_phys_wc_del(par->mtrr_handle);
release_mem_region(info->fix.smem_start, info->fix.smem_len);
fb_destroy_modedb(info->monspecs.modedb);
fb_dealloc_cmap(&info->cmap);
@@ -1930,6 +1891,9 @@
}
}
+ if (mtrr != 3 && mtrr != 1)
+ pr_warn("uvesafb: mtrr should be set to 0 or 3; %d is unsupported", mtrr);
+
return 0;
}
#endif /* !MODULE */