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Message-Id: <1692ae3da2fd85aaa267d7d38954bc701f9f7bfd.1367621039.git.luto@amacapital.net>
Date: Fri, 3 May 2013 16:00:35 -0700
From: Andy Lutomirski <luto@...capital.net>
To: linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org,
linux-fbdev@...r.kernel.org
Cc: Andy Lutomirski <luto@...capital.net>,
Michal Januszewski <spock@...too.org>
Subject: [PATCH 7/7] 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.
Signed-off-by: Andy Lutomirski <luto@...capital.net>
---
I can't test this -- the link to v86d in Documentation/fb/uvesafb.txt
seems to be broken, and Fedora doesn't seem to package it.
Documentation/fb/uvesafb.txt | 16 ++++------
drivers/video/uvesafb.c | 70 ++++++++++++--------------------------------
include/video/uvesafb.h | 1 +
3 files changed, 24 insertions(+), 63 deletions(-)
diff --git a/Documentation/fb/uvesafb.txt b/Documentation/fb/uvesafb.txt
index eefdd91..f6362d8 100644
--- a/Documentation/fb/uvesafb.txt
+++ b/Documentation/fb/uvesafb.txt
@@ -81,17 +81,11 @@ pmipal Use the protected mode interface for palette changes.
mtrr:n Setup memory type range registers for the framebuffer
where n:
- 0 - disabled (equivalent to nomtrr) (default)
- 1 - uncachable
- 2 - write-back
- 3 - write-combining
- 4 - write-through
-
- If you see the following in dmesg, choose the type that matches
- the old one. In this example, use "mtrr:2".
-...
-mtrr: type mismatch for e0000000,8000000 old: write-back new: write-combining
-...
+ 0 - disabled (equivalent to nomtrr)
+ 3 - write-combining (default)
+
+ Values other than 0 and 3 will result in a warning and will be
+ treated just like 3.
nomtrr Do not use memory type range registers.
diff --git a/drivers/video/uvesafb.c b/drivers/video/uvesafb.c
index d428445..4f447ad 100644
--- a/drivers/video/uvesafb.c
+++ b/drivers/video/uvesafb.c
@@ -24,9 +24,7 @@
#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 +1538,31 @@ static void uvesafb_init_info(struct fb_info *info, struct vbe_mode_ib *mode)
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 = mtrr_add_wc_if_needed(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 +1813,7 @@ static int uvesafb_remove(struct platform_device *dev)
unregister_framebuffer(info);
release_region(0x3c0, 32);
iounmap(info->screen_base);
+ mtrr_del_wc_if_needed(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 +1893,9 @@ static int uvesafb_setup(char *options)
}
}
+ if (mtrr != 3 && mtrr != 1)
+ pr_warn("uvesafb: mtrr should be set to 0 or 3; %d is unsupported", mtrr);
+
return 0;
}
#endif /* !MODULE */
diff --git a/include/video/uvesafb.h b/include/video/uvesafb.h
index 1a91850..30f5362 100644
--- a/include/video/uvesafb.h
+++ b/include/video/uvesafb.h
@@ -134,6 +134,7 @@ struct uvesafb_par {
int mode_idx;
struct vbe_crtc_ib crtc;
+ int mtrr_handle;
};
#endif /* _UVESAFB_H */
--
1.8.1.4
--
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