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fbcon: Move console_lock for register/unlink/unregister

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Ideally console_lock becomes an implementation detail of fbcon.c and
doesn't show up anywhere in fbmem.c. We're still pretty far from that,
but at least the register/unregister code is there now.

With this the do_fb_ioctl() handler is the only code in fbmem.c still
calling console_lock().

Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Du Cheng <ducheng2@gmail.com>
Cc: Claudio Suarez <cssk@net-c.es>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Zheyu Ma <zheyuma97@gmail.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405210335.3434130-15-daniel.vetter@ffwll.ch
This commit is contained in:
Daniel Vetter 2022-04-05 23:03:32 +02:00
parent 4355355912
commit 6e7da3af00
2 changed files with 29 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
drivers/video/fbdev/core/fbcon.c
View File

@ -2756,10 +2756,12 @@ void fbcon_fb_unbind(struct fb_info *info)
int i, new_idx = -1; int i, new_idx = -1;
int idx = info->node; int idx = info->node;
WARN_CONSOLE_UNLOCKED(); console_lock();
if (!fbcon_has_console_bind) if (!fbcon_has_console_bind) {
console_unlock();
return; return;
}
for (i = first_fb_vc; i <= last_fb_vc; i++) { for (i = first_fb_vc; i <= last_fb_vc; i++) {
if (con2fb_map[i] != idx && if (con2fb_map[i] != idx &&
@ -2794,6 +2796,8 @@ void fbcon_fb_unbind(struct fb_info *info)
} }
fbcon_unbind(); fbcon_unbind();
} }
console_unlock();
} }
/* called with console_lock held */ /* called with console_lock held */
@ -2801,10 +2805,12 @@ void fbcon_fb_unregistered(struct fb_info *info)
{ {
int i, idx; int i, idx;
WARN_CONSOLE_UNLOCKED(); console_lock();
if (deferred_takeover) if (deferred_takeover) {
console_unlock();
return; return;
}
idx = info->node; idx = info->node;
for (i = first_fb_vc; i <= last_fb_vc; i++) { for (i = first_fb_vc; i <= last_fb_vc; i++) {
@ -2833,6 +2839,7 @@ void fbcon_fb_unregistered(struct fb_info *info)
if (!num_registered_fb) if (!num_registered_fb)
do_unregister_con_driver(&fb_con); do_unregister_con_driver(&fb_con);
console_unlock();
} }
void fbcon_remap_all(struct fb_info *info) void fbcon_remap_all(struct fb_info *info)
@ -2890,19 +2897,27 @@ static inline void fbcon_select_primary(struct fb_info *info)
} }
#endif /* CONFIG_FRAMEBUFFER_DETECT_PRIMARY */ #endif /* CONFIG_FRAMEBUFFER_DETECT_PRIMARY */
static bool lockless_register_fb;
module_param_named_unsafe(lockless_register_fb, lockless_register_fb, bool, 0400);
MODULE_PARM_DESC(lockless_register_fb,
"Lockless framebuffer registration for debugging [default=off]");
/* called with console_lock held */ /* called with console_lock held */
int fbcon_fb_registered(struct fb_info *info) int fbcon_fb_registered(struct fb_info *info)
{ {
int ret = 0, i, idx; int ret = 0, i, idx;
WARN_CONSOLE_UNLOCKED(); if (!lockless_register_fb)
console_lock();
else
atomic_inc(&ignore_console_lock_warning);
idx = info->node; idx = info->node;
fbcon_select_primary(info); fbcon_select_primary(info);
if (deferred_takeover) { if (deferred_takeover) {
pr_info("fbcon: Deferring console take-over\n"); pr_info("fbcon: Deferring console take-over\n");
return 0; goto out;
} }
if (info_idx == -1) { if (info_idx == -1) {
@ -2922,6 +2937,12 @@ int fbcon_fb_registered(struct fb_info *info)
} }
} }
out:
if (!lockless_register_fb)
console_unlock();
else
atomic_dec(&ignore_console_lock_warning);
return ret; return ret;
} }

23
drivers/video/fbdev/core/fbmem.c
View File

@ -1590,14 +1590,9 @@ static void do_remove_conflicting_framebuffers(struct apertures_struct *a,
} }
} }
static bool lockless_register_fb;
module_param_named_unsafe(lockless_register_fb, lockless_register_fb, bool, 0400);
MODULE_PARM_DESC(lockless_register_fb,
"Lockless framebuffer registration for debugging [default=off]");
static int do_register_framebuffer(struct fb_info *fb_info) static int do_register_framebuffer(struct fb_info *fb_info)
{ {
int i, ret; int i;
struct fb_videomode mode; struct fb_videomode mode;
if (fb_check_foreignness(fb_info)) if (fb_check_foreignness(fb_info))
@ -1666,17 +1661,7 @@ static int do_register_framebuffer(struct fb_info *fb_info)
} }
#endif #endif
if (!lockless_register_fb) return fbcon_fb_registered(fb_info);
console_lock();
else
atomic_inc(&ignore_console_lock_warning);
ret = fbcon_fb_registered(fb_info);
if (!lockless_register_fb)
console_unlock();
else
atomic_dec(&ignore_console_lock_warning);
return ret;
} }
static void unbind_console(struct fb_info *fb_info) static void unbind_console(struct fb_info *fb_info)
@ -1686,9 +1671,7 @@ static void unbind_console(struct fb_info *fb_info)
if (WARN_ON(i < 0 || i >= FB_MAX || registered_fb[i] != fb_info)) if (WARN_ON(i < 0 || i >= FB_MAX || registered_fb[i] != fb_info))
return; return;
console_lock();
fbcon_fb_unbind(fb_info); fbcon_fb_unbind(fb_info);
console_unlock();
} }
static void unlink_framebuffer(struct fb_info *fb_info) static void unlink_framebuffer(struct fb_info *fb_info)
@ -1731,9 +1714,7 @@ static void do_unregister_framebuffer(struct fb_info *fb_info)
fb_notifier_call_chain(FB_EVENT_FB_UNREGISTERED, &event); fb_notifier_call_chain(FB_EVENT_FB_UNREGISTERED, &event);
} }
#endif #endif
console_lock();
fbcon_fb_unregistered(fb_info); fbcon_fb_unregistered(fb_info);
console_unlock();
/* this may free fb info */ /* this may free fb info */
put_fb_info(fb_info); put_fb_info(fb_info);