mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-25 11:40:53 +07:00
f23eb2b2b2
Using delayed-work for tty flip buffers ends up causing us to wait for the next tick to complete some actions. That's usually not all that noticeable, but for certain latency-critical workloads it ends up being totally unacceptable. As an extreme case of this, passing a token back-and-forth over a pty will take two ticks per iteration, so even just a thousand iterations will take 8 seconds assuming a common 250Hz configuration. Avoiding the whole delayed work issue brings that ping-pong test-case down to 0.009s on my machine. In more practical terms, this latency has been a performance problem for things like dive computer simulators (simulating the serial interface using the ptys) and for other environments (Alan mentions a CP/M emulator). Reported-by: Jef Driesen <jefdriesen@telenet.be> Acked-by: Greg KH <gregkh@suse.de> Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
166 lines
4.3 KiB
C
166 lines
4.3 KiB
C
#ifndef _KBD_KERN_H
|
|
#define _KBD_KERN_H
|
|
|
|
#include <linux/tty.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/keyboard.h>
|
|
|
|
extern struct tasklet_struct keyboard_tasklet;
|
|
|
|
extern int shift_state;
|
|
|
|
extern char *func_table[MAX_NR_FUNC];
|
|
extern char func_buf[];
|
|
extern char *funcbufptr;
|
|
extern int funcbufsize, funcbufleft;
|
|
|
|
/*
|
|
* kbd->xxx contains the VC-local things (flag settings etc..)
|
|
*
|
|
* Note: externally visible are LED_SCR, LED_NUM, LED_CAP defined in kd.h
|
|
* The code in KDGETLED / KDSETLED depends on the internal and
|
|
* external order being the same.
|
|
*
|
|
* Note: lockstate is used as index in the array key_map.
|
|
*/
|
|
struct kbd_struct {
|
|
|
|
unsigned char lockstate;
|
|
/* 8 modifiers - the names do not have any meaning at all;
|
|
they can be associated to arbitrarily chosen keys */
|
|
#define VC_SHIFTLOCK KG_SHIFT /* shift lock mode */
|
|
#define VC_ALTGRLOCK KG_ALTGR /* altgr lock mode */
|
|
#define VC_CTRLLOCK KG_CTRL /* control lock mode */
|
|
#define VC_ALTLOCK KG_ALT /* alt lock mode */
|
|
#define VC_SHIFTLLOCK KG_SHIFTL /* shiftl lock mode */
|
|
#define VC_SHIFTRLOCK KG_SHIFTR /* shiftr lock mode */
|
|
#define VC_CTRLLLOCK KG_CTRLL /* ctrll lock mode */
|
|
#define VC_CTRLRLOCK KG_CTRLR /* ctrlr lock mode */
|
|
unsigned char slockstate; /* for `sticky' Shift, Ctrl, etc. */
|
|
|
|
unsigned char ledmode:2; /* one 2-bit value */
|
|
#define LED_SHOW_FLAGS 0 /* traditional state */
|
|
#define LED_SHOW_IOCTL 1 /* only change leds upon ioctl */
|
|
#define LED_SHOW_MEM 2 /* `heartbeat': peek into memory */
|
|
|
|
unsigned char ledflagstate:4; /* flags, not lights */
|
|
unsigned char default_ledflagstate:4;
|
|
#define VC_SCROLLOCK 0 /* scroll-lock mode */
|
|
#define VC_NUMLOCK 1 /* numeric lock mode */
|
|
#define VC_CAPSLOCK 2 /* capslock mode */
|
|
#define VC_KANALOCK 3 /* kanalock mode */
|
|
|
|
unsigned char kbdmode:3; /* one 3-bit value */
|
|
#define VC_XLATE 0 /* translate keycodes using keymap */
|
|
#define VC_MEDIUMRAW 1 /* medium raw (keycode) mode */
|
|
#define VC_RAW 2 /* raw (scancode) mode */
|
|
#define VC_UNICODE 3 /* Unicode mode */
|
|
#define VC_OFF 4 /* disabled mode */
|
|
|
|
unsigned char modeflags:5;
|
|
#define VC_APPLIC 0 /* application key mode */
|
|
#define VC_CKMODE 1 /* cursor key mode */
|
|
#define VC_REPEAT 2 /* keyboard repeat */
|
|
#define VC_CRLF 3 /* 0 - enter sends CR, 1 - enter sends CRLF */
|
|
#define VC_META 4 /* 0 - meta, 1 - meta=prefix with ESC */
|
|
};
|
|
|
|
extern struct kbd_struct kbd_table[];
|
|
|
|
extern int kbd_init(void);
|
|
|
|
extern unsigned char getledstate(void);
|
|
extern void setledstate(struct kbd_struct *kbd, unsigned int led);
|
|
|
|
extern int do_poke_blanked_console;
|
|
|
|
extern void (*kbd_ledfunc)(unsigned int led);
|
|
|
|
extern int set_console(int nr);
|
|
extern void schedule_console_callback(void);
|
|
|
|
static inline void set_leds(void)
|
|
{
|
|
tasklet_schedule(&keyboard_tasklet);
|
|
}
|
|
|
|
static inline int vc_kbd_mode(struct kbd_struct * kbd, int flag)
|
|
{
|
|
return ((kbd->modeflags >> flag) & 1);
|
|
}
|
|
|
|
static inline int vc_kbd_led(struct kbd_struct * kbd, int flag)
|
|
{
|
|
return ((kbd->ledflagstate >> flag) & 1);
|
|
}
|
|
|
|
static inline void set_vc_kbd_mode(struct kbd_struct * kbd, int flag)
|
|
{
|
|
kbd->modeflags |= 1 << flag;
|
|
}
|
|
|
|
static inline void set_vc_kbd_led(struct kbd_struct * kbd, int flag)
|
|
{
|
|
kbd->ledflagstate |= 1 << flag;
|
|
}
|
|
|
|
static inline void clr_vc_kbd_mode(struct kbd_struct * kbd, int flag)
|
|
{
|
|
kbd->modeflags &= ~(1 << flag);
|
|
}
|
|
|
|
static inline void clr_vc_kbd_led(struct kbd_struct * kbd, int flag)
|
|
{
|
|
kbd->ledflagstate &= ~(1 << flag);
|
|
}
|
|
|
|
static inline void chg_vc_kbd_lock(struct kbd_struct * kbd, int flag)
|
|
{
|
|
kbd->lockstate ^= 1 << flag;
|
|
}
|
|
|
|
static inline void chg_vc_kbd_slock(struct kbd_struct * kbd, int flag)
|
|
{
|
|
kbd->slockstate ^= 1 << flag;
|
|
}
|
|
|
|
static inline void chg_vc_kbd_mode(struct kbd_struct * kbd, int flag)
|
|
{
|
|
kbd->modeflags ^= 1 << flag;
|
|
}
|
|
|
|
static inline void chg_vc_kbd_led(struct kbd_struct * kbd, int flag)
|
|
{
|
|
kbd->ledflagstate ^= 1 << flag;
|
|
}
|
|
|
|
#define U(x) ((x) ^ 0xf000)
|
|
|
|
#define BRL_UC_ROW 0x2800
|
|
|
|
/* keyboard.c */
|
|
|
|
struct console;
|
|
|
|
int getkeycode(unsigned int scancode);
|
|
int setkeycode(unsigned int scancode, unsigned int keycode);
|
|
void compute_shiftstate(void);
|
|
|
|
/* defkeymap.c */
|
|
|
|
extern unsigned int keymap_count;
|
|
|
|
/* console.c */
|
|
|
|
static inline void con_schedule_flip(struct tty_struct *t)
|
|
{
|
|
unsigned long flags;
|
|
spin_lock_irqsave(&t->buf.lock, flags);
|
|
if (t->buf.tail != NULL)
|
|
t->buf.tail->commit = t->buf.tail->used;
|
|
spin_unlock_irqrestore(&t->buf.lock, flags);
|
|
schedule_work(&t->buf.work);
|
|
}
|
|
|
|
#endif
|