freebsd-skq/sys/i386/include/cpu.h

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1993-06-12 14:58:17 +00:00
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)cpu.h 5.4 (Berkeley) 5/9/91
1999-08-28 01:08:13 +00:00
* $FreeBSD$
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*/
#ifndef _MACHINE_CPU_H_
#define _MACHINE_CPU_H_
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/*
* Definitions unique to i386 cpu support.
*/
#include <machine/psl.h>
#include <machine/frame.h>
#include <machine/segments.h>
#include <machine/globals.h>
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/*
* definitions of cpu-dependent requirements
* referenced in generic code
*/
#undef COPY_SIGCODE /* don't copy sigcode above user stack in exec */
#define cpu_exec(p) /* nothing */
#define cpu_swapin(p) /* nothing */
#define cpu_getstack(p) ((p)->p_md.md_regs->tf_esp)
#define cpu_setstack(p, ap) ((p)->p_md.md_regs->tf_esp = (ap))
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#define CLKF_USERMODE(framep) \
((ISPL((framep)->cf_cs) == SEL_UPL) || (framep->cf_eflags & PSL_VM))
#define CLKF_INTR(framep) (curproc->p_intr_nesting_level >= 2)
#define CLKF_PC(framep) ((framep)->cf_eip)
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/*
* astpending bits
*/
#define AST_PENDING 0x00000001
#define AST_RESCHED 0x00000002
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/*
* Preempt the current process if in interrupt from user mode,
* or after the current trap/syscall if in system mode.
Commit major SMP cleanups and move the BGL (big giant lock) in the syscall path inward. A system call may select whether it needs the MP lock or not (the default being that it does need it). A great deal of conditional SMP code for various deadended experiments has been removed. 'cil' and 'cml' have been removed entirely, and the locking around the cpl has been removed. The conditional separately-locked fast-interrupt code has been removed, meaning that interrupts must hold the CPL now (but they pretty much had to anyway). Another reason for doing this is that the original separate-lock for interrupts just doesn't apply to the interrupt thread mechanism being contemplated. Modifications to the cpl may now ONLY occur while holding the MP lock. For example, if an otherwise MP safe syscall needs to mess with the cpl, it must hold the MP lock for the duration and must (as usual) save/restore the cpl in a nested fashion. This is precursor work for the real meat coming later: avoiding having to hold the MP lock for common syscalls and I/O's and interrupt threads. It is expected that the spl mechanisms and new interrupt threading mechanisms will be able to run in tandem, allowing a slow piecemeal transition to occur. This patch should result in a moderate performance improvement due to the considerable amount of code that has been removed from the critical path, especially the simplification of the spl*() calls. The real performance gains will come later. Approved by: jkh Reviewed by: current, bde (exception.s) Some work taken from: luoqi's patch
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*
* XXX: if astpending is later changed to an |= here due to more flags being
* added, we will have an atomicy problem. The type of atomicy we need is
* a non-locked orl.
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*/
#define need_resched() do { \
PCPU_SET(astpending, AST_RESCHED|AST_PENDING); \
} while (0)
#define resched_wanted() (PCPU_GET(astpending) & AST_RESCHED)
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/*
* Arrange to handle pending profiling ticks before returning to user mode.
*
* XXX this is now poorly named and implemented. It used to handle only a
* single tick and the PS_OWEUPC flag served as a counter. Now there is a
* counter in the proc table and flag isn't really necessary.
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*/
#define need_proftick(p) do { \
Change and clean the mutex lock interface. mtx_enter(lock, type) becomes: mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks) mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized) similarily, for releasing a lock, we now have: mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN. We change the caller interface for the two different types of locks because the semantics are entirely different for each case, and this makes it explicitly clear and, at the same time, it rids us of the extra `type' argument. The enter->lock and exit->unlock change has been made with the idea that we're "locking data" and not "entering locked code" in mind. Further, remove all additional "flags" previously passed to the lock acquire/release routines with the exception of two: MTX_QUIET and MTX_NOSWITCH The functionality of these flags is preserved and they can be passed to the lock/unlock routines by calling the corresponding wrappers: mtx_{lock, unlock}_flags(lock, flag(s)) and mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN locks, respectively. Re-inline some lock acq/rel code; in the sleep lock case, we only inline the _obtain_lock()s in order to ensure that the inlined code fits into a cache line. In the spin lock case, we inline recursion and actually only perform a function call if we need to spin. This change has been made with the idea that we generally tend to avoid spin locks and that also the spin locks that we do have and are heavily used (i.e. sched_lock) do recurse, and therefore in an effort to reduce function call overhead for some architectures (such as alpha), we inline recursion for this case. Create a new malloc type for the witness code and retire from using the M_DEV type. The new type is called M_WITNESS and is only declared if WITNESS is enabled. Begin cleaning up some machdep/mutex.h code - specifically updated the "optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently need those. Finally, caught up to the interface changes in all sys code. Contributors: jake, jhb, jasone (in no particular order)
2001-02-09 06:11:45 +00:00
mtx_lock_spin(&sched_lock); \
(p)->p_sflag |= PS_OWEUPC; \
Change and clean the mutex lock interface. mtx_enter(lock, type) becomes: mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks) mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized) similarily, for releasing a lock, we now have: mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN. We change the caller interface for the two different types of locks because the semantics are entirely different for each case, and this makes it explicitly clear and, at the same time, it rids us of the extra `type' argument. The enter->lock and exit->unlock change has been made with the idea that we're "locking data" and not "entering locked code" in mind. Further, remove all additional "flags" previously passed to the lock acquire/release routines with the exception of two: MTX_QUIET and MTX_NOSWITCH The functionality of these flags is preserved and they can be passed to the lock/unlock routines by calling the corresponding wrappers: mtx_{lock, unlock}_flags(lock, flag(s)) and mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN locks, respectively. Re-inline some lock acq/rel code; in the sleep lock case, we only inline the _obtain_lock()s in order to ensure that the inlined code fits into a cache line. In the spin lock case, we inline recursion and actually only perform a function call if we need to spin. This change has been made with the idea that we generally tend to avoid spin locks and that also the spin locks that we do have and are heavily used (i.e. sched_lock) do recurse, and therefore in an effort to reduce function call overhead for some architectures (such as alpha), we inline recursion for this case. Create a new malloc type for the witness code and retire from using the M_DEV type. The new type is called M_WITNESS and is only declared if WITNESS is enabled. Begin cleaning up some machdep/mutex.h code - specifically updated the "optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently need those. Finally, caught up to the interface changes in all sys code. Contributors: jake, jhb, jasone (in no particular order)
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mtx_unlock_spin(&sched_lock); \
aston(); \
} while (0)
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/*
* Notify the current process (p) that it has a signal pending,
* process as soon as possible.
Commit major SMP cleanups and move the BGL (big giant lock) in the syscall path inward. A system call may select whether it needs the MP lock or not (the default being that it does need it). A great deal of conditional SMP code for various deadended experiments has been removed. 'cil' and 'cml' have been removed entirely, and the locking around the cpl has been removed. The conditional separately-locked fast-interrupt code has been removed, meaning that interrupts must hold the CPL now (but they pretty much had to anyway). Another reason for doing this is that the original separate-lock for interrupts just doesn't apply to the interrupt thread mechanism being contemplated. Modifications to the cpl may now ONLY occur while holding the MP lock. For example, if an otherwise MP safe syscall needs to mess with the cpl, it must hold the MP lock for the duration and must (as usual) save/restore the cpl in a nested fashion. This is precursor work for the real meat coming later: avoiding having to hold the MP lock for common syscalls and I/O's and interrupt threads. It is expected that the spl mechanisms and new interrupt threading mechanisms will be able to run in tandem, allowing a slow piecemeal transition to occur. This patch should result in a moderate performance improvement due to the considerable amount of code that has been removed from the critical path, especially the simplification of the spl*() calls. The real performance gains will come later. Approved by: jkh Reviewed by: current, bde (exception.s) Some work taken from: luoqi's patch
2000-03-28 07:16:37 +00:00
*
* XXX: aston() really needs to be an atomic (not locked, but an orl),
* in case need_resched() is set by an interrupt. But with astpending a
* per-cpu variable this is not trivial to do efficiently. For now we blow
* it off (asynchronous need_resched() conflicts are not critical).
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*/
#define signotify(p) aston()
#define aston() do { \
PCPU_SET(astpending, PCPU_GET(astpending) | AST_PENDING); \
} while (0)
New interrupt code from Bruce Evans. In additional to Bruce's attached list of changes, I've made the following additional changes: 1) i386/include/ipl.h renamed to spl.h as the name conflicts with the file of the same name in i386/isa/ipl.h. 2) changed all use of *mask (i.e. netmask, biomask, ttymask, etc) to *_imask (net_imask, etc). 3) changed vestige of splnet use in if_is to splimp. 4) got rid of "impmask" completely (Bruce had gotten rid of netmask), and are now using net_imask instead. 5) dozens of minor cruft to glue in Bruce's changes. These require changes I made to config(8) as well, and thus it must be rebuilt. -DG from Bruce Evans: sio: o No diff is supplied. Remove the define of setsofttty(). I hope that is enough. *.s: o i386/isa/debug.h no longer exists. The event counters became too much trouble to maintain. All function call entry and exception entry counters can be recovered by using profiling kernel (the new profiling supports all entry points; however, it is too slow to leave enabled all the time; it also). Only BDBTRAP() from debug.h is now used. That is moved to exception.s. It might be worth preserving SHOW_BITS() and calling it from _mcount() (if enabled). o T_ASTFLT is now only set just before calling trap(). o All exception handlers set SWI_AST_MASK in cpl as soon as possible after entry and arrange for _doreti to restore it atomically with exiting. It is not possible to set it atomically with entering the kernel, so it must be checked against the user mode bits in the trap frame before committing to using it. There is no place to store the old value of cpl for syscalls or traps, so there are some complications restoring it. Profiling stuff (mostly in *.s): o Changes to kern/subr_mcount.c, gcc and gprof are not supplied yet. o All interesting labels `foo' are renamed `_foo' and all uninteresting labels `_bar' are renamed `bar'. A small change to gprof allows ignoring labels not starting with underscores. o MCOUNT_LABEL() is to provide names for counters for times spent in exception handlers. o FAKE_MCOUNT() is a version of MCOUNT() suitable for exception handlers. Its arg is the pc where the exception occurred. The new mcount() pretends that this was a call from that pc to a suitable MCOUNT_LABEL(). o MEXITCOUNT is to turn off any timer started by MCOUNT(). /usr/src/sys/i386/i386/exception.s: o The non-BDB BPTTRAP() macros were doing a sti even when interrupts were disabled when the trap occurred. The sti (fixed) sti is actually a no-op unless you have my changes to machdep.c that make the debugger trap gates interrupt gates, but fixing that would make the ifdefs messier. ddb seems to be unharmed by both interrupts always disabled and always enabled (I had the branch in the fix back to front for some time :-(). o There is no known pushal bug. o tf_err can be left as garbage for syscalls. /usr/src/sys/i386/i386/locore.s: o Fix and update BDE_DEBUGGER support. o ENTRY(btext) before initialization was dangerous. o Warm boot shot was longer than intended. /usr/src/sys/i386/i386/machdep.c: o DON'T APPLY ALL OF THIS DIFF. It's what I'm using, but may require other changes. Use the following: o Remove aston() and setsoftclock(). Maybe use the following: o No netisr.h. o Spelling fix. o Delay to read the Rebooting message. o Fix for vm system unmapping a reduced area of memory after bounds_check_with_label() reduces the size of a physical i/o for a partition boundary. A similar fix is required in kern_physio.c. o Correct use of __CONCAT. It never worked here for non- ANSI cpp's. Is it time to drop support for non-ANSI? o gdt_segs init. 0xffffffffUL is bogus because ssd_limit is not 32 bits. The replacement may have the same value :-), but is more natural. o physmem was one page too low. Confusing variable names. Don't use the following: o Better numbers of buffers. Each 8K page requires up to 16 buffer headers. On my system, this results in 5576 buffers containing [up to] 2854912 bytes of memory. The usual allocation of about 384 buffers only holds 192K of disk if you use it on an fs with a block size of 512. o gdt changes for bdb. o *TGT -> *IDT changes for bdb. o #ifdefed changes for bdb. /usr/src/sys/i386/i386/microtime.s: o Use the correct asm macros. I think asm.h was copied from Mach just for microtime and isn't used now. It certainly doesn't belong in <sys>. Various macros are also duplicated in sys/i386/boot.h and libc/i386/*.h. o Don't switch to and from the IRR; it is guaranteed to be selected (default after ICU init and explicitly selected in isa.c too, and never changed until the old microtime clobbered it). /usr/src/sys/i386/i386/support.s: o Non-essential changes (none related to spls or profiling). o Removed slow loads of %gs again. The LDT support may require not relying on %gs, but loading it is not the way to fix it! Some places (copyin ...) forgot to load it. Loading it clobbers the user %gs. trap() still loads it after certain types of faults so that fuword() etc can rely on it without loading it explicitly. Exception handlers don't restore it. If we want to preserve the user %gs, then the fastest method is to not touch it except for context switches. Comparing with VM_MAXUSER_ADDRESS and branching takes only 2 or 4 cycles on a 486, while loading %gs takes 9 cycles and using it takes another. o Fixed a signed branch to unsigned. /usr/src/sys/i386/i386/swtch.s: o Move spl0() outside of idle loop. o Remove cli/sti from idle loop. sw1 does a cli, and in the unlikely event of an interrupt occurring and whichqs becoming zero, sw1 will just jump back to _idle. o There's no spl0() function in asm any more, so use splz(). o swtch() doesn't need to be superaligned, at least with the new mcounting. o Fixed a signed branch to unsigned. o Removed astoff(). /usr/src/sys/i386/i386/trap.c: o The decentralized extern decls were inconsistent, of course. o Fixed typo MATH_EMULTATE in comments. */ o Removed unused variables. o Old netmask is now impmask; print it instead. Perhaps we should print some of the new masks. o BTW, trap() should not print anything for normal debugger traps. /usr/src/sys/i386/include/asmacros.h: o DON'T APPLY ALL OF THIS DIFF. Just use some of the null macros as necessary. /usr/src/sys/i386/include/cpu.h: o CLKF_BASEPRI() changes since cpl == SWI_AST_MASK is now normal while the kernel is running. o Don't use var++ to set boolean variables. It fails after a mere 4G times :-) and is slower than storing a constant on [3-4]86s. /usr/src/sys/i386/include/cpufunc.h: o DON'T APPLY ALL OF THIS DIFF. You need mainly the include of <machine/ipl.h>. Unfortunately, <machine/ipl.h> is needed by almost everything for the inlines. /usr/src/sys/i386/include/ipl.h: o New file. Defines spl inlines and SWI macros and declares most variables related to hard and soft interrupt masks. /usr/src/sys/i386/isa/icu.h: o Moved definitions to <machine/ipl.h> /usr/src/sys/i386/isa/icu.s: o Software interrupts (SWIs) and delayed hardware interrupts (HWIs) are now handled uniformally, and dispatching them from splx() is more like dispatching them from _doreti. The dispatcher is essentially *(handler[ffs(ipending & ~cpl)](). o More care (not quite enough) is taken to avoid unbounded nesting of interrupts. o The interface to softclock() is changed so that a trap frame is not required. o Fast interrupt handlers are now handled more uniformally. Configuration is still too early (new handlers would require bits in <machine/ipl.h> and functions to vector.s). o splnnn() and splx() are no longer here; they are inline functions (could be macros for other compilers). splz() is the nontrivial part of the old splx(). /usr/src/sys/i386/isa/ipl.h o New file. Supposed to have only bus-dependent stuff. Perhaps the h/w masks should be declared here. /usr/src/sys/i386/isa/isa.c: o DON'T APPLY ALL OF THIS DIFF. You need only things involving *mask and *MASK and comments about them. netmask is now a pure software mask. It works like the softclock mask. /usr/src/sys/i386/isa/vector.s: o Reorganize AUTO_EOI* macros. o Option FAST_INTR_HANDLER_USERS_ES for people who don't trust fastintr handlers. o fastintr handlers need to metamorphose into ordinary interrupt handlers if their SWI bit has become set. Previously, sio had unintended latency for handling output completions and input of SLIP framing characters because this was not done. /usr/src/sys/net/netisr.h: o The machine-dependent stuff is now imported from <machine/ipl.h>. /usr/src/sys/sys/systm.h o DON'T APPLY ALL OF THIS DIFF. You need mainly the different splx() prototype. The spl*() prototypes are duplicated as inlines in <machine/ipl.h> but they need to be duplicated here in case there are no inlines. I sent systm.h and cpufunc.h to Garrett. We agree that spl0 should be replaced by splnone and not the other way around like I've done. /usr/src/sys/kern/kern_clock.c o splsoftclock() now lowers cpl so the direct call to softclock() works as intended. o softclock() interface changed to avoid passing the whole frame (some machines may need another change for profile_tick()). o profiling renamed _profiling to avoid ANSI namespace pollution. (I had to improve the mcount() interface and may as well fix it.) The GUPROF variant doesn't actually reference profiling here, but the 'U' in GUPROF should mean to select the microtimer mcount() and not change the interface.
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#define astoff()
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/*
* CTL_MACHDEP definitions.
*/
#define CPU_CONSDEV 1 /* dev_t: console terminal device */
#define CPU_ADJKERNTZ 2 /* int: timezone offset (seconds) */
#define CPU_DISRTCSET 3 /* int: disable resettodr() call */
#define CPU_BOOTINFO 4 /* struct: bootinfo */
#define CPU_WALLCLOCK 5 /* int: indicates wall CMOS clock */
#define CPU_MAXID 6 /* number of valid machdep ids */
#define CTL_MACHDEP_NAMES { \
{ 0, 0 }, \
{ "console_device", CTLTYPE_STRUCT }, \
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{ "adjkerntz", CTLTYPE_INT }, \
{ "disable_rtc_set", CTLTYPE_INT }, \
{ "bootinfo", CTLTYPE_STRUCT }, \
{ "wall_cmos_clock", CTLTYPE_INT }, \
}
#ifdef _KERNEL
extern char btext[];
extern char etext[];
The biggie: Get rid of the UPAGES from the top of the per-process address space. (!) Have each process use the kernel stack and pcb in the kvm space. Since the stacks are at a different address, we cannot copy the stack at fork() and allow the child to return up through the function call tree to return to user mode - create a new execution context and have the new process begin executing from cpu_switch() and go to user mode directly. In theory this should speed up fork a bit. Context switch the tss_esp0 pointer in the common tss. This is a lot simpler since than swithching the gdt[GPROC0_SEL].sd.sd_base pointer to each process's tss since the esp0 pointer is a 32 bit pointer, and the sd_base setting is split into three different bit sections at non-aligned boundaries and requires a lot of twiddling to reset. The 8K of memory at the top of the process space is now empty, and unmapped (and unmappable, it's higher than VM_MAXUSER_ADDRESS). Simplity the pmap code to manage process contexts, we no longer have to double map the UPAGES, this simplifies and should measuably speed up fork(). The following parts came from John Dyson: Set PG_G on the UPAGES that are now in kernel context, and invalidate them when swapping them out. Move the upages object (upobj) from the vmspace to the proc structure. Now that the UPAGES (pcb and kernel stack) are out of user space, make rfork(..RFMEM..) do what was intended by sharing the vmspace entirely via reference counting rather than simply inheriting the mappings.
1997-04-07 07:16:06 +00:00
void fork_trampoline __P((void));
#if defined(I386_CPU) || defined(I486_CPU)
extern u_int tsc_present;
#endif
/*
* Return contents of in-cpu fast counter as a sort of "bogo-time"
* for non-critical timing.
*/
static __inline u_int64_t
get_cyclecount(void)
{
#if defined(I386_CPU) || defined(I486_CPU)
struct timespec tv;
if (!tsc_present) {
nanotime(&tv);
return (tv.tv_sec * (u_int64_t)1000000000 + tv.tv_nsec);
}
#endif
return (rdtsc());
}
#endif
#endif /* !_MACHINE_CPU_H_ */