diff options
| -rw-r--r-- | console.c | 5 | ||||
| -rw-r--r-- | defs.h | 6 | ||||
| -rw-r--r-- | exec.c | 16 | ||||
| -rw-r--r-- | fs.c | 11 | ||||
| -rw-r--r-- | ide.c | 3 | ||||
| -rw-r--r-- | lapic.c | 25 | ||||
| -rw-r--r-- | main.c | 9 | ||||
| -rw-r--r-- | mmu.h | 9 | ||||
| -rw-r--r-- | pipe.c | 4 | ||||
| -rw-r--r-- | proc.c | 133 | ||||
| -rw-r--r-- | proc.h | 16 | ||||
| -rw-r--r-- | sleeplock.c | 2 | ||||
| -rw-r--r-- | spinlock.c | 14 | ||||
| -rw-r--r-- | syscall.c | 28 | ||||
| -rw-r--r-- | sysfile.c | 18 | ||||
| -rw-r--r-- | sysproc.c | 6 | ||||
| -rw-r--r-- | trap.c | 24 | ||||
| -rw-r--r-- | trapasm.S | 3 | ||||
| -rw-r--r-- | vm.c | 21 |
19 files changed, 181 insertions, 172 deletions
@@ -111,7 +111,8 @@ panic(char *s) cli(); cons.locking = 0; - cprintf("cpu with apicid %d: panic: ", cpu->apicid); + // use lapiccpunum so that we can call panic from mycpu() + cprintf("lapicid %d: panic: ", lapicid()); cprintf(s); cprintf("\n"); getcallerpcs(&s, pcs); @@ -242,7 +243,7 @@ consoleread(struct inode *ip, char *dst, int n) acquire(&cons.lock); while(n > 0){ while(input.r == input.w){ - if(proc->killed){ + if(myproc()->killed){ release(&cons.lock); ilock(ip); return -1; @@ -74,7 +74,7 @@ void kbdintr(void); // lapic.c void cmostime(struct rtcdate *r); -int cpunum(void); +int lapicid(void); extern volatile uint* lapic; void lapiceoi(void); void lapicinit(void); @@ -103,14 +103,18 @@ int pipewrite(struct pipe*, char*, int); //PAGEBREAK: 16 // proc.c +int cpuid(void); void exit(void); int fork(void); int growproc(int); int kill(int); +struct cpu* mycpu(void); +struct proc* myproc(); void pinit(void); void procdump(void); void scheduler(void) __attribute__((noreturn)); void sched(void); +void setproc(struct proc*); void sleep(void*, struct spinlock*); void userinit(void); int wait(void); @@ -17,11 +17,13 @@ exec(char *path, char **argv) struct inode *ip; struct proghdr ph; pde_t *pgdir, *oldpgdir; + struct proc *curproc = myproc(); begin_op(); if((ip = namei(path)) == 0){ end_op(); + cprintf("exec: fail\n"); return -1; } ilock(ip); @@ -89,15 +91,15 @@ exec(char *path, char **argv) for(last=s=path; *s; s++) if(*s == '/') last = s+1; - safestrcpy(proc->name, last, sizeof(proc->name)); + safestrcpy(curproc->name, last, sizeof(curproc->name)); // Commit to the user image. - oldpgdir = proc->pgdir; - proc->pgdir = pgdir; - proc->sz = sz; - proc->tf->eip = elf.entry; // main - proc->tf->esp = sp; - switchuvm(proc); + oldpgdir = curproc->pgdir; + curproc->pgdir = pgdir; + curproc->sz = sz; + curproc->tf->eip = elf.entry; // main + curproc->tf->esp = sp; + switchuvm(curproc); freevm(oldpgdir); return 0; @@ -169,7 +169,7 @@ iinit(int dev) for(i = 0; i < NINODE; i++) { initsleeplock(&icache.inode[i].lock, "inode"); } - + readsb(dev, &sb); cprintf("sb: size %d nblocks %d ninodes %d nlog %d logstart %d\ inodestart %d bmap start %d\n", sb.size, sb.nblocks, @@ -451,13 +451,6 @@ readi(struct inode *ip, char *dst, uint off, uint n) for(tot=0; tot<n; tot+=m, off+=m, dst+=m){ bp = bread(ip->dev, bmap(ip, off/BSIZE)); m = min(n - tot, BSIZE - off%BSIZE); - /* - cprintf("data off %d:\n", off); - for (int j = 0; j < min(m, 10); j++) { - cprintf("%x ", bp->data[off%BSIZE+j]); - } - cprintf("\n"); - */ memmove(dst, bp->data + off%BSIZE, m); brelse(bp); } @@ -617,7 +610,7 @@ namex(char *path, int nameiparent, char *name) if(*path == '/') ip = iget(ROOTDEV, ROOTINO); else - ip = idup(proc->cwd); + ip = idup(myproc()->cwd); while((path = skipelem(path, name)) != 0){ ilock(ip); @@ -108,9 +108,9 @@ ideintr(void) // First queued buffer is the active request. acquire(&idelock); + if((b = idequeue) == 0){ release(&idelock); - // cprintf("spurious IDE interrupt\n"); return; } idequeue = b->qnext; @@ -164,5 +164,6 @@ iderw(struct buf *b) sleep(b, &idelock); } + release(&idelock); } @@ -9,7 +9,6 @@ #include "traps.h" #include "mmu.h" #include "x86.h" -#include "proc.h" // ncpu // Local APIC registers, divided by 4 for use as uint[] indices. #define ID (0x0020/4) // ID @@ -99,31 +98,11 @@ lapicinit(void) } int -cpunum(void) +lapicid(void) { - int apicid, i; - - // Cannot call cpu when interrupts are enabled: - // result not guaranteed to last long enough to be used! - // Would prefer to panic but even printing is chancy here: - // almost everything, including cprintf and panic, calls cpu, - // often indirectly through acquire and release. - if(readeflags()&FL_IF){ - static int n; - if(n++ == 0) - cprintf("cpu called from %x with interrupts enabled\n", - __builtin_return_address(0)); - } - if (!lapic) return 0; - - apicid = lapic[ID] >> 24; - for (i = 0; i < ncpu; ++i) { - if (cpus[i].apicid == apicid) - return i; - } - panic("unknown apicid\n"); + return lapic[ID] >> 24; } // Acknowledge interrupt. @@ -22,7 +22,6 @@ main(void) mpinit(); // detect other processors lapicinit(); // interrupt controller seginit(); // segment descriptors - cprintf("\ncpu%d: starting xv6\n\n", cpunum()); picinit(); // another interrupt controller ioapicinit(); // another interrupt controller consoleinit(); // console hardware @@ -31,7 +30,7 @@ main(void) tvinit(); // trap vectors binit(); // buffer cache fileinit(); // file table - ideinit(); // disk + ideinit(); // disk if(!ismp) timerinit(); // uniprocessor timer startothers(); // start other processors @@ -54,9 +53,9 @@ mpenter(void) static void mpmain(void) { - cprintf("cpu%d: starting\n", cpunum()); + cprintf("cpu%d: starting %d\n", cpuid(), cpuid()); idtinit(); // load idt register - xchg(&cpu->started, 1); // tell startothers() we're up + xchg(&(mycpu()->started), 1); // tell startothers() we're up scheduler(); // start running processes } @@ -78,7 +77,7 @@ startothers(void) memmove(code, _binary_entryother_start, (uint)_binary_entryother_size); for(c = cpus; c < cpus+ncpu; c++){ - if(c == cpus+cpunum()) // We've started already. + if(c == mycpu()) // We've started already. continue; // Tell entryother.S what stack to use, where to enter, and what @@ -42,13 +42,12 @@ // various segment selectors. #define SEG_KCODE 1 // kernel code #define SEG_KDATA 2 // kernel data+stack -#define SEG_KCPU 3 // kernel per-cpu data -#define SEG_UCODE 4 // user code -#define SEG_UDATA 5 // user data+stack -#define SEG_TSS 6 // this process's task state +#define SEG_UCODE 3 // user code +#define SEG_UDATA 4 // user data+stack +#define SEG_TSS 5 // this process's task state // cpu->gdt[NSEGS] holds the above segments. -#define NSEGS 7 +#define NSEGS 6 //PAGEBREAK! #ifndef __ASSEMBLER__ @@ -83,7 +83,7 @@ pipewrite(struct pipe *p, char *addr, int n) acquire(&p->lock); for(i = 0; i < n; i++){ while(p->nwrite == p->nread + PIPESIZE){ //DOC: pipewrite-full - if(p->readopen == 0 || proc->killed){ + if(p->readopen == 0 || myproc()->killed){ release(&p->lock); return -1; } @@ -104,7 +104,7 @@ piperead(struct pipe *p, char *addr, int n) acquire(&p->lock); while(p->nread == p->nwrite && p->writeopen){ //DOC: pipe-empty - if(proc->killed){ + if(myproc()->killed){ release(&p->lock); return -1; } @@ -26,6 +26,45 @@ pinit(void) initlock(&ptable.lock, "ptable"); } +// Must be called with interrupts disabled +int +cpuid() { + return mycpu()-cpus; +} + +// Must be called with interrupts disabled to avoid the caller being rescheduled +// between reading lapicid and running through the loop. +struct cpu* +mycpu(void) +{ + int apicid, i; + + if(readeflags()&FL_IF) + panic("mycpu called with interrupts enabled\n"); + + apicid = lapicid(); + // APIC IDs are not guaranteed to be contiguous. Maybe we should have + // a reverse map, or reserve a register to store &cpus[i]. + for (i = 0; i < ncpu; ++i) { + if (cpus[i].apicid == apicid) + return &cpus[i]; + } + panic("unknown apicid\n"); +} + +// Disable interrupts so that we are not rescheduled +// while reading proc from the cpu structure +struct proc* +myproc(void) { + struct cpu *c; + struct proc *p; + pushcli(); + c = mycpu(); + p = c->proc; + popcli(); + return p; +} + //PAGEBREAK: 32 // Look in the process table for an UNUSED proc. // If found, change state to EMBRYO and initialize @@ -120,17 +159,18 @@ int growproc(int n) { uint sz; + struct proc *curproc = myproc(); - sz = proc->sz; + sz = curproc->sz; if(n > 0){ - if((sz = allocuvm(proc->pgdir, sz, sz + n)) == 0) + if((sz = allocuvm(curproc->pgdir, sz, sz + n)) == 0) return -1; } else if(n < 0){ - if((sz = deallocuvm(proc->pgdir, sz, sz + n)) == 0) + if((sz = deallocuvm(curproc->pgdir, sz, sz + n)) == 0) return -1; } - proc->sz = sz; - switchuvm(proc); + curproc->sz = sz; + switchuvm(curproc); return 0; } @@ -142,32 +182,33 @@ fork(void) { int i, pid; struct proc *np; + struct proc *curproc = myproc(); // Allocate process. if((np = allocproc()) == 0){ return -1; } - // Copy process state from p. - if((np->pgdir = copyuvm(proc->pgdir, proc->sz)) == 0){ + // Copy process state from proc. + if((np->pgdir = copyuvm(curproc->pgdir, curproc->sz)) == 0){ kfree(np->kstack); np->kstack = 0; np->state = UNUSED; return -1; } - np->sz = proc->sz; - np->parent = proc; - *np->tf = *proc->tf; + np->sz = curproc->sz; + np->parent = curproc; + *np->tf = *curproc->tf; // Clear %eax so that fork returns 0 in the child. np->tf->eax = 0; for(i = 0; i < NOFILE; i++) - if(proc->ofile[i]) - np->ofile[i] = filedup(proc->ofile[i]); - np->cwd = idup(proc->cwd); + if(curproc->ofile[i]) + np->ofile[i] = filedup(curproc->ofile[i]); + np->cwd = idup(curproc->cwd); - safestrcpy(np->name, proc->name, sizeof(proc->name)); + safestrcpy(np->name, curproc->name, sizeof(curproc->name)); pid = np->pid; @@ -186,33 +227,34 @@ fork(void) void exit(void) { + struct proc *curproc = myproc(); struct proc *p; int fd; - if(proc == initproc) + if(curproc == initproc) panic("init exiting"); // Close all open files. for(fd = 0; fd < NOFILE; fd++){ - if(proc->ofile[fd]){ - fileclose(proc->ofile[fd]); - proc->ofile[fd] = 0; + if(curproc->ofile[fd]){ + fileclose(curproc->ofile[fd]); + curproc->ofile[fd] = 0; } } begin_op(); - iput(proc->cwd); + iput(curproc->cwd); end_op(); - proc->cwd = 0; + curproc->cwd = 0; acquire(&ptable.lock); // Parent might be sleeping in wait(). - wakeup1(proc->parent); + wakeup1(curproc->parent); // Pass abandoned children to init. for(p = ptable.proc; p < &ptable.proc[NPROC]; p++){ - if(p->parent == proc){ + if(p->parent == curproc){ p->parent = initproc; if(p->state == ZOMBIE) wakeup1(initproc); @@ -220,7 +262,7 @@ exit(void) } // Jump into the scheduler, never to return. - proc->state = ZOMBIE; + curproc->state = ZOMBIE; sched(); panic("zombie exit"); } @@ -232,13 +274,14 @@ wait(void) { struct proc *p; int havekids, pid; - + struct proc *curproc = myproc(); + acquire(&ptable.lock); for(;;){ // Scan through table looking for exited children. havekids = 0; for(p = ptable.proc; p < &ptable.proc[NPROC]; p++){ - if(p->parent != proc) + if(p->parent != curproc) continue; havekids = 1; if(p->state == ZOMBIE){ @@ -258,13 +301,13 @@ wait(void) } // No point waiting if we don't have any children. - if(!havekids || proc->killed){ + if(!havekids || curproc->killed){ release(&ptable.lock); return -1; } // Wait for children to exit. (See wakeup1 call in proc_exit.) - sleep(proc, &ptable.lock); //DOC: wait-sleep + sleep(curproc, &ptable.lock); //DOC: wait-sleep } } @@ -280,7 +323,9 @@ void scheduler(void) { struct proc *p; - + struct cpu *c = mycpu(); + c->proc = 0; + for(;;){ // Enable interrupts on this processor. sti(); @@ -294,15 +339,16 @@ scheduler(void) // Switch to chosen process. It is the process's job // to release ptable.lock and then reacquire it // before jumping back to us. - proc = p; + c->proc = p; switchuvm(p); p->state = RUNNING; - swtch(&cpu->scheduler, p->context); + + swtch(&(c->scheduler), p->context); switchkvm(); // Process is done running for now. // It should have changed its p->state before coming back. - proc = 0; + c->proc = 0; } release(&ptable.lock); @@ -320,18 +366,19 @@ void sched(void) { int intena; + struct proc *p = myproc(); if(!holding(&ptable.lock)) panic("sched ptable.lock"); - if(cpu->ncli != 1) + if(mycpu()->ncli != 1) panic("sched locks"); - if(proc->state == RUNNING) + if(p->state == RUNNING) panic("sched running"); if(readeflags()&FL_IF) panic("sched interruptible"); - intena = cpu->intena; - swtch(&proc->context, cpu->scheduler); - cpu->intena = intena; + intena = mycpu()->intena; + swtch(&p->context, mycpu()->scheduler); + mycpu()->intena = intena; } // Give up the CPU for one scheduling round. @@ -339,7 +386,7 @@ void yield(void) { acquire(&ptable.lock); //DOC: yieldlock - proc->state = RUNNABLE; + myproc()->state = RUNNABLE; sched(); release(&ptable.lock); } @@ -370,7 +417,9 @@ forkret(void) void sleep(void *chan, struct spinlock *lk) { - if(proc == 0) + struct proc *p = myproc(); + + if(p == 0) panic("sleep"); if(lk == 0) @@ -386,14 +435,14 @@ sleep(void *chan, struct spinlock *lk) acquire(&ptable.lock); //DOC: sleeplock1 release(lk); } - // Go to sleep. - proc->chan = chan; - proc->state = SLEEPING; + p->chan = chan; + p->state = SLEEPING; + sched(); // Tidy up. - proc->chan = 0; + p->chan = 0; // Reacquire original lock. if(lk != &ptable.lock){ //DOC: sleeplock2 @@ -7,26 +7,12 @@ struct cpu { volatile uint started; // Has the CPU started? int ncli; // Depth of pushcli nesting. int intena; // Were interrupts enabled before pushcli? - - // Cpu-local storage variables; see below - struct cpu *cpu; - struct proc *proc; // The currently-running process. + struct proc *proc; // The process running on this cpu or null }; extern struct cpu cpus[NCPU]; extern int ncpu; -// Per-CPU variables, holding pointers to the -// current cpu and to the current process. -// The asm suffix tells gcc to use "%gs:0" to refer to cpu -// and "%gs:4" to refer to proc. seginit sets up the -// %gs segment register so that %gs refers to the memory -// holding those two variables in the local cpu's struct cpu. -// This is similar to how thread-local variables are implemented -// in thread libraries such as Linux pthreads. -extern struct cpu *cpu asm("%gs:0"); // &cpus[cpunum()] -extern struct proc *proc asm("%gs:4"); // cpus[cpunum()].proc - //PAGEBREAK: 17 // Saved registers for kernel context switches. // Don't need to save all the segment registers (%cs, etc), diff --git a/sleeplock.c b/sleeplock.c index 2ded78d..d0e4d91 100644 --- a/sleeplock.c +++ b/sleeplock.c @@ -27,7 +27,7 @@ acquiresleep(struct sleeplock *lk) sleep(lk, &lk->lk); } lk->locked = 1; - lk->pid = proc->pid; + lk->pid = myproc()->pid; release(&lk->lk); } @@ -38,7 +38,7 @@ acquire(struct spinlock *lk) __sync_synchronize(); // Record info about lock acquisition for debugging. - lk->cpu = cpu; + lk->cpu = mycpu(); getcallerpcs(&lk, lk->pcs); } @@ -89,7 +89,7 @@ getcallerpcs(void *v, uint pcs[]) int holding(struct spinlock *lock) { - return lock->locked && lock->cpu == cpu; + return lock->locked && lock->cpu == mycpu(); } @@ -104,9 +104,9 @@ pushcli(void) eflags = readeflags(); cli(); - if(cpu->ncli == 0) - cpu->intena = eflags & FL_IF; - cpu->ncli += 1; + if(mycpu()->ncli == 0) + mycpu()->intena = eflags & FL_IF; + mycpu()->ncli += 1; } void @@ -114,9 +114,9 @@ popcli(void) { if(readeflags()&FL_IF) panic("popcli - interruptible"); - if(--cpu->ncli < 0) + if(--mycpu()->ncli < 0) panic("popcli"); - if(cpu->ncli == 0 && cpu->intena) + if(mycpu()->ncli == 0 && mycpu()->intena) sti(); } @@ -17,7 +17,9 @@ int fetchint(uint addr, int *ip) { - if(addr >= proc->sz || addr+4 > proc->sz) + struct proc *curproc = myproc(); + + if(addr >= curproc->sz || addr+4 > curproc->sz) return -1; *ip = *(int*)(addr); return 0; @@ -30,14 +32,16 @@ int fetchstr(uint addr, char **pp) { char *s, *ep; + struct proc *curproc = myproc(); - if(addr >= proc->sz) + if(addr >= curproc->sz) return -1; *pp = (char*)addr; - ep = (char*)proc->sz; - for(s = *pp; s < ep; s++) + ep = (char*)curproc->sz; + for(s = *pp; s < ep; s++){ if(*s == 0) return s - *pp; + } return -1; } @@ -45,7 +49,7 @@ fetchstr(uint addr, char **pp) int argint(int n, int *ip) { - return fetchint(proc->tf->esp + 4 + 4*n, ip); + return fetchint((myproc()->tf->esp) + 4 + 4*n, ip); } // Fetch the nth word-sized system call argument as a pointer @@ -55,10 +59,11 @@ int argptr(int n, char **pp, int size) { int i; - + struct proc *curproc = myproc(); + if(argint(n, &i) < 0) return -1; - if(size < 0 || (uint)i >= proc->sz || (uint)i+size > proc->sz) + if(size < 0 || (uint)i >= curproc->sz || (uint)i+size > curproc->sz) return -1; *pp = (char*)i; return 0; @@ -127,13 +132,14 @@ void syscall(void) { int num; + struct proc *curproc = myproc(); - num = proc->tf->eax; + num = curproc->tf->eax; if(num > 0 && num < NELEM(syscalls) && syscalls[num]) { - proc->tf->eax = syscalls[num](); + curproc->tf->eax = syscalls[num](); } else { cprintf("%d %s: unknown sys call %d\n", - proc->pid, proc->name, num); - proc->tf->eax = -1; + curproc->pid, curproc->name, num); + curproc->tf->eax = -1; } } @@ -26,7 +26,7 @@ argfd(int n, int *pfd, struct file **pf) if(argint(n, &fd) < 0) return -1; - if(fd < 0 || fd >= NOFILE || (f=proc->ofile[fd]) == 0) + if(fd < 0 || fd >= NOFILE || (f=myproc()->ofile[fd]) == 0) return -1; if(pfd) *pfd = fd; @@ -41,10 +41,11 @@ static int fdalloc(struct file *f) { int fd; + struct proc *curproc = myproc(); for(fd = 0; fd < NOFILE; fd++){ - if(proc->ofile[fd] == 0){ - proc->ofile[fd] = f; + if(curproc->ofile[fd] == 0){ + curproc->ofile[fd] = f; return fd; } } @@ -97,7 +98,7 @@ sys_close(void) if(argfd(0, &fd, &f) < 0) return -1; - proc->ofile[fd] = 0; + myproc()->ofile[fd] = 0; fileclose(f); return 0; } @@ -373,7 +374,8 @@ sys_chdir(void) { char *path; struct inode *ip; - + struct proc *curproc = myproc(); + begin_op(); if(argstr(0, &path) < 0 || (ip = namei(path)) == 0){ end_op(); @@ -386,9 +388,9 @@ sys_chdir(void) return -1; } iunlock(ip); - iput(proc->cwd); + iput(curproc->cwd); end_op(); - proc->cwd = ip; + curproc->cwd = ip; return 0; } @@ -432,7 +434,7 @@ sys_pipe(void) fd0 = -1; if((fd0 = fdalloc(rf)) < 0 || (fd1 = fdalloc(wf)) < 0){ if(fd0 >= 0) - proc->ofile[fd0] = 0; + myproc()->ofile[fd0] = 0; fileclose(rf); fileclose(wf); return -1; @@ -39,7 +39,7 @@ sys_kill(void) int sys_getpid(void) { - return proc->pid; + return myproc()->pid; } int @@ -50,7 +50,7 @@ sys_sbrk(void) if(argint(0, &n) < 0) return -1; - addr = proc->sz; + addr = myproc()->sz; if(growproc(n) < 0) return -1; return addr; @@ -67,7 +67,7 @@ sys_sleep(void) acquire(&tickslock); ticks0 = ticks; while(ticks - ticks0 < n){ - if(proc->killed){ + if(myproc()->killed){ release(&tickslock); return -1; } @@ -37,18 +37,18 @@ void trap(struct trapframe *tf) { if(tf->trapno == T_SYSCALL){ - if(proc->killed) + if(myproc()->killed) exit(); - proc->tf = tf; + myproc()->tf = tf; syscall(); - if(proc->killed) + if(myproc()->killed) exit(); return; } switch(tf->trapno){ case T_IRQ0 + IRQ_TIMER: - if(cpunum() == 0){ + if(cpuid() == 0){ acquire(&tickslock); ticks++; wakeup(&ticks); @@ -74,38 +74,38 @@ trap(struct trapframe *tf) case T_IRQ0 + 7: case T_IRQ0 + IRQ_SPURIOUS: cprintf("cpu%d: spurious interrupt at %x:%x\n", - cpunum(), tf->cs, tf->eip); + cpuid(), tf->cs, tf->eip); lapiceoi(); break; //PAGEBREAK: 13 default: - if(proc == 0 || (tf->cs&3) == 0){ + if(myproc() == 0 || (tf->cs&3) == 0){ // In kernel, it must be our mistake. cprintf("unexpected trap %d from cpu %d eip %x (cr2=0x%x)\n", - tf->trapno, cpunum(), tf->eip, rcr2()); + tf->trapno, cpuid(), tf->eip, rcr2()); panic("trap"); } // In user space, assume process misbehaved. cprintf("pid %d %s: trap %d err %d on cpu %d " "eip 0x%x addr 0x%x--kill proc\n", - proc->pid, proc->name, tf->trapno, tf->err, cpunum(), tf->eip, + myproc()->pid, myproc()->name, tf->trapno, tf->err, cpuid(), tf->eip, rcr2()); - proc->killed = 1; + myproc()->killed = 1; } // Force process exit if it has been killed and is in user space. // (If it is still executing in the kernel, let it keep running // until it gets to the regular system call return.) - if(proc && proc->killed && (tf->cs&3) == DPL_USER) + if(myproc() && myproc()->killed && (tf->cs&3) == DPL_USER) exit(); // Force process to give up CPU on clock tick. // If interrupts were on while locks held, would need to check nlock. - if(proc && proc->state == RUNNING && tf->trapno == T_IRQ0+IRQ_TIMER) + if(myproc() && myproc()->state == RUNNING && tf->trapno == T_IRQ0+IRQ_TIMER) yield(); // Check if the process has been killed since we yielded - if(proc && proc->killed && (tf->cs&3) == DPL_USER) + if(myproc() && myproc()->killed && (tf->cs&3) == DPL_USER) exit(); } @@ -14,9 +14,6 @@ alltraps: movw $(SEG_KDATA<<3), %ax movw %ax, %ds movw %ax, %es - movw $(SEG_KCPU<<3), %ax - movw %ax, %fs - movw %ax, %gs # Call trap(tf), where tf=%esp pushl %esp @@ -21,21 +21,12 @@ seginit(void) // Cannot share a CODE descriptor for both kernel and user // because it would have to have DPL_USR, but the CPU forbids // an interrupt from CPL=0 to DPL=3. - c = &cpus[cpunum()]; + c = &cpus[cpuid()]; c->gdt[SEG_KCODE] = SEG(STA_X|STA_R, 0, 0xffffffff, 0); c->gdt[SEG_KDATA] = SEG(STA_W, 0, 0xffffffff, 0); c->gdt[SEG_UCODE] = SEG(STA_X|STA_R, 0, 0xffffffff, DPL_USER); c->gdt[SEG_UDATA] = SEG(STA_W, 0, 0xffffffff, DPL_USER); - - // Map cpu and proc -- these are private per cpu. - c->gdt[SEG_KCPU] = SEG(STA_W, &c->cpu, 8, 0); - lgdt(c->gdt, sizeof(c->gdt)); - loadgs(SEG_KCPU << 3); - - // Initialize cpu-local storage. - cpu = c; - proc = 0; } // Return the address of the PTE in page table pgdir @@ -173,13 +164,13 @@ switchuvm(struct proc *p) panic("switchuvm: no pgdir"); pushcli(); - cpu->gdt[SEG_TSS] = SEG16(STS_T32A, &cpu->ts, sizeof(cpu->ts)-1, 0); - cpu->gdt[SEG_TSS].s = 0; - cpu->ts.ss0 = SEG_KDATA << 3; - cpu->ts.esp0 = (uint)p->kstack + KSTACKSIZE; + mycpu()->gdt[SEG_TSS] = SEG16(STS_T32A, &mycpu()->ts, sizeof(mycpu()->ts)-1, 0); + mycpu()->gdt[SEG_TSS].s = 0; + mycpu()->ts.ss0 = SEG_KDATA << 3; + mycpu()->ts.esp0 = (uint)p->kstack + KSTACKSIZE; // setting IOPL=0 in eflags *and* iomb beyond the tss segment limit // forbids I/O instructions (e.g., inb and outb) from user space - cpu->ts.iomb = (ushort) 0xFFFF; + mycpu()->ts.iomb = (ushort) 0xFFFF; ltr(SEG_TSS << 3); lcr3(V2P(p->pgdir)); // switch to process's address space popcli(); |