diff options
Diffstat (limited to 'proc.h')
| -rw-r--r-- | proc.h | 64 |
1 files changed, 32 insertions, 32 deletions
@@ -8,6 +8,36 @@ #define SEG_TSS 6 // this process's task state #define NSEGS 7 +// Per-CPU state +struct cpu { + uchar id; // Local APIC ID; index into cpus[] below + struct context *scheduler; // swtch() here to enter scheduler + struct taskstate ts; // Used by x86 to find stack for interrupt + struct segdesc gdt[NSEGS]; // x86 global descriptor table + volatile uint booted; // 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. +}; + +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), // because they are constant across kernel contexts. @@ -31,13 +61,13 @@ enum procstate { UNUSED, EMBRYO, SLEEPING, RUNNABLE, RUNNING, ZOMBIE }; // Per-process state struct proc { uint sz; // Size of process memory (bytes) - pde_t* pgdir; // Linear address of proc's pgdir + pde_t* pgdir; // Page table char *kstack; // Bottom of kernel stack for this process enum procstate state; // Process state volatile int pid; // Process ID struct proc *parent; // Parent process struct trapframe *tf; // Trap frame for current syscall - struct context *context; // Switch here to run process + struct context *context; // swtch() here to run process void *chan; // If non-zero, sleeping on chan int killed; // If non-zero, have been killed struct file *ofile[NOFILE]; // Open files @@ -48,35 +78,5 @@ struct proc { // Process memory is laid out contiguously, low addresses first: // text // original data and bss -// invalid page // fixed-size stack // expandable heap - -// Per-CPU state -struct cpu { - uchar id; // Local APIC ID; index into cpus[] below - struct context *scheduler; // Switch here to enter scheduler - struct taskstate ts; // Used by x86 to find stack for interrupt - struct segdesc gdt[NSEGS]; // x86 global descriptor table - volatile uint booted; // 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; -}; - -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. ksegment 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"); // This cpu. -extern struct proc *proc asm("%gs:4"); // Current proc on this cpu. |