diff options
Diffstat (limited to 'proc.h')
| -rw-r--r-- | proc.h | 84 |
1 files changed, 57 insertions, 27 deletions
@@ -1,13 +1,30 @@ +// Saved registers for kernel context switches. +struct context { + uint64 ra; + uint64 sp; + + // callee-saved + uint64 s0; + uint64 s1; + uint64 s2; + uint64 s3; + uint64 s4; + uint64 s5; + uint64 s6; + uint64 s7; + uint64 s8; + uint64 s9; + uint64 s10; + uint64 s11; +}; + // Per-CPU state struct cpu { uint64 syscallno; // Temporary used by sysentry uint64 usp; // Temporary used by sysentry struct proc *proc; // The process running on this cpu or null struct cpu *cpu; // XXX - uchar apicid; // Local APIC ID - 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 + struct context scheduler; // swtch() here to enter scheduler volatile uint started; // Has the CPU started? int ncli; // Depth of pushcli nesting. int intena; // Were interrupts enabled before pushcli? @@ -17,39 +34,52 @@ extern struct cpu cpus[NCPU]; extern int ncpu; //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. -// Don't need to save %eax, %ecx, %edx, because the -// x86 convention is that the caller has saved them. -// Contexts are stored at the bottom of the stack they -// describe; the stack pointer is the address of the context. -// The layout of the context matches the layout of the stack in swtch.S -// at the "Switch stacks" comment. Switch doesn't save eip explicitly, -// but it is on the stack and allocproc() manipulates it. -struct context { - uint64 r15; - uint64 r14; - uint64 r13; - uint64 r12; - uint64 r11; - uint64 rbx; - uint64 rbp; - uint64 rip; + +// per-process data for the early trap handling code in trampoline.S. +// sits in a page by itself just under the trampoline page in the +// user page table. not specially mapped in the kernel page table. +// the sscratch register points here. +// trampoline.S saves user registers, then restores kernel_sp and +// kernel_satp. +// no need to save s0-s11 (callee-saved) since C code and swtch() save them. +struct trapframe { + /* 0 */ uint64 kernel_satp; + /* 8 */ uint64 kernel_sp; + /* 16 */ uint64 kernel_trap; // address of trap() + /* 24 */ uint64 epc; // saved user program counter + /* 32 */ uint64 ra; + /* 40 */ uint64 sp; + /* 48 */ uint64 gp; + /* 56 */ uint64 tp; + /* 64 */ uint64 t0; + /* 72 */ uint64 t1; + /* 80 */ uint64 t2; + /* 88 */ uint64 a0; + /* 96 */ uint64 a1; + /* 104 */ uint64 a2; + /* 112 */ uint64 a3; + /* 120 */ uint64 a4; + /* 128 */ uint64 a5; + /* 136 */ uint64 a6; + /* 144 */ uint64 a7; + /* 152 */ uint64 t3; + /* 160 */ uint64 t4; + /* 168 */ uint64 t5; + /* 176 */ uint64 t6; }; enum procstate { UNUSED, EMBRYO, SLEEPING, RUNNABLE, RUNNING, ZOMBIE }; // Per-process state struct proc { - char *kstack; // Bottom of kernel stack for this process, must be first entry + char *kstack; // Bottom of kernel stack for this process uint64 sz; // Size of process memory (bytes) - pde_t* pgdir; // Page table + pagetable_t pagetable; // Page table enum procstate state; // Process state int pid; // Process ID struct proc *parent; // Parent process - struct sysframe *sf; // Syscall frame for current syscall - struct context *context; // swtch() here to run process + struct trapframe *tf; // data page for trampoline.S + 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 |