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authorFrans Kaashoek <[email protected]>2017-01-31 17:47:16 -0500
committerFrans Kaashoek <[email protected]>2017-01-31 17:47:16 -0500
commitabf847a083888bbed4260ecacf849ea19f23e810 (patch)
tree4ae9b3487bbfe27f6382486bf877917dbb8bc030 /vm.c
parent59cdd6c63b89395d64ec9550181af5ed569b8466 (diff)
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Start of an experiment to remove the use of gs for cpu local variables.
Diffstat (limited to 'vm.c')
-rw-r--r--vm.c22
1 files changed, 10 insertions, 12 deletions
diff --git a/vm.c b/vm.c
index 9db8b67..cb159ad 100644
--- a/vm.c
+++ b/vm.c
@@ -21,21 +21,19 @@ 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[lapiccpunum()];
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);
-
+ c->cpu = c;
// Map cpu and proc -- these are private per cpu.
- c->gdt[SEG_KCPU] = SEG(STA_W, &c->cpu, 8, 0);
-
+ c->gdt[SEG_KCPU] = SEG(STA_W, &c->cpu, 4, 0);
lgdt(c->gdt, sizeof(c->gdt));
loadgs(SEG_KCPU << 3);
-
// Initialize cpu-local storage.
- cpu = c;
- proc = 0;
+ // setcpu(c);
+ setproc(0);
}
// Return the address of the PTE in page table pgdir
@@ -171,13 +169,13 @@ 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();