/* bring up an AP */
static void smp_boot(cpu_t *cpu)
{
/* figure out where the trampoline is */
extern int trampoline_start, trampoline_end, trampoline_stack;
size_t trampoline_len = (uintptr_t) &trampoline_end - (uintptr_t) &trampoline_start;
/* map the trampoline into low memory */
if (!vmm_map_range(TRAMPOLINE_BASE, TRAMPOLINE_BASE, trampoline_len, VM_R | VM_W | VM_X))
panic("couldn't map SMP trampoline code");
/* allocate a stack for this AP */
void *idle_stack = memalign(IDLE_STACK_ALIGN, IDLE_STACK_SIZE);
if (!idle_stack)
panic("couldn't allocate AP stack");
/* set up this cpu's bootstrap stack */
uint64_t *rsp = (uint64_t *) &trampoline_stack;
*rsp = (uint64_t) idle_stack + IDLE_STACK_SIZE;
/* set the pointer to the cpu struct of the cpu we are booting */
booted_cpu = cpu;
/* copy the trampoline into low memory */
memcpy((void *) TRAMPOLINE_BASE, &trampoline_start, trampoline_len);
/* reset the ack flag */
ack_sipi = false;
barrier();
/* send INIT IPI */
apic_ipi_init(cpu->lapic_id);
pit_mdelay(10);
/* send STARTUP IPI */
uint8_t vector = TRAMPOLINE_BASE / FRAME_SIZE;
apic_ipi_startup(cpu->lapic_id, vector);
pit_mdelay(1);
/* send STARTUP IPI again */
if (!ack_sipi)
{
apic_ipi_startup(cpu->lapic_id, vector);
pit_mdelay(1);
}
/* wait for the AP to come up */
while (!ack_sipi)
pause_once();
/* unmap the trampoline */
vmm_unmap_range(TRAMPOLINE_BASE, trampoline_len);
}
void mmio_unmap(void *virt, size_t len)
{
/* align the address and pad with extra length */
uintptr_t aligned_virt = PAGE_ALIGN_REVERSE((uintptr_t) virt);
size_t off = (uintptr_t) virt - aligned_virt;
len += off;
/* unmap the physical memory */
vmm_unmap_range(aligned_virt, len);
/* unreserve the virtual memory in the heap */
heap_free((void *) aligned_virt);
}
void shm_detach(vmm_context_t *context, shm_descriptor_t *desc)
{
uintptr_t start = (uintptr_t)desc->base & PAGE_MASK;
size_t num_pages = desc->context->size;
vmm_unmap_range(context, start, num_pages);
}
