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[kernel] Add vm_space::allocate

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Refactored out vm_space::handle_fault's allocation code into a separate
vm_space::allocate function, and reimplemented handle_fault in terms of
the new function.
This commit is contained in:
Justin C. Miller
2021-01-28 01:08:06 -08:00
parent e3ebaeb2c8
commit 35d8d2ab2d
2 changed files with 33 additions and 17 deletions
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43
src/kernel/vm_space.cpp
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@@ -256,31 +256,40 @@ vm_space::initialize_tcb(TCB &tcb)
~memory::page_offset;
}
size_t
vm_space::allocate(uintptr_t virt, size_t count, uintptr_t *phys)
{
uintptr_t base = 0;
vm_area *area = get(virt, &base);
uintptr_t offset = (virt & ~0xfffull) - base;
if (!area || !area->allowed(offset))
return 0;
uintptr_t addr = 0;
size_t n = frame_allocator::get().allocate(count, &addr);
void *mem = memory::to_virtual<void>(addr);
if (area->flags() && vm_flags::zero)
kutil::memset(mem, 0, count * memory::frame_size);
area->commit(addr, offset, 1);
if (phys)
*phys = addr;
return n;
}
bool
vm_space::handle_fault(uintptr_t addr, fault_type fault)
{
uintptr_t page = addr & ~0xfffull;
// TODO: Handle more fult types
if (fault && fault_type::present)
return false;
uintptr_t base = 0;
vm_area *area = get(addr, &base);
if (!area || !area->allowed(page-base))
return false;
uintptr_t phys = 0;
size_t n = frame_allocator::get().allocate(1, &phys);
size_t n = allocate(addr, 1, nullptr);
kassert(n, "Failed to allocate a new page during page fault");
if (area->flags() && vm_flags::zero)
kutil::memset(memory::to_virtual<void>(phys), 0, memory::frame_size);
uintptr_t offset = page - base;
area->commit(phys, offset, 1);
return true;
return n;
}
size_t