taigrr/gopher-os
1
0
Fork 0
mirror of https://github.com/taigrr/gopher-os synced 2025-01-18 04:43:13 -08:00
Code Issues Projects Releases Wiki Activity

Change boot allocator signature so it returns a kernel error

Browse Source
This commit is contained in:
Achilleas Anagnostopoulos 2017-05-31 14:48:07 +01:00
parent d7eb2547dd
commit 7156b09656
2 changed files with 19 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
kernel/mem/pmm/bootmem_allocator.go
View File

@ -1,6 +1,7 @@
package pmm
import (
"github.com/achilleasa/gopher-os/kernel"
"github.com/achilleasa/gopher-os/kernel/hal/multiboot"
"github.com/achilleasa/gopher-os/kernel/kfmt/early"
"github.com/achilleasa/gopher-os/kernel/mem"
@ -11,6 +12,9 @@ var (
// which is used to bootstrap the kernel before initializing a more
// advanced memory allocator.
EarlyAllocator BootMemAllocator
errBootAllocUnsupportedPageSize = &kernel.Error{Module: "pmm.BootMemAllocator", Message: "allocator only support allocation requests of order(0)"}
errBootAllocOutOfMemory = &kernel.Error{Module: "pmm.BootMemAllocator", Message: "out of memory"}
)
// BootMemAllocator implements a rudimentary physical memory allocator which is used
@ -56,18 +60,13 @@ func (alloc *BootMemAllocator) Init() {
}
// AllocFrame scans the system memory regions reported by the bootloader and
// reseves the next available free frame. AllocFrame returns false if no more
// memory can be allocated.
// reserves the next available free frame.
//
// The allocator only supports allocating blocks equal to the page size.
// Requests for a page order > 0 will cause the allocator to return false.
//
// The use of a bool return value is intentional; if this method returned an
// error then the compiler would call runtime.convT2I which in turn invokes the
// yet uninitialized Go allocator.
func (alloc *BootMemAllocator) AllocFrame(order mem.PageOrder) (Frame, bool) {
// AllocFrame returns an error if no more memory can be allocated or when the
// requested page order is > 0.
func (alloc *BootMemAllocator) AllocFrame(order mem.PageOrder) (Frame, *kernel.Error) {
if order > 0 {
return InvalidFrame, false
return InvalidFrame, errBootAllocUnsupportedPageSize
}
var (
@ -103,11 +102,11 @@ func (alloc *BootMemAllocator) AllocFrame(order mem.PageOrder) (Frame, bool) {
})
if foundPageIndex == -1 {
return InvalidFrame, false
return InvalidFrame, errBootAllocOutOfMemory
}
alloc.allocCount++
alloc.lastAllocIndex = foundPageIndex
return Frame(foundPageIndex), true
return Frame(foundPageIndex), nil
}

11
kernel/mem/pmm/bootmem_allocator_test.go
View File

@ -36,10 +36,13 @@ func TestBootMemoryAllocator(t *testing.T) {
allocFrameCount uint64
)
for alloc.Init(); ; allocFrameCount++ {
frame, ok := alloc.AllocFrame(mem.PageOrder(0))
if !ok {
frame, err := alloc.AllocFrame(mem.PageOrder(0))
if err != nil {
if err == errBootAllocOutOfMemory {
break
}
t.Fatalf("[frame %d] unexpected allocator error: %v", allocFrameCount, err)
}
expAddress := uintptr(uint64(alloc.lastAllocIndex) * uint64(mem.PageSize))
if got := frame.Address(); got != expAddress {
@ -56,8 +59,8 @@ func TestBootMemoryAllocator(t *testing.T) {
}
// This allocator only works with order(0) blocks
if frame, ok := alloc.AllocFrame(mem.PageOrder(1)); ok || frame.IsValid() {
t.Fatalf("expected allocator to return false and an invalid frame when requested to allocate a block with order > 0; got %t, %v", ok, frame)
if frame, err := alloc.AllocFrame(mem.PageOrder(1)); err != errBootAllocUnsupportedPageSize || frame.IsValid() {
t.Fatalf("expected allocator to return errBootAllocUnsupportedPageSize and an invalid frame when requested to allocate a block with order > 0; got %v, %v", err, frame)
}
}