vm_page_grab: allow allocating in high memory

vm_page_grab was systematically using the VM_PAGE_SEL_DIRECTMAP selector
to play safe with existing code.

This adds a flags parameter to let callers of vm_page_grab specify their
constraints.

Linux drivers need 32bit dmas, Xen drivers use kvtophys to clear some
data. Callers of kmem_pagealloc_physmem and vm_page_grab_phys_addr also use
kvtophys. Otherwise allocations can go to highmem.

This fixes the allocation jam in the directmap segment.

* vm/vm_page.h (VM_PAGE_DMA, VM_PAGE_DMA32, VM_PAGE_DIRECTMAP,
VM_PAGE_HIGHMEM): New macros.
(vm_page_grab): Add flags parameter.
* vm/vm_resident.c (vm_page_grab): Choose allocation selector according
to flags parameter.
(vm_page_convert, vm_page_alloc): Pass VM_PAGE_HIGHMEM to vm_page_grab.
(vm_page_grab_phys_addr): Pass VM_PAGE_DIRECTMAP to vm_page_grab.
* vm/vm_fault.c (vm_fault_page): Pass VM_PAGE_HIGHMEM to vm_page_grab.
* vm/vm_map.c (vm_map_copy_steal_pages): Pass VM_PAGE_HIGHMEM to vm_page_grab.
* kern/slab.c (kmem_pagealloc_physmem): Pass VM_PAGE_DIRECTMAP to vm_page_grab.
* i386/intel/pmap.c (pmap_page_table_page_alloc): Pass VM_PAGE_DIRECTMAP to
vm_page_grab.
* xen/block.c (device_read): Pass VM_PAGE_DIRECTMAP to vm_page_grab.
* linux/dev/glue/block.c (alloc_buffer): Pass VM_PAGE_DMA32 to vm_page_grab.

1 files changed, 1 insertions, 1 deletions

diff --git a/kern/slab.c b/kern/slab.c
index d4ef847e..d44da165 100644
--- a/kern/slab.c
+++ b/kern/slab.c
@@ -370,7 +370,7 @@ kmem_pagealloc_physmem(vm_size_t size)
     assert(size == PAGE_SIZE);
 
     for (;;) {
-        page = vm_page_grab();
+        page = vm_page_grab(VM_PAGE_DIRECTMAP);
 
         if (page != NULL)
             break;