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In pmap_mapdev(), first check whether a static mapping exists, and if so

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use it rather than allocating kva space and making another mapping.  In
pmap_unmapdev(), don't unmap/free if the mapping is static.
This commit is contained in:
Ian Lepore 2014-01-04 21:38:41 +00:00
parent ad6ea57585
commit c18fc3ff67
1 changed files with 19 additions and 4 deletions
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23
sys/arm/arm/devmap.c
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@ -207,13 +207,23 @@ arm_devmap_vtop(void * vpva, vm_size_t size)
/*
* Map a set of physical memory pages into the kernel virtual address space.
* Return a pointer to where it is mapped. This routine is intended to be used
* for mapping device memory, NOT real memory.
* Return a pointer to where it is mapped.
*
* This uses a pre-established static mapping if one exists for the requested
* range, otherwise it allocates kva space and maps the physical pages into it.
*
* This routine is intended to be used for mapping device memory, NOT real
* memory; the mapping type is inherently PTE_DEVICE in pmap_kenter_device().
*/
void *
pmap_mapdev(vm_offset_t pa, vm_size_t size)
{
vm_offset_t va, tmpva, offset;
void * rva;
/* First look in the static mapping table. */
if ((rva = arm_devmap_ptov(pa, size)) != NULL)
return (rva);
offset = pa & PAGE_MASK;
pa = trunc_page(pa);
@ -240,8 +250,13 @@ void
pmap_unmapdev(vm_offset_t va, vm_size_t size)
{
vm_offset_t tmpva, offset;
vm_size_t origsize = size;
vm_size_t origsize;
/* Nothing to do if we find the mapping in the static table. */
if (arm_devmap_vtop((void*)va, size) != DEVMAP_PADDR_NOTFOUND)
return;
origsize = size;
offset = va & PAGE_MASK;
va = trunc_page(va);
size = round_page(size + offset);