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kmm_map: Add function to map a single page of kernel memory

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Mapping a physical page to a kernel virtual page is very simple and does
not need the kernel vma list, just get the kernel addressable virtual
address for the page.
This commit is contained in:
Ville Juven 2023-10-05 15:33:03 +03:00 committed by Petro Karashchenko
parent 04bfaf3a55
commit 7c893ddfc2
1 changed files with 28 additions and 0 deletions
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28
mm/kmap/kmm_map.c
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@ -192,6 +192,27 @@ static FAR void *map_single_user_page(uintptr_t vaddr)
return (FAR void *)vaddr;
}
/****************************************************************************
* Name: map_single_page
*
* Description:
* Map (find) a single page from the kernel addressable virtual memory
* pool.
*
* Input Parameters:
* page - The physical page.
*
* Returned Value:
* The kernel virtual address for the page, or NULL if page is not kernel
* addressable.
*
****************************************************************************/
static FAR void *map_single_page(uintptr_t page)
{
return (FAR void *)up_addrenv_page_vaddr(page);
}
/****************************************************************************
* Name: is_kmap_vaddr
*
@ -290,6 +311,13 @@ FAR void *kmm_map(FAR void **pages, size_t npages, int prot)
return NULL;
}
/* A single page can be addressed directly, if it is a kernel page */
if (npages == 1)
{
return map_single_page((uintptr_t)pages[0]);
}
/* Attempt to map the pages */
vaddr = (uintptr_t)map_pages(pages, npages, prot);