Implement memory range mapping/unmapping; Cleanup and standardize vmap API #308
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wipawel
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Signed-off-by: Pawel Wieczorkiewicz <[email protected]>
wipawel
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Great work, Pawel. Only a few nits and questions left, but really no more code changes required.
The comment regarding only being able to unmap single pages via SYSCALL_MUNMAP still applies. But I guess, now with v[un]map_range() available, it's easy to extend the functionality to cover multiple pages. But this can (and should!) be a follow-up change.
Thanks again for the hard work!
Thanks very much Mathias! I created a dedicated issue for the mmap/munmap usermode extension: #332. This should also depend on another issue: #331, but in general should be much easier to implement now. |
Summary of the changes:
* Get rid of kmap() API - it was confusing and non-standard
* Add set of generic vmap APIs and make them public
- These functions allow to specify all parameters
* All level PT flags
* Address space (via CR3 pointer)
* Add set of order-specific (4K, 2M, 1G) public vmap APIs
- Use default PT flags for non-last level
- Allow to propagate user bit on request
* Add separate sets of APIs for kernel and user address spaces
* Move all interface definitions from page.h to pagetable.h
Signed-off-by: Pawel Wieczorkiewicz <[email protected]>
This API allows to automatically map (or unmap) a range of physical
addresses specified with a start address and length.
Both vmap_range() and vunmap_range() allow to automatically map
the physical address range into multiple different memory areas
specified via vmap_flags parameter.
Support memory areas via vmap_flags:
* VMAP_IDENT - kernel address space, identity mapping
* VMAP_KERNEL - high kernel addresses (small area)
* VMAP_KERNEL_MAP - low kernel addresses (large area)
* VMAP_KERNEL_USER - kernel address space, but user memory area
* VMAP_KERNEL_USER_ACCESS - kernel address space, but user memory
area with user access permission
* VMAP_USER - user address space, user memory area
* VMAP_USER_IDENT - user address space, identity mapping, no user
access
* VMAP_USER_KERNEL - user address space, high kernel addresses, no
user access
* VMAP_USER_KERNEL_MAP - user address space, low kernel addresses,
no user access
The vmap_range() tries to use as many huge pages as possible for the
mapping.
Signed-off-by: Pawel Wieczorkiewicz <[email protected]>
Use vmap_range() to handle multiple mapping areas automatically and consistently. Standardize rules for virtual address returned by get_free_pages(). Signed-off-by: Pawel Wieczorkiewicz <[email protected]>
This resolves #253.