Commit Graph

10 Commits

Author SHA1 Message Date
Ville Juven 7c893ddfc2 kmm_map: Add function to map a single page of kernel memory
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.
2023-10-09 18:59:43 +03:00
Ville Juven 04bfaf3a55 kmm_map.c: Remember to free the temporary 'pages' variable
The temp variable was freed only in error cases, but it needs to be freed
in the happy case as well.
2023-10-09 18:59:43 +03:00
Ville Juven 5dd0474269 kmm_map.c: Add way to test if addr is within kmap area or not
is_kmap_vaddr is added and used to test that a given (v)addr is actually
inside the kernel map area. This gives a speed optimization for kmm_unmap,
as it is no longer necessary to take the mm_map_lock to check if such a
mapping exists; obviously if the address is not within the kmap area, it
won't be in the list either.
2023-10-09 18:59:43 +03:00
Ville Juven a444435f8b kmm_map.c: Fix user page mapping
User pages are mapped from the currently active address environment. If
the process is running on a borrowed address environment, then the
mapping should be created from there.

This happens during (new) process creation only.
2023-10-09 18:59:43 +03:00
Ville Juven b2f9926a1b kmm_map.c: Fix call to gran_alloc
Provide the handle to gran_alloc, not pointer to handle.
2023-10-09 18:59:43 +03:00
Ville Juven c57c11c516 mm/kmap: Fix bug in kmm_unmap
Searching the current process mappings for kmappings is quite futile,
do the search in the kernel's mappings instead.
2023-09-29 21:06:16 +08:00
Ville Juven 51f8611fc0 mm/kmap: Change kmm_user_map to kmm_map_user
Naming consistency wrt kmm_map_user_page
2023-09-29 21:06:16 +08:00
Ville Juven a41f752ecc kmm/kmm_map: Add missing FAR qualifiers 2023-06-05 12:03:37 +03:00
Ville Juven 61a46ad39e mm/kmm_map: Fix code style error
As pointed out in https://github.com/apache/nuttx/pull/9368
2023-06-02 22:40:23 +08:00
Ville Juven 0476e30a6d mm/kmm_map: Add support to dynamically map pages into kernel virtual memory
This adds functionality to map pages dynamically into kernel virtual
memory. This allows implementing I/O remap for example, which is a useful
(future) feature.

Now, the first target is to support mapping user pages for the kernel.

Why? There are some userspace structures that might be needed when the
userspace process is not running. Semaphores are one such example. Signals
and the WDT timeout both need access to the user semaphore to work
properly. Even though for this only obtaining the kernel addressable
page pool virtual address is needed, for completeness a procedure is
provided to map several pages.
2023-06-02 10:50:26 +08:00