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Diffstat (limited to 'drivers/staging/xillybus/README')
| -rw-r--r-- | drivers/staging/xillybus/README | 23 |
1 files changed, 0 insertions, 23 deletions
diff --git a/drivers/staging/xillybus/README b/drivers/staging/xillybus/README index d2d848ae3169..81d111b4dc28 100644 --- a/drivers/staging/xillybus/README +++ b/drivers/staging/xillybus/README @@ -26,7 +26,6 @@ Contents: -- Data granularity -- Probing -- Buffer allocation - -- Memory management -- The "nonempty" message (supporting poll) @@ -365,28 +364,6 @@ Or, if there already is a partially used page at hand, the buffer is packed into that page. It can be shown that all pages requested from the kernel (except possibly for the last) are 100% utilized this way. -Memory management ------------------ - -The tricky part about the buffer allocation procedure described above is -freeing and unmapping the buffers, in particular if something goes wrong in -the middle, and the allocations need to be rolled back. The three-stage -probing procedure makes this even more crucial, since temporary buffers are -set up and mapped in the first of its two stages. - -To keep the code clean from complicated and bug-prone memory release routines, -there are special routines for allocating memory. For example, instead of -calling kzalloc, there's - -void *xilly_malloc(struct xilly_cleanup *mem, size_t size) - -which effectively allocates a zeroed buffer of size "size". Its first -argument, "mem", is where this allocation is enlisted, so that it's released -when xillybus_do_cleanup() is called with the same "mem" structure. - -Two other functions enlist allocations in this structure: xilly_pagealloc() -for page allocations and xilly_map_single_*() for DMA mapping. - The "nonempty" message (supporting poll) --------------------------------------- |