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author | Mauro Carvalho Chehab <mchehab@redhat.com> | 2012-04-16 13:18:12 (GMT) |
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committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2012-05-28 22:10:59 (GMT) |
commit | 93e4fe64ece4eccf0ff4ac69bceb389290b8ab7c (patch) | |
tree | 5794c15f0d2c47568e49379b56e9a8d139532050 /drivers/edac/edac_mc.c | |
parent | a895bf8b1e1ea4c032a8fa8a09475a2ce09fe77a (diff) | |
download | linux-93e4fe64ece4eccf0ff4ac69bceb389290b8ab7c.tar.xz |
edac: rewrite edac_align_ptr()
The edac_align_ptr() function is used to prepare data for a single
memory allocation kzalloc() call. It counts how many bytes are needed
by some data structure.
Using it as-is is not that trivial, as the quantity of memory elements
reserved is not there, but, instead, it is on a next call.
In order to avoid mistakes when using it, move the number of allocated
elements into it, making easier to use it.
Reviewed-by: Borislav Petkov <bp@amd64.org>
Cc: Aristeu Rozanski <arozansk@redhat.com>
Cc: Doug Thompson <norsk5@yahoo.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/edac/edac_mc.c')
-rw-r--r-- | drivers/edac/edac_mc.c | 44 |
1 files changed, 33 insertions, 11 deletions
diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c index 072aa81..ff8c002 100644 --- a/drivers/edac/edac_mc.c +++ b/drivers/edac/edac_mc.c @@ -101,18 +101,37 @@ const char *edac_mem_types[] = { }; EXPORT_SYMBOL_GPL(edac_mem_types); -/* 'ptr' points to a possibly unaligned item X such that sizeof(X) is 'size'. - * Adjust 'ptr' so that its alignment is at least as stringent as what the - * compiler would provide for X and return the aligned result. +/** + * edac_align_ptr - Prepares the pointer offsets for a single-shot allocation + * @p: pointer to a pointer with the memory offset to be used. At + * return, this will be incremented to point to the next offset + * @size: Size of the data structure to be reserved + * @n_elems: Number of elements that should be reserved * * If 'size' is a constant, the compiler will optimize this whole function - * down to either a no-op or the addition of a constant to the value of 'ptr'. + * down to either a no-op or the addition of a constant to the value of '*p'. + * + * The 'p' pointer is absolutely needed to keep the proper advancing + * further in memory to the proper offsets when allocating the struct along + * with its embedded structs, as edac_device_alloc_ctl_info() does it + * above, for example. + * + * At return, the pointer 'p' will be incremented to be used on a next call + * to this function. */ -void *edac_align_ptr(void *ptr, unsigned size) +void *edac_align_ptr(void **p, unsigned size, int n_elems) { unsigned align, r; + void *ptr = *p; - /* Here we assume that the alignment of a "long long" is the most + *p += size * n_elems; + + /* + * 'p' can possibly be an unaligned item X such that sizeof(X) is + * 'size'. Adjust 'p' so that its alignment is at least as + * stringent as what the compiler would provide for X and return + * the aligned result. + * Here we assume that the alignment of a "long long" is the most * stringent alignment that the compiler will ever provide by default. * As far as I know, this is a reasonable assumption. */ @@ -132,6 +151,8 @@ void *edac_align_ptr(void *ptr, unsigned size) if (r == 0) return (char *)ptr; + *p += align - r; + return (void *)(((unsigned long)ptr) + align - r); } @@ -154,6 +175,7 @@ void *edac_align_ptr(void *ptr, unsigned size) struct mem_ctl_info *edac_mc_alloc(unsigned sz_pvt, unsigned nr_csrows, unsigned nr_chans, int edac_index) { + void *ptr = NULL; struct mem_ctl_info *mci; struct csrow_info *csi, *csrow; struct rank_info *chi, *chp, *chan; @@ -168,11 +190,11 @@ struct mem_ctl_info *edac_mc_alloc(unsigned sz_pvt, unsigned nr_csrows, * stringent as what the compiler would provide if we could simply * hardcode everything into a single struct. */ - mci = (struct mem_ctl_info *)0; - csi = edac_align_ptr(&mci[1], sizeof(*csi)); - chi = edac_align_ptr(&csi[nr_csrows], sizeof(*chi)); - dimm = edac_align_ptr(&chi[nr_chans * nr_csrows], sizeof(*dimm)); - pvt = edac_align_ptr(&dimm[nr_chans * nr_csrows], sz_pvt); + mci = edac_align_ptr(&ptr, sizeof(*mci), 1); + csi = edac_align_ptr(&ptr, sizeof(*csi), nr_csrows); + chi = edac_align_ptr(&ptr, sizeof(*chi), nr_csrows * nr_chans); + dimm = edac_align_ptr(&ptr, sizeof(*dimm), nr_csrows * nr_chans); + pvt = edac_align_ptr(&ptr, sz_pvt, 1); size = ((unsigned long)pvt) + sz_pvt; mci = kzalloc(size, GFP_KERNEL); |