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authorMauro Carvalho Chehab <mchehab@redhat.com>2012-04-16 15:18:12 +0200
committerMauro Carvalho Chehab <mchehab@redhat.com>2012-05-29 00:10:59 +0200
commit93e4fe64ece4eccf0ff4ac69bceb389290b8ab7c (patch)
tree5794c15f0d2c47568e49379b56e9a8d139532050 /drivers/edac/edac_mc.c
parentedac: move nr_pages to dimm struct (diff)
downloadlinux-93e4fe64ece4eccf0ff4ac69bceb389290b8ab7c.tar.xz
linux-93e4fe64ece4eccf0ff4ac69bceb389290b8ab7c.zip
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.c44
1 files changed, 33 insertions, 11 deletions
diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c
index 072aa81b4a70..ff8c0020649c 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);