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authorMike Travis <travis@sgi.com>2011-05-24 17:13:12 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-05-25 08:39:45 -0700
commit4b060420a596095869a6d7849caa798d23839cd1 (patch)
treeebbbc25555d0358f73527f114f78691ac849ce3e /lib
parente50c1f609c63223adaa38f5a79b18759a00adf72 (diff)
downloadlinux-4b060420a596095869a6d7849caa798d23839cd1.tar.gz
bitmap, irq: add smp_affinity_list interface to /proc/irq
Manually adjusting the smp_affinity for IRQ's becomes unwieldy when the cpu count is large. Setting smp affinity to cpus 256 to 263 would be: echo 000000ff,00000000,00000000,00000000,00000000,00000000,00000000,00000000 > smp_affinity instead of: echo 256-263 > smp_affinity_list Think about what it looks like for cpus around say, 4088 to 4095. We already have many alternate "list" interfaces: /sys/devices/system/cpu/cpuX/indexY/shared_cpu_list /sys/devices/system/cpu/cpuX/topology/thread_siblings_list /sys/devices/system/cpu/cpuX/topology/core_siblings_list /sys/devices/system/node/nodeX/cpulist /sys/devices/pci***/***/local_cpulist Add a companion interface, smp_affinity_list to use cpu lists instead of cpu maps. This conforms to other companion interfaces where both a map and a list interface exists. This required adding a bitmap_parselist_user() function in a manner similar to the bitmap_parse_user() function. [akpm@linux-foundation.org: make __bitmap_parselist() static] Signed-off-by: Mike Travis <travis@sgi.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jack Steiner <steiner@sgi.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/bitmap.c109
1 files changed, 97 insertions, 12 deletions
diff --git a/lib/bitmap.c b/lib/bitmap.c
index 91e0ccfdb42..41baf02924e 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -571,8 +571,11 @@ int bitmap_scnlistprintf(char *buf, unsigned int buflen,
EXPORT_SYMBOL(bitmap_scnlistprintf);
/**
- * bitmap_parselist - convert list format ASCII string to bitmap
+ * __bitmap_parselist - convert list format ASCII string to bitmap
* @bp: read nul-terminated user string from this buffer
+ * @buflen: buffer size in bytes. If string is smaller than this
+ * then it must be terminated with a \0.
+ * @is_user: location of buffer, 0 indicates kernel space
* @maskp: write resulting mask here
* @nmaskbits: number of bits in mask to be written
*
@@ -587,20 +590,63 @@ EXPORT_SYMBOL(bitmap_scnlistprintf);
* %-EINVAL: invalid character in string
* %-ERANGE: bit number specified too large for mask
*/
-int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits)
+static int __bitmap_parselist(const char *buf, unsigned int buflen,
+ int is_user, unsigned long *maskp,
+ int nmaskbits)
{
unsigned a, b;
+ int c, old_c, totaldigits;
+ const char __user *ubuf = buf;
+ int exp_digit, in_range;
+ totaldigits = c = 0;
bitmap_zero(maskp, nmaskbits);
do {
- if (!isdigit(*bp))
- return -EINVAL;
- b = a = simple_strtoul(bp, (char **)&bp, BASEDEC);
- if (*bp == '-') {
- bp++;
- if (!isdigit(*bp))
+ exp_digit = 1;
+ in_range = 0;
+ a = b = 0;
+
+ /* Get the next cpu# or a range of cpu#'s */
+ while (buflen) {
+ old_c = c;
+ if (is_user) {
+ if (__get_user(c, ubuf++))
+ return -EFAULT;
+ } else
+ c = *buf++;
+ buflen--;
+ if (isspace(c))
+ continue;
+
+ /*
+ * If the last character was a space and the current
+ * character isn't '\0', we've got embedded whitespace.
+ * This is a no-no, so throw an error.
+ */
+ if (totaldigits && c && isspace(old_c))
+ return -EINVAL;
+
+ /* A '\0' or a ',' signal the end of a cpu# or range */
+ if (c == '\0' || c == ',')
+ break;
+
+ if (c == '-') {
+ if (exp_digit || in_range)
+ return -EINVAL;
+ b = 0;
+ in_range = 1;
+ exp_digit = 1;
+ continue;
+ }
+
+ if (!isdigit(c))
return -EINVAL;
- b = simple_strtoul(bp, (char **)&bp, BASEDEC);
+
+ b = b * 10 + (c - '0');
+ if (!in_range)
+ a = b;
+ exp_digit = 0;
+ totaldigits++;
}
if (!(a <= b))
return -EINVAL;
@@ -610,13 +656,52 @@ int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits)
set_bit(a, maskp);
a++;
}
- if (*bp == ',')
- bp++;
- } while (*bp != '\0' && *bp != '\n');
+ } while (buflen && c == ',');
return 0;
}
+
+int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits)
+{
+ char *nl = strchr(bp, '\n');
+ int len;
+
+ if (nl)
+ len = nl - bp;
+ else
+ len = strlen(bp);
+
+ return __bitmap_parselist(bp, len, 0, maskp, nmaskbits);
+}
EXPORT_SYMBOL(bitmap_parselist);
+
+/**
+ * bitmap_parselist_user()
+ *
+ * @ubuf: pointer to user buffer containing string.
+ * @ulen: buffer size in bytes. If string is smaller than this
+ * then it must be terminated with a \0.
+ * @maskp: pointer to bitmap array that will contain result.
+ * @nmaskbits: size of bitmap, in bits.
+ *
+ * Wrapper for bitmap_parselist(), providing it with user buffer.
+ *
+ * We cannot have this as an inline function in bitmap.h because it needs
+ * linux/uaccess.h to get the access_ok() declaration and this causes
+ * cyclic dependencies.
+ */
+int bitmap_parselist_user(const char __user *ubuf,
+ unsigned int ulen, unsigned long *maskp,
+ int nmaskbits)
+{
+ if (!access_ok(VERIFY_READ, ubuf, ulen))
+ return -EFAULT;
+ return __bitmap_parselist((const char *)ubuf,
+ ulen, 1, maskp, nmaskbits);
+}
+EXPORT_SYMBOL(bitmap_parselist_user);
+
+
/**
* bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap
* @buf: pointer to a bitmap