[Xen-changelog] [xen master] xen/vsprintf: Introduce %*pb[l] for printing bitmaps

[p***@xen.org]

commit 8cd9500958d818e3deabdd0d4164ea6fe1623d7c
Author: Andrew Cooper <***@citrix.com>
AuthorDate: Thu Sep 6 10:25:59 2018 +0000
Commit: Andrew Cooper <***@citrix.com>
CommitDate: Mon Oct 22 13:39:22 2018 +0100

xen/vsprintf: Introduce %*pb[l] for printing bitmaps

The format identifier is consistent with Linux. The code is adapted from
bitmap_scn{,list}printf() but cleaned up.

This change allows all callers to avoid needing a secondary buffer to render a
cpumask/nodemask into.

Signed-off-by: Andrew Cooper <***@citrix.com>
Acked-by: Wei Liu <***@citrix.com>
Acked-by: <***@suse.com>
---
docs/misc/printk-formats.txt | 8 ++++
xen/common/vsprintf.c | 97 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 105 insertions(+)

diff --git a/docs/misc/printk-formats.txt b/docs/misc/printk-formats.txt
index b5570bc1f1..080f498f65 100644
--- a/docs/misc/printk-formats.txt
+++ b/docs/misc/printk-formats.txt
@@ -13,6 +13,14 @@ Raw buffer as hex string:
Up to 64 characters. Buffer length expected via the field_width
paramter. i.e. printk("%*ph", 8, buffer);

+Bitmaps (e.g. cpumask/nodemask):
+
+ %*pb 4321
+ %*pbl 0,5,8-9,14
+
+ Print a bitmap as either a hex string, or a range list. Bitmap length
+ (in bits) expected via the field_width parameter.
+
Symbol/Function pointers:

%ps Symbol name with condition offset and size (iff offset != 0)
diff --git a/xen/common/vsprintf.c b/xen/common/vsprintf.c
index b0ff00c883..352d43b425 100644
--- a/xen/common/vsprintf.c
+++ b/xen/common/vsprintf.c
@@ -264,6 +264,88 @@ static char *string(char *str, char *end, const char *s,
return str;
}

+/* Print a bitmap as '0-3,6-15' */
+static char *print_bitmap_list(
+ char *str, char *end, const unsigned long *bitmap, unsigned int nr_bits)
+{
+ /* current bit is 'cur', most recently seen range is [rbot, rtop] */
+ unsigned int cur, rbot, rtop;
+ bool first = true;
+
+ rbot = cur = find_first_bit(bitmap, nr_bits);
+ while ( cur < nr_bits )
+ {
+ rtop = cur;
+ cur = find_next_bit(bitmap, nr_bits, cur + 1);
+
+ if ( cur < nr_bits && cur <= rtop + 1 )
+ continue;
+
+ if ( !first )
+ {
+ if ( str < end )
+ *str = ',';
+ str++;
+ }
+ first = false;
+
+ str = number(str, end, rbot, 10, -1, -1, 0);
+ if ( rbot < rtop )
+ {
+ if ( str < end )
+ *str = '-';
+ str++;
+
+ str = number(str, end, rtop, 10, -1, -1, 0);
+ }
+
+ rbot = cur;
+ }
+
+ return str;
+}
+
+/* Print a bitmap as a comma separated hex string. */
+static char *print_bitmap_string(
+ char *str, char *end, const unsigned long *bitmap, unsigned int nr_bits)
+{
+ const unsigned int CHUNKSZ = 32;
+ unsigned int chunksz;
+ int i;
+ bool first = true;
+
+ chunksz = nr_bits & (CHUNKSZ - 1);
+ if ( chunksz == 0 )
+ chunksz = CHUNKSZ;
+
+ /*
+ * First iteration copes with the trailing partial word if nr_bits isn't a
+ * round multiple of CHUNKSZ. All subsequent iterations work on a
+ * complete CHUNKSZ block.
+ */
+ for ( i = ROUNDUP(nr_bits, CHUNKSZ) - CHUNKSZ; i >= 0; i -= CHUNKSZ )
+ {
+ unsigned int chunkmask = (1ull << chunksz) - 1;
+ unsigned int word = i / BITS_PER_LONG;
+ unsigned int offset = i % BITS_PER_LONG;
+ unsigned long val = (bitmap[word] >> offset) & chunkmask;
+
+ if ( !first )
+ {
+ if ( str < end )
+ *str = ',';
+ str++;
+ }
+ first = false;
+
+ str = number(str, end, val, 16, DIV_ROUND_UP(chunksz, 4), -1, ZEROPAD);
+
+ chunksz = CHUNKSZ;
+ }
+
+ return str;
+}
+
/* Print a domain id, using names for system domains. (e.g. d0 or d[IDLE]) */
static char *print_domain(char *str, char *end, const struct domain *d)
{
@@ -319,6 +401,21 @@ static char *pointer(char *str, char *end, const char **fmt_ptr,
/* Custom %p suffixes. See XEN_ROOT/docs/misc/printk-formats.txt */
switch ( fmt[1] )
{
+ case 'b': /* Bitmap as hex, or list */
+ ++*fmt_ptr;
+
+ if ( field_width < 0 )
+ return str;
+
+ if ( fmt[2] == 'l' )
+ {
+ ++*fmt_ptr;
+
+ return print_bitmap_list(str, end, arg, field_width);
+ }
+
+ return print_bitmap_string(str, end, arg, field_width);
+
case 'd': /* Domain ID from a struct domain *. */
++*fmt_ptr;
return print_domain(str, end, arg);
--
generated by git-patchbot for /home/xen/git/xen.git#master