path: root/Documentation/printk-formats.txt
diff options
authorStepan Moskovchenko <>2013-02-21 16:43:09 -0800
committerLinus Torvalds <>2013-02-21 17:22:20 -0800
commit7d7992108d02aa92ad4c77e5d9ce14088c942e75 (patch)
treeefa7e3cbbac8f7fde794f0062d98420b551697c6 /Documentation/printk-formats.txt
parentf3cbd435b02fb45efc2c8a39c2ea19816669c412 (diff)
lib/vsprintf.c: add %pa format specifier for phys_addr_t types
Add the %pa format specifier for printing a phys_addr_t type and its derivative types (such as resource_size_t), since the physical address size on some platforms can vary based on build options, regardless of the native integer type. Signed-off-by: Stepan Moskovchenko <> Cc: Rob Landley <> Cc: George Spelvin <> Cc: Andy Shevchenko <> Cc: Stephen Boyd <> Cc: Andrei Emeltchenko <> Cc: Ingo Molnar <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
Diffstat (limited to 'Documentation/printk-formats.txt')
1 files changed, 11 insertions, 3 deletions
diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
index 8ffb274367c7..e8a6aa473bab 100644
--- a/Documentation/printk-formats.txt
+++ b/Documentation/printk-formats.txt
@@ -53,6 +53,14 @@ Struct Resources:
For printing struct resources. The 'R' and 'r' specifiers result in a
printed resource with ('R') or without ('r') a decoded flags member.
+Physical addresses:
+ %pa 0x01234567 or 0x0123456789abcdef
+ For printing a phys_addr_t type (and its derivatives, such as
+ resource_size_t) which can vary based on build options, regardless of
+ the width of the CPU data path. Passed by reference.
Raw buffer as a hex string:
%*ph 00 01 02 ... 3f
%*phC 00:01:02: ... :3f
@@ -150,9 +158,9 @@ s64 SHOULD be printed with %lld/%llx, (long long):
printk("%lld", (long long)s64_var);
If <type> is dependent on a config option for its size (e.g., sector_t,
-blkcnt_t, phys_addr_t, resource_size_t) or is architecture-dependent
-for its size (e.g., tcflag_t), use a format specifier of its largest
-possible type and explicitly cast to it. Example:
+blkcnt_t) or is architecture-dependent for its size (e.g., tcflag_t), use a
+format specifier of its largest possible type and explicitly cast to it.
printk("test: sector number/total blocks: %llu/%llu\n",
(unsigned long long)sector, (unsigned long long)blockcount);