[PATCH -next] vsprintf: add %pad extension for dma_addr_t use

From: Joe Perches
Date: Tue Dec 03 2013 - 17:17:07 EST


dma_addr_t's can be either u32 or u64 depending
on a CONFIG option.

There are a few hundred dma_addr_t's printed via
either cast to unsigned long long, unsigned long
or no cast at all.

Add %pad to be able to emit them without the cast.

Update Documentation/printk-formats.txt too.

Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
---
Documentation/printk-formats.txt | 11 +++++++++--
lib/vsprintf.c | 33 +++++++++++++++++++++++++++------
2 files changed, 36 insertions(+), 8 deletions(-)

diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
index 445ad74..6f4eb32 100644
--- a/Documentation/printk-formats.txt
+++ b/Documentation/printk-formats.txt
@@ -55,14 +55,21 @@ 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:
+Physical addresses types phys_addr_t:

- %pa 0x01234567 or 0x0123456789abcdef
+ %pa[p] 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.

+DMA addresses types dma_addr_t:
+
+ %pad 0x01234567 or 0x0123456789abcdef
+
+ For printing a dma_addr_t type 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
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 10909c5..185b6d3 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1155,6 +1155,30 @@ char *netdev_feature_string(char *buf, char *end, const u8 *addr,
return number(buf, end, *(const netdev_features_t *)addr, spec);
}

+static noinline_for_stack
+char *address_val(char *buf, char *end, const void *addr,
+ struct printf_spec spec, const char *fmt)
+{
+ unsigned long long num;
+
+ spec.flags |= SPECIAL | SMALL | ZEROPAD;
+ spec.base = 16;
+
+ switch (fmt[1]) {
+ case 'd':
+ num = *(const dma_addr_t *)addr;
+ spec.field_width = sizeof(dma_addr_t) * 2 + 2;
+ break;
+ case 'p':
+ default:
+ num = *(const phys_addr_t *)addr;
+ spec.field_width = sizeof(phys_addr_t) * 2 + 2;
+ break;
+ }
+
+ return number(buf, end, num, spec);
+}
+
int kptr_restrict __read_mostly;

/*
@@ -1218,7 +1242,8 @@ int kptr_restrict __read_mostly;
* N no separator
* The maximum supported length is 64 bytes of the input. Consider
* to use print_hex_dump() for the larger input.
- * - 'a' For a phys_addr_t type and its derivative types (passed by reference)
+ * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
+ * (default assumed to be phys_addr_t, passed by reference)
* - 'd[234]' For a dentry name (optionally 2-4 last components)
* - 'D[234]' Same as 'd' but for a struct file
*
@@ -1353,11 +1378,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
}
break;
case 'a':
- spec.flags |= SPECIAL | SMALL | ZEROPAD;
- spec.field_width = sizeof(phys_addr_t) * 2 + 2;
- spec.base = 16;
- return number(buf, end,
- (unsigned long long) *((phys_addr_t *)ptr), spec);
+ return address_val(buf, end, ptr, spec, fmt);
case 'd':
return dentry_name(buf, end, ptr, spec, fmt);
case 'D':


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