Re: [PATCH] dma: use %pa to print dma_addr_t

From: Joe Perches
Date: Thu Sep 12 2013 - 13:29:57 EST


On Thu, 2013-09-12 at 10:05 -0700, Randy Dunlap wrote:
> On 09/11/13 21:38, Olof Johansson wrote:
> > This resolves some warnings seen when building with CONFIG_ARM_LPAE=y, since
> > dma_addr_t might then be 64-bit:
> >
> > drivers/dma/imx-sdma.c:1092:3: warning: format '%x' expects argument of type 'unsigned int', but argument 6 has type 'dma_addr_t' [-Wformat=]
> > drivers/dma/imx-sdma.c:1166:3: warning: format '%x' expects argument of type 'unsigned int', but argument 6 has type 'dma_addr_t' [-Wformat=]
> > drivers/dma/imx-dma.c:579:3: warning: format '%x' expects argument of type 'unsigned int', but argument 6 has type 'dma_addr_t' [-Wformat=]
> > drivers/dma/imx-dma.c:579:3: warning: format '%x' expects argument of type 'unsigned int', but argument 7 has type 'dma_addr_t' [-Wformat=]
> > drivers/dma/imx-dma.c:593:4: warning: format '%x' expects argument of type 'unsigned int', but argument 9 has type 'dma_addr_t' [-Wformat=]
> > drivers/dma/imx-dma.c:603:4: warning: format '%x' expects argument of type 'unsigned int', but argument 9 has type 'dma_addr_t' [-Wformat=]
> > drivers/dma/imx-dma.c:930:2: warning: format '%x' expects argument of type 'unsigned int', but argument 6 has type 'dma_addr_t' [-Wformat=]
> > drivers/dma/imx-dma.c:930:2: warning: format '%x' expects argument of type 'unsigned int', but argument 7 has type 'dma_addr_t' [-Wformat=]
> > drivers/dma/imx-dma.c:960:2: warning: format '%x' expects argument of type 'unsigned int', but argument 6 has type 'dma_addr_t' [-Wformat=]
> > drivers/dma/imx-dma.c:960:2: warning: format '%x' expects argument of type 'unsigned int', but argument 7 has type 'dma_addr_t' [-Wformat=]
> > drivers/dma/ipu/ipu_idmac.c:1235:2: warning: format '%x' expects argument of type 'unsigned int', but argument 5 has type 'dma_addr_t' [-Wformat=]
>
>
> I've been tempted to make similar patches, but CONFIG_PHYS_ADDR_T_64BIT
> and CONFIG_ARCH_DMA_ADDR_T_64BIT are independent AFAICT,
> and %pa is for physical addresses, not necessarily DMA addresses.
>
> Am I confused?

No.

https://lkml.org/lkml/2013/6/1/202

No. If a dma_addr_t is really needed, then maybe
something like this:

---

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 43c2ea0..4df18bc 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1154,6 +1154,30 @@ 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;

/*
@@ -1217,7 +1241,8 @@ 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 phys_addr_t, dma_addr_t and derivatives
+ * (default assumed to be phys_addr_t, passed by reference)
*
* Note: The difference between 'S' and 'F' is that on ia64 and ppc64
* function pointers are really function descriptors, which contain a
@@ -1324,11 +1349,7 @@ 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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