vsprintf: Add support for IORESOURCE_UNSET in %pR

Sometimes we have a struct resource where we know the type (MEM/IO/etc.)
and the size, but we haven't assigned address space for it.  The
IORESOURCE_UNSET flag is a way to indicate this situation.  For these
"unset" resources, the start address is meaningless, so print only the
size, e.g.,

  - pci 0000:0c:00.0: reg 184: [mem 0x00000000-0x00001fff 64bit]
  + pci 0000:0c:00.0: reg 184: [mem size 0x2000 64bit]

For %pr (printing with raw flags), we still print the address range,
because %pr is mostly used for debugging anyway.

Thanks to Fengguang Wu <fengguang.wu@intel.com> for suggesting
resource_size().

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

2 files changed, 10 insertions, 5 deletions

diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index 9fcaac8bc4f6..5e3a906cc089 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -51,7 +51,7 @@ struct resource {
 
 #define IORESOURCE_EXCLUSIVE    0x08000000      /* Userland may not map this resource */
 #define IORESOURCE_DISABLED     0x10000000
-#define IORESOURCE_UNSET        0x20000000
+#define IORESOURCE_UNSET        0x20000000      /* No address assigned yet */
 #define IORESOURCE_AUTO         0x40000000
 #define IORESOURCE_BUSY         0x80000000      /* Driver has marked this resource busy */
 
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 185b6d300ebc..5e2cf6f342f8 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -719,10 +719,15 @@ char *resource_string(char *buf, char *end, struct resource *res,
                 specp = &mem_spec;
                 decode = 0;
         }
-        p = number(p, pend, res->start, *specp);
-        if (res->start != res->end) {
-                *p++ = '-';
-                p = number(p, pend, res->end, *specp);
+        if (decode && res->flags & IORESOURCE_UNSET) {
+                p = string(p, pend, "size ", str_spec);
+                p = number(p, pend, resource_size(res), *specp);
+        } else {
+                p = number(p, pend, res->start, *specp);
+                if (res->start != res->end) {
+                        *p++ = '-';
+                        p = number(p, pend, res->end, *specp);
+                }
         }
         if (decode) {
                 if (res->flags & IORESOURCE_MEM_64)