From mboxrd@z Thu Jan  1 00:00:00 1970
From: mark.rutland@arm.com (Mark Rutland)
Date: Fri, 29 Apr 2016 16:16:39 +0100
Subject: [PATCH 10/12] kexec: arrange for paddr_vmcoreinfo_note() to
 return phys_addr_t
In-Reply-To: <CAHB_Gur-6oyEheN-Pom7OwivdvrQpCBaXvM1V2H0JPFRCFZthA@mail.gmail.com>
References: <20160428092644.GX19428@n2100.arm.linux.org.uk>
 <E1aviFP-0000je-5t@rmk-PC.arm.linux.org.uk>
 <CAHB_Gur-6oyEheN-Pom7OwivdvrQpCBaXvM1V2H0JPFRCFZthA@mail.gmail.com>
Message-ID: <20160429151639.GC23726@leverpostej>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Fri, Apr 29, 2016 at 08:36:43PM +0530, Pratyush Anand wrote:
> > +       phys_addr_t vmcore_base = paddr_vmcoreinfo_note();
> > +       return sprintf(buf, "%pa %x\n", &vmcore_base,
> 
> Why do we pass &vmcore_base? Shouldn't it be vmcore_base?

The %pa* printk format specifiers take the value by reference (as
phys_addr_t and friends are not necessarily the same width as a
pointer). Per Documentation/printk-formats.txt:

Physical addresses types phys_addr_t:

        %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.

So the above prints the value of vmcore_base as expected.

Mark.