On Tue, Feb 24, 2015 at 7:00 AM, Boaz Harrosh <b...@plexistor.com> wrote:
>
> Resource providers set this flag if they want
> that request_region will print a warning in dmesg
> if this particular memory resource is locked by a driver.
>
> Thous acting as a Protocol Police about experimental
> devices that did not pass a committee approval.
>
> The Only user of this flag is x86/kernel/e820.c that
> wants to WARN about UNKNOWN memory types.
>
> NOTE: It would be preferred if I defined a general flag say
> IORESOURCE_WARN, where any kind of resource provider
> can WARN on use, but we have run out of flags in the
> 32bit long systems. So I defined a free bit from the
> resource specific flags for mem resources. This is
> why I need to check if this is a memory resource first
> so not to conflict with other resource specific flags.
> (Though actually no one is using this specific bit)
>
> CC: Thomas Gleixner <t...@linutronix.de>
> CC: Ingo Molnar <mi...@redhat.com>
> CC: "H. Peter Anvin" <h...@zytor.com>
> CC: x...@kernel.org
> CC: Dan Williams <dan.j.willi...@intel.com>
> CC: Andrew Morton <a...@linux-foundation.org>
> CC: Bjorn Helgaas <bhelg...@google.com>
> CC: Vivek Goyal <vgo...@redhat.com>
> Signed-off-by: Boaz Harrosh <b...@plexistor.com>
> ---
> arch/x86/kernel/e820.c | 3 +++
> include/linux/ioport.h | 1 +
> kernel/resource.c | 9 ++++++++-
> 3 files changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
> index 1a8a1c3..105bb37 100644
> --- a/arch/x86/kernel/e820.c
> +++ b/arch/x86/kernel/e820.c
> @@ -961,6 +961,9 @@ void __init e820_reserve_resources(void)
>
> res->flags = IORESOURCE_MEM;
>
> + if (_is_unknown_type(e820.map[i].type))
> + res->flags |= IORESOURCE_MEM_WARN;
> +
> /*
> * don't register the region that could be conflicted with
> * pci device BAR resource and insert them later in
> diff --git a/include/linux/ioport.h b/include/linux/ioport.h
> index 2c525022..f78972b 100644
> --- a/include/linux/ioport.h
> +++ b/include/linux/ioport.h
> @@ -90,6 +90,7 @@ struct resource {
> #define IORESOURCE_MEM_32BIT (3<<3)
> #define IORESOURCE_MEM_SHADOWABLE (1<<5) /* dup: IORESOURCE_SHADOWABLE
> */
> #define IORESOURCE_MEM_EXPANSIONROM (1<<6)
> +#define IORESOURCE_MEM_WARN (1<<7) /* WARN if requested by
> driver */
>
> /* PnP I/O specific bits (IORESOURCE_BITS) */
> #define IORESOURCE_IO_16BIT_ADDR (1<<0)
> diff --git a/kernel/resource.c b/kernel/resource.c
> index 19f2357..4bab16f 100644
> --- a/kernel/resource.c
> +++ b/kernel/resource.c
> @@ -1075,8 +1075,15 @@ struct resource * __request_region(struct resource
> *parent,
> break;
> if (conflict != parent) {
> parent = conflict;
> - if (!(conflict->flags & IORESOURCE_BUSY))
> + if (!(conflict->flags & IORESOURCE_BUSY)) {
> + if (unlikely(
No need for unlikely(), this isn't a hot path.
> + (resource_type(conflict) ==
> IORESOURCE_MEM)
> + && (conflict->flags &
> IORESOURCE_MEM_WARN)))
> + pr_warn("request region with unknown
> memory type [mem %#010llx-%#010llx] %s\n",
> + conflict->start,
> conflict->end,
> + conflict->name);
I think this should also dump the res->name to identify who is requesting it.
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