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Subject[PATCH 2/3] resource: Add new flag IORESOURCE_MEM_WARN

memory 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 <tglx@linutronix.de>
CC: Ingo Molnar <mingo@redhat.com>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: x86@kernel.org
CC: Dan Williams <dan.j.williams@intel.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Bjorn Helgaas <bhelgaas@google.com>
CC: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Boaz Harrosh <boaz@plexistor.com>
---
arch/x86/kernel/e820.c | 3 +++
include/linux/ioport.h | 1 +
kernel/resource.c | 11 ++++++++++-
3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index c3a11cd..c2f2da2 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..f886666 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -1075,8 +1075,17 @@ struct resource * __request_region(struct resource *parent,
break;
if (conflict != parent) {
parent = conflict;
- if (!(conflict->flags & IORESOURCE_BUSY))
+ if (!(conflict->flags & IORESOURCE_BUSY)) {
+ if ((resource_type(conflict) == IORESOURCE_MEM)
+ && (conflict->flags & IORESOURCE_MEM_WARN)) {
+ add_taint(TAINT_FIRMWARE_WORKAROUND,
+ LOCKDEP_STILL_OK);
+ pr_warn("%s requested an unknown memory type [mem %#010llx-%#010llx] %s\n",
+ name, conflict->start,
+ conflict->end, conflict->name);
+ }
continue;
+ }
}
if (conflict->flags & flags & IORESOURCE_MUXED) {
add_wait_queue(&muxed_resource_wait, &wait);
--
1.9.3



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