Resource providers set this flag if they want
that request_region_XXX will print a warning in dmesg
if this particular resource is locked by a driver.
Thous acting as a Protocol Police about experimental
devices that did not pass a comity approval.
The warn print looks like this:
[Feb22 19:59] resource: request unknown region [mem 0x100000000-0x1ffffffff]
unkown-12
Where the unkown-12 is taken from the res->name
The Only user of this flag is x86/kernel/e820.c that
wants to WARN about UNKNOWN memory types.
NOTE: This patch looks very simple, a bit flag
communicates between a resource provider ie e820.c
that a warning should be printed, and resource.c
prints such a message, when the resource is locked
for use.
BUT the basic flaw here is that we have run out of flags
for a 32-bit long. My route here is to create wrappers
that at 32-bit do nothing.
Since only current user is e820.c for DDR3-NvDIMMs, this
should be fine, because DDR3-NvDIMMs are not very useful
with 32-bit ARCHES. In fact the smallest chip I know is
4G, and NvDIMM is not currently supported as highmem (nor
are there any plans to support it)
OR: Maybe there is an extra bit that can be used at:
/* PnP memory I/O specific bits */
@@ -92,6 +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 used by
drivers */
/* PnP I/O specific bits (IORESOURCE_BITS) */
#define IORESOURCE_IO_16BIT_ADDR (1<<0)
And get rid of the wrappers, Please advise ?
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 | 23 +++++++++++++++++++++++
kernel/resource.c | 7 ++++++-
3 files changed, 32 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 1a8a1c3..18a9850 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))
+ resource_set_warn_on_use(res, true);
+
/*
* 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..9a51738 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -54,6 +54,8 @@ struct resource {
#define IORESOURCE_UNSET 0x20000000 /* No address assigned yet */
#define IORESOURCE_AUTO 0x40000000
#define IORESOURCE_BUSY 0x80000000 /* Driver has marked
this resource busy */
+/* Flags only on 64bit */
+#define IORESOURCE_WARN 0x100000000 /* Use with wrapper
Only */
/* PnP IRQ specific bits (IORESOURCE_BITS) */
#define IORESOURCE_IRQ_HIGHEDGE (1<<0)
@@ -255,6 +257,27 @@ static inline bool resource_overlaps(struct resource *r1,
struct resource *r2)
return (r1->start <= r2->end && r1->end >= r2->start);
}
+static inline void resource_set_warn_on_use(struct resource *r, bool warn)
+{
+ if (sizeof(r->flags) > sizeof(u32)) {
+ if (warn)
+ r->flags |= IORESOURCE_WARN;
+ else
+ r->flags &= ~IORESOURCE_WARN;
+ }
+ /* I'm not doing any prints here for the else case because I do not want
+ * to add the extra chain of includes this needs. This is a pretty low
+ * level Header
+ */
+}
+
+static inline bool resource_warn_on_use(struct resource *r)
+{
+ if (sizeof(r->flags) > sizeof(u32))
+ return (r->flags & IORESOURCE_WARN) != 0;
+ else
+ return false;
+}
#endif /* __ASSEMBLY__ */
#endif /* _LINUX_IOPORT_H */
diff --git a/kernel/resource.c b/kernel/resource.c
index 19f2357..eca6920 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -1075,8 +1075,13 @@ 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_warn_on_use(conflict))
+ pr_warn("request unknown region [mem
%#010llx-%#010llx] %s\n",
+ 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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