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The presense of a writeq() implementation on 32-bit x86 that splits the
64-bit write into two 32-bit writes turns out to break the mpt2sas driver
(and in general is risky for drivers as was discussed in
<http://lkml.kernel.org/r/adaab6c1h7c.fsf@cisco.com>). To fix this,
revert 2c5643b1c5c7 ("x86: provide readq()/writeq() on 32-bit too") and
follow-on cleanups.
This unfortunately leads to pushing non-atomic definitions of readq() and
write() to various x86-only drivers that in the meantime started using the
definitions in the x86 version of <asm/io.h>. However as discussed
exhaustively, this is actually the right thing to do, because the right
way to split a 64-bit transaction is hardware dependent and therefore
belongs in the hardware driver (eg mpt2sas needs a spinlock to make sure
no other accesses occur in between the two halves of the access).
Build tested on 32- and 64-bit x86 allmodconfig.
Link: http://lkml.kernel.org/r/x86-32-writeq-is-broken@mdm.bga.com
Acked-by: Hitoshi Mitake <h.mitake@gmail.com>
Cc: Kashyap Desai <Kashyap.Desai@lsi.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Ravi Anand <ravi.anand@qlogic.com>
Cc: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Jason Uhlenkott <juhlenko@akamai.com>
Acked-by: James Bottomley <James.Bottomley@parallels.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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After we ioremap() a new region, we call __acpi_try_ioremap() to
see whether another thread has already mapped the same region.
This check clobbers "vaddr", so compute the return value of
acpi_pre_map() using the ioremap() result "map->vaddr" instead.
v2:
Modified the unsuitable description of patch.
v3:
Removed unlikely() check and made description simpler.
Signed-off-by: Jin Dongming <jin.dongming@np.css.fujitsu.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
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Implicit slab.h inclusion via percpu.h is about to go away. Make sure
gfp.h or slab.h is included as necessary.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
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Some ACPI IO accessing need to be done in atomic context. For example,
APEI ERST operations may be used for permanent storage in hardware
error handler. That is, it may be called in atomic contexts such as
IRQ or NMI, etc. And, ERST/EINJ implement their operations via IO
memory/port accessing. But the IO memory accessing method provided by
ACPI (acpi_read/acpi_write) maps the IO memory during it is accessed,
so it can not be used in atomic context. To solve the issue, the IO
memory should be pre-mapped during EINJ/ERST initializing. A linked
list is used to record which memory area has been mapped, when memory
is accessed in hardware error handler, search the linked list for the
mapped virtual address from the given physical address.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
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