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path: root/drivers/acpi/atomicio.c
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2011-05-25x86: remove 32-bit versions of readq()/writeq()Roland Dreier
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>
2010-09-29ACPI, APEI, Fix acpi_pre_map() return valueJin Dongming
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>
2010-06-28acpi: update gfp/slab.h includesTejun Heo
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>
2010-05-19ACPI, IO memory pre-mapping and atomic accessingHuang Ying
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>