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path: root/arch/powerpc/kernel/io-workarounds.c
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* powerpc/mm/thp: Make page table walk safe against thp split/collapseAneesh Kumar K.V2015-04-171-5/+5
| | | | | | | | | | | | | | | | | | | | We can disable a THP split or a hugepage collapse by disabling irq. We do send IPI to all the cpus in the early part of split/collapse, and disabling local irq ensure we don't make progress with split/collapse. If the THP is getting split we return NULL from find_linux_pte_or_hugepte(). For all the current callers it should be ok. We need to be careful if we want to use returned pte_t pointer outside the irq disabled region. W.r.t to THP split, the pfn remains the same, but then a hugepage collapse will result in a pfn change. There are few steps we can take to avoid a hugepage collapse.One way is to take page reference inside the irq disable region. Other option is to take mmap_sem so that a parallel collapse will not happen. We can also disable collapse by taking pmd_lock. Another method used by kvm subsystem is to check whether we had a mmu_notifer update in between using mmu_notifier_retry(). Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc: Better split CONFIG_PPC_INDIRECT_PIO and CONFIG_PPC_INDIRECT_MMIOBenjamin Herrenschmidt2013-08-141-1/+18
| | | | | | | | Remove the generic PPC_INDIRECT_IO and ensure we only add overhead to the right accessors. IE. If only CONFIG_PPC_INDIRECT_PIO is set, we don't add overhead to all MMIO accessors. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc: Replace find_linux_pte with find_linux_pte_or_hugepteAneesh Kumar K.V2013-06-211-2/+9
| | | | | | | | Replace find_linux_pte with find_linux_pte_or_hugepte and explicitly document why we don't need to handle transparent hugepages at callsites. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* POWERPC: drivers: remove __dev* attributes.Greg Kroah-Hartman2013-01-031-5/+4
| | | | | | | | | | | | | | | | CONFIG_HOTPLUG is going away as an option. As a result, the __dev* markings need to be removed. This change removes the use of __devinit, __devexit_p, __devinitdata, __devinitconst, and __devexit from these drivers. Based on patches originally written by Bill Pemberton, but redone by me in order to handle some of the coding style issues better, by hand. Cc: Bill Pemberton <wfp5p@virginia.edu> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* powerpc: io-workarounds.c was implicitly getting init_mmPaul Gortmaker2011-10-311-0/+1
| | | | | | | | It was coming in via device.h --> module.h etc. but we want to clean that up. So explicitly include the header where init_mm is being declared. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* powerpc/pci: Properly initialize IO workaround "private"Michael Ellerman2011-04-271-0/+1
| | | | | | | | Even when no initfunc is provided. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/pci: Make IO workarounds init implicit when first bus is registeredMichael Ellerman2011-04-271-12/+15
| | | | | | Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* powerpc/pci: Move IO workarounds to the common kernel dirMichael Ellerman2011-04-271-0/+184
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
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