kernel/linux.git/arch/powerpc/include/asm/mmu_context.h, branch linux-4.4.y

powerpc/mm: tracking vDSO remap

2015-06-25T00:49:41+00:00

Some processes (CRIU) are moving the vDSO area using the mremap system call. As a consequence the kernel reference to the vDSO base address is no more valid and the signal return frame built once the vDSO has been moved is not pointing to the new sigreturn address. This patch handles vDSO remapping and unmapping. Signed-off-by: Laurent Dufour Reviewed-by: Ingo Molnar Cc: "Kirill A. Shutemov" Cc: Hugh Dickins Cc: Rik van Riel Cc: Mel Gorman Cc: Pavel Emelyanov Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

powerpc/mmu: Add userspace-to-physical addresses translation cache

2015-06-11T05:16:54+00:00

We are adding support for DMA memory pre-registration to be used in conjunction with VFIO. The idea is that the userspace which is going to run a guest may want to pre-register a user space memory region so it all gets pinned once and never goes away. Having this done, a hypervisor will not have to pin/unpin pages on every DMA map/unmap request. This is going to help with multiple pinning of the same memory. Another use of it is in-kernel real mode (mmu off) acceleration of DMA requests where real time translation of guest physical to host physical addresses is non-trivial and may fail as linux ptes may be temporarily invalid. Also, having cached host physical addresses (compared to just pinning at the start and then walking the page table again on every H_PUT_TCE), we can be sure that the addresses which we put into TCE table are the ones we already pinned. This adds a list of memory regions to mm_context_t. Each region consists of a header and a list of physical addresses. This adds API to: 1. register/unregister memory regions; 2. do final cleanup (which puts all pre-registered pages); 3. do userspace to physical address translation; 4. manage usage counters; multiple registration of the same memory is allowed (once per container). This implements 2 counters per registered memory region: - @mapped: incremented on every DMA mapping; decremented on unmapping; initialized to 1 when a region is just registered; once it becomes zero, no more mappings allowe; - @used: incremented on every "register" ioctl; decremented on "unregister"; unregistration is allowed for DMA mapped regions unless it is the very last reference. For the very last reference this checks that the region is still mapped and returns -EBUSY so the userspace gets to know that memory is still pinned and unregistration needs to be retried; @used remains 1. Host physical addresses are stored in vmalloc'ed array. In order to access these in the real mode (mmu off), there is a real_vmalloc_addr() helper. In-kernel acceleration patchset will move it from KVM to MMU code. Signed-off-by: Alexey Kardashevskiy Reviewed-by: David Gibson Reviewed-by: David Gibson Signed-off-by: Michael Ellerman

powerpc: Remove MMU_FTR_SLB

2014-07-28T04:10:23+00:00

We now only support cpus that use an SLB, so we don't need an MMU feature to indicate that. Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt

powerpc: Remove STAB code

2014-07-28T04:10:22+00:00

Old cpus didn't have a Segment Lookaside Buffer (SLB), instead they had a Segment Table (STAB). Now that we've dropped support for those cpus, we can remove the STAB support entirely. Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt

sched: Rename sched.c as sched/core.c in comments and Documentation

2013-06-19T10:58:42+00:00

Most of the stuff from kernel/sched.c was moved to kernel/sched/core.c long time back and the comments/Documentation never got updated. I figured it out when I was going through sched-domains.txt and so thought of fixing it globally. I haven't crossed check if the stuff that is referenced in sched/core.c by all these files is still present and hasn't changed as that wasn't the motive behind this patch. Signed-off-by: Viresh Kumar Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/cdff76a265326ab8d71922a1db5be599f20aad45.1370329560.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar

powerpc: Add Initiate Coprocessor Store Word (icswx) support

2011-05-04T05:19:26+00:00

Icswx is a PowerPC instruction to send data to a co-processor. On Book-S processors the LPAR_ID and process ID (PID) of the owning process are registered in the window context of the co-processor at initialization time. When the icswx instruction is executed the L2 generates a cop-reg transaction on PowerBus. The transaction has no address and the processor does not perform an MMU access to authenticate the transaction. The co-processor compares the LPAR_ID and the PID included in the transaction and the LPAR_ID and PID held in the window context to determine if the process is authorized to generate the transaction. The OS needs to assign a 16-bit PID for the process. This cop-PID needs to be updated during context switch. The cop-PID needs to be destroyed when the context is destroyed. Signed-off-by: Sonny Rao Signed-off-by: Tseng-Hui (Frank) Lin Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt

powerpc: Free up some CPU feature bits by moving out MMU-related features

2011-04-27T04:18:52+00:00

Some of the 64bit PPC CPU features are MMU-related, so this patch moves them to MMU_FTR_ bits. All cpu_has_feature()-style tests are moved to mmu_has_feature(), and seven feature bits are freed as a result. Signed-off-by: Matt Evans Signed-off-by: Benjamin Herrenschmidt

PPC: Split context init/destroy functions

2010-05-17T09:18:20+00:00

We need to reserve a context from KVM to make sure we have our own segment space. While we did that split for Book3S_64 already, 32 bit is still outstanding. So let's split it now. Signed-off-by: Alexander Graf Acked-by: Benjamin Herrenschmidt CC: Benjamin Herrenschmidt Signed-off-by: Avi Kivity

Split init_new_context and destroy_context

2009-11-05T05:50:25+00:00

For KVM we need to allocate a new context id, but don't really care about all the mm context around it. So let's split the alloc and destroy functions for the context id, so we can grab one without allocating an mm context. Signed-off-by: Alexander Graf Signed-off-by: Benjamin Herrenschmidt

powerpc: Add TLB management code for 64-bit Book3E

2009-08-20T00:25:09+00:00

This adds the TLB miss handler assembly, the low level TLB flush routines along with the necessary hook for dealing with our virtual page tables or indirect TLB entries that need to be flushes when PTE pages are freed. There is currently no support for hugetlbfs Signed-off-by: Benjamin Herrenschmidt