- 10 8月, 2016 5 次提交
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由 Nicholas Piggin 提交于
When using if_changed, we need to add FORCE as a dependency (see Documentation/kbuild/makefiles.txt) otherwise we don't get command line change checking amongst other things. This has resulted in vdsos not being rebuilt when switching between big and little endian. The vdso64/32ld commands have to be changed around to avoid pulling FORCE into the linker command line (code copied from x86). Signed-off-by: NNicholas Piggin <npiggin@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Benjamin Herrenschmidt 提交于
We cannot do those initializations from apply_feature_fixups() as this function runs in a very restricted environment on 32-bit where the kernel isn't running at its linked address and the PTRRELOC() macro must be used for any global accesss. Instead, split them into a separtate steup_feature_keys() function which is called in a more suitable spot on ppc32. Fixes: 309b315b ("powerpc: Call jump_label_init() in apply_feature_fixups()") Reported-and-tested-by: NChristian Kujau <lists@nerdbynature.de> Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Benjamin Herrenschmidt 提交于
We don't identify the machine type anymore... Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Benjamin Herrenschmidt 提交于
This makes it easier to debug crashes that happen very early before the kernel takes over Open Firmware by allowing us to relate the OF reported crashing addresses to offsets within the kernel. Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Cyril Bur 提交于
Commit 8d460f61 ("powerpc/process: Add the function flush_tmregs_to_thread") added flush_tmregs_to_thread() and included the assumption that it would only be called for a task which is not current. Although this is correct for ptrace, when generating a core dump, some of the routines which call flush_tmregs_to_thread() are called. This leads to a WARNing such as: Not expecting ptrace on self: TM regs may be incorrect ------------[ cut here ]------------ WARNING: CPU: 123 PID: 7727 at arch/powerpc/kernel/process.c:1088 flush_tmregs_to_thread+0x78/0x80 CPU: 123 PID: 7727 Comm: libvirtd Not tainted 4.8.0-rc1-gcc6x-g61e8a0d5 #1 task: c000000fe631b600 task.stack: c000000fe63b0000 NIP: c00000000001a1a8 LR: c00000000001a1a4 CTR: c000000000717780 REGS: c000000fe63b3420 TRAP: 0700 Not tainted (4.8.0-rc1-gcc6x-g61e8a0d5) MSR: 900000010282b033 <SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE,TM[E]> CR: 28004222 XER: 20000000 ... NIP [c00000000001a1a8] flush_tmregs_to_thread+0x78/0x80 LR [c00000000001a1a4] flush_tmregs_to_thread+0x74/0x80 Call Trace: flush_tmregs_to_thread+0x74/0x80 (unreliable) vsr_get+0x64/0x1a0 elf_core_dump+0x604/0x1430 do_coredump+0x5fc/0x1200 get_signal+0x398/0x740 do_signal+0x54/0x2b0 do_notify_resume+0x98/0xb0 ret_from_except_lite+0x70/0x74 So fix flush_tmregs_to_thread() to detect the case where it is called on current, and a transaction is active, and in that case flush the TM regs to the thread_struct. This patch also moves flush_tmregs_to_thread() into ptrace.c as it is only called from that file. Fixes: 8d460f61 ("powerpc/process: Add the function flush_tmregs_to_thread") Signed-off-by: NCyril Bur <cyrilbur@gmail.com> [mpe: Flesh out change log] Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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- 09 8月, 2016 7 次提交
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由 Mahesh Salgaonkar 提交于
When machine check occurs with MSR(RI=0), it means MC interrupt is unrecoverable and kernel goes down to panic path. But the console message still shows it as recovered. This patch fixes the MCE console messages. Fixes: 36df96f8 ("powerpc/book3s: Decode and save machine check event.") Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Michael Ellerman 提交于
The recent commit 63a72284 ("powerpc/pci: Assign fixed PHB number based on device-tree properties"), added code to read a 64-bit property from the device tree, and if not found read a 32-bit property (reg). There was a bug in the 32-bit case, on big endian machines, due to the use of the 64-bit value to read the 32-bit property. The cast of &prop means we end up writing to the high 32-bit of prop, leaving the low 32-bits containing whatever junk was on the stack. If that junk value was non-zero, and < MAX_PHBS, we would end up using it as the PHB id. This results in users seeing what appear to be random PHB ids. Fix it by reading into a u32 property and then assigning that to the u64 value, letting the CPU do the correct conversions for us. Fixes: 63a72284 ("powerpc/pci: Assign fixed PHB number based on device-tree properties") Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Guilherme G. Piccoli 提交于
This is a very minor/trivial fix for the output of PCI address on EEH logs. The PCI address on "OF node" field currently is using ":" as a separator for the function, but the usual separator is ".". This patch changes the separator to dot, so the PCI address is printed as usual. Signed-off-by: NGuilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com> Reviewed-by: NGavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Guenter Roeck 提交于
Some powerpc builds fail with the following buld error. In file included from ./arch/powerpc/include/asm/mmu_context.h:11:0, from arch/powerpc/kernel/vdso.c:28: arch/powerpc/include/asm/cputhreads.h: In function 'get_tensr': arch/powerpc/include/asm/cputhreads.h:101:2: error: implicit declaration of function 'cpu_has_feature' Fixes: b92a226e ("powerpc: Move cpu_has_feature() to a separate file") Signed-off-by: NGuenter Roeck <linux@roeck-us.net> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Mahesh Salgaonkar 提交于
The current implementation of MCE early handling modifies CR0/1 registers without saving its old values. Fix this by moving early check for powersaving mode to machine_check_handle_early(). The power architecture 2.06 or later allows the possibility of getting machine check while in nap/sleep/winkle. The last bit of HSPRG0 is set to 1, if thread is woken up from winkle. Hence, clear the last bit of HSPRG0 (r13) before MCE handler starts using it as paca pointer. Also, the current code always puts the thread into nap state irrespective of whatever idle state it woke up from. Fix that by looking at paca->thread_idle_state and put the thread back into same state where it came from. Fixes: 1c51089f ("powerpc/book3s: Return from interrupt if coming from evil context.") Reported-by: NPaul Mackerras <paulus@samba.org> Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Reviewed-by: NShreyas B. Prabhu <shreyas@linux.vnet.ibm.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Mahesh Salgaonkar 提交于
Move IDLE_STATE_ENTER_SEQ macro to cpuidle.h so that MCE handler changes in subsequent patch can use it. No functionality change. Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Mahesh Salgaonkar 提交于
The function pnv_restore_hyp_resource() loads the TOC into r2 from the invalid PACA pointer before fixing r13 value. This do not affect POWER ISA 3.0 but it does have an impact on POWER ISA 2.07 or less leading CPU to get stuck forever. login: [ 471.830433] Processor 120 is stuck. This can be easily reproducible using following steps: - Turn off SMT $ ppc64_cpu --smt=off - offline/online any online cpu (Thread 0 of any core which is online) $ echo 0 > /sys/devices/system/cpu/cpu<num>/online $ echo 1 > /sys/devices/system/cpu/cpu<num>/online For POWER ISA 2.07 or less, the last bit of HSPRG0 is set indicating that thread is waking up from winkle. Hence, the last bit of HSPRG0(r13) needs to be clear before accessing it as PACA to avoid loading invalid values from invalid PACA pointer. Fix this by loading TOC after r13 register is corrected. Fixes: bcef83a0 ("powerpc/powernv: Add platform support for stop instruction") Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Acked-by: NVaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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- 04 8月, 2016 1 次提交
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由 Krzysztof Kozlowski 提交于
The dma-mapping core and the implementations do not change the DMA attributes passed by pointer. Thus the pointer can point to const data. However the attributes do not have to be a bitfield. Instead unsigned long will do fine: 1. This is just simpler. Both in terms of reading the code and setting attributes. Instead of initializing local attributes on the stack and passing pointer to it to dma_set_attr(), just set the bits. 2. It brings safeness and checking for const correctness because the attributes are passed by value. Semantic patches for this change (at least most of them): virtual patch virtual context @r@ identifier f, attrs; @@ f(..., - struct dma_attrs *attrs + unsigned long attrs , ...) { ... } @@ identifier r.f; @@ f(..., - NULL + 0 ) and // Options: --all-includes virtual patch virtual context @r@ identifier f, attrs; type t; @@ t f(..., struct dma_attrs *attrs); @@ identifier r.f; @@ f(..., - NULL + 0 ) Link: http://lkml.kernel.org/r/1468399300-5399-2-git-send-email-k.kozlowski@samsung.comSigned-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com> Acked-by: NVineet Gupta <vgupta@synopsys.com> Acked-by: NRobin Murphy <robin.murphy@arm.com> Acked-by: NHans-Christian Noren Egtvedt <egtvedt@samfundet.no> Acked-by: Mark Salter <msalter@redhat.com> [c6x] Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> [cris] Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> [drm] Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com> Acked-by: Joerg Roedel <jroedel@suse.de> [iommu] Acked-by: Fabien Dessenne <fabien.dessenne@st.com> [bdisp] Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> [vb2-core] Acked-by: David Vrabel <david.vrabel@citrix.com> [xen] Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> [xen swiotlb] Acked-by: Joerg Roedel <jroedel@suse.de> [iommu] Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon] Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [s390] Acked-by: NBjorn Andersson <bjorn.andersson@linaro.org> Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> [avr32] Acked-by: Vineet Gupta <vgupta@synopsys.com> [arc] Acked-by: Robin Murphy <robin.murphy@arm.com> [arm64 and dma-iommu] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 01 8月, 2016 22 次提交
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由 Anshuman Khandual 提交于
This patch enables support for Performance monitor registers related ELF core note NT_PPC_PMU based ptrace requests through PTRACE_GETREGSET, PTRACE_SETREGSET calls. This is achieved through adding one new register sets REGSET_PMU in powerpc corresponding to the ELF core note sections added in this regard. It also implements the get, set and active functions for this new register sets added. Signed-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: NSimon Guo <wei.guo.simon@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anshuman Khandual 提交于
This patch enables support for EBB state registers related ELF core note NT_PPC_EBB based ptrace requests through PTRACE_GETREGSET, PTRACE_SETREGSET calls. This is achieved through adding one new register sets REGSET_EBB in powerpc corresponding to the ELF core note sections added in this regard. It also implements the get, set and active functions for this new register sets added. Signed-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: NSimon Guo <wei.guo.simon@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anshuman Khandual 提交于
This patch enables support for running TAR, PPR, DSCR registers related ELF core notes NT_PPPC_TAR, NT_PPC_PPR, NT_PPC_DSCR based ptrace requests through PTRACE_GETREGSET, PTRACE_SETREGSET calls. This is achieved through adding three new register sets REGSET_TAR, REGSET_PPR, REGSET_DSCR in powerpc corresponding to the ELF core note sections added in this regad. It implements the get, set and active functions for all these new register sets added. Signed-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: NSimon Guo <wei.guo.simon@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anshuman Khandual 提交于
This patch enables support for all three TM checkpointed SPR states related ELF core note NT_PPC_TM_CTAR, NT_PPC_TM_CPPR, NT_PPC_TM_CDSCR based ptrace requests through PTRACE_GETREGSET, PTRACE_SETREGSET calls. This is achieved through adding three new register sets REGSET_TM_CTAR, REGSET_TM_CPPR and REGSET_TM_CDSCR in powerpc corresponding to the ELF core note sections added. It implements the get, set and active functions for all these new register sets added. Signed-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: NSimon Guo <wei.guo.simon@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anshuman Khandual 提交于
This patch enables support for TM SPR state related ELF core note NT_PPC_TM_SPR based ptrace requests through PTRACE_GETREGSET, PTRACE_SETREGSET calls. This is achieved through adding a register set REGSET_TM_SPR in powerpc corresponding to the ELF core note section added. It implements the get, set and active functions for this new register set added. Signed-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: NSimon Guo <wei.guo.simon@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anshuman Khandual 提交于
This patch enables support for TM checkpointed VSX register set ELF core note NT_PPC_CVSX based ptrace requests through PTRACE_GETREGSET, PTRACE_SETREGSET calls. This is achieved through adding a register set REGSET_CVSX in powerpc corresponding to the ELF core note section added. It implements the get, set and active functions for this new register set added. Signed-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: NSimon Guo <wei.guo.simon@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anshuman Khandual 提交于
This patch enables support for TM checkpointed VMX register set ELF core note NT_PPC_CVMX based ptrace requests through PTRACE_GETREGSET, PTRACE_SETREGSET calls. This is achieved through adding a register set REGSET_CVMX in powerpc corresponding to the ELF core note section added. It implements the get, set and active functions for this new register set added. Signed-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: NSimon Guo <wei.guo.simon@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anshuman Khandual 提交于
This patch enables support for TM checkpointed FPR register set ELF core note NT_PPC_CFPR based ptrace requests through PTRACE_GETREGSET, PTRACE_SETREGSET calls. This is achieved through adding a register set REGSET_CFPR in powerpc corresponding to the ELF core note section added. It implements the get, set and active functions for this new register set added. Signed-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: NSimon Guo <wei.guo.simon@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anshuman Khandual 提交于
This patch enables support for TM checkpointed GPR register set ELF core note NT_PPC_CGPR based ptrace requests through PTRACE_GETREGSET, PTRACE_SETREGSET calls. This is achieved through adding a register set REGSET_CGPR in powerpc corresponding to the ELF core note section added. It implements the get, set and active functions for this new register set added. Signed-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: NSimon Guo <wei.guo.simon@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anshuman Khandual 提交于
This patch splits gpr32_get, gpr32_set functions to accommodate in transaction ptrace requests implemented in patches later in the series. Signed-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: NSimon Guo <wei.guo.simon@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anshuman Khandual 提交于
This patch enables in transaction NT_PPC_VSX ptrace requests. The function vsr_get which gets the running value of all VSX registers and the function vsr_set which sets the running value of of all VSX registers work on the running set of VMX registers whose location will be different if transaction is active. This patch makes these functions adapt to situations when the transaction is active. Signed-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: NSimon Guo <wei.guo.simon@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anshuman Khandual 提交于
This patch enables in transaction NT_PPC_VMX ptrace requests. The function vr_get which gets the running value of all VMX registers and the function vr_set which sets the running value of of all VMX registers work on the running set of VMX registers whose location will be different if transaction is active. This patch makes these functions adapt to situations when the transaction is active. Signed-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: NSimon Guo <wei.guo.simon@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anshuman Khandual 提交于
This patch enables in transaction NT_PRFPREG ptrace requests. The function fpr_get which gets the running value of all FPR registers and the function fpr_set which sets the running value of of all FPR registers work on the running set of FPR registers whose location will be different if transaction is active. This patch makes these functions adapt to situations when the transaction is active. Signed-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: NSimon Guo <wei.guo.simon@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Anshuman Khandual 提交于
This patch creates a function flush_tmregs_to_thread which will then be used by subsequent patches in this series. The function checks for self tracing ptrace interface attempts while in the TM context and logs appropriate warning message. Signed-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: NSimon Guo <wei.guo.simon@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Kevin Hao 提交于
As we just did for CPU features. Signed-off-by: NKevin Hao <haokexin@gmail.com> Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Kevin Hao 提交于
We do binary patching of asm code using CPU features, which is a one-time operation, done during early boot. However checks of CPU features in C code are currently done at run time, even though the set of CPU features can never change after boot. We can optimise this by using jump labels to implement cpu_has_feature(), meaning checks in C code are binary patched into a single nop or branch. For a C sequence along the lines of: if (cpu_has_feature(FOO)) return 2; The generated code before is roughly: ld r9,-27640(r2) ld r9,0(r9) lwz r9,32(r9) cmpwi cr7,r9,0 bge cr7, 1f li r3,2 blr 1: ... After (true): nop li r3,2 blr After (false): b 1f li r3,2 blr 1: ... mpe: Rename MAX_CPU_FEATURES as we already have a #define with that name, and define it simply as a constant, rather than doing tricks with sizeof and NULL pointers. Rename the array to cpu_feature_keys. Use the kconfig we added to guard it. Add BUILD_BUG_ON() if the feature is not a compile time constant. Rewrite the change log. Signed-off-by: NKevin Hao <haokexin@gmail.com> Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Kevin Hao 提交于
We plan to use jump label for cpu_has_feature(). In order to implement this we need to include the linux/jump_label.h in asm/cputable.h. Unfortunately if we do that it leads to an include loop. The root of the problem seems to be that reg.h needs cputable.h (for CPU_FTRs), and then cputable.h via jump_label.h eventually pulls in hw_irq.h which needs reg.h (for MSR_EE). So move cpu_has_feature() to a separate file on its own. Signed-off-by: NKevin Hao <haokexin@gmail.com> Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [mpe: Rename to cpu_has_feature.h and flesh out change log] Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Aneesh Kumar K.V 提交于
This switches early feature checks to use the non static key variant of the function. In later patches we will be switching cpu_has_feature() and mmu_has_feature() to use static keys and we can use them only after static key/jump label is initialized. Any check for feature before jump label init should be done using this new helper. Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Aneesh Kumar K.V 提交于
MMU feature bits are defined such that we use the lower half to present MMU family features. Remove the strict split of half and also move Radix to a mmu family feature. Radix introduce a new MMU model and strictly speaking it is a new MMU family. This also free up bits which can be used for individual features later. Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Michael Ellerman 提交于
Up until now we needed to do the MMU init before feature patching, because part of the MMU init was scanning the device tree and setting and/or clearing some MMU feature bits. Now that we have split that MMU feature modification out into routines called from early_init_devtree() (called earlier) we can now do feature patching before calling MMU init. The advantage of this is it means the remainder of the MMU init runs with the final set of features which will apply for the rest of the life of the system. This means we don't have to special case anything called from MMU init to deal with a changing set of feature bits. Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Michael Ellerman 提交于
Move the handling of the disable_radix command line argument into the newly created mmu_early_init_devtree(). It's an MMU option so it's preferable to have it in an mm related file, and it also means platforms that don't support radix don't have to carry the code. Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Michael Ellerman 提交于
Empty for now, but we'll add to it in the next patch. Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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- 26 7月, 2016 1 次提交
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由 Anton Blanchard 提交于
The comment explaining why we modify VRSAVE is misleading, glibc does rely on the behaviour. Update the comment. Signed-off-by: NAnton Blanchard <anton@samba.org> Reviewed-by: NCyril Bur <cyrilbur@gmail.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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- 21 7月, 2016 4 次提交
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由 Michael Ellerman 提交于
In the module loader we process relocations, and for long jumps we generate trampolines (aka stubs). At the call site for one of these trampolines we usually need to generate a load instruction to restore the TOC pointer into r2. There is one exception however, which is calls to mcount() using the mprofile-kernel ABI, they handle the TOC inside the stub, and so for them we do not generate a TOC load. The bug is in how the code in restore_r2() decides if it needs to generate the TOC load. It does so by looking for a nop following the branch, and if it sees a nop, it replaces it with the load. In general the compiler has no reason to generate a nop following the mcount() call and so that check works OK. However if we combine a jump label at the start of a function, with an early return, such that GCC applies the shrink-wrapping optimisation, we can then end up with an mcount call followed immediately by a nop. However the nop is not there for a TOC load, it is for the jump label. That confuses restore_r2() into replacing the jump label nop with a TOC load, which in turn confuses ftrace into replacing the mcount call with a b +8 (fixed in the previous commit). The end result is we jump over the jump label, which if it was supposed to return means we incorrectly run the body of the function. We have seen this in practice with some yet-to-be-merged patches that use jump labels more extensively. The fix is relatively simple, in restore_r2() we check for an mprofile-kernel style mcount() call first, before looking for the presence of a nop. Fixes: 15308664 ("powerpc/ftrace: Add support for -mprofile-kernel ftrace ABI") Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Michael Ellerman 提交于
In __ftrace_make_nop() (the 64-bit version), we have code to deal with two ftrace ABIs. There is the original ABI, which looks mostly like a function call, and then the mprofile-kernel ABI which is just a branch. The code tries to handle both cases, by looking for the presence of a load to restore the TOC pointer (PPC_INST_LD_TOC). If we detect the TOC load, we assume the call site is for an mcount() call using the old ABI. That means we patch the mcount() call with a b +8, to branch over the TOC load. However if the kernel was built with mprofile-kernel, then there will never be a call site using the original ftrace ABI. If for some reason we do see a TOC load, then it's there for a good reason, and we should not jump over it. So split the code, using the existing CC_USING_MPROFILE_KERNEL. Kernels built with mprofile-kernel will only look for, and expect, the new ABI, and similarly for the original ABI. Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Benjamin Herrenschmidt 提交于
There is little enough differences now. mpe: Add a/p/k/setup.h to contain the prototypes and empty versions of functions we need, rather than using weak functions. Add a few other empty versions to avoid as many #ifdefs as possible in the code. Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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由 Benjamin Herrenschmidt 提交于
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
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