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2020-10-22Merge branch 'work.set_fs' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull initial set_fs() removal from Al Viro: "Christoph's set_fs base series + fixups" * 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: Allow a NULL pos pointer to __kernel_read fs: Allow a NULL pos pointer to __kernel_write powerpc: remove address space overrides using set_fs() powerpc: use non-set_fs based maccess routines x86: remove address space overrides using set_fs() x86: make TASK_SIZE_MAX usable from assembly code x86: move PAGE_OFFSET, TASK_SIZE & friends to page_{32,64}_types.h lkdtm: remove set_fs-based tests test_bitmap: remove user bitmap tests uaccess: add infrastructure for kernel builds with set_fs() fs: don't allow splice read/write without explicit ops fs: don't allow kernel reads and writes without iter ops sysctl: Convert to iter interfaces proc: add a read_iter method to proc proc_ops proc: cleanup the compat vs no compat file ops proc: remove a level of indentation in proc_get_inode
2020-10-16Merge tag 'powerpc-5.10-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: - A series from Nick adding ARCH_WANT_IRQS_OFF_ACTIVATE_MM & selecting it for powerpc, as well as a related fix for sparc. - Remove support for PowerPC 601. - Some fixes for watchpoints & addition of a new ptrace flag for detecting ISA v3.1 (Power10) watchpoint features. - A fix for kernels using 4K pages and the hash MMU on bare metal Power9 systems with > 16TB of RAM, or RAM on the 2nd node. - A basic idle driver for shallow stop states on Power10. - Tweaks to our sched domains code to better inform the scheduler about the hardware topology on Power9/10, where two SMT4 cores can be presented by firmware as an SMT8 core. - A series doing further reworks & cleanups of our EEH code. - Addition of a filter for RTAS (firmware) calls done via sys_rtas(), to prevent root from overwriting kernel memory. - Other smaller features, fixes & cleanups. Thanks to: Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Athira Rajeev, Biwen Li, Cameron Berkenpas, Cédric Le Goater, Christophe Leroy, Christoph Hellwig, Colin Ian King, Daniel Axtens, David Dai, Finn Thain, Frederic Barrat, Gautham R. Shenoy, Greg Kurz, Gustavo Romero, Ira Weiny, Jason Yan, Joel Stanley, Jordan Niethe, Kajol Jain, Konrad Rzeszutek Wilk, Laurent Dufour, Leonardo Bras, Liu Shixin, Luca Ceresoli, Madhavan Srinivasan, Mahesh Salgaonkar, Nathan Lynch, Nicholas Mc Guire, Nicholas Piggin, Nick Desaulniers, Oliver O'Halloran, Pedro Miraglia Franco de Carvalho, Pratik Rajesh Sampat, Qian Cai, Qinglang Miao, Ravi Bangoria, Russell Currey, Satheesh Rajendran, Scott Cheloha, Segher Boessenkool, Srikar Dronamraju, Stan Johnson, Stephen Kitt, Stephen Rothwell, Thiago Jung Bauermann, Tyrel Datwyler, Vaibhav Jain, Vaidyanathan Srinivasan, Vasant Hegde, Wang Wensheng, Wolfram Sang, Yang Yingliang, zhengbin. * tag 'powerpc-5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (228 commits) Revert "powerpc/pci: unmap legacy INTx interrupts when a PHB is removed" selftests/powerpc: Fix eeh-basic.sh exit codes cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_reboot_notifier powerpc/time: Make get_tb() common to PPC32 and PPC64 powerpc/time: Make get_tbl() common to PPC32 and PPC64 powerpc/time: Remove get_tbu() powerpc/time: Avoid using get_tbl() and get_tbu() internally powerpc/time: Make mftb() common to PPC32 and PPC64 powerpc/time: Rename mftbl() to mftb() powerpc/32s: Remove #ifdef CONFIG_PPC_BOOK3S_32 in head_book3s_32.S powerpc/32s: Rename head_32.S to head_book3s_32.S powerpc/32s: Setup the early hash table at all time. powerpc/time: Remove ifdef in get_dec() and set_dec() powerpc: Remove get_tb_or_rtc() powerpc: Remove __USE_RTC() powerpc: Tidy up a bit after removal of PowerPC 601. powerpc: Remove support for PowerPC 601 powerpc: Remove PowerPC 601 powerpc: Drop SYNC_601() ISYNC_601() and SYNC() powerpc: Remove CONFIG_PPC601_SYNC_FIX ...
2020-10-14powerpc32: don't adjust unmoved stack pointer in csum_partial_copy_generic() ↵Jason A. Donenfeld
epilogue A recent change to the checksum code removed usage of some extra arguments, alongside with storage on the stack for those, and the stack pointer no longer needed to be adjusted in the function prologue. But a left over subtraction wasn't removed in the function epilogue, causing the function to return with the stack pointer moved 16 bytes away from where it should have. This corrupted local state and lead to weird crashes. This simply removes the leftover instruction from the epilogue. Fixes: 70d65cd555c5 ("ppc: propagate the calling conventions change down to csum_partial_copy_generic()") Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-12Merge branch 'work.csum_and_copy' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull copy_and_csum cleanups from Al Viro: "Saner calling conventions for csum_and_copy_..._user() and friends" [ Removing 800+ lines of code and cleaning stuff up is good - Linus ] * 'work.csum_and_copy' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: ppc: propagate the calling conventions change down to csum_partial_copy_generic() amd64: switch csum_partial_copy_generic() to new calling conventions sparc64: propagate the calling convention changes down to __csum_partial_copy_...() xtensa: propagate the calling conventions change down into csum_partial_copy_generic() mips: propagate the calling convention change down into __csum_partial_copy_..._user() mips: __csum_partial_copy_kernel() has no users left mips: csum_and_copy_{to,from}_user() are never called under KERNEL_DS sparc32: propagate the calling conventions change down to __csum_partial_copy_sparc_generic() i386: propagate the calling conventions change down to csum_partial_copy_generic() sh: propage the calling conventions change down to csum_partial_copy_generic() m68k: get rid of zeroing destination on error in csum_and_copy_from_user() arm: propagate the calling convention changes down to csum_partial_copy_from_user() alpha: propagate the calling convention changes down to csum_partial_copy.c helpers saner calling conventions for csum_and_copy_..._user() csum_and_copy_..._user(): pass 0xffffffff instead of 0 as initial sum csum_partial_copy_nocheck(): drop the last argument unify generic instances of csum_partial_copy_nocheck() icmp_push_reply(): reorder adding the checksum up skb_copy_and_csum_bits(): don't bother with the last argument
2020-10-06x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}()Dan Williams
In reaction to a proposal to introduce a memcpy_mcsafe_fast() implementation Linus points out that memcpy_mcsafe() is poorly named relative to communicating the scope of the interface. Specifically what addresses are valid to pass as source, destination, and what faults / exceptions are handled. Of particular concern is that even though x86 might be able to handle the semantics of copy_mc_to_user() with its common copy_user_generic() implementation other archs likely need / want an explicit path for this case: On Fri, May 1, 2020 at 11:28 AM Linus Torvalds <torvalds@linux-foundation.org> wrote: > > On Thu, Apr 30, 2020 at 6:21 PM Dan Williams <dan.j.williams@intel.com> wrote: > > > > However now I see that copy_user_generic() works for the wrong reason. > > It works because the exception on the source address due to poison > > looks no different than a write fault on the user address to the > > caller, it's still just a short copy. So it makes copy_to_user() work > > for the wrong reason relative to the name. > > Right. > > And it won't work that way on other architectures. On x86, we have a > generic function that can take faults on either side, and we use it > for both cases (and for the "in_user" case too), but that's an > artifact of the architecture oddity. > > In fact, it's probably wrong even on x86 - because it can hide bugs - > but writing those things is painful enough that everybody prefers > having just one function. Replace a single top-level memcpy_mcsafe() with either copy_mc_to_user(), or copy_mc_to_kernel(). Introduce an x86 copy_mc_fragile() name as the rename for the low-level x86 implementation formerly named memcpy_mcsafe(). It is used as the slow / careful backend that is supplanted by a fast copy_mc_generic() in a follow-on patch. One side-effect of this reorganization is that separating copy_mc_64.S to its own file means that perf no longer needs to track dependencies for its memcpy_64.S benchmarks. [ bp: Massage a bit. ] Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: <stable@vger.kernel.org> Link: http://lore.kernel.org/r/CAHk-=wjSqtXAqfUJxFtWNwmguFASTgB0dz1dT3V-78Quiezqbg@mail.gmail.com Link: https://lkml.kernel.org/r/160195561680.2163339.11574962055305783722.stgit@dwillia2-desk3.amr.corp.intel.com
2020-09-18powerpc/sstep: Remove empty if statement checking for invalid formCédric Le Goater
The check should be performed by the caller. This fixes a compile error with W=1. ../arch/powerpc/lib/sstep.c: In function ‘mlsd_8lsd_ea’: ../arch/powerpc/lib/sstep.c:225:3: error: suggest braces around empty body in an ‘if’ statement [-Werror=empty-body] ; /* Invalid form. Should already be checked for by caller! */ ^ Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200914211007.2285999-4-clg@kaod.org
2020-09-15powerpc/uaccess: Switch __patch_instruction() to __put_user_asm_goto()Christophe Leroy
__patch_instruction() is the only user of __put_user_asm() outside of asm/uaccess.h Switch to the new __put_user_asm_goto() to enable retirement of __put_user_asm() in a later patch. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/b9745b122f4a9ae72cef445c61320022ab8b77b7.1599216721.git.christophe.leroy@csgroup.eu
2020-09-08powerpc: remove address space overrides using set_fs()Christoph Hellwig
Stop providing the possibility to override the address space using set_fs() now that there is no need for that any more. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-08-20ppc: propagate the calling conventions change down to ↵Al Viro
csum_partial_copy_generic() ... and get rid of the pointless fallback in the wrappers. On error it used to zero the unwritten area and calculate the csum of the entire thing. Not wanting to do it in assembler part had been very reasonable; doing that in the first place, OTOH... In case of an error the caller discards the data we'd copied, along with whatever checksum it might've had. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-08-20saner calling conventions for csum_and_copy_..._user()Al Viro
All callers of these primitives will * discard anything we might've copied in case of error * ignore the csum value in case of error * always pass 0xffffffff as the initial sum, so the resulting csum value (in case of success, that is) will never be 0. That suggest the following calling conventions: * don't pass err_ptr - just return 0 on error. * don't bother with zeroing destination, etc. in case of error * don't pass the initial sum - just use 0xffffffff. This commit does the minimal conversion in the instances of csum_and_copy_...(); the changes of actual asm code behind them are done later in the series. Note that this asm code is often shared with csum_partial_copy_nocheck(); the difference is that csum_partial_copy_nocheck() passes 0 for initial sum while csum_and_copy_..._user() pass 0xffffffff. Fortunately, we are free to pass 0xffffffff in all cases and subsequent patches will use that freedom without any special comments. A part that could be split off: parisc and uml/i386 claimed to have csum_and_copy_to_user() instances of their own, but those were identical to the generic one, so we simply drop them. Not sure if it's worth a separate commit... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-07-29powerpc/test_emulate_step: Add testcases for divde[.] and divdeu[.] instructionsBalamuruhan S
Add testcases for divde, divde., divdeu, divdeu. emulated instructions to cover few scenarios, - with same dividend and divisor to have undefine RT for divdeu[.] - with divide by zero to have undefine RT for both divde[.] and divdeu[.] - with negative dividend to cover -|divisor| < r <= 0 if the dividend is negative for divde[.] - normal case with proper dividend and divisor for both divde[.] and divdeu[.] Signed-off-by: Balamuruhan S <bala24@linux.ibm.com> Reviewed-by: Sandipan Das <sandipan@linux.ibm.com> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200728130308.1790982-4-bala24@linux.ibm.com
2020-07-29powerpc/sstep: Add support for divde[.] and divdeu[.] instructionsBalamuruhan S
This patch adds emulation support for divde, divdeu instructions, - Divide Doubleword Extended (divde[.]) - Divide Doubleword Extended Unsigned (divdeu[.]) Signed-off-by: Balamuruhan S <bala24@linux.ibm.com> Reviewed-by: Sandipan Das <sandipan@linux.ibm.com> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200728130308.1790982-3-bala24@linux.ibm.com
2020-07-27powerpc/lib: remove memcpy_flushcache redundant returnLi RongQing
Align it with other architectures and none of the callers has been interested its return Signed-off-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1556278590-14727-1-git-send-email-lirongqing@baidu.com
2020-07-27powerpc/lib: Prepare code-patching for modules allocated outside vmalloc spaceChristophe Leroy
Use is_vmalloc_or_module_addr() instead of is_vmalloc_addr() Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7d884db0e5a6f521331639d8c0f13e520d5a4fef.1593428200.git.christophe.leroy@csgroup.eu
2020-07-27powerpc/64s: Implement queued spinlocks and rwlocksNicholas Piggin
These have shown significantly improved performance and fairness when spinlock contention is moderate to high on very large systems. With this series including subsequent patches, on a 16 socket 1536 thread POWER9, a stress test such as same-file open/close from all CPUs gets big speedups, 11620op/s aggregate with simple spinlocks vs 384158op/s (33x faster), where the difference in throughput between the fastest and slowest thread goes from 7x to 1.4x. Thanks to the fast path being identical in terms of atomics and barriers (after a subsequent optimisation patch), single threaded performance is not changed (no measurable difference). On smaller systems, performance and fairness seems to be generally improved. Using dbench on tmpfs as a test (that starts to run into kernel spinlock contention), a 2-socket OpenPOWER POWER9 system was tested with bare metal and KVM guest configurations. Results can be found here: https://github.com/linuxppc/issues/issues/305#issuecomment-663487453 Observations are: - Queued spinlocks are equal when contention is insignificant, as expected and as measured with microbenchmarks. - When there is contention, on bare metal queued spinlocks have better throughput and max latency at all points. - When virtualised, queued spinlocks are slightly worse approaching peak throughput, but significantly better throughput and max latency at all points beyond peak, until queued spinlock maximum latency rises when clients are 2x vCPUs. The regressions haven't been analysed very well yet, there are a lot of things that can be tuned, particularly the paravirtualised locking, but the numbers already look like a good net win even on relatively small systems. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Waiman Long <longman@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200724131423.1362108-4-npiggin@gmail.com
2020-07-26powerpc/pseries: Move some PAPR paravirt functions to their own fileNicholas Piggin
These functions will be used by the queued spinlock implementation, and may be useful elsewhere too, so move them out of spinlock.h. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Waiman Long <longman@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200724131423.1362108-2-npiggin@gmail.com
2020-07-24powerpc/sstep: Fix incorrect CONFIG symbol in scv handlingMichael Ellerman
When I "fixed" the ppc64e build in Nick's recent patch, I typoed the CONFIG symbol, resulting in one that doesn't exist. Fix it to use the correct symbol. Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu> Fixes: 7fa95f9adaee ("powerpc/64s: system call support for scv/rfscv instructions") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200724131609.1640533-1-mpe@ellerman.id.au
2020-07-24powerpc/test_emulate_sstep: Fix build errorMichael Ellerman
ppc64_book3e_allmodconfig fails with: arch/powerpc/lib/test_emulate_step.c: In function 'test_pld': arch/powerpc/lib/test_emulate_step.c:113:7: error: implicit declaration of function 'cpu_has_feature' 113 | if (!cpu_has_feature(CPU_FTR_ARCH_31)) { | ^~~~~~~~~~~~~~~ Add an include of cpu_has_feature.h to fix it. Fixes: b6b54b42722a ("powerpc/sstep: Add tests for prefixed integer load/stores") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200724004109.1461709-1-mpe@ellerman.id.au
2020-07-23Merge branch 'scv' support into nextMichael Ellerman
From Nick's cover letter: Linux powerpc new system call instruction and ABI System Call Vectored (scv) ABI ============================== The scv instruction is introduced with POWER9 / ISA3, it comes with an rfscv counter-part. The benefit of these instructions is performance (trading slower SRR0/1 with faster LR/CTR registers, and entering the kernel with MSR[EE] and MSR[RI] left enabled, which can reduce MSR updates. The scv instruction has 128 levels (not enough to cover the Linux system call space). Assignment and advertisement ---------------------------- The proposal is to assign scv levels conservatively, and advertise them with HWCAP feature bits as we add support for more. Linux has not enabled FSCR[SCV] yet, so executing the scv instruction will cause the kernel to log a "SCV facility unavilable" message, and deliver a SIGILL with ILL_ILLOPC to the process. Linux has defined a HWCAP2 bit PPC_FEATURE2_SCV for SCV support, but does not set it. This change allocates the zero level ('scv 0'), advertised with PPC_FEATURE2_SCV, which will be used to provide normal Linux system calls (equivalent to 'sc'). Attempting to execute scv with other levels will cause a SIGILL to be delivered the same as before, but will not log a "SCV facility unavailable" message (because the processor facility is enabled). Calling convention ------------------ The proposal is for scv 0 to provide the standard Linux system call ABI with the following differences from sc convention[1]: - LR is to be volatile across scv calls. This is necessary because the scv instruction clobbers LR. From previous discussion, this should be possible to deal with in GCC clobbers and CFI. - cr1 and cr5-cr7 are volatile. This matches the C ABI and would allow the kernel system call exit to avoid restoring the volatile cr registers (although we probably still would anyway to avoid information leaks). - Error handling: The consensus among kernel, glibc, and musl is to move to using negative return values in r3 rather than CR0[SO]=1 to indicate error, which matches most other architectures, and is closer to a function call. Notes ----- - r0,r4-r8 are documented as volatile in the ABI, but the kernel patch as submitted currently preserves them. This is to leave room for deciding which way to go with these. Some small benefit was found by preserving them[1] but I'm not convinced it's worth deviating from the C function call ABI just for this. Release code should follow the ABI. Previous discussions: https://lists.ozlabs.org/pipermail/linuxppc-dev/2020-April/208691.html https://lists.ozlabs.org/pipermail/linuxppc-dev/2020-April/209268.html [1] https://github.com/torvalds/linux/blob/master/Documentation/powerpc/syscall64-abi.rst [2] https://lists.ozlabs.org/pipermail/linuxppc-dev/2020-April/209263.html
2020-07-23powerpc/test_emulate_step: Move extern declaration to sstep.hBalamuruhan S
fix checkpatch.pl warnings by moving extern declaration from source file to headerfile. Signed-off-by: Balamuruhan S <bala24@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200626095158.1031507-5-bala24@linux.ibm.com
2020-07-23powerpc/sstep: Introduce macros to retrieve Prefix instruction operandsBalamuruhan S
retrieve prefix instruction operands RA and pc relative bit R values using macros and adopt it in sstep.c and test_emulate_step.c. Signed-off-by: Balamuruhan S <bala24@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200626095158.1031507-4-bala24@linux.ibm.com
2020-07-23powerpc/test_emulate_step: Add negative tests for prefixed addiBalamuruhan S
testcases for `paddi` instruction to cover the negative case, if R is equal to 1 and RA is not equal to 0, the instruction form is invalid. Signed-off-by: Balamuruhan S <bala24@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200626095158.1031507-3-bala24@linux.ibm.com
2020-07-23powerpc/test_emulate_step: Enhancement to test negative scenariosBalamuruhan S
add provision to declare test is a negative scenario, verify whether emulation fails and avoid executing it. Signed-off-by: Balamuruhan S <bala24@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200626095158.1031507-2-bala24@linux.ibm.com
2020-07-23powerpc: Add a ppc_inst_as_str() helperJordan Niethe
There are quite a few places where instructions are printed, this is done using a '%x' format specifier. With the introduction of prefixed instructions, this does not work well. Currently in these places, ppc_inst_val() is used for the value for %x so only the first word of prefixed instructions are printed. When the instructions are word instructions, only a single word should be printed. For prefixed instructions both the prefix and suffix should be printed. To accommodate both of these situations, instead of a '%x' specifier use '%s' and introduce a helper, __ppc_inst_as_str() which returns a char *. The char * __ppc_inst_as_str() returns is buffer that is passed to it by the caller. It is cumbersome to require every caller of __ppc_inst_as_str() to now declare a buffer. To make it more convenient to use __ppc_inst_as_str(), wrap it in a macro that uses a compound statement to allocate a buffer on the caller's stack before calling it. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Reviewed-by: Joel Stanley <joel@jms.id.au> Acked-by: Segher Boessenkool <segher@kernel.crashing.org> [mpe: Drop 0x prefix to match most existings uses, especially xmon] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200602052728.18227-1-jniethe5@gmail.com
2020-07-23powerpc/sstep: Add tests for Prefixed Add ImmediateJordan Niethe
Use the existing support for testing compute type instructions to test Prefixed Add Immediate (paddi). The R bit of the paddi instruction controls whether current instruction address is used. Add test cases for when R=1 and for R=0. paddi has a 34 bit immediate field formed by concatenating si0 and si1. Add tests for the extreme values of this field. Skip the paddi tests if ISA v3.1 is unsupported. Some of these test cases were added by Balamuruhan S. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> [mpe: Fix conflicts with ppc-opcode.h changes, squash in .balign] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200525025923.19843-5-jniethe5@gmail.com
2020-07-23powerpc/sstep: Let compute tests specify a required cpu featureJordan Niethe
An a array of struct compute_test's are used to declare tests for compute instructions. Add a cpu_feature field to struct compute_test as an optional way to specify a cpu feature that must be present. If not present then skip the test. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200525025923.19843-4-jniethe5@gmail.com
2020-07-23powerpc/sstep: Set NIP in instruction emulation testsJordan Niethe
The tests for emulation of compute instructions execute and emulate an instruction and then compare the results to verify the emulation. In ISA v3.1 there are instructions that operate relative to the NIP. Therefore set the NIP in the regs used for the emulated instruction to the location of the executed instruction so they will give the same result. This is a rework of a patch by Balamuruhan S. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200525025923.19843-3-jniethe5@gmail.com
2020-07-23powerpc/sstep: Add tests for prefixed floating-point load/storesJordan Niethe
Add tests for the prefixed versions of the floating-point load/stores that are currently tested. This includes the following instructions: * Prefixed Load Floating-Point Single (plfs) * Prefixed Load Floating-Point Double (plfd) * Prefixed Store Floating-Point Single (pstfs) * Prefixed Store Floating-Point Double (pstfd) Skip the new tests if ISA v3.10 is unsupported. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> [mpe: Fix conflicts with ppc-opcode.h changes] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200525025923.19843-2-jniethe5@gmail.com
2020-07-23powerpc/sstep: Add tests for prefixed integer load/storesJordan Niethe
Add tests for the prefixed versions of the integer load/stores that are currently tested. This includes the following instructions: * Prefixed Load Doubleword (pld) * Prefixed Load Word and Zero (plwz) * Prefixed Store Doubleword (pstd) Skip the new tests if ISA v3.1 is unsupported. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> [mpe: Fix conflicts with ppc-opcode.h changes] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200525025923.19843-1-jniethe5@gmail.com
2020-07-22powerpc/64s: system call support for scv/rfscv instructionsNicholas Piggin
Add support for the scv instruction on POWER9 and later CPUs. For now this implements the zeroth scv vector 'scv 0', as identical to 'sc' system calls, with the exception that LR is not preserved, nor are volatile CR registers, and error is not indicated with CR0[SO], but by returning a negative errno. rfscv is implemented to return from scv type system calls. It can not be used to return from sc system calls because those are defined to preserve LR. getpid syscall throughput on POWER9 is improved by 26% (428 to 318 cycles), largely due to reducing mtmsr and mtspr. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Fix ppc64e build] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200611081203.995112-3-npiggin@gmail.com
2020-07-16powerpc/ppc-opcode: Move ppc instruction encoding from test_emulate_stepBalamuruhan S
Few ppc instructions are encoded in test_emulate_step.c, consolidate them and use it from ppc-opcode.h Signed-off-by: Balamuruhan S <bala24@linux.ibm.com> Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Sandipan Das <sandipan@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200624113038.908074-3-bala24@linux.ibm.com
2020-07-16powerpc/pmem: Avoid the barrier in flush routinesAneesh Kumar K.V
nvdimm expect the flush routines to just mark the cache clean. The barrier that mark the store globally visible is done in nvdimm_flush(). Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200701072235.223558-7-aneesh.kumar@linux.ibm.com
2020-07-16powerpc/pmem: Add flush routines using new pmem store and sync instructionAneesh Kumar K.V
Start using dcbstps; phwsync; sequence for flushing persistent memory range. The new instructions are implemented as a variant of dcbf and hwsync and on P8 and P9 they will be executed as those instructions. We avoid using them on older hardware. This helps to avoid difficult to debug bugs. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200701072235.223558-4-aneesh.kumar@linux.ibm.com
2020-06-17maccess: rename probe_user_{read,write} to copy_{from,to}_user_nofaultChristoph Hellwig
Better describe what these functions do. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-17maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofaultChristoph Hellwig
Better describe what these functions do. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09mm: don't include asm/pgtable.h if linux/mm.h is already includedMike Rapoport
Patch series "mm: consolidate definitions of page table accessors", v2. The low level page table accessors (pXY_index(), pXY_offset()) are duplicated across all architectures and sometimes more than once. For instance, we have 31 definition of pgd_offset() for 25 supported architectures. Most of these definitions are actually identical and typically it boils down to, e.g. static inline unsigned long pmd_index(unsigned long address) { return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1); } static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) { return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address); } These definitions can be shared among 90% of the arches provided XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined. For architectures that really need a custom version there is always possibility to override the generic version with the usual ifdefs magic. These patches introduce include/linux/pgtable.h that replaces include/asm-generic/pgtable.h and add the definitions of the page table accessors to the new header. This patch (of 12): The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the functions involving page table manipulations, e.g. pte_alloc() and pmd_alloc(). So, there is no point to explicitly include <asm/pgtable.h> in the files that include <linux/mm.h>. The include statements in such cases are remove with a simple loop: for f in $(git grep -l "include <linux/mm.h>") ; do sed -i -e '/include <asm\/pgtable.h>/ d' $f done Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-05Merge tag 'powerpc-5.8-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: - Support for userspace to send requests directly to the on-chip GZIP accelerator on Power9. - Rework of our lockless page table walking (__find_linux_pte()) to make it safe against parallel page table manipulations without relying on an IPI for serialisation. - A series of fixes & enhancements to make our machine check handling more robust. - Lots of plumbing to add support for "prefixed" (64-bit) instructions on Power10. - Support for using huge pages for the linear mapping on 8xx (32-bit). - Remove obsolete Xilinx PPC405/PPC440 support, and an associated sound driver. - Removal of some obsolete 40x platforms and associated cruft. - Initial support for booting on Power10. - Lots of other small features, cleanups & fixes. Thanks to: Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan, Andrey Abramov, Aneesh Kumar K.V, Balamuruhan S, Bharata B Rao, Bulent Abali, Cédric Le Goater, Chen Zhou, Christian Zigotzky, Christophe JAILLET, Christophe Leroy, Dmitry Torokhov, Emmanuel Nicolet, Erhard F., Gautham R. Shenoy, Geoff Levand, George Spelvin, Greg Kurz, Gustavo A. R. Silva, Gustavo Walbon, Haren Myneni, Hari Bathini, Joel Stanley, Jordan Niethe, Kajol Jain, Kees Cook, Leonardo Bras, Madhavan Srinivasan., Mahesh Salgaonkar, Markus Elfring, Michael Neuling, Michal Simek, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Paul Mackerras, Pingfan Liu, Qian Cai, Ram Pai, Raphael Moreira Zinsly, Ravi Bangoria, Sam Bobroff, Sandipan Das, Segher Boessenkool, Stephen Rothwell, Sukadev Bhattiprolu, Tyrel Datwyler, Wolfram Sang, Xiongfeng Wang. * tag 'powerpc-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (299 commits) powerpc/pseries: Make vio and ibmebus initcalls pseries specific cxl: Remove dead Kconfig options powerpc: Add POWER10 architected mode powerpc/dt_cpu_ftrs: Add MMA feature powerpc/dt_cpu_ftrs: Enable Prefixed Instructions powerpc/dt_cpu_ftrs: Advertise support for ISA v3.1 if selected powerpc: Add support for ISA v3.1 powerpc: Add new HWCAP bits powerpc/64s: Don't set FSCR bits in INIT_THREAD powerpc/64s: Save FSCR to init_task.thread.fscr after feature init powerpc/64s: Don't let DT CPU features set FSCR_DSCR powerpc/64s: Don't init FSCR_DSCR in __init_FSCR() powerpc/32s: Fix another build failure with CONFIG_PPC_KUAP_DEBUG powerpc/module_64: Use special stub for _mcount() with -mprofile-kernel powerpc/module_64: Simplify check for -mprofile-kernel ftrace relocations powerpc/module_64: Consolidate ftrace code powerpc/32: Disable KASAN with pages bigger than 16k powerpc/uaccess: Don't set KUEP by default on book3s/32 powerpc/uaccess: Don't set KUAP by default on book3s/32 powerpc/8xx: Reduce time spent in allow_user_access() and friends ...
2020-06-04powerpc: add support for folded p4d page tablesMike Rapoport
Implement primitives necessary for the 4th level folding, add walks of p4d level where appropriate and replace 5level-fixup.h with pgtable-nop4d.h. [rppt@linux.ibm.com: powerpc/xmon: drop unused pgdir varialble in show_pte() function] Link: http://lkml.kernel.org/r/20200519181454.GI1059226@linux.ibm.com [rppt@linux.ibm.com; build fix] Link: http://lkml.kernel.org/r/20200423141845.GI13521@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Christophe Leroy <christophe.leroy@c-s.fr> # 8xx and 83xx Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: James Morse <james.morse@arm.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Julien Thierry <julien.thierry.kdev@gmail.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200414153455.21744-9-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-05-26powerpc: Add ppc_inst_as_u64()Michael Ellerman
The code patching code wants to get the value of a struct ppc_inst as a u64 when the instruction is prefixed, so we can pass the u64 down to __put_user_asm() and write it with a single store. The optprobes code wants to load a struct ppc_inst as an immediate into a register so it is useful to have it as a u64 to use the existing helper function. Currently this is a bit awkward because the value differs based on the CPU endianness, so add a helper to do the conversion. This fixes the usage in arch_prepare_optimized_kprobe() which was previously incorrect on big endian. Fixes: 650b55b707fd ("powerpc: Add prefixed instructions to instruction data type") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Tested-by: Jordan Niethe <jniethe5@gmail.com> Link: https://lore.kernel.org/r/20200526072630.2487363-1-mpe@ellerman.id.au
2020-05-26powerpc: Add ppc_inst_next()Michael Ellerman
In a few places we want to calculate the address of the next instruction. Previously that was simple, we just added 4 bytes, or if using a u32 * we incremented that pointer by 1. But prefixed instructions make it more complicated, we need to advance by either 4 or 8 bytes depending on the actual instruction. We also can't do pointer arithmetic using struct ppc_inst, because it is always 8 bytes in size on 64-bit, even though we might only need to advance by 4 bytes. So add a ppc_inst_next() helper which calculates the location of the next instruction, if the given instruction was located at the given address. Note the instruction doesn't need to actually be at the address in memory. Although it would seem natural for the value to be passed by value, that makes it too easy to write a loop that will read off the end of a page, eg: for (; src < end; src = ppc_inst_next(src, *src), dest = ppc_inst_next(dest, *dest)) As noticed by Christophe and Jordan, if end is the exact end of a page, and the next page is not mapped, this will fault, because *dest will read 8 bytes, 4 bytes into the next page. So value is passed by reference, so the helper can be careful to use ppc_inst_read() on it. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Jordan Niethe <jniethe5@gmail.com> Link: https://lore.kernel.org/r/20200522133318.1681406-1-mpe@ellerman.id.au
2020-05-19powerpc sstep: Add support for prefixed fixed-point arithmeticJordan Niethe
This adds emulation support for the following prefixed Fixed-Point Arithmetic instructions: * Prefixed Add Immediate (paddi) Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Reviewed-by: Balamuruhan S <bala24@linux.ibm.com> [mpe: Squash in get_op() usage] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-31-jniethe5@gmail.com
2020-05-19powerpc sstep: Add support for prefixed load/storesJordan Niethe
This adds emulation support for the following prefixed integer load/stores: * Prefixed Load Byte and Zero (plbz) * Prefixed Load Halfword and Zero (plhz) * Prefixed Load Halfword Algebraic (plha) * Prefixed Load Word and Zero (plwz) * Prefixed Load Word Algebraic (plwa) * Prefixed Load Doubleword (pld) * Prefixed Store Byte (pstb) * Prefixed Store Halfword (psth) * Prefixed Store Word (pstw) * Prefixed Store Doubleword (pstd) * Prefixed Load Quadword (plq) * Prefixed Store Quadword (pstq) the follow prefixed floating-point load/stores: * Prefixed Load Floating-Point Single (plfs) * Prefixed Load Floating-Point Double (plfd) * Prefixed Store Floating-Point Single (pstfs) * Prefixed Store Floating-Point Double (pstfd) and for the following prefixed VSX load/stores: * Prefixed Load VSX Scalar Doubleword (plxsd) * Prefixed Load VSX Scalar Single-Precision (plxssp) * Prefixed Load VSX Vector [0|1] (plxv, plxv0, plxv1) * Prefixed Store VSX Scalar Doubleword (pstxsd) * Prefixed Store VSX Scalar Single-Precision (pstxssp) * Prefixed Store VSX Vector [0|1] (pstxv, pstxv0, pstxv1) Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Reviewed-by: Balamuruhan S <bala24@linux.ibm.com> [mpe: Use CONFIG_PPC64 not __powerpc64__, use get_op()] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-30-jniethe5@gmail.com
2020-05-19powerpc: Test prefixed instructions in feature fixupsJordan Niethe
Expand the feature-fixups self-tests to includes tests for prefixed instructions. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> [mpe: Use CONFIG_PPC64 not __powerpc64__, add empty inlines] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-26-jniethe5@gmail.com
2020-05-19powerpc: Test prefixed code patchingJordan Niethe
Expand the code-patching self-tests to includes tests for patching prefixed instructions. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> [mpe: Use CONFIG_PPC64 not __powerpc64__] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-25-jniethe5@gmail.com
2020-05-19powerpc: Add prefixed instructions to instruction data typeJordan Niethe
For powerpc64, redefine the ppc_inst type so both word and prefixed instructions can be represented. On powerpc32 the type will remain the same. Update places which had assumed instructions to be 4 bytes long. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Reviewed-by: Alistair Popple <alistair@popple.id.au> [mpe: Rework the get_user_inst() macros to be parameterised, and don't assign to the dest if an error occurred. Use CONFIG_PPC64 not __powerpc64__ in a few places. Address other comments from Christophe. Fix some sparse complaints.] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-24-jniethe5@gmail.com
2020-05-19powerpc: Make test_translate_branch() independent of instruction lengthJordan Niethe
test_translate_branch() uses two pointers to instructions within a buffer, p and q, to test patch_branch(). The pointer arithmetic done on them assumes a size of 4. This will not work if the instruction length changes. Instead do the arithmetic relative to the void * to the buffer. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Alistair Popple <alistair@popple.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-21-jniethe5@gmail.com
2020-05-19powerpc: Introduce a function for reporting instruction lengthJordan Niethe
Currently all instructions have the same length, but in preparation for prefixed instructions introduce a function for returning instruction length. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Alistair Popple <alistair@popple.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-18-jniethe5@gmail.com
2020-05-19powerpc: Add a probe_kernel_read_inst() functionJordan Niethe
Introduce a probe_kernel_read_inst() function to use in cases where probe_kernel_read() is used for getting an instruction. This will be more useful for prefixed instructions. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Reviewed-by: Alistair Popple <alistair@popple.id.au> [mpe: Don't write to *inst on error] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-15-jniethe5@gmail.com
2020-05-19powerpc: Add a probe_user_read_inst() functionJordan Niethe
Introduce a probe_user_read_inst() function to use in cases where probe_user_read() is used for getting an instruction. This will be more useful for prefixed instructions. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Reviewed-by: Alistair Popple <alistair@popple.id.au> [mpe: Don't write to *inst on error, fold in __user annotations] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-14-jniethe5@gmail.com
2020-05-19powerpc: Use a function for reading instructionsJordan Niethe
Prefixed instructions will mean there are instructions of different length. As a result dereferencing a pointer to an instruction will not necessarily give the desired result. Introduce a function for reading instructions from memory into the instruction data type. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Alistair Popple <alistair@popple.id.au> Link: https://lore.kernel.org/r/20200506034050.24806-13-jniethe5@gmail.com