wireguard-linux/arch/powerpc/xmon, branch jd/orphan-parallel

powerpc/watchpoint: Add hw_len wherever missing

2020-09-15T12:13:20Z

There are couple of places where we set len but not hw_len. For ptrace/perf watchpoints, when CONFIG_HAVE_HW_BREAKPOINT=Y, hw_len will be calculated and set internally while parsing watchpoint. But when CONFIG_HAVE_HW_BREAKPOINT=N, we need to manually set 'hw_len'. Similarly for xmon as well, hw_len needs to be set directly. Fixes: b57aeab811db ("powerpc/watchpoint: Fix length calculation for unaligned target") Signed-off-by: Ravi Bangoria Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200902042945.129369-7-ravi.bangoria@linux.ibm.com

Merge tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2020-08-09T21:10:26Z

Pull Kbuild updates from Masahiro Yamada: - run the checker (e.g. sparse) after the compiler - remove unneeded cc-option tests for old compiler flags - fix tar-pkg to install dtbs - introduce ccflags-remove-y and asflags-remove-y syntax - allow to trace functions in sub-directories of lib/ - introduce hostprogs-always-y and userprogs-always-y syntax - various Makefile cleanups * tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option base kbuild: include scripts/Makefile.* only when relevant CONFIG is enabled kbuild: introduce hostprogs-always-y and userprogs-always-y kbuild: sort hostprogs before passing it to ifneq kbuild: move host .so build rules to scripts/gcc-plugins/Makefile kbuild: Replace HTTP links with HTTPS ones kbuild: trace functions in subdirectories of lib/ kbuild: introduce ccflags-remove-y and asflags-remove-y kbuild: do not export LDFLAGS_vmlinux kbuild: always create directories of targets powerpc/boot: add DTB to 'targets' kbuild: buildtar: add dtbs support kbuild: remove cc-option test of -ffreestanding kbuild: remove cc-option test of -fno-stack-protector Revert "kbuild: Create directory for target DTB" kbuild: run the checker after the compiler

kbuild: introduce ccflags-remove-y and asflags-remove-y

2020-08-09T16:32:59Z

CFLAGS_REMOVE_.o filters out flags when compiling a particular object, but there is no convenient way to do that for every object in a directory. Add ccflags-remove-y and asflags-remove-y to make it easily. Use ccflags-remove-y to clean up some Makefiles. The add/remove order works as follows: [1] KBUILD_CFLAGS specifies compiler flags used globally [2] ccflags-y adds compiler flags for all objects in the current Makefile [3] ccflags-remove-y removes compiler flags for all objects in the current Makefile (New feature) [4] CFLAGS_ adds compiler flags per file. [5] CFLAGS_REMOVE_ removes compiler flags per file. Having [3] before [4] allows us to remove flags from most (but not all) objects in the current Makefile. For example, kernel/trace/Makefile removes $(CC_FLAGS_FTRACE) from all objects in the directory, then adds it back to trace_selftest_dynamic.o and CFLAGS_trace_kprobe_selftest.o The same applies to lib/livepatch/Makefile. Please note ccflags-remove-y has no effect to the sub-directories. In contrast, the previous notation got rid of compiler flags also from all the sub-directories. The following are not affected because they have no sub-directories: arch/arm/boot/compressed/ arch/powerpc/xmon/ arch/sh/ kernel/trace/ However, lib/ has several sub-directories. To keep the behavior, I added ccflags-remove-y to all Makefiles in subdirectories of lib/, except the following: lib/vdso/Makefile - Kbuild does not descend into this Makefile lib/raid/test/Makefile - This is not used for the kernel build I think commit 2464a609ded0 ("ftrace: do not trace library functions") excluded too much. In the next commit, I will remove ccflags-remove-y from the sub-directories of lib/. Suggested-by: Sami Tolvanen Signed-off-by: Masahiro Yamada Acked-by: Steven Rostedt (VMware) Acked-by: Michael Ellerman (powerpc) Acked-by: Brendan Higgins (KUnit) Tested-by: Anders Roxell

powerpc: Use fallthrough pseudo-keyword

2020-07-29T11:09:37Z

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200727224201.GA10133@embeddedor

powerpc/xmon: Use `dcbf` inplace of `dcbi` instruction for 64bit Book3S

2020-07-29T11:08:30Z

Data Cache Block Invalidate (dcbi) instruction implemented back in PowerPC architecture version 2.03. But as per Power Processor Users Manual it is obsolete and not supported by POWER8/POWER9 core. Attempt to use of this illegal instruction results in a hypervisor emulation assistance interrupt. So, ifdef it out the option `i` in xmon for 64bit Book3S. 0:mon> fi cpu 0x0: Vector: 700 (Program Check) at [c000000003be74a0] pc: c000000000102030: cacheflush+0x180/0x1a0 lr: c000000000101f3c: cacheflush+0x8c/0x1a0 sp: c000000003be7730 msr: 8000000000081033 current = 0xc0000000035e5c00 paca = 0xc000000001910000 irqmask: 0x03 irq_happened: 0x01 pid = 1025, comm = bash Linux version 5.6.0-rc5-g5aa19adac (root@ltc-wspoon6) (gcc version 7.4.0 (Ubuntu 7.4.0-1ubuntu1~18.04.1)) #1 SMP Tue Mar 10 04:38:41 CDT 2020 cpu 0x0: Exception 700 (Program Check) in xmon, returning to main loop [c000000003be7c50] c00000000084abb0 __handle_sysrq+0xf0/0x2a0 [c000000003be7d00] c00000000084b3c0 write_sysrq_trigger+0xb0/0xe0 [c000000003be7d30] c0000000004d1edc proc_reg_write+0x8c/0x130 [c000000003be7d60] c00000000040dc7c __vfs_write+0x3c/0x70 [c000000003be7d80] c000000000410e70 vfs_write+0xd0/0x210 [c000000003be7dd0] c00000000041126c ksys_write+0xdc/0x130 [c000000003be7e20] c00000000000b9d0 system_call+0x5c/0x68 --- Exception: c01 (System Call) at 00007fffa345e420 SP (7ffff0b08ab0) is in userspace Signed-off-by: Balamuruhan S Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200330075954.538773-1-bala24@linux.ibm.com

Merge branch 'scv' support into next

2020-07-23T07:43:44Z

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

powerpc/xmon: Improve dumping prefixed instructions

2020-07-23T07:41:59Z

Currently prefixed instructions are dumped as two separate word instructions. Use mread_instr() so that prefixed instructions are read as such and update the incrementor in the loop to take this into account. 'dump_func' is print_insn_powerpc() which comes from ppc-dis.c which is taken from binutils. When this is updated prefixed instructions will be disassembled. Currently dumping prefixed instructions looks like this: 0:mon> di c000000000094168 c000000000094168 0x06000000 .long 0x6000000 c00000000009416c 0x392a0003 addi r9,r10,3 c000000000094170 0x913f0028 stw r9,40(r31) c000000000094174 0xe93f002a lwa r9,40(r31) c000000000094178 0x7d234b78 mr r3,r9 c00000000009417c 0x383f0040 addi r1,r31,64 c000000000094180 0xebe1fff8 ld r31,-8(r1) c000000000094184 0x4e800020 blr c000000000094188 0x60000000 nop ... c000000000094190 0x3c4c0121 addis r2,r12,289 c000000000094194 0x38429670 addi r2,r2,-27024 c000000000094198 0x7c0802a6 mflr r0 c00000000009419c 0x60000000 nop c0000000000941a0 0xe9240100 ld r9,256(r4) c0000000000941a4 0x39400001 li r10,1 After this it looks like: 0:mon> di c000000000094168 c000000000094168 0x06000000 0x392a0003 .long 0x392a000306000000 c000000000094170 0x913f0028 stw r9,40(r31) c000000000094174 0xe93f002a lwa r9,40(r31) c000000000094178 0x7d234b78 mr r3,r9 c00000000009417c 0x383f0040 addi r1,r31,64 c000000000094180 0xebe1fff8 ld r31,-8(r1) c000000000094184 0x4e800020 blr c000000000094188 0x60000000 nop ... c000000000094190 0x3c4c0121 addis r2,r12,289 c000000000094194 0x38429570 addi r2,r2,-27280 c000000000094198 0x7c0802a6 mflr r0 c00000000009419c 0x60000000 nop c0000000000941a0 0xe9240100 ld r9,256(r4) c0000000000941a4 0x39400001 li r10,1 c0000000000941a8 0x3d02000b addis r8,r2,11 Signed-off-by: Jordan Niethe Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200602052728.18227-2-jniethe5@gmail.com

powerpc: Add a ppc_inst_as_str() helper

2020-07-23T07:41:36Z

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 Reviewed-by: Joel Stanley Acked-by: Segher Boessenkool [mpe: Drop 0x prefix to match most existings uses, especially xmon] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200602052728.18227-1-jniethe5@gmail.com

powerpc/64s: system call support for scv/rfscv instructions

2020-07-22T13:00:27Z

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 [mpe: Fix ppc64e build] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200611081203.995112-3-npiggin@gmail.com

powerpc/xmon: Add PowerISA v3.1 PMU SPRs

2020-07-22T11:56:41Z

PowerISA v3.1 added three new perfromance monitoring unit (PMU) speical purpose register (SPR). They are Monitor Mode Control Register 3 (MMCR3), Sampled Instruction Event Register 2 (SIER2), Sampled Instruction Event Register 3 (SIER3). Patch here adds a new dump function dump_310_sprs to print these SPR values. Signed-off-by: Madhavan Srinivasan Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/1594996707-3727-7-git-send-email-atrajeev@linux.vnet.ibm.com