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2022-09-28powerpc/64: asm use consistent global variable declaration and accessNicholas Piggin1-2/+2
Use helper macros to access global variables, and place them in .data sections rather than in .toc. Putting addresses in TOC is not required because the kernel is linked with a single TOC. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220926034057.2360083-3-npiggin@gmail.com
2022-09-26powerpc: Simplify redundant Kconfig testsChristophe Leroy1-1/+1
PPC_85xx implies PPC32 so no need to check PPC32 in addition. PPC64 && !PPC_BOOK3E_64 means PPC_BOOK3S_64. PPC_BOOK3E_64 implies PPC_E500. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/244cce3e603f2b79796314c0c1c46cab927b9adc.1663606876.git.christophe.leroy@csgroup.eu
2022-09-26powerpc: Remove CONFIG_PPC_BOOK3EChristophe Leroy1-8/+8
CONFIG_PPC_BOOK3E is redundant with CONFIG_PPC_BOOK3E_64. The later is more explicit about the fact that it's a 64 bits target. Remove CONFIG_PPC_BOOK3E. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5d0891490813c19cdcfc04678f512ea68cba3e64.1663606876.git.christophe.leroy@csgroup.eu
2022-09-15powerpc/xmon: remove unused ppc_parse_cpu() declarationGaosheng Cui1-2/+0
ppc_parse_cpu() has been removed since commit 5b102782c7f4 ("powerpc/xmon: Enable disassembly files (compilation changes)"), so remove it. Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220913075029.682327-2-cuigaosheng1@huawei.com
2022-07-27powerpc/ppc-opcode: Define and use PPC_RAW_TRAP() and PPC_RAW_TW()Christophe Leroy1-1/+1
Add and use PPC_RAW_TRAP() instead of opencoding. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/52c7e522e56a38e3ff0363906919445920005a8f.1657205708.git.christophe.leroy@csgroup.eu
2022-06-29powerpc/64: Drop ppc_inst_as_str()Michael Ellerman1-1/+1
The ppc_inst_as_str() macro tries to make printing variable length, aka "prefixed", instructions convenient. It mostly succeeds, but it does hide an on-stack buffer, which triggers stack protector. More problematically it doesn't compile at all with GCC 12, with -Wdangling-pointer, due to the fact that it returns the char buffer declared inside the macro: arch/powerpc/kernel/trace/ftrace.c: In function '__ftrace_modify_call': ./include/linux/printk.h:475:44: error: using a dangling pointer to '__str' [-Werror=dangling-pointer=] 475 | #define printk(fmt, ...) printk_index_wrap(_printk, fmt, ##__VA_ARGS__) ... arch/powerpc/kernel/trace/ftrace.c:567:17: note: in expansion of macro 'pr_err' 567 | pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op)); | ^~~~~~ ./arch/powerpc/include/asm/inst.h:156:14: note: '__str' declared here 156 | char __str[PPC_INST_STR_LEN]; \ | ^~~~~ This could be fixed by having the caller declare the buffer, but in some places there'd need to be two buffers. In all cases where ppc_inst_as_str() is used the output is not really meant for user consumption, it's almost always indicative of a kernel bug. A simpler solution is to just print the value as an unsigned long. For normal instructions the output is identical. For prefixed instructions the value is printed as a single 64-bit quantity, whereas previously the low half was printed first. But that is good enough for debug output, especially as prefixed instructions will be rare in kernel code in practice. Old: c000000000111170 60420000 ori r2,r2,0 c000000000111174 04100001 e580fb00 .long 0xe580fb0004100001 New: c00000000010f90c 60420000 ori r2,r2,0 c00000000010f910 e580fb0004100001 .long 0xe580fb0004100001 Reported-by: Bagas Sanjaya <bagasdotme@gmail.com> Reported-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Tested-by: Bagas Sanjaya <bagasdotme@gmail.com> Link: https://lore.kernel.org/r/20220531065936.3674348-1-mpe@ellerman.id.au
2022-05-30Merge tag 'pm-5.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pmLinus Torvalds1-2/+1
Pull more power management updates from Rafael Wysocki: "These update the ARM cpufreq drivers and fix up the CPPC cpufreq driver after recent changes, update the OPP code and PM documentation and add power sequences support to the system reboot and power off code. Specifics: - Add Tegra234 cpufreq support (Sumit Gupta) - Clean up and enhance the Mediatek cpufreq driver (Wan Jiabing, Rex-BC Chen, and Jia-Wei Chang) - Fix up the CPPC cpufreq driver after recent changes (Zheng Bin, Pierre Gondois) - Minor update to dt-binding for Qcom's opp-v2-kryo-cpu (Yassine Oudjana) - Use list iterator only inside the list_for_each_entry loop (Xiaomeng Tong, and Jakob Koschel) - New APIs related to finding OPP based on interconnect bandwidth (Krzysztof Kozlowski) - Fix the missing of_node_put() in _bandwidth_supported() (Dan Carpenter) - Cleanups (Krzysztof Kozlowski, and Viresh Kumar) - Add Out of Band mode description to the intel-speed-select utility documentation (Srinivas Pandruvada) - Add power sequences support to the system reboot and power off code and make related platform-specific changes for multiple platforms (Dmitry Osipenko, Geert Uytterhoeven)" * tag 'pm-5.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (60 commits) cpufreq: CPPC: Fix unused-function warning cpufreq: CPPC: Fix build error without CONFIG_ACPI_CPPC_CPUFREQ_FIE Documentation: admin-guide: PM: Add Out of Band mode kernel/reboot: Change registration order of legacy power-off handler m68k: virt: Switch to new sys-off handler API kernel/reboot: Add devm_register_restart_handler() kernel/reboot: Add devm_register_power_off_handler() soc/tegra: pmc: Use sys-off handler API to power off Nexus 7 properly reboot: Remove pm_power_off_prepare() regulator: pfuze100: Use devm_register_sys_off_handler() ACPI: power: Switch to sys-off handler API memory: emif: Use kernel_can_power_off() mips: Use do_kernel_power_off() ia64: Use do_kernel_power_off() x86: Use do_kernel_power_off() sh: Use do_kernel_power_off() m68k: Switch to new sys-off handler API powerpc: Use do_kernel_power_off() xen/x86: Use do_kernel_power_off() parisc: Use do_kernel_power_off() ...
2022-05-22powerpc: Fix all occurences of "the the"Michael Ellerman1-1/+1
Rather than waiting for the bots to fix these one-by-one, fix all occurences of "the the" throughout arch/powerpc. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220518142629.513007-1-mpe@ellerman.id.au
2022-05-19powerpc: Use do_kernel_power_off()Dmitry Osipenko1-2/+1
Kernel now supports chained power-off handlers. Use do_kernel_power_off() that invokes chained power-off handlers. It also invokes legacy pm_power_off() for now, which will be removed once all drivers will be converted to the new sys-off API. Acked-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-05-08powerpc: Remove asm/prom.h from all files that don't need itChristophe Leroy1-1/+0
Several files include asm/prom.h for no reason. Clean it up. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Drop change to prom_parse.c as reported by lkp@intel.com] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7c9b8fda63dcf63e1b28f43e7ebdb95182cbc286.1646767214.git.christophe.leroy@csgroup.eu
2022-05-06powerpc: Reject probes on instructions that can't be single steppedNaveen N. Rao1-6/+5
Per the ISA, a Trace interrupt is not generated for: - [h|u]rfi[d] - rfscv - sc, scv, and Trap instructions that trap - Power-Saving Mode instructions - other instructions that cause interrupts (other than Trace interrupts) - the first instructions of any interrupt handler (applies to Branch and Single Step tracing; CIABR matches may still occur) - instructions that are emulated by software Add a helper to check for instructions belonging to the first four categories above and to reject kprobes, uprobes and xmon breakpoints on such instructions. We reject probing on instructions belonging to these categories across all ISA versions and across both BookS and BookE. For trap instructions, we can't know in advance if they can cause a trap, and there is no good reason to allow probing on those. Also, uprobes already refuses to probe trap instructions and kprobes does not allow probes on trap instructions used for kernel warnings and bugs. As such, stop allowing any type of probes/breakpoints on trap instruction across uprobes, kprobes and xmon. For some of the fp/altivec instructions that can generate an interrupt and which we emulate in the kernel (altivec assist, for example), we check and turn off single stepping in emulate_single_step(). Instructions generating a DSI are restarted and single stepping normally completes once the instruction is completed. In uprobes, if a single stepped instruction results in a non-fatal signal to be delivered to the task, such signals are "delayed" until after the instruction completes. For fatal signals, single stepping is cancelled and the instruction restarted in-place so that core dump captures proper addresses. In kprobes, we do not allow probes on instructions having an extable entry and we also do not allow probing interrupt vectors. Signed-off-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/f56ee979d50b8711fae350fc97870f3ca34acd75.1648648712.git.naveen.n.rao@linux.vnet.ibm.com
2022-05-05powerpc: fix typos in commentsJulia Lawall2-2/+2
Various spelling mistakes in comments. Detected with the help of Coccinelle. Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr> Reviewed-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220430185654.5855-1-Julia.Lawall@inria.fr
2022-01-06powerpc/xmon: Dump XIVE information for online-only processors.Sachin Sant1-2/+2
dxa command in XMON debugger iterates through all possible processors. As a result, empty lines are printed even for processors which are not online. CPU 47:pp=00 CPPR=ff IPI=0x0040002f PQ=-- EQ idx=699 T=0 00000000 00000000 CPU 48: CPU 49: Restrict XIVE information(dxa) to be displayed for online processors only. Signed-off-by: Sachin Sant <sachinp@linux.vnet.ibm.com> Reviewed-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/164139226833.12930.272224382183014664.sendpatchset@MacBook-Pro.local
2021-12-23powerpc/xmon: Add __init attribute to eligible functionsNick Child1-1/+1
`xmon_register_spus` defined in 'arch/powerpc/xmon' is deserving of an `__init` macro attribute. This functions is only called by other initialization functions and therefore should inherit the attribute. Also, change the function declaration in the header file to include `__init`. Signed-off-by: Nick Child <nick.child@ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211216220035.605465-7-nick.child@ibm.com
2021-12-09powerpc/inst: Define ppc_inst_tChristophe Leroy2-9/+9
In order to stop using 'struct ppc_inst' on PPC32, define a ppc_inst_t typedef. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/fe5baa2c66fea9db05a8b300b3e8d2880a42596c.1638208156.git.christophe.leroy@csgroup.eu
2021-12-09powerpc/64s: Move hash MMU support code under CONFIG_PPC_64S_HASH_MMUNicholas Piggin1-3/+5
Compiling out hash support code when CONFIG_PPC_64S_HASH_MMU=n saves 128kB kernel image size (90kB text) on powernv_defconfig minus KVM, 350kB on pseries_defconfig minus KVM, 40kB on a tiny config. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Fixup defined(ARCH_HAS_MEMREMAP_COMPAT_ALIGN), which needs CONFIG. Fix radix_enabled() use in setup_initial_memory_limit(). Add some stubs to reduce number of ifdefs.] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211201144153.2456614-18-npiggin@gmail.com
2021-11-24powerpc/64s: guard optional TIDR SPR with CPU ftr testNicholas Piggin1-2/+8
The TIDR SPR only exists on POWER9. Avoid accessing it when the feature bit for it is not set. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211123095231.1036501-3-npiggin@gmail.com
2021-10-28powerpc/xmon: fix task state outputDenis Kirjanov1-2/+1
p_state is unsigned since the commit 2f064a59a11f The patch also uses TASK_RUNNING instead of null. Fixes: 2f064a59a11f ("sched: Change task_struct::state") Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20211026133108.7113-1-kda@linux-powerpc.org
2021-08-26powerpc: Refactor verification of MSR_RIChristophe Leroy1-13/+3
40x and BOOKE don't have MSR_RI therefore all tests involving MSR_RI may be problematic on those plateforms. Create helpers to check or set MSR_RI in regs, and use them in common code. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c2fb93708196734f4176dda334aaa3055f213b89.1629707037.git.christophe.leroy@csgroup.eu
2021-08-13powerpc: rename powerpc_debugfs_root to arch_debugfs_dirAneesh Kumar K.V1-3/+3
No functional change in this patch. arch_debugfs_dir is the generic kernel name declared in linux/debugfs.h for arch-specific debugfs directory. Architectures like x86/s390 already use the name. Rename powerpc specific powerpc_debugfs_root to arch_debugfs_dir. 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/20210812132831.233794-2-aneesh.kumar@linux.ibm.com
2021-07-02Merge tag 'powerpc-5.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linuxLinus Torvalds1-46/+150
Pull powerpc updates from Michael Ellerman: - A big series refactoring parts of our KVM code, and converting some to C. - Support for ARCH_HAS_SET_MEMORY, and ARCH_HAS_STRICT_MODULE_RWX on some CPUs. - Support for the Microwatt soft-core. - Optimisations to our interrupt return path on 64-bit. - Support for userspace access to the NX GZIP accelerator on PowerVM on Power10. - Enable KUAP and KUEP by default on 32-bit Book3S CPUs. - Other smaller features, fixes & cleanups. Thanks to: Andy Shevchenko, Aneesh Kumar K.V, Arnd Bergmann, Athira Rajeev, Baokun Li, Benjamin Herrenschmidt, Bharata B Rao, Christophe Leroy, Daniel Axtens, Daniel Henrique Barboza, Finn Thain, Geoff Levand, Haren Myneni, Jason Wang, Jiapeng Chong, Joel Stanley, Jordan Niethe, Kajol Jain, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Nick Desaulniers, Paul Mackerras, Russell Currey, Sathvika Vasireddy, Shaokun Zhang, Stephen Rothwell, Sudeep Holla, Suraj Jitindar Singh, Tom Rix, Vaibhav Jain, YueHaibing, Zhang Jianhua, and Zhen Lei. * tag 'powerpc-5.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (218 commits) powerpc: Only build restart_table.c for 64s powerpc/64s: move ret_from_fork etc above __end_soft_masked powerpc/64s/interrupt: clean up interrupt return labels powerpc/64/interrupt: add missing kprobe annotations on interrupt exit symbols powerpc/64: enable MSR[EE] in irq replay pt_regs powerpc/64s/interrupt: preserve regs->softe for NMI interrupts powerpc/64s: add a table of implicit soft-masked addresses powerpc/64e: remove implicit soft-masking and interrupt exit restart logic powerpc/64e: fix CONFIG_RELOCATABLE build warnings powerpc/64s: fix hash page fault interrupt handler powerpc/4xx: Fix setup_kuep() on SMP powerpc/32s: Fix setup_{kuap/kuep}() on SMP powerpc/interrupt: Use names in check_return_regs_valid() powerpc/interrupt: Also use exit_must_hard_disable() on PPC32 powerpc/sysfs: Replace sizeof(arr)/sizeof(arr[0]) with ARRAY_SIZE powerpc/ptrace: Refactor regs_set_return_{msr/ip} powerpc/ptrace: Move set_return_regs_changed() before regs_set_return_{msr/ip} powerpc/stacktrace: Fix spurious "stale" traces in raise_backtrace_ipi() powerpc/pseries/vas: Include irqdomain.h powerpc: mark local variables around longjmp as volatile ...
2021-06-25powerpc: mark local variables around longjmp as volatileArnd Bergmann1-11/+11
gcc-11 points out that modifying local variables next to a longjmp/setjmp may cause undefined behavior: arch/powerpc/kexec/crash.c: In function 'crash_kexec_prepare_cpus.constprop': arch/powerpc/kexec/crash.c:108:22: error: variable 'ncpus' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbere d] arch/powerpc/kexec/crash.c:109:13: error: variable 'tries' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbere d] arch/powerpc/xmon/xmon.c: In function 'xmon_print_symbol': arch/powerpc/xmon/xmon.c:3625:21: error: variable 'name' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered] arch/powerpc/xmon/xmon.c: In function 'stop_spus': arch/powerpc/xmon/xmon.c:4057:13: error: variable 'i' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered] arch/powerpc/xmon/xmon.c: In function 'restart_spus': arch/powerpc/xmon/xmon.c:4098:13: error: variable 'i' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered] arch/powerpc/xmon/xmon.c: In function 'dump_opal_msglog': arch/powerpc/xmon/xmon.c:3008:16: error: variable 'pos' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered] arch/powerpc/xmon/xmon.c: In function 'show_pte': arch/powerpc/xmon/xmon.c:3207:29: error: variable 'tsk' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered] arch/powerpc/xmon/xmon.c: In function 'show_tasks': arch/powerpc/xmon/xmon.c:3302:29: error: variable 'tsk' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered] arch/powerpc/xmon/xmon.c: In function 'xmon_core': arch/powerpc/xmon/xmon.c:494:13: error: variable 'cmd' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered] arch/powerpc/xmon/xmon.c:860:21: error: variable 'bp' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered] arch/powerpc/xmon/xmon.c:860:21: error: variable 'bp' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered] arch/powerpc/xmon/xmon.c:492:48: error: argument 'fromipi' might be clobbered by 'longjmp' or 'vfork' [-Werror=clobbered] According to the documentation, marking these as 'volatile' is sufficient to avoid the problem, and it shuts up the warning. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210429080708.1520360-1-arnd@kernel.org
2021-06-25powerpc/xmon: Add support for running a command on all cpus in xmonNaveen N. Rao1-22/+126
It is sometimes desirable to run a command on all cpus in xmon. A typical scenario is to obtain the backtrace from all cpus in xmon if there is a soft lockup. Add rudimentary support for the same. The command to be run on all cpus should be prefixed with 'c#'. As an example, 'c#t' will run 't' command and produce a backtrace on all cpus in xmon. Since many xmon commands are not sensible for running in this manner, we only allow a predefined list of commands -- 'r', 'S' and 't' for now. Signed-off-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/20210601074801.617363-1-naveen.n.rao@linux.vnet.ibm.com
2021-06-25powerpc/64s: avoid reloading (H)SRR registers if they are still validNicholas Piggin1-7/+7
When an interrupt is taken, the SRR registers are set to return to where it left off. Unless they are modified in the meantime, or the return address or MSR are modified, there is no need to reload these registers when returning from interrupt. Introduce per-CPU flags that track the validity of SRR and HSRR registers. These are cleared when returning from interrupt, when using the registers for something else (e.g., OPAL calls), when adjusting the return address or MSR of a context, and when context switching (which changes the return address and MSR). This improves the performance of interrupt returns. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Fold in fixup patch from Nick] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210617155116.2167984-5-npiggin@gmail.com
2021-06-18sched: Change task_struct::statePeter Zijlstra1-6/+7
Change the type and name of task_struct::state. Drop the volatile and shrink it to an 'unsigned int'. Rename it in order to find all uses such that we can use READ_ONCE/WRITE_ONCE as appropriate. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com> Acked-by: Will Deacon <will@kernel.org> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Link: https://lore.kernel.org/r/20210611082838.550736351@infradead.org
2021-06-17powerpc: Don't use 'struct ppc_inst' to reference instruction locationChristophe Leroy1-5/+5
'struct ppc_inst' is an internal representation of an instruction, but in-memory instructions are and will remain a table of 'u32' forever. Replace all 'struct ppc_inst *' used for locating an instruction in memory by 'u32 *'. This removes a lot of undue casts to 'struct ppc_inst *'. It also helps locating ab-use of 'struct ppc_inst' dereference. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Fix ppc_inst_next(), use u32 instead of unsigned int] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7062722b087228e42cbd896e39bfdf526d6a340a.1621516826.git.christophe.leroy@csgroup.eu
2021-05-23powerpc/xmon: make dumping log buffer contents more reliableNathan Lynch1-1/+1
Log buffer entries that are too long for dump_log_buf()'s small local buffer are: * silently discarded when a single-line entry is too long; kmsg_dump_get_line() returns true but sets &len to 0. * silently truncated to the last fitting new line when a multi-line entry is too long, e.g. register dumps from __show_regs(); this seems undetectable via the kmsg_dump API. xmon_printf()'s internal buffer is already 1KB; enlarge dump_log_buf()'s own buffer to match and make it statically allocated. Verified that this allows complete printing of register dumps on ppc64le with both CONFIG_PRINTK_TIME=y and CONFIG_PRINTK_CALLER=y. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210514162420.2911458-1-nathanl@linux.ibm.com
2021-04-30Merge tag 'powerpc-5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linuxLinus Torvalds1-52/+24
Pull powerpc updates from Michael Ellerman: - Enable KFENCE for 32-bit. - Implement EBPF for 32-bit. - Convert 32-bit to do interrupt entry/exit in C. - Convert 64-bit BookE to do interrupt entry/exit in C. - Changes to our signal handling code to use user_access_begin/end() more extensively. - Add support for time namespaces (CONFIG_TIME_NS) - A series of fixes that allow us to reenable STRICT_KERNEL_RWX. - Other smaller features, fixes & cleanups. Thanks to Alexey Kardashevskiy, Andreas Schwab, Andrew Donnellan, Aneesh Kumar K.V, Athira Rajeev, Bhaskar Chowdhury, Bixuan Cui, Cédric Le Goater, Chen Huang, Chris Packham, Christophe Leroy, Christopher M. Riedl, Colin Ian King, Dan Carpenter, Daniel Axtens, Daniel Henrique Barboza, David Gibson, Davidlohr Bueso, Denis Efremov, dingsenjie, Dmitry Safonov, Dominic DeMarco, Fabiano Rosas, Ganesh Goudar, Geert Uytterhoeven, Geetika Moolchandani, Greg Kurz, Guenter Roeck, Haren Myneni, He Ying, Jiapeng Chong, Jordan Niethe, Laurent Dufour, Lee Jones, Leonardo Bras, Li Huafei, Madhavan Srinivasan, Mahesh Salgaonkar, Masahiro Yamada, Nathan Chancellor, Nathan Lynch, Nicholas Piggin, Oliver O'Halloran, Paul Menzel, Pu Lehui, Randy Dunlap, Ravi Bangoria, Rosen Penev, Russell Currey, Santosh Sivaraj, Sebastian Andrzej Siewior, Segher Boessenkool, Shivaprasad G Bhat, Srikar Dronamraju, Stephen Rothwell, Thadeu Lima de Souza Cascardo, Thomas Gleixner, Tony Ambardar, Tyrel Datwyler, Vaibhav Jain, Vincenzo Frascino, Xiongwei Song, Yang Li, Yu Kuai, and Zhang Yunkai. * tag 'powerpc-5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (302 commits) powerpc/signal32: Fix erroneous SIGSEGV on RT signal return powerpc: Avoid clang uninitialized warning in __get_user_size_allowed powerpc/papr_scm: Mark nvdimm as unarmed if needed during probe powerpc/kvm: Fix build error when PPC_MEM_KEYS/PPC_PSERIES=n powerpc/kasan: Fix shadow start address with modules powerpc/kernel/iommu: Use largepool as a last resort when !largealloc powerpc/kernel/iommu: Align size for IOMMU_PAGE_SIZE() to save TCEs powerpc/44x: fix spelling mistake in Kconfig "varients" -> "variants" powerpc/iommu: Annotate nested lock for lockdep powerpc/iommu: Do not immediately panic when failed IOMMU table allocation powerpc/iommu: Allocate it_map by vmalloc selftests/powerpc: remove unneeded semicolon powerpc/64s: remove unneeded semicolon powerpc/eeh: remove unneeded semicolon powerpc/selftests: Add selftest to test concurrent perf/ptrace events powerpc/selftests/perf-hwbreak: Add testcases for 2nd DAWR powerpc/selftests/perf-hwbreak: Coalesce event creation code powerpc/selftests/ptrace-hwbreak: Add testcases for 2nd DAWR powerpc/configs: Add IBMVNIC to some 64-bit configs selftests/powerpc: Add uaccess flush test ...
2021-04-27Merge tag 'printk-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linuxLinus Torvalds1-3/+3
Pull printk updates from Petr Mladek: - Stop synchronizing kernel log buffer readers by logbuf_lock. As a result, the access to the buffer is fully lockless now. Note that printk() itself still uses locks because it tries to flush the messages to the console immediately. Also the per-CPU temporary buffers are still there because they prevent infinite recursion and serialize backtraces from NMI. All this is going to change in the future. - kmsg_dump API rework and cleanup as a side effect of the logbuf_lock removal. - Make bstr_printf() aware that %pf and %pF formats could deference the given pointer. - Show also page flags by %pGp format. - Clarify the documentation for plain pointer printing. - Do not show no_hash_pointers warning multiple times. - Update Senozhatsky email address. - Some clean up. * tag 'printk-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (24 commits) lib/vsprintf.c: remove leftover 'f' and 'F' cases from bstr_printf() printk: clarify the documentation for plain pointer printing kernel/printk.c: Fixed mundane typos printk: rename vprintk_func to vprintk vsprintf: dump full information of page flags in pGp mm, slub: don't combine pr_err with INFO mm, slub: use pGp to print page flags MAINTAINERS: update Senozhatsky email address lib/vsprintf: do not show no_hash_pointers message multiple times printk: console: remove unnecessary safe buffer usage printk: kmsg_dump: remove _nolock() variants printk: remove logbuf_lock printk: introduce a kmsg_dump iterator printk: kmsg_dumper: remove @active field printk: add syslog_lock printk: use atomic64_t for devkmsg_user.seq printk: use seqcount_latch for clear_seq printk: introduce CONSOLE_LOG_MAX printk: consolidate kmsg_dump_get_buffer/syslog_print_all code printk: refactor kmsg_dump_get_buffer() ...
2021-04-21powerpc/inst: ppc_inst_as_u64() becomes ppc_inst_as_ulong()Christophe Leroy1-1/+1
In order to simplify use on PPC32, change ppc_inst_as_u64() into ppc_inst_as_ulong() that returns the 32 bits instruction on PPC32. Will be used when porting OPTPROBES to PPC32. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/22cadf29620664b600b82026d2a72b8b23351777.1618927318.git.christophe.leroy@csgroup.eu
2021-04-17powerpc/traps: Enhance readability for trap typesXiongwei Song1-7/+13
Define macros to list ppc interrupt types in interttupt.h, replace the reference of the trap hex values with these macros. Referred the hex numbers in arch/powerpc/kernel/exceptions-64e.S, arch/powerpc/kernel/exceptions-64s.S, arch/powerpc/kernel/head_*.S, arch/powerpc/kernel/head_booke.h and arch/powerpc/include/asm/kvm_asm.h. Signed-off-by: Xiongwei Song <sxwjean@gmail.com> [mpe: Resolve conflicts in nmi_disables_ftrace(), fix 40x build] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1618398033-13025-1-git-send-email-sxwjean@me.com
2021-04-14powerpc: remove partial register save logicNicholas Piggin1-16/+7
All subarchitectures always save all GPRs to pt_regs interrupt frames now. Remove FULL_REGS and associated bits. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210316104206.407354-11-npiggin@gmail.com
2021-04-14powerpc/xmon: Make symbol 'spu_inst_dump' staticPu Lehui1-2/+1
Fix sparse warning: arch/powerpc/xmon/xmon.c:4216:1: warning: symbol 'spu_inst_dump' was not declared. Should it be static? This symbol is not used outside of xmon.c, so make it static. Signed-off-by: Pu Lehui <pulehui@huawei.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210409070151.163424-1-pulehui@huawei.com
2021-04-14powerpc/xive: Simplify the dump of XIVE interrupts under xmonCédric Le Goater1-26/+2
Move the xmon routine under XIVE subsystem and rework the loop on the interrupts taking into account the xive_irq_domain to filter out IPIs. Signed-off-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: Greg Kurz <groug@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210331144514.892250-7-clg@kaod.org
2021-03-08printk: kmsg_dump: remove _nolock() variantsJohn Ogness1-2/+2
kmsg_dump_rewind() and kmsg_dump_get_line() are lockless, so there is no need for _nolock() variants. Remove these functions and switch all callers of the _nolock() variants. The functions without _nolock() were chosen because they are already exported to kernel modules. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210303101528.29901-15-john.ogness@linutronix.de
2021-03-08printk: introduce a kmsg_dump iteratorJohn Ogness1-3/+3
Rather than storing the iterator information in the registered kmsg_dumper structure, create a separate iterator structure. The kmsg_dump_iter structure can reside on the stack of the caller, thus allowing lockless use of the kmsg_dump functions. Update code that accesses the kernel logs using the kmsg_dumper structure to use the new kmsg_dump_iter structure. For kmsg_dumpers, this also means adding a call to kmsg_dump_rewind() to initialize the iterator. All this is in preparation for removal of @logbuf_lock. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> # pstore Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210303101528.29901-13-john.ogness@linutronix.de
2021-03-08printk: kmsg_dumper: remove @active fieldJohn Ogness1-1/+1
All 6 kmsg_dumpers do not benefit from the @active flag: (provide their own synchronization) - arch/powerpc/kernel/nvram_64.c - arch/um/kernel/kmsg_dump.c - drivers/mtd/mtdoops.c - fs/pstore/platform.c (only dump on KMSG_DUMP_PANIC, which does not require synchronization) - arch/powerpc/platforms/powernv/opal-kmsg.c - drivers/hv/vmbus_drv.c The other 2 kmsg_dump users also do not rely on @active: (hard-code @active to always be true) - arch/powerpc/xmon/xmon.c - kernel/debug/kdb/kdb_main.c Therefore, @active can be removed. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20210303101528.29901-12-john.ogness@linutronix.de
2021-02-09powerpc/32s: mfsrin()/mtsrin() become mfsr()/mtsr()Christophe Leroy1-1/+1
Function names should tell what the function does, not how. mfsrin() and mtsrin() are read/writing segment registers. They are called that way because they are using mfsrin and mtsrin instructions, but it doesn't matter for the caller. In preparation of following patch, change their name to mfsr() and mtsr() in order to make it obvious they manipulate segment registers without messing up with how they do it. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/f92d99f4349391b77766745900231aa880a0efb5.1612612022.git.christophe.leroy@csgroup.eu
2021-01-31powerpc/xmon: Enable breakpoints on 8xxChristophe Leroy1-4/+0
Since commit 4ad8622dc548 ("powerpc/8xx: Implement hw_breakpoint"), 8xx has breakpoints so there is no reason to opt breakpoint logic out of xmon for the 8xx. Fixes: 4ad8622dc548 ("powerpc/8xx: Implement hw_breakpoint") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/b0607f1113d1558e73476bb06db0ee16d31a6e5b.1608716197.git.christophe.leroy@csgroup.eu
2020-12-04powerpc/xmon: Change printk() to pr_cont()Christophe Leroy1-1/+1
Since some time now, printk() adds carriage return, leading to unusable xmon output if there is no udbg backend available: [ 54.288722] sysrq: Entering xmon [ 54.292209] Vector: 0 at [cace3d2c] [ 54.292274] pc: [ 54.292331] c0023650 [ 54.292468] : xmon+0x28/0x58 [ 54.292519] [ 54.292574] lr: [ 54.292630] c0023724 [ 54.292749] : sysrq_handle_xmon+0xa4/0xfc [ 54.292801] [ 54.292867] sp: cace3de8 [ 54.292931] msr: 9032 [ 54.292999] current = 0xc28d0000 [ 54.293072] pid = 377, comm = sh [ 54.293157] Linux version 5.10.0-rc6-s3k-dev-01364-gedf13f0ccd76-dirty (root@po17688vm.idsi0.si.c-s.fr) (powerpc64-linux-gcc (GCC) 10.1.0, GNU ld (GNU Binutils) 2.34) #4211 PREEMPT Fri Dec 4 09:32:11 UTC 2020 [ 54.293287] enter ? for help [ 54.293470] [cace3de8] [ 54.293532] c0023724 [ 54.293654] sysrq_handle_xmon+0xa4/0xfc [ 54.293711] (unreliable) ... [ 54.296002] [ 54.296159] --- Exception: c01 (System Call) at [ 54.296217] 0fd4e784 [ 54.296303] [ 54.296375] SP (7fca6ff0) is in userspace [ 54.296431] mon> [ 54.296484] <no input ...> Use pr_cont() instead. Fixes: 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing continuation lines") Cc: stable@vger.kernel.org # v4.9+ Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Mention that it only happens when udbg is not available] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c8a6ec704416ecd5ff2bd26213c9bc026bdd19de.1607077340.git.christophe.leroy@csgroup.eu
2020-12-04powerpc: Allow relative pointers in bug table entriesJordan Niethe1-2/+2
This enables GENERIC_BUG_RELATIVE_POINTERS on Power so that 32-bit offsets are stored in the bug entries rather than 64-bit pointers. While this doesn't save space for 32-bit machines, use it anyway so there is only one code path. Signed-off-by: Jordan Niethe <jniethe5@gmail.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201201005203.15210-1-jniethe5@gmail.com
2020-12-04powerpc/xmon: Fix build failure for 8xxRavi Bangoria1-0/+2
With CONFIG_PPC_8xx and CONFIG_XMON set, kernel build fails with arch/powerpc/xmon/xmon.c:1379:12: error: 'find_free_data_bpt' defined but not used [-Werror=unused-function] Fix it by enclosing find_free_data_bpt() inside #ifndef CONFIG_PPC_8xx. Fixes: 30df74d67d48 ("powerpc/watchpoint/xmon: Support 2nd DAWR") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201130034406.288047-1-ravi.bangoria@linux.ibm.com
2020-09-15powerpc/watchpoint: Add hw_len wherever missingRavi Bangoria1-0/+1
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 <ravi.bangoria@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200902042945.129369-7-ravi.bangoria@linux.ibm.com
2020-08-09Merge tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuildLinus Torvalds1-2/+1
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
2020-08-10kbuild: introduce ccflags-remove-y and asflags-remove-yMasahiro Yamada1-2/+1
CFLAGS_REMOVE_<file>.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_<file> adds compiler flags per file. [5] CFLAGS_REMOVE_<file> 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 <samitolvanen@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Acked-by: Brendan Higgins <brendanhiggins@google.com> (KUnit) Tested-by: Anders Roxell <anders.roxell@linaro.org>
2020-07-29powerpc: Use fallthrough pseudo-keywordGustavo A. R. Silva1-1/+1
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 <gustavoars@kernel.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200727224201.GA10133@embeddedor
2020-07-29powerpc/xmon: Use `dcbf` inplace of `dcbi` instruction for 64bit Book3SBalamuruhan S1-1/+1
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 <bala24@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200330075954.538773-1-bala24@linux.ibm.com
2020-07-23Merge branch 'scv' support into nextMichael Ellerman1-0/+1
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/xmon: Improve dumping prefixed instructionsJordan Niethe1-5/+6
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 <jniethe5@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200602052728.18227-2-jniethe5@gmail.com
2020-07-23powerpc: Add a ppc_inst_as_str() helperJordan Niethe1-1/+1
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
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