kernel/arch/powerpc/lib/test_emulate_step.c, branch linux-6.2.y

powerpc/ppc-opcode: Define and use PPC_RAW_SETB()

2022-07-27T11:36:05Z

We have PPC_INST_SETB then build the 'setb' instruction in the user. Instead, define PPC_RAW_SETB() and use it. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/b08a4f26919a8f8cdcf7544ab552d9c1c63418b5.1657205708.git.christophe.leroy@csgroup.eu

powerpc/64: Drop ppc_inst_as_str()

2022-06-29T09:37:07Z

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 Reported-by: Petr Mladek Signed-off-by: Michael Ellerman Tested-by: Bagas Sanjaya Link: https://lore.kernel.org/r/20220531065936.3674348-1-mpe@ellerman.id.au

powerpc/inst: Define ppc_inst_t

2021-12-09T11:41:21Z

In order to stop using 'struct ppc_inst' on PPC32, define a ppc_inst_t typedef. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/fe5baa2c66fea9db05a8b300b3e8d2880a42596c.1638208156.git.christophe.leroy@csgroup.eu

powerpc/64s: avoid reloading (H)SRR registers if they are still valid

2021-06-24T14:06:55Z

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 [mpe: Fold in fixup patch from Nick] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210617155116.2167984-5-npiggin@gmail.com

powerpc: Replace PPC_INST_NOP by PPC_RAW_NOP()

2021-06-15T14:16:49Z

On the road to removing all PPC_INST_xx defines in asm/ppc-opcodes.h, change PPC_INST_NOP to PPC_RAW_NOP(). Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/ad46c195ca1b8572629ef07ba6bfe247585239a6.1621506159.git.christophe.leroy@csgroup.eu

powerpc: Rework PPC_RAW_xxx() macros for prefixed instructions

2021-06-15T14:16:47Z

At the time being, we have PPC_RAW_PLXVP() and PPC_RAW_PSTXVP() which provide a 64 bits value, and then it gets split by open coding to format it into a 'struct ppc_inst' instruction. Instead, define a PPC_RAW_xxx_P() and a PPC_RAW_xxx_S() to be used as is. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/5d146b31b943e7ad674894421db4feef54804b9b.1621506159.git.christophe.leroy@csgroup.eu

powerpc/sstep: Add tests for setb instruction

2021-05-23T10:51:35Z

This adds selftests for setb instruction. Signed-off-by: Sathvika Vasireddy Tested-by: Naveen N. Rao Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/b05b61ccb5f10279d46fed490796f32ea2ccc270.1620727160.git.sathvika@linux.vnet.ibm.com

powerpc/sstep: Add testcases for VSX vector paired load/store instructions

2020-12-10T13:09:10Z

Add testcases for VSX vector paired load/store instructions. Sample o/p: emulate_step_test: lxvp : PASS emulate_step_test: stxvp : PASS emulate_step_test: lxvpx : PASS emulate_step_test: stxvpx : PASS emulate_step_test: plxvp : PASS emulate_step_test: pstxvp : PASS Signed-off-by: Balamuruhan S Signed-off-by: Ravi Bangoria Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201011050908.72173-6-ravi.bangoria@linux.ibm.com

powerpc/test_emulate_step: Add testcases for divde[.] and divdeu[.] instructions

2020-07-29T13:47:52Z

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 Reviewed-by: Sandipan Das Acked-by: Naveen N. Rao Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200728130308.1790982-4-bala24@linux.ibm.com

powerpc/test_emulate_sstep: Fix build error

2020-07-24T00:41:19Z

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 Link: https://lore.kernel.org/r/20200724004109.1461709-1-mpe@ellerman.id.au