Originally, the check_unaligned_access_emulated_all_cpus function only checked the boot hart. This fixes the function to check all harts.

Fixes: 71c54b3d169d ("riscv: report misaligned accesses emulation to hwprobe") Signed-off-by: Jesse Taube jesse@rivosinc.com Reviewed-by: Charlie Jenkins charlie@rivosinc.com Reviewed-by: Evan Green evan@rivosinc.com Cc: stable@vger.kernel.org --- V1 -> V2: - New patch V2 -> V3: - Split patch V3 -> V4: - Re-add check for a system where a heterogeneous CPU is hotplugged into a previously homogenous system. V4 -> V5: - Change work_struct *unused to work_struct *work __always_unused V5 -> V6: - Change check_unaligned_access_emulated to extern V6 -> V7: - No changes V7 -> V8: - Rebase onto fixes V8 -> V9: - No changes --- arch/riscv/include/asm/cpufeature.h | 2 ++ arch/riscv/kernel/traps_misaligned.c | 14 +++++++------- 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h index 45f9c1171a48..dfa5cdddd367 100644 --- a/arch/riscv/include/asm/cpufeature.h +++ b/arch/riscv/include/asm/cpufeature.h @@ -8,6 +8,7 @@

#include <linux/bitmap.h> #include <linux/jump_label.h> +#include <linux/workqueue.h> #include <asm/hwcap.h> #include <asm/alternative-macros.h> #include <asm/errno.h> @@ -60,6 +61,7 @@ void riscv_user_isa_enable(void);

#if defined(CONFIG_RISCV_MISALIGNED) bool check_unaligned_access_emulated_all_cpus(void); +void check_unaligned_access_emulated(struct work_struct *work __always_unused); void unaligned_emulation_finish(void); bool unaligned_ctl_available(void); DECLARE_PER_CPU(long, misaligned_access_speed); diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/traps_misaligned.c index 192cd5603e95..1ad981b2c7a3 100644 --- a/arch/riscv/kernel/traps_misaligned.c +++ b/arch/riscv/kernel/traps_misaligned.c @@ -526,11 +526,11 @@ int handle_misaligned_store(struct pt_regs *regs) return 0; }

-static bool check_unaligned_access_emulated(int cpu) +void check_unaligned_access_emulated(struct work_struct *work __always_unused) { + int cpu = smp_processor_id(); long *mas_ptr = per_cpu_ptr(&misaligned_access_speed, cpu); unsigned long tmp_var, tmp_val; - bool misaligned_emu_detected;

*mas_ptr = RISCV_HWPROBE_MISALIGNED_SCALAR_UNKNOWN;

@@ -538,19 +538,16 @@ static bool check_unaligned_access_emulated(int cpu) " "REG_L" %[tmp], 1(%[ptr])\n" : [tmp] "=r" (tmp_val) : [ptr] "r" (&tmp_var) : "memory");

- misaligned_emu_detected = (*mas_ptr == RISCV_HWPROBE_MISALIGNED_SCALAR_EMULATED); /* * If unaligned_ctl is already set, this means that we detected that all * CPUS uses emulated misaligned access at boot time. If that changed * when hotplugging the new cpu, this is something we don't handle. */ - if (unlikely(unaligned_ctl && !misaligned_emu_detected)) { + if (unlikely(unaligned_ctl && (*mas_ptr != RISCV_HWPROBE_MISALIGNED_SCALAR_EMULATED))) { pr_crit("CPU misaligned accesses non homogeneous (expected all emulated)\n"); while (true) cpu_relax(); } - - return misaligned_emu_detected; }

bool check_unaligned_access_emulated_all_cpus(void) @@ -562,8 +559,11 @@ bool check_unaligned_access_emulated_all_cpus(void) * accesses emulated since tasks requesting such control can run on any * CPU. */ + schedule_on_each_cpu(check_unaligned_access_emulated); + for_each_online_cpu(cpu) - if (!check_unaligned_access_emulated(cpu)) + if (per_cpu(misaligned_access_speed, cpu) + != RISCV_HWPROBE_MISALIGNED_SCALAR_EMULATED) return false;

unaligned_ctl = true;