On Thu, Jul 11, 2024 at 05:58:42PM -0400, Jesse Taube wrote:
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 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.
arch/riscv/kernel/traps_misaligned.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/traps_misaligned.c index b62d5a2f4541..1a1bb41472ea 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) +static void check_unaligned_access_emulated(struct work_struct *unused)
Small change, can you give this a different name like "work" and instead give it the attribute "__always_unused" like:
struct work_struct *work __always_unused
Otherwise,
Reviewed-by: Charlie Jenkins charlie@rivosinc.com
{
- 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_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_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_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_EMULATED) return false;unaligned_ctl = true; -- 2.45.2