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RISC-V: Check scalar unaligned access on all CPUs

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

Fixes: 71c54b3d16 ("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
Link: https://lore.kernel.org/r/20241017-jesse_unaligned_vector-v10-1-5b33500160f8@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This commit is contained in:
Jesse Taube 2024-10-17 12:00:18 -07:00 committed by Palmer Dabbelt
parent 9852d85ec9
commit 8d20a739f1
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GPG Key ID: 2E1319F35FBB1889
2 changed files with 9 additions and 7 deletions
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2
arch/riscv/include/asm/cpufeature.h
View File

@ -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);

14
arch/riscv/kernel/traps_misaligned.c
View File

@ -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;