diff options
| -rw-r--r-- | Documentation/arch/riscv/hwprobe.rst | 36 | ||||
| -rw-r--r-- | arch/riscv/include/asm/hwprobe.h | 2 | ||||
| -rw-r--r-- | arch/riscv/include/uapi/asm/hwprobe.h | 6 | ||||
| -rw-r--r-- | arch/riscv/kernel/sys_hwprobe.c | 11 | ||||
| -rw-r--r-- | arch/riscv/kernel/traps_misaligned.c | 6 | ||||
| -rw-r--r-- | arch/riscv/kernel/unaligned_access_speed.c | 12 |
6 files changed, 44 insertions, 29 deletions
diff --git a/Documentation/arch/riscv/hwprobe.rst b/Documentation/arch/riscv/hwprobe.rst index 3db60a0911df..85b709257918 100644 --- a/Documentation/arch/riscv/hwprobe.rst +++ b/Documentation/arch/riscv/hwprobe.rst @@ -239,25 +239,33 @@ The following keys are defined: ratified in commit 98918c844281 ("Merge pull request #1217 from riscv/zawrs") of riscv-isa-manual. -* :c:macro:`RISCV_HWPROBE_KEY_CPUPERF_0`: A bitmask that contains performance - information about the selected set of processors. +* :c:macro:`RISCV_HWPROBE_KEY_CPUPERF_0`: Deprecated. Returns similar values to + :c:macro:`RISCV_HWPROBE_KEY_MISALIGNED_SCALAR_PERF`, but the key was + mistakenly classified as a bitmask rather than a value. - * :c:macro:`RISCV_HWPROBE_MISALIGNED_UNKNOWN`: The performance of misaligned - accesses is unknown. +* :c:macro:`RISCV_HWPROBE_KEY_MISALIGNED_SCALAR_PERF`: An enum value describing + the performance of misaligned scalar native word accesses on the selected set + of processors. - * :c:macro:`RISCV_HWPROBE_MISALIGNED_EMULATED`: Misaligned accesses are - emulated via software, either in or below the kernel. These accesses are - always extremely slow. + * :c:macro:`RISCV_HWPROBE_MISALIGNED_SCALAR_UNKNOWN`: The performance of + misaligned scalar accesses is unknown. - * :c:macro:`RISCV_HWPROBE_MISALIGNED_SLOW`: Misaligned accesses are slower - than equivalent byte accesses. Misaligned accesses may be supported - directly in hardware, or trapped and emulated by software. + * :c:macro:`RISCV_HWPROBE_MISALIGNED_SCALAR_EMULATED`: Misaligned scalar + accesses are emulated via software, either in or below the kernel. These + accesses are always extremely slow. - * :c:macro:`RISCV_HWPROBE_MISALIGNED_FAST`: Misaligned accesses are faster - than equivalent byte accesses. + * :c:macro:`RISCV_HWPROBE_MISALIGNED_SCALAR_SLOW`: Misaligned scalar native + word sized accesses are slower than the equivalent quantity of byte + accesses. Misaligned accesses may be supported directly in hardware, or + trapped and emulated by software. - * :c:macro:`RISCV_HWPROBE_MISALIGNED_UNSUPPORTED`: Misaligned accesses are - not supported at all and will generate a misaligned address fault. + * :c:macro:`RISCV_HWPROBE_MISALIGNED_SCALAR_FAST`: Misaligned scalar native + word sized accesses are faster than the equivalent quantity of byte + accesses. + + * :c:macro:`RISCV_HWPROBE_MISALIGNED_SCALAR_UNSUPPORTED`: Misaligned scalar + accesses are not supported at all and will generate a misaligned address + fault. * :c:macro:`RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE`: An unsigned int which represents the size of the Zicboz block in bytes. diff --git a/arch/riscv/include/asm/hwprobe.h b/arch/riscv/include/asm/hwprobe.h index ef01c182af2b..ffb9484531af 100644 --- a/arch/riscv/include/asm/hwprobe.h +++ b/arch/riscv/include/asm/hwprobe.h @@ -8,7 +8,7 @@ #include <uapi/asm/hwprobe.h> -#define RISCV_HWPROBE_MAX_KEY 8 +#define RISCV_HWPROBE_MAX_KEY 9 static inline bool riscv_hwprobe_key_is_valid(__s64 key) { diff --git a/arch/riscv/include/uapi/asm/hwprobe.h b/arch/riscv/include/uapi/asm/hwprobe.h index b706c8e47b02..1e153cda57db 100644 --- a/arch/riscv/include/uapi/asm/hwprobe.h +++ b/arch/riscv/include/uapi/asm/hwprobe.h @@ -82,6 +82,12 @@ struct riscv_hwprobe { #define RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE 6 #define RISCV_HWPROBE_KEY_HIGHEST_VIRT_ADDRESS 7 #define RISCV_HWPROBE_KEY_TIME_CSR_FREQ 8 +#define RISCV_HWPROBE_KEY_MISALIGNED_SCALAR_PERF 9 +#define RISCV_HWPROBE_MISALIGNED_SCALAR_UNKNOWN 0 +#define RISCV_HWPROBE_MISALIGNED_SCALAR_EMULATED 1 +#define RISCV_HWPROBE_MISALIGNED_SCALAR_SLOW 2 +#define RISCV_HWPROBE_MISALIGNED_SCALAR_FAST 3 +#define RISCV_HWPROBE_MISALIGNED_SCALAR_UNSUPPORTED 4 /* Increase RISCV_HWPROBE_MAX_KEY when adding items. */ /* Flags */ diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c index 8d1b5c35d2a7..cea0ca2bf2a2 100644 --- a/arch/riscv/kernel/sys_hwprobe.c +++ b/arch/riscv/kernel/sys_hwprobe.c @@ -178,13 +178,13 @@ static u64 hwprobe_misaligned(const struct cpumask *cpus) perf = this_perf; if (perf != this_perf) { - perf = RISCV_HWPROBE_MISALIGNED_UNKNOWN; + perf = RISCV_HWPROBE_MISALIGNED_SCALAR_UNKNOWN; break; } } if (perf == -1ULL) - return RISCV_HWPROBE_MISALIGNED_UNKNOWN; + return RISCV_HWPROBE_MISALIGNED_SCALAR_UNKNOWN; return perf; } @@ -192,12 +192,12 @@ static u64 hwprobe_misaligned(const struct cpumask *cpus) static u64 hwprobe_misaligned(const struct cpumask *cpus) { if (IS_ENABLED(CONFIG_RISCV_EFFICIENT_UNALIGNED_ACCESS)) - return RISCV_HWPROBE_MISALIGNED_FAST; + return RISCV_HWPROBE_MISALIGNED_SCALAR_FAST; if (IS_ENABLED(CONFIG_RISCV_EMULATED_UNALIGNED_ACCESS) && unaligned_ctl_available()) - return RISCV_HWPROBE_MISALIGNED_EMULATED; + return RISCV_HWPROBE_MISALIGNED_SCALAR_EMULATED; - return RISCV_HWPROBE_MISALIGNED_SLOW; + return RISCV_HWPROBE_MISALIGNED_SCALAR_SLOW; } #endif @@ -225,6 +225,7 @@ static void hwprobe_one_pair(struct riscv_hwprobe *pair, break; case RISCV_HWPROBE_KEY_CPUPERF_0: + case RISCV_HWPROBE_KEY_MISALIGNED_SCALAR_PERF: pair->value = hwprobe_misaligned(cpus); break; diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/traps_misaligned.c index b62d5a2f4541..192cd5603e95 100644 --- a/arch/riscv/kernel/traps_misaligned.c +++ b/arch/riscv/kernel/traps_misaligned.c @@ -338,7 +338,7 @@ int handle_misaligned_load(struct pt_regs *regs) perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr); #ifdef CONFIG_RISCV_PROBE_UNALIGNED_ACCESS - *this_cpu_ptr(&misaligned_access_speed) = RISCV_HWPROBE_MISALIGNED_EMULATED; + *this_cpu_ptr(&misaligned_access_speed) = RISCV_HWPROBE_MISALIGNED_SCALAR_EMULATED; #endif if (!unaligned_enabled) @@ -532,13 +532,13 @@ static bool check_unaligned_access_emulated(int cpu) unsigned long tmp_var, tmp_val; bool misaligned_emu_detected; - *mas_ptr = RISCV_HWPROBE_MISALIGNED_UNKNOWN; + *mas_ptr = RISCV_HWPROBE_MISALIGNED_SCALAR_UNKNOWN; __asm__ __volatile__ ( " "REG_L" %[tmp], 1(%[ptr])\n" : [tmp] "=r" (tmp_val) : [ptr] "r" (&tmp_var) : "memory"); - misaligned_emu_detected = (*mas_ptr == RISCV_HWPROBE_MISALIGNED_EMULATED); + 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 diff --git a/arch/riscv/kernel/unaligned_access_speed.c b/arch/riscv/kernel/unaligned_access_speed.c index a9a6bcb02acf..160628a2116d 100644 --- a/arch/riscv/kernel/unaligned_access_speed.c +++ b/arch/riscv/kernel/unaligned_access_speed.c @@ -34,9 +34,9 @@ static int check_unaligned_access(void *param) struct page *page = param; void *dst; void *src; - long speed = RISCV_HWPROBE_MISALIGNED_SLOW; + long speed = RISCV_HWPROBE_MISALIGNED_SCALAR_SLOW; - if (per_cpu(misaligned_access_speed, cpu) != RISCV_HWPROBE_MISALIGNED_UNKNOWN) + if (per_cpu(misaligned_access_speed, cpu) != RISCV_HWPROBE_MISALIGNED_SCALAR_UNKNOWN) return 0; /* Make an unaligned destination buffer. */ @@ -95,14 +95,14 @@ static int check_unaligned_access(void *param) } if (word_cycles < byte_cycles) - speed = RISCV_HWPROBE_MISALIGNED_FAST; + speed = RISCV_HWPROBE_MISALIGNED_SCALAR_FAST; ratio = div_u64((byte_cycles * 100), word_cycles); pr_info("cpu%d: Ratio of byte access time to unaligned word access is %d.%02d, unaligned accesses are %s\n", cpu, ratio / 100, ratio % 100, - (speed == RISCV_HWPROBE_MISALIGNED_FAST) ? "fast" : "slow"); + (speed == RISCV_HWPROBE_MISALIGNED_SCALAR_FAST) ? "fast" : "slow"); per_cpu(misaligned_access_speed, cpu) = speed; @@ -110,7 +110,7 @@ static int check_unaligned_access(void *param) * Set the value of fast_misaligned_access of a CPU. These operations * are atomic to avoid race conditions. */ - if (speed == RISCV_HWPROBE_MISALIGNED_FAST) + if (speed == RISCV_HWPROBE_MISALIGNED_SCALAR_FAST) cpumask_set_cpu(cpu, &fast_misaligned_access); else cpumask_clear_cpu(cpu, &fast_misaligned_access); @@ -188,7 +188,7 @@ static int riscv_online_cpu(unsigned int cpu) static struct page *buf; /* We are already set since the last check */ - if (per_cpu(misaligned_access_speed, cpu) != RISCV_HWPROBE_MISALIGNED_UNKNOWN) + if (per_cpu(misaligned_access_speed, cpu) != RISCV_HWPROBE_MISALIGNED_SCALAR_UNKNOWN) goto exit; buf = alloc_pages(GFP_KERNEL, MISALIGNED_BUFFER_ORDER); |