diff options
| author |  Evan Green <evan@rivosinc.com>
| 2023-04-07 16:11:03 -0700 |
|---|---|---|
| committer |  Palmer Dabbelt <palmer@rivosinc.com>
| 2023-04-18 15:48:18 -0700 |
| commit | aa5af0aa90bad3f1cad5a90ee5eecd92ac9f3096 (patch) | |
| tree | 4047028646908985a844d3423b5213009f59bd42 /arch/riscv/include | |
| parent | selftests: Test the new RISC-V hwprobe interface (diff) | |
| download | linux-aa5af0aa90bad3f1cad5a90ee5eecd92ac9f3096.tar.gz linux-aa5af0aa90bad3f1cad5a90ee5eecd92ac9f3096.tar.bz2 linux-aa5af0aa90bad3f1cad5a90ee5eecd92ac9f3096.zip | |
RISC-V: Add hwprobe vDSO function and data
Add a vDSO function __vdso_riscv_hwprobe, which can sit in front of the
riscv_hwprobe syscall and answer common queries. We stash a copy of
static answers for the "all CPUs" case in the vDSO data page. This data
is private to the vDSO, so we can decide later to change what's stored
there or under what conditions we defer to the syscall. Currently all
data can be discovered at boot, so the vDSO function answers all queries
when the cpumask is set to the "all CPUs" hint.
There's also a boolean in the data that lets the vDSO function know that
all CPUs are the same. In that case, the vDSO will also answer queries
for arbitrary CPU masks in addition to the "all CPUs" hint.
Signed-off-by: Evan Green <evan@rivosinc.com>
Link: https://lore.kernel.org/r/20230407231103.2622178-7-evan@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/include')
| -rw-r--r-- | arch/riscv/include/asm/vdso/data.h | 17 | ||||
| -rw-r--r-- | arch/riscv/include/asm/vdso/gettimeofday.h | 8 |
2 files changed, 25 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/vdso/data.h b/arch/riscv/include/asm/vdso/data.h new file mode 100644 index 000000000000..dc2f76f58b76 --- /dev/null +++ b/arch/riscv/include/asm/vdso/data.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __RISCV_ASM_VDSO_DATA_H +#define __RISCV_ASM_VDSO_DATA_H + +#include <linux/types.h> +#include <vdso/datapage.h> +#include <asm/hwprobe.h> + +struct arch_vdso_data { + /* Stash static answers to the hwprobe queries when all CPUs are selected. */ + __u64 all_cpu_hwprobe_values[RISCV_HWPROBE_MAX_KEY + 1]; + + /* Boolean indicating all CPUs have the same static hwprobe values. */ + __u8 homogeneous_cpus; +}; + +#endif /* __RISCV_ASM_VDSO_DATA_H */ diff --git a/arch/riscv/include/asm/vdso/gettimeofday.h b/arch/riscv/include/asm/vdso/gettimeofday.h index 77d9c2f721c4..ba3283cf7acc 100644 --- a/arch/riscv/include/asm/vdso/gettimeofday.h +++ b/arch/riscv/include/asm/vdso/gettimeofday.h @@ -9,6 +9,12 @@ #include <asm/csr.h> #include <uapi/linux/time.h> +/* + * 32-bit land is lacking generic time vsyscalls as well as the legacy 32-bit + * time syscalls like gettimeofday. Skip these definitions since on 32-bit. + */ +#ifdef CONFIG_GENERIC_TIME_VSYSCALL + #define VDSO_HAS_CLOCK_GETRES 1 static __always_inline @@ -60,6 +66,8 @@ int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts) return ret; } +#endif /* CONFIG_GENERIC_TIME_VSYSCALL */ + static __always_inline u64 __arch_get_hw_counter(s32 clock_mode, const struct vdso_data *vd) { |