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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/x86/lib/msr.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/lib/msr.c')
-rw-r--r-- | arch/x86/lib/msr.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/arch/x86/lib/msr.c b/arch/x86/lib/msr.c new file mode 100644 index 000000000..b09cd2ad4 --- /dev/null +++ b/arch/x86/lib/msr.c @@ -0,0 +1,138 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/export.h> +#include <linux/percpu.h> +#include <linux/preempt.h> +#include <asm/msr.h> +#define CREATE_TRACE_POINTS +#include <asm/msr-trace.h> + +struct msr *msrs_alloc(void) +{ + struct msr *msrs = NULL; + + msrs = alloc_percpu(struct msr); + if (!msrs) { + pr_warn("%s: error allocating msrs\n", __func__); + return NULL; + } + + return msrs; +} +EXPORT_SYMBOL(msrs_alloc); + +void msrs_free(struct msr *msrs) +{ + free_percpu(msrs); +} +EXPORT_SYMBOL(msrs_free); + +/** + * Read an MSR with error handling + * + * @msr: MSR to read + * @m: value to read into + * + * It returns read data only on success, otherwise it doesn't change the output + * argument @m. + * + */ +static int msr_read(u32 msr, struct msr *m) +{ + int err; + u64 val; + + err = rdmsrl_safe(msr, &val); + if (!err) + m->q = val; + + return err; +} + +/** + * Write an MSR with error handling + * + * @msr: MSR to write + * @m: value to write + */ +static int msr_write(u32 msr, struct msr *m) +{ + return wrmsrl_safe(msr, m->q); +} + +static inline int __flip_bit(u32 msr, u8 bit, bool set) +{ + struct msr m, m1; + int err = -EINVAL; + + if (bit > 63) + return err; + + err = msr_read(msr, &m); + if (err) + return err; + + m1 = m; + if (set) + m1.q |= BIT_64(bit); + else + m1.q &= ~BIT_64(bit); + + if (m1.q == m.q) + return 0; + + err = msr_write(msr, &m1); + if (err) + return err; + + return 1; +} + +/** + * Set @bit in a MSR @msr. + * + * Retval: + * < 0: An error was encountered. + * = 0: Bit was already set. + * > 0: Hardware accepted the MSR write. + */ +int msr_set_bit(u32 msr, u8 bit) +{ + return __flip_bit(msr, bit, true); +} + +/** + * Clear @bit in a MSR @msr. + * + * Retval: + * < 0: An error was encountered. + * = 0: Bit was already cleared. + * > 0: Hardware accepted the MSR write. + */ +int msr_clear_bit(u32 msr, u8 bit) +{ + return __flip_bit(msr, bit, false); +} + +#ifdef CONFIG_TRACEPOINTS +void do_trace_write_msr(unsigned int msr, u64 val, int failed) +{ + trace_write_msr(msr, val, failed); +} +EXPORT_SYMBOL(do_trace_write_msr); +EXPORT_TRACEPOINT_SYMBOL(write_msr); + +void do_trace_read_msr(unsigned int msr, u64 val, int failed) +{ + trace_read_msr(msr, val, failed); +} +EXPORT_SYMBOL(do_trace_read_msr); +EXPORT_TRACEPOINT_SYMBOL(read_msr); + +void do_trace_rdpmc(unsigned counter, u64 val, int failed) +{ + trace_rdpmc(counter, val, failed); +} +EXPORT_SYMBOL(do_trace_rdpmc); +EXPORT_TRACEPOINT_SYMBOL(rdpmc); + +#endif |