Alexey Dobriyan | b077ffb | 2007-02-16 01:48:11 -0800 | [diff] [blame] | 1 | #include <linux/module.h> |
| 2 | #include <linux/preempt.h> |
Alexey Dobriyan | b077ffb | 2007-02-16 01:48:11 -0800 | [diff] [blame] | 3 | #include <asm/msr.h> |
Andi Kleen | 7f47d8c | 2015-12-01 17:00:59 -0800 | [diff] [blame] | 4 | #define CREATE_TRACE_POINTS |
| 5 | #include <asm/msr-trace.h> |
Alexey Dobriyan | b077ffb | 2007-02-16 01:48:11 -0800 | [diff] [blame] | 6 | |
Borislav Petkov | 5054225 | 2009-12-11 18:14:40 +0100 | [diff] [blame] | 7 | struct msr *msrs_alloc(void) |
| 8 | { |
| 9 | struct msr *msrs = NULL; |
| 10 | |
| 11 | msrs = alloc_percpu(struct msr); |
| 12 | if (!msrs) { |
Borislav Petkov | 22085a6 | 2014-03-09 18:05:23 +0100 | [diff] [blame] | 13 | pr_warn("%s: error allocating msrs\n", __func__); |
Borislav Petkov | 5054225 | 2009-12-11 18:14:40 +0100 | [diff] [blame] | 14 | return NULL; |
| 15 | } |
| 16 | |
| 17 | return msrs; |
| 18 | } |
| 19 | EXPORT_SYMBOL(msrs_alloc); |
| 20 | |
| 21 | void msrs_free(struct msr *msrs) |
| 22 | { |
| 23 | free_percpu(msrs); |
| 24 | } |
| 25 | EXPORT_SYMBOL(msrs_free); |
Borislav Petkov | 22085a6 | 2014-03-09 18:05:23 +0100 | [diff] [blame] | 26 | |
| 27 | /** |
| 28 | * Read an MSR with error handling |
| 29 | * |
| 30 | * @msr: MSR to read |
| 31 | * @m: value to read into |
| 32 | * |
| 33 | * It returns read data only on success, otherwise it doesn't change the output |
| 34 | * argument @m. |
| 35 | * |
| 36 | */ |
| 37 | int msr_read(u32 msr, struct msr *m) |
| 38 | { |
| 39 | int err; |
| 40 | u64 val; |
| 41 | |
| 42 | err = rdmsrl_safe(msr, &val); |
| 43 | if (!err) |
| 44 | m->q = val; |
| 45 | |
| 46 | return err; |
| 47 | } |
| 48 | |
| 49 | /** |
| 50 | * Write an MSR with error handling |
| 51 | * |
| 52 | * @msr: MSR to write |
| 53 | * @m: value to write |
| 54 | */ |
| 55 | int msr_write(u32 msr, struct msr *m) |
| 56 | { |
| 57 | return wrmsrl_safe(msr, m->q); |
| 58 | } |
| 59 | |
| 60 | static inline int __flip_bit(u32 msr, u8 bit, bool set) |
| 61 | { |
| 62 | struct msr m, m1; |
| 63 | int err = -EINVAL; |
| 64 | |
| 65 | if (bit > 63) |
| 66 | return err; |
| 67 | |
| 68 | err = msr_read(msr, &m); |
| 69 | if (err) |
| 70 | return err; |
| 71 | |
| 72 | m1 = m; |
| 73 | if (set) |
| 74 | m1.q |= BIT_64(bit); |
| 75 | else |
| 76 | m1.q &= ~BIT_64(bit); |
| 77 | |
| 78 | if (m1.q == m.q) |
| 79 | return 0; |
| 80 | |
Andres Freund | 722a0d2 | 2014-05-09 03:29:16 +0200 | [diff] [blame] | 81 | err = msr_write(msr, &m1); |
Borislav Petkov | 22085a6 | 2014-03-09 18:05:23 +0100 | [diff] [blame] | 82 | if (err) |
| 83 | return err; |
| 84 | |
| 85 | return 1; |
| 86 | } |
| 87 | |
| 88 | /** |
| 89 | * Set @bit in a MSR @msr. |
| 90 | * |
| 91 | * Retval: |
| 92 | * < 0: An error was encountered. |
| 93 | * = 0: Bit was already set. |
| 94 | * > 0: Hardware accepted the MSR write. |
| 95 | */ |
| 96 | int msr_set_bit(u32 msr, u8 bit) |
| 97 | { |
| 98 | return __flip_bit(msr, bit, true); |
| 99 | } |
| 100 | |
| 101 | /** |
| 102 | * Clear @bit in a MSR @msr. |
| 103 | * |
| 104 | * Retval: |
| 105 | * < 0: An error was encountered. |
| 106 | * = 0: Bit was already cleared. |
| 107 | * > 0: Hardware accepted the MSR write. |
| 108 | */ |
| 109 | int msr_clear_bit(u32 msr, u8 bit) |
| 110 | { |
| 111 | return __flip_bit(msr, bit, false); |
| 112 | } |
Andi Kleen | 7f47d8c | 2015-12-01 17:00:59 -0800 | [diff] [blame] | 113 | |
| 114 | #ifdef CONFIG_TRACEPOINTS |
| 115 | void do_trace_write_msr(unsigned msr, u64 val, int failed) |
| 116 | { |
| 117 | trace_write_msr(msr, val, failed); |
| 118 | } |
| 119 | EXPORT_SYMBOL(do_trace_write_msr); |
| 120 | EXPORT_TRACEPOINT_SYMBOL(write_msr); |
| 121 | |
| 122 | void do_trace_read_msr(unsigned msr, u64 val, int failed) |
| 123 | { |
| 124 | trace_read_msr(msr, val, failed); |
| 125 | } |
| 126 | EXPORT_SYMBOL(do_trace_read_msr); |
| 127 | EXPORT_TRACEPOINT_SYMBOL(read_msr); |
| 128 | |
| 129 | void do_trace_rdpmc(unsigned counter, u64 val, int failed) |
| 130 | { |
| 131 | trace_rdpmc(counter, val, failed); |
| 132 | } |
| 133 | EXPORT_SYMBOL(do_trace_rdpmc); |
| 134 | EXPORT_TRACEPOINT_SYMBOL(rdpmc); |
| 135 | |
| 136 | #endif |