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author | Suzuki K Poulose <suzuki.poulose@arm.com> | 2021-02-01 11:13:33 -0700 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-02-04 17:00:33 +0100 |
commit | 03336d0f4d0d74e7a5f899bf9d4933e0d4397c94 (patch) | |
tree | a78850dcefb5e7e98a240fd3ab93329538f21334 /drivers/hwtracing/coresight/coresight-etm4x-core.c | |
parent | coresight: etm4x: Add commentary on the registers (diff) | |
download | linux-dev-03336d0f4d0d74e7a5f899bf9d4933e0d4397c94.tar.xz linux-dev-03336d0f4d0d74e7a5f899bf9d4933e0d4397c94.zip |
coresight: etm4x: Add sysreg access helpers
ETM architecture defines the system instructions for accessing
via register accesses. Add basic support for accessing a given
register via system instructions.
We split the list of registers as :
1) Accessible only from memory mapped interface
2) Accessible from system register instructions.
All registers are accessible via the memory-mapped interface.
However, some registers are not accessible via the system
instructions. This list is then used to further filter out
the files we expose via sysfs.
Link: https://lore.kernel.org/r/20210110224850.1880240-12-suzuki.poulose@arm.com
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20210201181351.1475223-14-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hwtracing/coresight/coresight-etm4x-core.c')
-rw-r--r-- | drivers/hwtracing/coresight/coresight-etm4x-core.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index 9331281b931f..37f90d380436 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -75,6 +75,38 @@ static inline bool etm4x_sspcicrn_present(struct etmv4_drvdata *drvdata, int n) (drvdata->config.ss_status[n] & TRCSSCSRn_PC); } +u64 etm4x_sysreg_read(u32 offset, bool _relaxed, bool _64bit) +{ + u64 res = 0; + + switch (offset) { + ETM4x_READ_SYSREG_CASES(res) + default : + pr_warn_ratelimited("etm4x: trying to read unsupported register @%x\n", + offset); + } + + if (!_relaxed) + __iormb(res); /* Imitate the !relaxed I/O helpers */ + + return res; +} + +void etm4x_sysreg_write(u64 val, u32 offset, bool _relaxed, bool _64bit) +{ + if (!_relaxed) + __iowmb(); /* Imitate the !relaxed I/O helpers */ + if (!_64bit) + val &= GENMASK(31, 0); + + switch (offset) { + ETM4x_WRITE_SYSREG_CASES(val) + default : + pr_warn_ratelimited("etm4x: trying to write to unsupported register @%x\n", + offset); + } +} + static void etm4_os_unlock_csa(struct etmv4_drvdata *drvdata, struct csdev_access *csa) { /* Writing 0 to TRCOSLAR unlocks the trace registers */ |