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2020-07-17drivers/perf: Prevent forced unbinding of PMU driversQi Liu
Forcefully unbinding PMU drivers during perf sampling will lead to a kernel panic, because the perf upper-layer framework call a NULL pointer in this situation. To solve this issue, "suppress_bind_attrs" should be set to true, so that bind/unbind can be disabled via sysfs and prevent unbinding PMU drivers during perf sampling. Signed-off-by: Qi Liu <liuqi115@huawei.com> Reviewed-by: John Garry <john.garry@huawei.com> Link: https://lore.kernel.org/r/1594975763-32966-1-git-send-email-liuqi115@huawei.com Signed-off-by: Will Deacon <will@kernel.org>
2020-07-16drivers/perf: Fix kernel panic when rmmod PMU modules during perf samplingQi Liu
When users try to remove PMU modules during perf sampling, kernel panic will happen because the pmu->read() is a NULL pointer here. INFO on HiSilicon hip08 platform as follow: pc : hisi_uncore_pmu_event_update+0x30/0xa4 [hisi_uncore_pmu] lr : hisi_uncore_pmu_read+0x20/0x2c [hisi_uncore_pmu] sp : ffff800010103e90 x29: ffff800010103e90 x28: ffff0027db0c0e40 x27: ffffa29a76f129d8 x26: ffffa29a77ceb000 x25: ffffa29a773a5000 x24: ffffa29a77392000 x23: ffffddffe5943f08 x22: ffff002784285960 x21: ffff002784285800 x20: ffff0027d2e76c80 x19: ffff0027842859e0 x18: ffff80003498bcc8 x17: ffffa29a76afe910 x16: ffffa29a7583f530 x15: 16151a1512061a1e x14: 0000000000000000 x13: ffffa29a76f1e238 x12: 0000000000000001 x11: 0000000000000400 x10: 00000000000009f0 x9 : ffff8000107b3e70 x8 : ffff0027db0c1890 x7 : ffffa29a773a7000 x6 : 00000007f5131013 x5 : 00000007f5131013 x4 : 09f257d417c00000 x3 : 00000002187bd7ce x2 : ffffa29a38f0f0d8 x1 : ffffa29a38eae268 x0 : ffff0027d2e76c80 Call trace: hisi_uncore_pmu_event_update+0x30/0xa4 [hisi_uncore_pmu] hisi_uncore_pmu_read+0x20/0x2c [hisi_uncore_pmu] __perf_event_read+0x1a0/0x1f8 flush_smp_call_function_queue+0xa0/0x160 generic_smp_call_function_single_interrupt+0x18/0x20 handle_IPI+0x31c/0x4dc gic_handle_irq+0x2c8/0x310 el1_irq+0xcc/0x180 arch_cpu_idle+0x4c/0x20c default_idle_call+0x20/0x30 do_idle+0x1b4/0x270 cpu_startup_entry+0x28/0x30 secondary_start_kernel+0x1a4/0x1fc To solve the above issue, current module should be registered to kernel, so that try_module_get() can be invoked when perf sampling starts. This adds the reference counting of module and could prevent users from removing modules during sampling. Reported-by: Haifeng Wang <wang.wanghaifeng@huawei.com> Signed-off-by: Qi Liu <liuqi115@huawei.com> Reviewed-by: John Garry <john.garry@huawei.com> Link: https://lore.kernel.org/r/1594891165-8228-1-git-send-email-liuqi115@huawei.com Signed-off-by: Will Deacon <will@kernel.org>
2020-03-02drivers/perf: fsl_imx8_ddr: Correct the CLEAR bit definitionJoakim Zhang
When disabling a counter from ddr_perf_event_stop(), the counter value is reset to 0 at the same time. Preserve the counter value by performing a read-modify-write of the PMU register and clearing only the enable bit. Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com> Signed-off-by: Will Deacon <will@kernel.org>
2020-01-15perf/imx_ddr: Fix cpu hotplug state cleanupLeonard Crestez
This driver allocates a dynamic cpu hotplug state but never releases it. If reloaded in a loop it will quickly trigger a WARN message: "No more dynamic states available for CPU hotplug" Fix by calling cpuhp_remove_multi_state on remove like several other perf pmu drivers. Also fix the cleanup logic on probe error paths: add the missing cpuhp_remove_multi_state call and properly check the return value from cpuhp_state_add_instant_nocalls. Fixes: 9a66d36cc7ac ("drivers/perf: imx_ddr: Add DDR performance counter support to perf") Acked-by: Joakim Zhang <qiangqing.zhang@nxp.com> Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-11-04perf/imx_ddr: Dump AXI ID filter info to userspaceJoakim Zhang
caps/filter indicates whether HW supports AXI ID filter or not. caps/enhanced_filter indicates whether HW supports enhanced AXI ID filter or not. Users can check filter features from userspace with these attributions. Suggested-by: Will Deacon <will@kernel.org> Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com> [will: reworked cap switch to be less error-prone] Signed-off-by: Will Deacon <will@kernel.org>
2019-11-04perf/imx_ddr: Add driver for DDR PMU in i.MX8MPlusJoakim Zhang
Add driver for DDR PMU in i.MX8MPlus. Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-11-04perf/imx_ddr: Add enhanced AXI ID filter supportJoakim Zhang
With DDR_CAP_AXI_ID_FILTER quirk, indicating HW supports AXI ID filter which only can get bursts from DDR transaction, i.e. DDR read/write requests. This patch add DDR_CAP_AXI_ID_ENHANCED_FILTER quirk, indicating HW supports AXI ID filter which can get bursts and bytes from DDR transaction at the same time. We hope PMU always return bytes in the driver due to it is more meaningful for users. Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-28perf/imx_ddr: Add support for AXI ID filteringJoakim Zhang
AXI filtering is used by events 0x41 and 0x42 to count reads or writes with an ARID or AWID matching a specified filter. The filter is exposed to userspace as an (ID, MASK) pair, where each set bit in the mask causes the corresponding bit in the ID to be ignored when matching against the ID of memory transactions for the purposes of incrementing the counter. For example: # perf stat -a -e imx8_ddr0/axid-read,axi_mask=0xff,axi_id=0x800/ cmd will count all read transactions from AXI IDs 0x800 - 0x8ff. If the 'axi_mask' is omitted, then it is treated as 0x0 which means that the 'axi_id' will be matched exactly. Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-07-31perf/imx_ddr: Add MODULE_DEVICE_TABLELeonard Crestez
This is required for automatic probing when driver is built as a module. Fixes: 9a66d36cc7ac ("drivers/perf: imx_ddr: Add DDR performance counter support to perf") Acked-by: Frank Li <frank.li@nxp.com> Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-06-13drivers/perf: imx_ddr: Add DDR performance counter support to perfFrank Li
Add DDR performance monitor support for iMX8QXP. The PMU consists of 3 programmable event counters and a single dedicated cycle counter. Example usage: $ perf stat -a -e \ imx8_ddr0/read-cycles/,imx8_ddr0/write-cycles/,imx8_ddr0/precharge/ ls - or - $ perf stat -a -e \ imx8_ddr0/cycles/,imx8_ddr0/read-access/,imx8_ddr0/write-access/ ls Other events are supported, and advertised via perf list. Reviewed-by: Andrey Smirnov <andrew.smirnov@gmail.com> Signed-off-by: Frank Li <Frank.Li@nxp.com> [will: rewrote commit message/kconfig and used #defines for dev/cpuhp names] Signed-off-by: Will Deacon <will.deacon@arm.com>