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>
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>
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: 9a66d36cc7 ("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>
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>
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>
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>
This is required for automatic probing when driver is built as a module.
Fixes: 9a66d36cc7 ("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>
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>
Qi Liu
Joakim Zhang
Leonard Crestez
Frank Li