perf: Use device_show_string() helper for sysfs attributes

Deduplicate sysfs ->show() callbacks which expose a string at a static
memory location. Use the newly introduced device_show_string() helper
in the driver core instead by declaring those sysfs attributes with
DEVICE_STRING_ATTR_RO().

No functional change intended.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/3a297850312b4ecb62d6872121de04496900f502.1713608122.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

perf/alibaba_uncore: Assign parents for event_source device

Currently the PMU device appears directly under /sys/devices/
Only root busses should appear there, so instead assign the pmu->dev
parent to be the platform device.

Link: https://lore.kernel.org/linux-cxl/ZCLI9A40PJsyqAmq@kroah.com/
Reviewed-by: Shuai Xue <xueshuai@linux.alibaba.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20240412161057.14099-18-Jonathan.Cameron@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>

perf/alibaba_uncore_drw: Avoid placing cpumask on the stack

In general it's preferable to avoid placing cpumasks on the stack, as
for large values of NR_CPUS these can consume significant amounts of
stack space and make stack overflows more likely.

Use cpumask_any_and_but() to avoid the need for a temporary cpumask on
the stack.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Dawei Li <dawei.li@shingroup.cn>
Reviewed-by: Shuai Xue <xueshuai@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240403155950.2068109-3-dawei.li@shingroup.cn
Signed-off-by: Will Deacon <will@kernel.org>

perf: alibaba_uncore_drw: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/e6dd47f791ddcc4cc6f7a80efcede245528220e6.1702648124.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Will Deacon <will@kernel.org>

driver/perf: Add identifier sysfs file for Yitian 710 DDR

To allow userspace to identify the specific implementation of the device,
add an "identifier" sysfs file.

The perf tool can match the Yitian 710 DDR metric through the identifier.

Signed-off-by: Jing Zhang <renyu.zj@linux.alibaba.com>
Acked-by: Ian Rogers <irogers@google.com>
Reviewed-by: Shuai Xue <xueshuai@linux.alibaba.com>
Link: https://lore.kernel.org/r/1687245156-61215-2-git-send-email-renyu.zj@linux.alibaba.com
Signed-off-by: Will Deacon <will@kernel.org>

drivers/perf: Use devm_platform_get_and_ioremap_resource()

Convert platform_get_resource(), devm_ioremap_resource() to a single
call to devm_platform_get_and_ioremap_resource(), as this is exactly
what this function does.

Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Reviewed-by: Shuai Xue <xueshuai@linux.alibaba.com>
Link: https://lore.kernel.org/r/20230216063403.9753-1-yang.lee@linux.alibaba.com
Signed-off-by: Will Deacon <will@kernel.org>

drivers/perf: fix return value check in ali_drw_pmu_probe()

In case of error, devm_ioremap_resource() returns ERR_PTR(),
and never returns NULL. The NULL test in the return value
check should be replaced with IS_ERR().

Fixes: cf7b61073e45 ("drivers/perf: add DDR Sub-System Driveway PMU driver for Yitian 710 SoC")
Signed-off-by: Sun Ke <sunke32@huawei.com>
Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Shuai Xue <xueshuai@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220924032127.313156-1-sunke32@huawei.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

drivers/perf: add DDR Sub-System Driveway PMU driver for Yitian 710 SoC

Add the DDR Sub-System Driveway Performance Monitoring Unit (PMU) driver
support for Alibaba T-Head Yitian 710 SoC chip. Yitian supports DDR5/4
DRAM and targets cloud computing and HPC.

Each PMU is registered as a device in /sys/bus/event_source/devices, and
users can select event to monitor in each sub-channel, independently. For
example, ali_drw_21000 and ali_drw_21080 are two PMU devices for two
sub-channels of the same channel in die 0. And the PMU device of die 1 is
prefixed with ali_drw_400XXXXX, e.g. ali_drw_40021000.

Due to hardware limitation, one of DDRSS Driveway PMU overflow interrupt
shares the same irq number with MPAM ERR_IRQ. To register DDRSS PMU and
MPAM drivers successfully, add IRQF_SHARED flag.

Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
Co-developed-by: Hongbo Yao <yaohongbo@linux.alibaba.com>
Signed-off-by: Hongbo Yao <yaohongbo@linux.alibaba.com>
Co-developed-by: Neng Chen <nengchen@linux.alibaba.com>
Signed-off-by: Neng Chen <nengchen@linux.alibaba.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220818031822.38415-3-xueshuai@linux.alibaba.com
Signed-off-by: Will Deacon <will@kernel.org>