kernel.git/drivers/perf/arm-cci.c, branch linux-6.3.y

perf/arm-cci: Use the bitmap API to allocate bitmaps

2022-07-06T10:02:58Z

Use devm_bitmap_zalloc() instead of hand-writing it. It is less verbose and it improves the semantic. While at it, use bitmap_zero() instead of hand-writing it. Signed-off-by: Christophe JAILLET Link: https://lore.kernel.org/r/fbde85a5e8ae99b10a2115d8ea1e69320a62947f.1657084786.git.christophe.jaillet@wanadoo.fr Signed-off-by: Will Deacon

perf/arm-cci: fix typo in comment

2022-06-23T14:44:59Z

Spelling mistake (triple letters) in comment. Detected with the help of Coccinelle. Signed-off-by: Julia Lawall Link: https://lore.kernel.org/r/20220521111145.81697-67-Julia.Lawall@inria.fr Signed-off-by: Will Deacon

perf: replace bitmap_weight with bitmap_empty where appropriate

2022-02-15T14:38:57Z

In some places, drivers/perf code calls bitmap_weight() to check if any bit of a given bitmap is set. It's better to use bitmap_empty() in that case because bitmap_empty() stops traversing the bitmap as soon as it finds first set bit, while bitmap_weight() counts all bits unconditionally. Signed-off-by: Yury Norov Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20220210224933.379149-13-yury.norov@gmail.com Signed-off-by: Will Deacon

drivers/perf: arm-cci: Fix checkpatch spacing error

2021-05-25T17:59:23Z

Fix some coding style issues reported by checkpatch.pl, including following types: ERROR: need consistent spacing around '-' (ctx:WxV) ERROR: space required before the open parenthesis '(' Signed-off-by: Junhao He Signed-off-by: Jay Fang Link: https://lore.kernel.org/r/1620736054-58412-5-git-send-email-f.fangjian@huawei.com Signed-off-by: Will Deacon

drivers/perf: convert sysfs snprintf family to sysfs_emit

2021-03-25T12:55:44Z

Fix the following coccicheck warning: ./drivers/perf/hisilicon/hisi_uncore_pmu.c:128:8-16: WARNING: use scnprintf or sprintf. ./drivers/perf/fsl_imx8_ddr_perf.c:173:8-16: WARNING: use scnprintf or sprintf. ./drivers/perf/arm_spe_pmu.c:129:8-16: WARNING: use scnprintf or sprintf. ./drivers/perf/arm_smmu_pmu.c:563:8-16: WARNING: use scnprintf or sprintf. ./drivers/perf/arm_dsu_pmu.c:149:8-16: WARNING: use scnprintf or sprintf. ./drivers/perf/arm_dsu_pmu.c:139:8-16: WARNING: use scnprintf or sprintf. ./drivers/perf/arm-cmn.c:563:8-16: WARNING: use scnprintf or sprintf. ./drivers/perf/arm-cmn.c:351:8-16: WARNING: use scnprintf or sprintf. ./drivers/perf/arm-ccn.c:224:8-16: WARNING: use scnprintf or sprintf. ./drivers/perf/arm-cci.c:708:8-16: WARNING: use scnprintf or sprintf. ./drivers/perf/arm-cci.c:699:8-16: WARNING: use scnprintf or sprintf. ./drivers/perf/arm-cci.c:528:8-16: WARNING: use scnprintf or sprintf. ./drivers/perf/arm-cci.c:309:8-16: WARNING: use scnprintf or sprintf. Signed-off-by: Zihao Tang Signed-off-by: Qi Liu Link: https://lore.kernel.org/r/1616148273-16374-2-git-send-email-liuqi115@huawei.com Signed-off-by: Will Deacon

drivers/perf: Replace spin_lock_irqsave to spin_lock

2021-02-10T18:50:42Z

There is no need to do spin_lock_irqsave in context of hard IRQ, so replace them with spin_lock. Signed-off-by: Qi Liu Link: https://lore.kernel.org/r/1612863742-1551-1-git-send-email-liuqi115@huawei.com Signed-off-by: Will Deacon

perf: Constify static struct attribute_group

2021-01-20T17:51:23Z

The only usage is to put their addresses in an array of pointers to const struct attribute group. Make them const to allow the compiler to put them in read-only memory. Signed-off-by: Rikard Falkeborn Link: https://lore.kernel.org/r/20210117212847.21319-5-rikard.falkeborn@gmail.com Signed-off-by: Will Deacon

drivers/perf: Prevent forced unbinding of PMU drivers

2020-07-17T09:51:44Z

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 Reviewed-by: John Garry Link: https://lore.kernel.org/r/1594975763-32966-1-git-send-email-liuqi115@huawei.com Signed-off-by: Will Deacon

perf/arm-cci: use devm_platform_ioremap_resource() to simplify code

2019-10-01T11:28:47Z

Use devm_platform_ioremap_resource() to simplify the code a bit. This is detected by coccinelle. Signed-off-by: YueHaibing Signed-off-by: Will Deacon

perf/arm-cci: Remove broken race mitigation

2019-04-23T11:29:23Z

Uncore PMU drivers face an awkward cyclic dependency wherein: - They have to pick a valid online CPU to associate with before registering the PMU device, since it will get exposed to userspace immediately. - The PMU registration has to be be at least partly complete before hotplug events can be handled, since trying to migrate an uninitialised context would be bad. - The hotplug handler has to be ready as soon as a CPU is chosen, lest it go offline without the user-visible cpumask value getting updated. The arm-cci driver has tried to solve this by using get_cpu() to pick the current CPU and prevent it from disappearing while both registrations are performed, but that results in taking mutexes with preemption disabled, which makes certain configurations very unhappy: [ 1.983337] BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:2004 [ 1.983340] in_atomic(): 1, irqs_disabled(): 0, pid: 1, name: swapper/0 [ 1.983342] Preemption disabled at: [ 1.983353] [] cci_pmu_probe+0x1dc/0x488 [ 1.983360] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.18.20-rt8-yocto-preempt-rt #1 [ 1.983362] Hardware name: ZynqMP ZCU102 Rev1.0 (DT) [ 1.983364] Call trace: [ 1.983369] dump_backtrace+0x0/0x158 [ 1.983372] show_stack+0x24/0x30 [ 1.983378] dump_stack+0x80/0xa4 [ 1.983383] ___might_sleep+0x138/0x160 [ 1.983386] __might_sleep+0x58/0x90 [ 1.983391] __rt_mutex_lock_state+0x30/0xc0 [ 1.983395] _mutex_lock+0x24/0x30 [ 1.983400] perf_pmu_register+0x2c/0x388 [ 1.983404] cci_pmu_probe+0x2bc/0x488 [ 1.983409] platform_drv_probe+0x58/0xa8 It is not feasible to resolve all the possible races outside of the perf core itself, so address the immediate bug by following the example of nearly every other PMU driver and not even trying to do so. Registering the hotplug notifier first should minimise the window in which things can go wrong, so that's about as much as we can reasonably do here. This also revealed an additional race in assigning the global pointer too late relative to the hotplug notifier, which gets fixed in the process. Reported-by: Li, Meng Tested-by: Corentin Labbe Reviewed-by: Suzuki K Poulose Signed-off-by: Robin Murphy Signed-off-by: Will Deacon