From: James Morse <james.morse@arm.com> maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8T2RT Reference: https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git/log/?h=mpam/... --------------------------- Carl reports that when both the MPAM driver and CMN driver are built into the kernel, they fight over who can claim the resources associated with their registers. This prevents the second of these two drivers from probing. Currently the CMN PMU driver claims all the CMN registers. The MPAM registers are grouped together in a small number of pages, whereas the PMU registers that the CMN PMU driver uses appear throughout the CMN register space. Having the CMN driver claim all the resources is the wrong thing to do, and claiming individual registers here and there is not worthwhile. Instead, stop the CMN driver from claiming any resources as its registers are not grouped together. Reported-by: Carl Worth <carl@os.amperecomputing.com> Tested-by: Carl Worth <carl@os.amperecomputing.com> Signed-off-by: James Morse <james.morse@arm.com> CC: Ilkka Koskinen <ilkka@os.amperecomputing.com> Signed-off-by: Zeng Heng <zengheng4@huawei.com> --- drivers/perf/arm-cmn.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c index 0b3ce7713645..b5507068ba67 100644 --- a/drivers/perf/arm-cmn.c +++ b/drivers/perf/arm-cmn.c @@ -2435,6 +2435,7 @@ static int arm_cmn_probe(struct platform_device *pdev) struct arm_cmn *cmn; const char *name; static atomic_t id; + struct resource *cfg; int err, rootnode, this_id; cmn = devm_kzalloc(&pdev->dev, sizeof(*cmn), GFP_KERNEL); @@ -2449,7 +2450,16 @@ static int arm_cmn_probe(struct platform_device *pdev) rootnode = arm_cmn600_acpi_probe(pdev, cmn); } else { rootnode = 0; - cmn->base = devm_platform_ioremap_resource(pdev, 0); + + /* + * Avoid registering resources as the PMUs registers are + * scattered through CMN, and may appear either side of + * registers for other 'devices'. (e.g. the MPAM MSC controls). + */ + cfg = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!cfg) + return -EINVAL; + cmn->base = devm_ioremap(&pdev->dev, cfg->start, resource_size(cfg)); if (IS_ERR(cmn->base)) return PTR_ERR(cmn->base); if (cmn->part == PART_CMN600) -- 2.25.1