diff options
Diffstat (limited to 'drivers/iommu/intel/perfmon.c')
| -rw-r--r-- | drivers/iommu/intel/perfmon.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/drivers/iommu/intel/perfmon.c b/drivers/iommu/intel/perfmon.c new file mode 100644 index 000000000..db5791a54 --- /dev/null +++ b/drivers/iommu/intel/perfmon.c @@ -0,0 +1,172 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Support Intel IOMMU PerfMon + * Copyright(c) 2023 Intel Corporation. + */ +#define pr_fmt(fmt) "DMAR: " fmt +#define dev_fmt(fmt) pr_fmt(fmt) + +#include <linux/dmar.h> +#include "iommu.h" +#include "perfmon.h" + +static inline void __iomem * +get_perf_reg_address(struct intel_iommu *iommu, u32 offset) +{ + u32 off = dmar_readl(iommu->reg + offset); + + return iommu->reg + off; +} + +int alloc_iommu_pmu(struct intel_iommu *iommu) +{ + struct iommu_pmu *iommu_pmu; + int i, j, ret; + u64 perfcap; + u32 cap; + + if (!ecap_pms(iommu->ecap)) + return 0; + + /* The IOMMU PMU requires the ECMD support as well */ + if (!cap_ecmds(iommu->cap)) + return -ENODEV; + + perfcap = dmar_readq(iommu->reg + DMAR_PERFCAP_REG); + /* The performance monitoring is not supported. */ + if (!perfcap) + return -ENODEV; + + /* Sanity check for the number of the counters and event groups */ + if (!pcap_num_cntr(perfcap) || !pcap_num_event_group(perfcap)) + return -ENODEV; + + /* The interrupt on overflow is required */ + if (!pcap_interrupt(perfcap)) + return -ENODEV; + + iommu_pmu = kzalloc(sizeof(*iommu_pmu), GFP_KERNEL); + if (!iommu_pmu) + return -ENOMEM; + + iommu_pmu->num_cntr = pcap_num_cntr(perfcap); + iommu_pmu->cntr_width = pcap_cntr_width(perfcap); + iommu_pmu->filter = pcap_filters_mask(perfcap); + iommu_pmu->cntr_stride = pcap_cntr_stride(perfcap); + iommu_pmu->num_eg = pcap_num_event_group(perfcap); + + iommu_pmu->evcap = kcalloc(iommu_pmu->num_eg, sizeof(u64), GFP_KERNEL); + if (!iommu_pmu->evcap) { + ret = -ENOMEM; + goto free_pmu; + } + + /* Parse event group capabilities */ + for (i = 0; i < iommu_pmu->num_eg; i++) { + u64 pcap; + + pcap = dmar_readq(iommu->reg + DMAR_PERFEVNTCAP_REG + + i * IOMMU_PMU_CAP_REGS_STEP); + iommu_pmu->evcap[i] = pecap_es(pcap); + } + + iommu_pmu->cntr_evcap = kcalloc(iommu_pmu->num_cntr, sizeof(u32 *), GFP_KERNEL); + if (!iommu_pmu->cntr_evcap) { + ret = -ENOMEM; + goto free_pmu_evcap; + } + for (i = 0; i < iommu_pmu->num_cntr; i++) { + iommu_pmu->cntr_evcap[i] = kcalloc(iommu_pmu->num_eg, sizeof(u32), GFP_KERNEL); + if (!iommu_pmu->cntr_evcap[i]) { + ret = -ENOMEM; + goto free_pmu_cntr_evcap; + } + /* + * Set to the global capabilities, will adjust according + * to per-counter capabilities later. + */ + for (j = 0; j < iommu_pmu->num_eg; j++) + iommu_pmu->cntr_evcap[i][j] = (u32)iommu_pmu->evcap[j]; + } + + iommu_pmu->cfg_reg = get_perf_reg_address(iommu, DMAR_PERFCFGOFF_REG); + iommu_pmu->cntr_reg = get_perf_reg_address(iommu, DMAR_PERFCNTROFF_REG); + iommu_pmu->overflow = get_perf_reg_address(iommu, DMAR_PERFOVFOFF_REG); + + /* + * Check per-counter capabilities. All counters should have the + * same capabilities on Interrupt on Overflow Support and Counter + * Width. + */ + for (i = 0; i < iommu_pmu->num_cntr; i++) { + cap = dmar_readl(iommu_pmu->cfg_reg + + i * IOMMU_PMU_CFG_OFFSET + + IOMMU_PMU_CFG_CNTRCAP_OFFSET); + if (!iommu_cntrcap_pcc(cap)) + continue; + + /* + * It's possible that some counters have a different + * capability because of e.g., HW bug. Check the corner + * case here and simply drop those counters. + */ + if ((iommu_cntrcap_cw(cap) != iommu_pmu->cntr_width) || + !iommu_cntrcap_ios(cap)) { + iommu_pmu->num_cntr = i; + pr_warn("PMU counter capability inconsistent, counter number reduced to %d\n", + iommu_pmu->num_cntr); + } + + /* Clear the pre-defined events group */ + for (j = 0; j < iommu_pmu->num_eg; j++) + iommu_pmu->cntr_evcap[i][j] = 0; + + /* Override with per-counter event capabilities */ + for (j = 0; j < iommu_cntrcap_egcnt(cap); j++) { + cap = dmar_readl(iommu_pmu->cfg_reg + i * IOMMU_PMU_CFG_OFFSET + + IOMMU_PMU_CFG_CNTREVCAP_OFFSET + + (j * IOMMU_PMU_OFF_REGS_STEP)); + iommu_pmu->cntr_evcap[i][iommu_event_group(cap)] = iommu_event_select(cap); + /* + * Some events may only be supported by a specific counter. + * Track them in the evcap as well. + */ + iommu_pmu->evcap[iommu_event_group(cap)] |= iommu_event_select(cap); + } + } + + iommu_pmu->iommu = iommu; + iommu->pmu = iommu_pmu; + + return 0; + +free_pmu_cntr_evcap: + for (i = 0; i < iommu_pmu->num_cntr; i++) + kfree(iommu_pmu->cntr_evcap[i]); + kfree(iommu_pmu->cntr_evcap); +free_pmu_evcap: + kfree(iommu_pmu->evcap); +free_pmu: + kfree(iommu_pmu); + + return ret; +} + +void free_iommu_pmu(struct intel_iommu *iommu) +{ + struct iommu_pmu *iommu_pmu = iommu->pmu; + + if (!iommu_pmu) + return; + + if (iommu_pmu->evcap) { + int i; + + for (i = 0; i < iommu_pmu->num_cntr; i++) + kfree(iommu_pmu->cntr_evcap[i]); + kfree(iommu_pmu->cntr_evcap); + } + kfree(iommu_pmu->evcap); + kfree(iommu_pmu); + iommu->pmu = NULL; +} |