| Message ID | 20231123040355.82139-20-david.e.box@linux.intel.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | intel_pmc: Add telemetry API to read counters | expand |
On Wed, 22 Nov 2023, David E. Box wrote: > Add a "die_c6_us_show" debugfs attribute. Reads the counter value using > Intel Platform Monitoring Technology (PMT) driver API. This counter is > useful for determining the idle residency of CPUs in the compute tile. > Also adds a missing forward declaration for punit_ep which was declared in > an earlier upstream commit but only used for the first time in this one. > > Signed-off-by: David E. Box <david.e.box@linux.intel.com> > --- > V5 - Change comment for crystal error and return value > > V4 - no change > > V3 - Split previous PATCH V2 13. Separates implementation (this patch) from > platform specific use (next patch) > > V2 - Remove use of __func__ > - Use HZ_PER_MHZ > - Fix missing newlines in printks > > drivers/platform/x86/intel/pmc/core.c | 55 +++++++++++++++++++++++++++ > drivers/platform/x86/intel/pmc/core.h | 4 ++ > 2 files changed, 59 insertions(+) > > diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c > index 4a38d52558fd..fb2c84fba0ae 100644 > --- a/drivers/platform/x86/intel/pmc/core.c > +++ b/drivers/platform/x86/intel/pmc/core.c > +static int pmc_core_die_c6_us_show(struct seq_file *s, void *unused) > +{ > + struct pmc_dev *pmcdev = s->private; > + u64 die_c6_res, count; > + int ret; > + > + if (!pmcdev->crystal_freq) { > + dev_warn_once(&pmcdev->pdev->dev, "Crystal frequency unavailable\n"); > + return -ENXIO; > + } I actually started to wonder whether it would be better to just not show the file in this case (using .is_visible())? (I'm sorry I forgot to send the note about that earlier.)
On Thu, 23 Nov 2023, Ilpo Järvinen wrote: > On Wed, 22 Nov 2023, David E. Box wrote: > > > Add a "die_c6_us_show" debugfs attribute. Reads the counter value using > > Intel Platform Monitoring Technology (PMT) driver API. This counter is > > useful for determining the idle residency of CPUs in the compute tile. > > Also adds a missing forward declaration for punit_ep which was declared in > > an earlier upstream commit but only used for the first time in this one. > > > > Signed-off-by: David E. Box <david.e.box@linux.intel.com> > > --- > > V5 - Change comment for crystal error and return value > > > > V4 - no change > > > > V3 - Split previous PATCH V2 13. Separates implementation (this patch) from > > platform specific use (next patch) > > > > V2 - Remove use of __func__ > > - Use HZ_PER_MHZ > > - Fix missing newlines in printks > > > > drivers/platform/x86/intel/pmc/core.c | 55 +++++++++++++++++++++++++++ > > drivers/platform/x86/intel/pmc/core.h | 4 ++ > > 2 files changed, 59 insertions(+) > > > > diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c > > index 4a38d52558fd..fb2c84fba0ae 100644 > > --- a/drivers/platform/x86/intel/pmc/core.c > > +++ b/drivers/platform/x86/intel/pmc/core.c > > > +static int pmc_core_die_c6_us_show(struct seq_file *s, void *unused) > > +{ > > + struct pmc_dev *pmcdev = s->private; > > + u64 die_c6_res, count; > > + int ret; > > + > > + if (!pmcdev->crystal_freq) { > > + dev_warn_once(&pmcdev->pdev->dev, "Crystal frequency unavailable\n"); > > + return -ENXIO; > > + } > > I actually started to wonder whether it would be better to just not show > the file in this case (using .is_visible())? (I'm sorry I forgot to send > the note about that earlier.) Ah, sorry, this was actually a debugfs file, not a sysfs one (and that's why I didn't end up noting it earlier). Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c index 4a38d52558fd..fb2c84fba0ae 100644 --- a/drivers/platform/x86/intel/pmc/core.c +++ b/drivers/platform/x86/intel/pmc/core.c @@ -20,6 +20,7 @@ #include <linux/pci.h> #include <linux/slab.h> #include <linux/suspend.h> +#include <linux/units.h> #include <asm/cpu_device_id.h> #include <asm/intel-family.h> @@ -27,6 +28,7 @@ #include <asm/tsc.h> #include "core.h" +#include "../pmt/telemetry.h" /* Maximum number of modes supported by platfoms that has low power mode capability */ const char *pmc_lpm_modes[] = { @@ -817,6 +819,47 @@ static int pmc_core_substate_req_regs_show(struct seq_file *s, void *unused) } DEFINE_SHOW_ATTRIBUTE(pmc_core_substate_req_regs); +static unsigned int pmc_core_get_crystal_freq(void) +{ + unsigned int eax_denominator, ebx_numerator, ecx_hz, edx; + + if (boot_cpu_data.cpuid_level < 0x15) + return 0; + + eax_denominator = ebx_numerator = ecx_hz = edx = 0; + + /* CPUID 15H TSC/Crystal ratio, plus optionally Crystal Hz */ + cpuid(0x15, &eax_denominator, &ebx_numerator, &ecx_hz, &edx); + + if (ebx_numerator == 0 || eax_denominator == 0) + return 0; + + return ecx_hz; +} + +static int pmc_core_die_c6_us_show(struct seq_file *s, void *unused) +{ + struct pmc_dev *pmcdev = s->private; + u64 die_c6_res, count; + int ret; + + if (!pmcdev->crystal_freq) { + dev_warn_once(&pmcdev->pdev->dev, "Crystal frequency unavailable\n"); + return -ENXIO; + } + + ret = pmt_telem_read(pmcdev->punit_ep, pmcdev->die_c6_offset, + &count, 1); + if (ret) + return ret; + + die_c6_res = div64_u64(count * HZ_PER_MHZ, pmcdev->crystal_freq); + seq_printf(s, "%llu\n", die_c6_res); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(pmc_core_die_c6_us); + static int pmc_core_lpm_latch_mode_show(struct seq_file *s, void *unused) { struct pmc_dev *pmcdev = s->private; @@ -1113,6 +1156,12 @@ static void pmc_core_dbgfs_register(struct pmc_dev *pmcdev) pmcdev->dbgfs_dir, pmcdev, &pmc_core_substate_req_regs_fops); } + + if (pmcdev->has_die_c6) { + debugfs_create_file("die_c6_us_show", 0444, + pmcdev->dbgfs_dir, pmcdev, + &pmc_core_die_c6_us_fops); + } } static const struct x86_cpu_id intel_pmc_core_ids[] = { @@ -1207,6 +1256,10 @@ static void pmc_core_clean_structure(struct platform_device *pdev) pci_dev_put(pmcdev->ssram_pcidev); pci_disable_device(pmcdev->ssram_pcidev); } + + if (pmcdev->punit_ep) + pmt_telem_unregister_endpoint(pmcdev->punit_ep); + platform_set_drvdata(pdev, NULL); mutex_destroy(&pmcdev->lock); } @@ -1227,6 +1280,8 @@ static int pmc_core_probe(struct platform_device *pdev) if (!pmcdev) return -ENOMEM; + pmcdev->crystal_freq = pmc_core_get_crystal_freq(); + platform_set_drvdata(pdev, pmcdev); pmcdev->pdev = pdev; diff --git a/drivers/platform/x86/intel/pmc/core.h b/drivers/platform/x86/intel/pmc/core.h index 85b6f6ae4995..6d7673145f90 100644 --- a/drivers/platform/x86/intel/pmc/core.h +++ b/drivers/platform/x86/intel/pmc/core.h @@ -16,6 +16,8 @@ #include <linux/bits.h> #include <linux/platform_device.h> +struct telem_endpoint; + #define SLP_S0_RES_COUNTER_MASK GENMASK(31, 0) #define PMC_BASE_ADDR_DEFAULT 0xFE000000 @@ -357,6 +359,7 @@ struct pmc { * @devs: pointer to an array of pmc pointers * @pdev: pointer to platform_device struct * @ssram_pcidev: pointer to pci device struct for the PMC SSRAM + * @crystal_freq: crystal frequency from cpuid * @dbgfs_dir: path to debugfs interface * @pmc_xram_read_bit: flag to indicate whether PMC XRAM shadow registers * used to read MPHY PG and PLL status are available @@ -374,6 +377,7 @@ struct pmc_dev { struct dentry *dbgfs_dir; struct platform_device *pdev; struct pci_dev *ssram_pcidev; + unsigned int crystal_freq; int pmc_xram_read_bit; struct mutex lock; /* generic mutex lock for PMC Core */
Add a "die_c6_us_show" debugfs attribute. Reads the counter value using Intel Platform Monitoring Technology (PMT) driver API. This counter is useful for determining the idle residency of CPUs in the compute tile. Also adds a missing forward declaration for punit_ep which was declared in an earlier upstream commit but only used for the first time in this one. Signed-off-by: David E. Box <david.e.box@linux.intel.com> --- V5 - Change comment for crystal error and return value V4 - no change V3 - Split previous PATCH V2 13. Separates implementation (this patch) from platform specific use (next patch) V2 - Remove use of __func__ - Use HZ_PER_MHZ - Fix missing newlines in printks drivers/platform/x86/intel/pmc/core.c | 55 +++++++++++++++++++++++++++ drivers/platform/x86/intel/pmc/core.h | 4 ++ 2 files changed, 59 insertions(+)