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From:   Rajat Jain <rajatja@google.com>
Date:   Mon, 8 Apr 2019 11:42:37 -0700
Message-ID: <CACK8Z6HcqsRxRNGhN9sTRGp5kx=kVCTgqL_cVGy_Tznu=gL6jQ@mail.gmail.com>
Subject: Re: [PATCH v3 1/3] platform/x86: intel_pmc_core: Convert to a platform_driver
To:     Andy Shevchenko <andy.shevchenko@gmail.com>
Cc:     Rajneesh Bhardwaj <rajneesh.bhardwaj@intel.com>,
        Vishwanath Somayaji <vishwanath.somayaji@intel.com>,
        Darren Hart <dvhart@infradead.org>,
        Andy Shevchenko <andy@infradead.org>,
        Platform Driver <platform-driver-x86@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Wysocki@google.com, Rafael J <rafael.j.wysocki@intel.com>,
        Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
        Furquan Shaikh <furquan@google.com>,
        Evan Green <evgreen@google.com>,
        Rajat Jain <rajatxjain@gmail.com>
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Sender: linux-kernel-owner@vger.kernel.org
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Hi,

Thank you for the review.

On Mon, Apr 8, 2019 at 9:51 AM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
>
> On Fri, Apr 5, 2019 at 11:36 PM Rajat Jain <rajatja@google.com> wrote:
> >
> > Convert the intel_pmc_core driver to a platform driver, and attach using
> > the ACPI enumeration method (via the ACPI device "INT33A1").
> >
> > Signed-off-by: Rajat Jain <rajatja@google.com>
>
> > -static const struct x86_cpu_id intel_pmc_core_ids[] = {
> > -       INTEL_CPU_FAM6(SKYLAKE_MOBILE, spt_reg_map),
> > -       INTEL_CPU_FAM6(SKYLAKE_DESKTOP, spt_reg_map),
> > -       INTEL_CPU_FAM6(KABYLAKE_MOBILE, spt_reg_map),
> > -       INTEL_CPU_FAM6(KABYLAKE_DESKTOP, spt_reg_map),
> > -       INTEL_CPU_FAM6(CANNONLAKE_MOBILE, cnp_reg_map),
> > -       INTEL_CPU_FAM6(ICELAKE_MOBILE, icl_reg_map),
> > -       {}
> > -};
> > -
> > -MODULE_DEVICE_TABLE(x86cpu, intel_pmc_core_ids);
> > -
>
> > +static int pmc_core_probe(struct platform_device *pdev)
> >  {
> > +       static bool device_initialized;
> >         struct pmc_dev *pmcdev = &pmc;
> > -       const struct x86_cpu_id *cpu_id;
> >         u64 slp_s0_addr;
> >         int err;
> >
> > -       cpu_id = x86_match_cpu(intel_pmc_core_ids);
> > -       if (!cpu_id)
> > +       if (device_initialized)
> >                 return -ENODEV;
> >
> > -       pmcdev->map = (struct pmc_reg_map *)cpu_id->driver_data;
>
> > +       switch (boot_cpu_data.x86_model) {
>
> I didn't get why this should be boot CPU?
> Otherwise, leave the structure and leave the x86_match_cpu() call.

I didn't quite understand the concern. The x86_match_cpu() also uses
the same boot_cpu_data that I've used, am I missing something?

Thanks,

Rajat


>
> > +       case INTEL_FAM6_SKYLAKE_MOBILE:
> > +       case INTEL_FAM6_SKYLAKE_DESKTOP:
> > +       case INTEL_FAM6_KABYLAKE_MOBILE:
> > +       case INTEL_FAM6_KABYLAKE_DESKTOP:
> >
> > -       /*
> > -        * Coffeelake has CPU ID of Kabylake and Cannonlake PCH. So here
> > -        * Sunrisepoint PCH regmap can't be used. Use Cannonlake PCH regmap
> > -        * in this case.
> > -        */
> > -       if (pmcdev->map == &spt_reg_map && !pci_dev_present(pmc_pci_ids))
> > +               pmcdev->map = &spt_reg_map;
> > +
> > +               /*
> > +                * Special case: Coffeelake has CPU ID of Kabylake, but has
> > +                * Cannonlake PCH. So need to use cnp_reg_map instead of
> > +                * spt_reg_map for this special case. The PMC core PCI device
> > +                * on Coffeelake is hidden, so use that as the deciding factor.
> > +                */
> > +               if (!pci_dev_present(pmc_pci_ids))
> > +                       pmcdev->map = &cnp_reg_map;
> > +
> > +               break;
> > +
> > +       case INTEL_FAM6_CANNONLAKE_MOBILE:
> >                 pmcdev->map = &cnp_reg_map;
> > +               break;
> > +
> > +       case INTEL_FAM6_ICELAKE_MOBILE:
> > +               pmcdev->map = &icl_reg_map;
> > +               break;
> > +       default:
> > +               /*
> > +                * Which map should we use by default? If not specified
> > +                * explicitly, assume Icelake by default for now.
> > +                */
> > +               pmcdev->map = &icl_reg_map;
> > +               break;
> > +       }
> >
> >         if (lpit_read_residency_count_address(&slp_s0_addr))
> >                 pmcdev->base_addr = PMC_BASE_ADDR_DEFAULT;
> > @@ -890,26 +903,47 @@ static int __init pmc_core_probe(void)
> >
> >         err = pmc_core_dbgfs_register(pmcdev);
> >         if (err < 0) {
> > -               pr_warn(" debugfs register failed.\n");
> > +               dev_warn(&pdev->dev, "debugfs register failed.\n");
> >                 iounmap(pmcdev->regbase);
> >                 return err;
> >         }
> >
> >         dmi_check_system(pmc_core_dmi_table);
> > -       pr_info(" initialized\n");
> > +       platform_set_drvdata(pdev, pmcdev);
> > +
> > +       dev_info(&pdev->dev, " initialized\n");
> > +       device_initialized = true;
> > +
> >         return 0;
> >  }
> > -module_init(pmc_core_probe)
> >
> > -static void __exit pmc_core_remove(void)
> > +static int pmc_core_remove(struct platform_device *pdev)
> >  {
> > -       struct pmc_dev *pmcdev = &pmc;
> > +       struct pmc_dev *pmcdev = platform_get_drvdata(pdev);
> >
> > +       platform_set_drvdata(pdev, NULL);
> >         pmc_core_dbgfs_unregister(pmcdev);
> >         mutex_destroy(&pmcdev->lock);
> >         iounmap(pmcdev->regbase);
> > +       return 0;
> >  }
> > -module_exit(pmc_core_remove)
> > +
> > +static const struct acpi_device_id pmc_core_acpi_ids[] = {
> > +       {"INT33A1", 0}, /* _HID for Intel Power Engine, _CID PNP0D80*/
> > +       { }
> > +};
> > +MODULE_DEVICE_TABLE(acpi, pmc_core_acpi_ids);
> > +
> > +static struct platform_driver pmc_core_driver = {
> > +       .driver = {
> > +               .name = "pmc_core",
> > +               .acpi_match_table = ACPI_PTR(pmc_core_acpi_ids),
> > +       },
> > +       .probe = pmc_core_probe,
> > +       .remove = pmc_core_remove,
> > +};
> > +
> > +module_platform_driver(pmc_core_driver);
> >
> >  MODULE_LICENSE("GPL v2");
> >  MODULE_DESCRIPTION("Intel PMC Core Driver");
> > --
> > 2.21.0.392.gf8f6787159e-goog
> >
>
>
> --
> With Best Regards,
> Andy Shevchenko