From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755864AbcHTAna (ORCPT ); Fri, 19 Aug 2016 20:43:30 -0400 Received: from cloudserver094114.home.net.pl ([79.96.170.134]:63114 "HELO cloudserver094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1755671AbcHTAn2 (ORCPT ); Fri, 19 Aug 2016 20:43:28 -0400 From: "Rafael J. Wysocki" To: Srinivas Pandruvada Cc: mingo@redhat.com, tglx@linutronix.de, hpa@zytor.com, peterz@infradead.org, x86@kernel.org, bp@suse.de, sudeep.holla@arm.com, ak@linux.intel.com, linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org, alexey.klimov@arm.com, viresh.kumar@linaro.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, lenb@kernel.org, tim.c.chen@linux.intel.com, paul.gortmaker@windriver.com, jpoimboe@redhat.com, mcgrof@kernel.org, jgross@suse.com, robert.moore@intel.com, dvyukov@google.com, jeyu@redhat.com Subject: Re: [PATCH 07/11] acpi: cppc: Add support for function fixed hardware address Date: Sat, 20 Aug 2016 02:49:02 +0200 Message-ID: <15999750.VXIvtIj0kC@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/4.8.0-rc1+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <1471559812-19967-8-git-send-email-srinivas.pandruvada@linux.intel.com> References: <1471559812-19967-1-git-send-email-srinivas.pandruvada@linux.intel.com> <1471559812-19967-8-git-send-email-srinivas.pandruvada@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday, August 18, 2016 03:36:48 PM Srinivas Pandruvada wrote: > The CPPC registers can also be accessed via function fixed hardware > addresses in X86. Add support by modifying cpc_read and cpc_write > to be able to read/write MSRs on x86 platform. Also with this change, > acpi_cppc_processor_probe doesn't bail out if space id is not equal to > PCC or memory address space. > > Signed-off-by: Srinivas Pandruvada > --- > drivers/acpi/cppc_acpi.c | 77 +++++++++++++++++++++++++++++++++++++++++------- > 1 file changed, 66 insertions(+), 11 deletions(-) > > diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c > index 34209f5..939fb5c 100644 > --- a/drivers/acpi/cppc_acpi.c > +++ b/drivers/acpi/cppc_acpi.c > @@ -42,6 +42,10 @@ > #include > > #include > +#ifdef CONFIG_X86 > +#include > +#endif Please figure out how to avoid this. > + > /* > * Lock to provide mutually exclusive access to the PCC > * channel. e.g. When the remote updates the shared region > @@ -585,8 +589,9 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) > pr_debug("Mismatched PCC ids.\n"); > goto out_free; > } > - } else if (gas_t->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) { > - /* Support only PCC and SYS MEM type regs */ > + } else if (gas_t->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY && > + gas_t->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) { > + /* Support only PCC, FFH and SYS MEM type regs */ > pr_debug("Unsupported register type: %d\n", gas_t->space_id); > goto out_free; > } > @@ -645,13 +650,59 @@ void acpi_cppc_processor_exit(struct acpi_processor *pr) > } > EXPORT_SYMBOL_GPL(acpi_cppc_processor_exit); > > +#ifdef CONFIG_X86 > +static int cpc_read_ffh(int cpunum, struct cpc_reg *reg, u64 *val) > +{ > + int err; > + > + err = rdmsrl_on_cpu(cpunum, reg->address, val); > + if (!err) { > + u64 mask = GENMASK_ULL(reg->bit_offset + reg->bit_width - 1, > + reg->bit_offset); > + > + *val &= mask; > + *val >>= reg->bit_offset; > + } > + return err; > +} > + > +static int cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val) > +{ > + u64 rd_val; > + int err; > + > + err = rdmsrl_on_cpu(cpunum, reg->address, &rd_val); > + if (!err) { > + u64 mask = GENMASK_ULL(reg->bit_offset + reg->bit_width - 1, > + reg->bit_offset); > + > + val <<= reg->bit_offset; > + val &= mask; > + rd_val &= ~mask; > + rd_val |= val; > + err = wrmsrl_on_cpu(cpunum, reg->address, rd_val); > + } > + return err; > +} The above really should go somewhere under arch/x86/. > +#else > +static int cpc_read_ffh(int cpunum, struct cpc_reg *reg, u64 *val) > +{ > + return -EINVAL; > +} > +static int cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val) > +{ > + return -EINVAL; > + > +} And I would defined these as __weak functions. Also another return value like -ENOTSUPP for example would better IMO. > +#endif > + > /* > * Since cpc_read and cpc_write are called while holding pcc_lock, it should be > * as fast as possible. We have already mapped the PCC subspace during init, so > * we can directly write to it. > */ > > -static int cpc_read(struct cpc_register_resource *res, u64 *val) > +static int cpc_read(int cpunum, struct cpc_register_resource *res, u64 *val) > { > struct cpc_reg *reg = &res->cpc_entry.reg; > int ret_val = 0; > @@ -684,13 +735,15 @@ static int cpc_read(struct cpc_register_resource *res, u64 *val) > reg->bit_width); > ret_val = -EFAULT; > } > + } else if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) { > + ret_val = cpc_read_ffh(cpunum, reg, val); > } else > ret_val = acpi_os_read_memory((acpi_physical_address)reg->address, > val, reg->bit_width); > return ret_val; > } > > -static int cpc_write(struct cpc_reg *reg, u64 val) > +static int cpc_write(int cpunum, struct cpc_reg *reg, u64 val) > { > int ret_val = 0; > > @@ -716,6 +769,8 @@ static int cpc_write(struct cpc_reg *reg, u64 val) > ret_val = -EFAULT; > break; > } > + } else if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) { > + ret_val = cpc_write_ffh(cpunum, reg, val); > } else > ret_val = acpi_os_write_memory((acpi_physical_address)reg->address, > val, reg->bit_width); > @@ -761,16 +816,16 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps) > } > } > > - cpc_read(highest_reg, &high); > + cpc_read(cpunum, highest_reg, &high); > perf_caps->highest_perf = high; > > - cpc_read(lowest_reg, &low); > + cpc_read(cpunum, lowest_reg, &low); > perf_caps->lowest_perf = low; > > - cpc_read(ref_perf, &ref); > + cpc_read(cpunum, ref_perf, &ref); > perf_caps->reference_perf = ref; > > - cpc_read(nom_perf, &nom); > + cpc_read(cpunum, nom_perf, &nom); > perf_caps->nominal_perf = nom; > > if (!ref) > @@ -819,8 +874,8 @@ int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs) > } > } > > - cpc_read(delivered_reg, &delivered); > - cpc_read(reference_reg, &reference); > + cpc_read(cpunum, delivered_reg, &delivered); > + cpc_read(cpunum, reference_reg, &reference); > > if (!delivered || !reference) { > ret = -EFAULT; > @@ -875,7 +930,7 @@ int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls) > * Skip writing MIN/MAX until Linux knows how to come up with > * useful values. > */ > - cpc_write(&desired_reg->cpc_entry.reg, perf_ctrls->desired_perf); > + cpc_write(cpu, &desired_reg->cpc_entry.reg, perf_ctrls->desired_perf); > > /* Is this a PCC reg ?*/ > if (desired_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) { > Thanks, Rafael