[PATCH v2 0/4] CPPC only changes for supporting ITMT 3.0

[PATCH v2 0/4] CPPC only changes for supporting ITMT 3.0

[Srinivas Pandruvada]

This patchset is CPPC only changes from original "Support Intel® Turbo
Boost Max Technology 3.0" series.

v2
- Rebased on top of bleeding edge branch of Linux-pm git 
- Instead of #ifdef in cppc_acpi using __weak attribute for
functions implemented in arch/x86/kernel/acpi/
- Removed integer support patch as this was already implemented
in the latest code base
- Instead of error return print warning on cppc probe failure

Srinivas Pandruvada (4):
  acpi: cppc: Allow build with ACPI_CPU_FREQ_PSS config
  acpi: cppc: Don't return on CPPC probe failure
  acpi: cppc: Add support for functional fixed hardware address
  acpi: cppc: Add prefix cppc to cpudata structure name

 arch/x86/kernel/acpi/Makefile   |  1 +
 arch/x86/kernel/acpi/cppc_msr.c | 58 ++++++++++++++++++++++++++++++
 drivers/acpi/Kconfig            |  1 -
 drivers/acpi/cppc_acpi.c        | 79 +++++++++++++++++++++++++++++++++--------
 drivers/acpi/processor_driver.c |  4 +--
 drivers/cpufreq/cppc_cpufreq.c  | 14 ++++----
 include/acpi/cppc_acpi.h        |  4 +--
 7 files changed, 134 insertions(+), 27 deletions(-)
 create mode 100644 arch/x86/kernel/acpi/cppc_msr.c

-- 
2.7.4

[PATCH v2 1/4] acpi: cppc: Allow build with ACPI_CPU_FREQ_PSS config

[Srinivas Pandruvada]

Some newer x86 platforms have support for both _CPC and _PSS object. So
kernel config can have both ACPI_CPU_FREQ_PSS and ACPI_CPPC_LIB. So remove
restriction for ACPI_CPPC_LIB to build only when ACPI_CPU_FREQ_PSS is not
defined.
Also for legacy systems with only _PSS, we shouldn't bail out if
acpi_cppc_processor_probe() fails, if ACPI_CPU_FREQ_PSS is also defined.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
 drivers/acpi/Kconfig            | 1 -
 drivers/acpi/processor_driver.c | 2 +-
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 445ce28..c6bb6aa 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -227,7 +227,6 @@ config ACPI_MCFG
 config ACPI_CPPC_LIB
 	bool
 	depends on ACPI_PROCESSOR
-	depends on !ACPI_CPU_FREQ_PSS
 	select MAILBOX
 	select PCC
 	help
diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index 0553aee..f5c92be 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -245,7 +245,7 @@ static int __acpi_processor_start(struct acpi_device *device)
 		return 0;
 
 	result = acpi_cppc_processor_probe(pr);
-	if (result)
+	if (result && !IS_ENABLED(CONFIG_ACPI_CPU_FREQ_PSS))
 		return -ENODEV;
 
 	if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
-- 
2.7.4

[PATCH v2 2/4] acpi: cppc: Don't return on CPPC probe failure

[Srinivas Pandruvada]

It is still possible to continue even CPPC data is invalid or missing.

Suggested-by: Alexey Klimov <alexey.klimov@arm.com>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
 drivers/acpi/processor_driver.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index f5c92be..8f8552a 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -246,7 +246,7 @@ static int __acpi_processor_start(struct acpi_device *device)
 
 	result = acpi_cppc_processor_probe(pr);
 	if (result && !IS_ENABLED(CONFIG_ACPI_CPU_FREQ_PSS))
-		return -ENODEV;
+		dev_warn(&device->dev, "CPPC data invalid or not present\n");
 
 	if (!cpuidle_get_driver() || cpuidle_get_driver() == &acpi_idle_driver)
 		acpi_processor_power_init(pr);
-- 
2.7.4

[PATCH v2 3/4] acpi: cppc: Add support for functional fixed hardware address

[Srinivas Pandruvada]

The CPPC registers can also be accessed via functional fixed hardware
addresse(FFH) in X86. Add support by modifying cpc_read and cpc_write to
be able to read/write MSRs on x86 platform on per cpu basis.
Also with this change, acpi_cppc_processor_probe doesn't bail out if
address space id is not equal to PCC or memory address space and FFH
is supported on the system.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
 arch/x86/kernel/acpi/Makefile   |  1 +
 arch/x86/kernel/acpi/cppc_msr.c | 58 +++++++++++++++++++++++++++++++
 drivers/acpi/cppc_acpi.c        | 75 ++++++++++++++++++++++++++++++++++-------
 3 files changed, 121 insertions(+), 13 deletions(-)
 create mode 100644 arch/x86/kernel/acpi/cppc_msr.c

diff --git a/arch/x86/kernel/acpi/Makefile b/arch/x86/kernel/acpi/Makefile
index 3242e59..26b78d8 100644
--- a/arch/x86/kernel/acpi/Makefile
+++ b/arch/x86/kernel/acpi/Makefile
@@ -1,6 +1,7 @@
 obj-$(CONFIG_ACPI)		+= boot.o
 obj-$(CONFIG_ACPI_SLEEP)	+= sleep.o wakeup_$(BITS).o
 obj-$(CONFIG_ACPI_APEI)		+= apei.o
+obj-$(CONFIG_ACPI_CPPC_LIB)	+= cppc_msr.o
 
 ifneq ($(CONFIG_ACPI_PROCESSOR),)
 obj-y				+= cstate.o
diff --git a/arch/x86/kernel/acpi/cppc_msr.c b/arch/x86/kernel/acpi/cppc_msr.c
new file mode 100644
index 0000000..6fb478b
--- /dev/null
+++ b/arch/x86/kernel/acpi/cppc_msr.c
@@ -0,0 +1,58 @@
+/*
+ * cppc_msr.c:  MSR Interface for CPPC
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ */
+
+#include <acpi/cppc_acpi.h>
+#include <asm/msr.h>
+
+/* Refer to drivers/acpi/cppc_acpi.c for the description of functions */
+
+bool cpc_ffh_supported(void)
+{
+	return true;
+}
+
+int cpc_read_ffh(int cpunum, struct cpc_reg *reg, u64 *val)
+{
+	int err;
+
+	err = rdmsrl_safe_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;
+}
+
+int cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val)
+{
+	u64 rd_val;
+	int err;
+
+	err = rdmsrl_safe_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_safe_on_cpu(cpunum, reg->address, rd_val);
+	}
+	return err;
+}
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index ed58883..715fe80 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -579,6 +579,19 @@ static int register_pcc_channel(int pcc_subspace_idx)
 	return 0;
 }
 
+/**
+ * cpc_ffh_supported() - check if FFH reading supported
+ *
+ * Check if the architecture has support for functional fixed hardware
+ * read/write capability.
+ *
+ * Return: true for supported, false for not supported
+ */
+bool __weak cpc_ffh_supported(void)
+{
+	return false;
+}
+
 /*
  * An example CPC table looks like the following.
  *
@@ -728,9 +741,11 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
 					cpc_ptr->cpc_regs[i-2].sys_mem_vaddr = addr;
 				}
 			} else {
-				/* Support only PCC and SYS MEM type regs */
-				pr_debug("Unsupported register type: %d\n", gas_t->space_id);
-				goto out_free;
+				if (gas_t->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE || !cpc_ffh_supported()) {
+					/* Support only PCC ,SYS MEM and FFH type regs */
+					pr_debug("Unsupported register type: %d\n", gas_t->space_id);
+					goto out_free;
+				}
 			}
 
 			cpc_ptr->cpc_regs[i-2].type = ACPI_TYPE_BUFFER;
@@ -819,13 +834,43 @@ void acpi_cppc_processor_exit(struct acpi_processor *pr)
 }
 EXPORT_SYMBOL_GPL(acpi_cppc_processor_exit);
 
+/**
+ * cpc_read_ffh() - Read FFH register
+ * @cpunum:	cpu number to read
+ * @reg:	cppc register information
+ * @val:	place holder for return value
+ *
+ * Read bit_width bits from a specified address and bit_offset
+ *
+ * Return: 0 for success and error code
+ */
+int __weak cpc_read_ffh(int cpunum, struct cpc_reg *reg, u64 *val)
+{
+	return -ENOTSUPP;
+}
+
+/**
+ * cpc_write_ffh() - Write FFH register
+ * @cpunum:	cpu number to write
+ * @reg:	cppc register information
+ * @val:	value to write
+ *
+ * Write value of bit_width bits to a specified address and bit_offset
+ *
+ * Return: 0 for success and error code
+ */
+int __weak cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val)
+{
+	return -ENOTSUPP;
+}
+
 /*
  * 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 *reg_res, u64 *val)
+static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val)
 {
 	int ret_val = 0;
 	void __iomem *vaddr = 0;
@@ -841,6 +886,8 @@ static int cpc_read(struct cpc_register_resource *reg_res, u64 *val)
 		vaddr = GET_PCC_VADDR(reg->address);
 	else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
 		vaddr = reg_res->sys_mem_vaddr;
+	else if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE)
+		return cpc_read_ffh(cpu, reg, val);
 	else
 		return acpi_os_read_memory((acpi_physical_address)reg->address,
 				val, reg->bit_width);
@@ -867,7 +914,7 @@ static int cpc_read(struct cpc_register_resource *reg_res, u64 *val)
 	return ret_val;
 }
 
-static int cpc_write(struct cpc_register_resource *reg_res, u64 val)
+static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
 {
 	int ret_val = 0;
 	void __iomem *vaddr = 0;
@@ -877,6 +924,8 @@ static int cpc_write(struct cpc_register_resource *reg_res, u64 val)
 		vaddr = GET_PCC_VADDR(reg->address);
 	else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
 		vaddr = reg_res->sys_mem_vaddr;
+	else if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE)
+		return cpc_write_ffh(cpu, reg, val);
 	else
 		return acpi_os_write_memory((acpi_physical_address)reg->address,
 				val, reg->bit_width);
@@ -941,13 +990,13 @@ 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(nom_perf, &nom);
+	cpc_read(cpunum, nom_perf, &nom);
 	perf_caps->nominal_perf = nom;
 
 	if (!high || !low || !nom)
@@ -1004,9 +1053,9 @@ 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(ref_perf_reg, &ref_perf);
+	cpc_read(cpunum, delivered_reg, &delivered);
+	cpc_read(cpunum, reference_reg, &reference);
+	cpc_read(cpunum, ref_perf_reg, &ref_perf);
 
 	/*
 	 * Per spec, if ctr_wrap_time optional register is unsupported, then the
@@ -1015,7 +1064,7 @@ int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
 	 */
 	ctr_wrap_time = (u64)(~((u64)0));
 	if (CPC_SUPPORTED(ctr_wrap_reg))
-		cpc_read(ctr_wrap_reg, &ctr_wrap_time);
+		cpc_read(cpunum, ctr_wrap_reg, &ctr_wrap_time);
 
 	if (!delivered || !reference ||	!ref_perf) {
 		ret = -EFAULT;
@@ -1082,7 +1131,7 @@ 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, perf_ctrls->desired_perf);
+	cpc_write(cpu, desired_reg, perf_ctrls->desired_perf);
 
 	if (CPC_IN_PCC(desired_reg))
 		up_read(&pcc_data.pcc_lock);	/* END Phase-I */
-- 
2.7.4

[PATCH v2 4/4] acpi: cppc: Add prefix cppc to cpudata structure name

[Srinivas Pandruvada]

Since struct cpudata is defined in a header file, add prefix cppc_ to
make it not a generic name. Otherwise it causes compile issue in locally
define structure with the same name.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
 drivers/acpi/cppc_acpi.c       |  4 ++--
 drivers/cpufreq/cppc_cpufreq.c | 14 +++++++-------
 include/acpi/cppc_acpi.h       |  4 ++--
 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 715fe80..3d1ae6d 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -409,13 +409,13 @@ end:
  *
  *	Return: 0 for success or negative value for err.
  */
-int acpi_get_psd_map(struct cpudata **all_cpu_data)
+int acpi_get_psd_map(struct cppc_cpudata **all_cpu_data)
 {
 	int count_target;
 	int retval = 0;
 	unsigned int i, j;
 	cpumask_var_t covered_cpus;
-	struct cpudata *pr, *match_pr;
+	struct cppc_cpudata *pr, *match_pr;
 	struct acpi_psd_package *pdomain;
 	struct acpi_psd_package *match_pdomain;
 	struct cpc_desc *cpc_ptr, *match_cpc_ptr;
diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
index e6a3359..6588ec5 100644
--- a/drivers/cpufreq/cppc_cpufreq.c
+++ b/drivers/cpufreq/cppc_cpufreq.c
@@ -30,13 +30,13 @@
  * performance capabilities, desired performance level
  * requested etc.
  */
-static struct cpudata **all_cpu_data;
+static struct cppc_cpudata **all_cpu_data;
 
 static int cppc_cpufreq_set_target(struct cpufreq_policy *policy,
 		unsigned int target_freq,
 		unsigned int relation)
 {
-	struct cpudata *cpu;
+	struct cppc_cpudata *cpu;
 	struct cpufreq_freqs freqs;
 	int ret = 0;
 
@@ -66,7 +66,7 @@ static int cppc_verify_policy(struct cpufreq_policy *policy)
 static void cppc_cpufreq_stop_cpu(struct cpufreq_policy *policy)
 {
 	int cpu_num = policy->cpu;
-	struct cpudata *cpu = all_cpu_data[cpu_num];
+	struct cppc_cpudata *cpu = all_cpu_data[cpu_num];
 	int ret;
 
 	cpu->perf_ctrls.desired_perf = cpu->perf_caps.lowest_perf;
@@ -79,7 +79,7 @@ static void cppc_cpufreq_stop_cpu(struct cpufreq_policy *policy)
 
 static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
 {
-	struct cpudata *cpu;
+	struct cppc_cpudata *cpu;
 	unsigned int cpu_num = policy->cpu;
 	int ret = 0;
 
@@ -135,7 +135,7 @@ static struct cpufreq_driver cppc_cpufreq_driver = {
 static int __init cppc_cpufreq_init(void)
 {
 	int i, ret = 0;
-	struct cpudata *cpu;
+	struct cppc_cpudata *cpu;
 
 	if (acpi_disabled)
 		return -ENODEV;
@@ -145,7 +145,7 @@ static int __init cppc_cpufreq_init(void)
 		return -ENOMEM;
 
 	for_each_possible_cpu(i) {
-		all_cpu_data[i] = kzalloc(sizeof(struct cpudata), GFP_KERNEL);
+		all_cpu_data[i] = kzalloc(sizeof(struct cppc_cpudata), GFP_KERNEL);
 		if (!all_cpu_data[i])
 			goto out;
 
@@ -176,7 +176,7 @@ out:
 
 static void __exit cppc_cpufreq_exit(void)
 {
-	struct cpudata *cpu;
+	struct cppc_cpudata *cpu;
 	int i;
 
 	cpufreq_unregister_driver(&cppc_cpufreq_driver);
diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
index 0e83cc3..427a7c3 100644
--- a/include/acpi/cppc_acpi.h
+++ b/include/acpi/cppc_acpi.h
@@ -119,7 +119,7 @@ struct cppc_perf_fb_ctrs {
 };
 
 /* Per CPU container for runtime CPPC management. */
-struct cpudata {
+struct cppc_cpudata {
 	int cpu;
 	struct cppc_perf_caps perf_caps;
 	struct cppc_perf_ctrls perf_ctrls;
@@ -132,7 +132,7 @@ struct cpudata {
 extern int cppc_get_perf_ctrs(int cpu, struct cppc_perf_fb_ctrs *perf_fb_ctrs);
 extern int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls);
 extern int cppc_get_perf_caps(int cpu, struct cppc_perf_caps *caps);
-extern int acpi_get_psd_map(struct cpudata **);
+extern int acpi_get_psd_map(struct cppc_cpudata **);
 extern unsigned int cppc_get_transition_latency(int cpu);
 
 #endif /* _CPPC_ACPI_H*/
-- 
2.7.4

Re: [PATCH v2 0/4] CPPC only changes for supporting ITMT 3.0

[Rafael J. Wysocki]

On Thursday, September 01, 2016 01:37:07 PM Srinivas Pandruvada wrote:
> This patchset is CPPC only changes from original "Support Intel® Turbo
> Boost Max Technology 3.0" series.
> 
> v2
> - Rebased on top of bleeding edge branch of Linux-pm git 
> - Instead of #ifdef in cppc_acpi using __weak attribute for
> functions implemented in arch/x86/kernel/acpi/
> - Removed integer support patch as this was already implemented
> in the latest code base
> - Instead of error return print warning on cppc probe failure
> 
> Srinivas Pandruvada (4):
>   acpi: cppc: Allow build with ACPI_CPU_FREQ_PSS config
>   acpi: cppc: Don't return on CPPC probe failure
>   acpi: cppc: Add support for functional fixed hardware address
>   acpi: cppc: Add prefix cppc to cpudata structure name

All applied.

Thanks,
Rafael