diff mbox

[v2,2/2] ARM64: kernel: PSCI: move PSCI idle management code to drivers/firmware

Message ID 1444648628-24790-3-git-send-email-lorenzo.pieralisi@arm.com (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Lorenzo Pieralisi Oct. 12, 2015, 11:17 a.m. UTC 
ARM64 PSCI kernel interfaces that initialize idle states and implement
the suspend API to enter them are generic and can be shared with the
ARM architecture.

To achieve that goal, this patch moves ARM64 PSCI idle management
code to drivers/firmware by creating a file that contains PSCI
helper functions implementing the common kernel interface required
by ARM and ARM64 to share the PSCI idle management code.

The ARM generic CPUidle implementation also requires the definition of
a cpuidle_ops section entry for the kernel to initialize the CPUidle
operations at boot based on the enable-method (ie ARM64 has the
statically initialized cpu_ops counterparts for that purpose); therefore
this patch also adds the required section entry on CONFIG_ARM for PSCI so
that the kernel can initialize the PSCI CPUidle back-end when PSCI is
the probed enable-method.

On ARM64 this patch provides no functional change.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Jisheng Zhang <jszhang@marvell.com>
---
 arch/arm64/kernel/psci.c       |  99 +-----------------------------
 drivers/firmware/Makefile      |   2 +-
 drivers/firmware/psci_cpuops.c | 133 +++++++++++++++++++++++++++++++++++++++++
 include/linux/psci.h           |   3 +
 4 files changed, 139 insertions(+), 98 deletions(-)
 create mode 100644 drivers/firmware/psci_cpuops.c

Comments

Mark Rutland Oct. 12, 2015, 2:29 p.m. UTC | #1 
Hi Lorenzo,

On Mon, Oct 12, 2015 at 12:17:08PM +0100, Lorenzo Pieralisi wrote:
> ARM64 PSCI kernel interfaces that initialize idle states and implement
> the suspend API to enter them are generic and can be shared with the
> ARM architecture.
> 
> To achieve that goal, this patch moves ARM64 PSCI idle management
> code to drivers/firmware by creating a file that contains PSCI
> helper functions implementing the common kernel interface required
> by ARM and ARM64 to share the PSCI idle management code.
> 
> The ARM generic CPUidle implementation also requires the definition of
> a cpuidle_ops section entry for the kernel to initialize the CPUidle
> operations at boot based on the enable-method (ie ARM64 has the
> statically initialized cpu_ops counterparts for that purpose); therefore
> this patch also adds the required section entry on CONFIG_ARM for PSCI so
> that the kernel can initialize the PSCI CPUidle back-end when PSCI is
> the probed enable-method.
> 
> On ARM64 this patch provides no functional change.
> 
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Sudeep Holla <sudeep.holla@arm.com>
> Cc: Russell King <linux@arm.linux.org.uk>
> Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Jisheng Zhang <jszhang@marvell.com>
> ---
>  arch/arm64/kernel/psci.c       |  99 +-----------------------------
>  drivers/firmware/Makefile      |   2 +-
>  drivers/firmware/psci_cpuops.c | 133 +++++++++++++++++++++++++++++++++++++++++

Do we really need the new file, given most of this lived happily in
psci.c previously?

> +#ifdef CONFIG_ARM
> +struct cpuidle_ops psci_cpuidle_ops __initdata = {
> +	.suspend = psci_cpu_suspend_enter,
> +	.init = psci_dt_cpu_init_idle,
> +};
> +
> +CPUIDLE_METHOD_OF_DECLARE(psci, "arm,psci", &psci_cpuidle_ops);
> +#endif

Don't these also need to be guarded for CONFIG_CPU_IDLE?

The definitions of cpuidle_ops and CPUIDLE_METHOD_OF_DECLARE in
arch/arm/include/asm/cpuidle.h depend on it.

Otherwise this looks fine to me.

Thanks,
Mark.
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Lorenzo Pieralisi Oct. 12, 2015, 3:12 p.m. UTC | #2 
Hi Mark,

On Mon, Oct 12, 2015 at 03:29:26PM +0100, Mark Rutland wrote:
> Hi Lorenzo,
> 
> On Mon, Oct 12, 2015 at 12:17:08PM +0100, Lorenzo Pieralisi wrote:
> > ARM64 PSCI kernel interfaces that initialize idle states and implement
> > the suspend API to enter them are generic and can be shared with the
> > ARM architecture.
> > 
> > To achieve that goal, this patch moves ARM64 PSCI idle management
> > code to drivers/firmware by creating a file that contains PSCI
> > helper functions implementing the common kernel interface required
> > by ARM and ARM64 to share the PSCI idle management code.
> > 
> > The ARM generic CPUidle implementation also requires the definition of
> > a cpuidle_ops section entry for the kernel to initialize the CPUidle
> > operations at boot based on the enable-method (ie ARM64 has the
> > statically initialized cpu_ops counterparts for that purpose); therefore
> > this patch also adds the required section entry on CONFIG_ARM for PSCI so
> > that the kernel can initialize the PSCI CPUidle back-end when PSCI is
> > the probed enable-method.
> > 
> > On ARM64 this patch provides no functional change.
> > 
> > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> > Cc: Will Deacon <will.deacon@arm.com>
> > Cc: Sudeep Holla <sudeep.holla@arm.com>
> > Cc: Russell King <linux@arm.linux.org.uk>
> > Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
> > Cc: Catalin Marinas <catalin.marinas@arm.com>
> > Cc: Mark Rutland <mark.rutland@arm.com>
> > Cc: Jisheng Zhang <jszhang@marvell.com>
> > ---
> >  arch/arm64/kernel/psci.c       |  99 +-----------------------------
> >  drivers/firmware/Makefile      |   2 +-
> >  drivers/firmware/psci_cpuops.c | 133 +++++++++++++++++++++++++++++++++++++++++
> 
> Do we really need the new file, given most of this lived happily in
> psci.c previously?

No, I thought we could separate the PSCI FW API (eg psci_cpu_suspend())
from helper functions that are basically a kernel glue layer (but we have
already helper functions in psci.c like psci_tos_resident_on() so..),
if we think it is fine to keep them in the same file I can move the
functions to psci.c.

> > +#ifdef CONFIG_ARM
> > +struct cpuidle_ops psci_cpuidle_ops __initdata = {
> > +	.suspend = psci_cpu_suspend_enter,
> > +	.init = psci_dt_cpu_init_idle,
> > +};
> > +
> > +CPUIDLE_METHOD_OF_DECLARE(psci, "arm,psci", &psci_cpuidle_ops);
> > +#endif
> 
> Don't these also need to be guarded for CONFIG_CPU_IDLE?
> 
> The definitions of cpuidle_ops and CPUIDLE_METHOD_OF_DECLARE in
> arch/arm/include/asm/cpuidle.h depend on it.

Not really, they are not guarded, the side effect of not having
a CONFIG_CPU_IDLE guard is just a struct that is compiled in
and freed after boot, I thought about that but I am tempted to leave
it as is to avoid further ifdeffery, I am not fussed either way.

> Otherwise this looks fine to me.

Great, I will prepare a v3 shortly.

Thanks !
Lorenzo
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Mark Rutland Oct. 12, 2015, 3:35 p.m. UTC | #3 
On Mon, Oct 12, 2015 at 04:12:20PM +0100, Lorenzo Pieralisi wrote:
> Hi Mark,
> 
> On Mon, Oct 12, 2015 at 03:29:26PM +0100, Mark Rutland wrote:
> > Hi Lorenzo,
> > 
> > On Mon, Oct 12, 2015 at 12:17:08PM +0100, Lorenzo Pieralisi wrote:
> > > ARM64 PSCI kernel interfaces that initialize idle states and implement
> > > the suspend API to enter them are generic and can be shared with the
> > > ARM architecture.
> > > 
> > > To achieve that goal, this patch moves ARM64 PSCI idle management
> > > code to drivers/firmware by creating a file that contains PSCI
> > > helper functions implementing the common kernel interface required
> > > by ARM and ARM64 to share the PSCI idle management code.
> > > 
> > > The ARM generic CPUidle implementation also requires the definition of
> > > a cpuidle_ops section entry for the kernel to initialize the CPUidle
> > > operations at boot based on the enable-method (ie ARM64 has the
> > > statically initialized cpu_ops counterparts for that purpose); therefore
> > > this patch also adds the required section entry on CONFIG_ARM for PSCI so
> > > that the kernel can initialize the PSCI CPUidle back-end when PSCI is
> > > the probed enable-method.
> > > 
> > > On ARM64 this patch provides no functional change.
> > > 
> > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> > > Cc: Will Deacon <will.deacon@arm.com>
> > > Cc: Sudeep Holla <sudeep.holla@arm.com>
> > > Cc: Russell King <linux@arm.linux.org.uk>
> > > Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
> > > Cc: Catalin Marinas <catalin.marinas@arm.com>
> > > Cc: Mark Rutland <mark.rutland@arm.com>
> > > Cc: Jisheng Zhang <jszhang@marvell.com>
> > > ---
> > >  arch/arm64/kernel/psci.c       |  99 +-----------------------------
> > >  drivers/firmware/Makefile      |   2 +-
> > >  drivers/firmware/psci_cpuops.c | 133 +++++++++++++++++++++++++++++++++++++++++
> > 
> > Do we really need the new file, given most of this lived happily in
> > psci.c previously?
> 
> No, I thought we could separate the PSCI FW API (eg psci_cpu_suspend())
> from helper functions that are basically a kernel glue layer (but we have
> already helper functions in psci.c like psci_tos_resident_on() so..),
> if we think it is fine to keep them in the same file I can move the
> functions to psci.c.

Ok. I guess I don't have strong feelings either way, but it seemed
simpler to keep them in the same file for now.

I understand your rationale, so either way I'm happy.

> > > +#ifdef CONFIG_ARM
> > > +struct cpuidle_ops psci_cpuidle_ops __initdata = {
> > > +	.suspend = psci_cpu_suspend_enter,
> > > +	.init = psci_dt_cpu_init_idle,
> > > +};
> > > +
> > > +CPUIDLE_METHOD_OF_DECLARE(psci, "arm,psci", &psci_cpuidle_ops);
> > > +#endif
> > 
> > Don't these also need to be guarded for CONFIG_CPU_IDLE?
> > 
> > The definitions of cpuidle_ops and CPUIDLE_METHOD_OF_DECLARE in
> > arch/arm/include/asm/cpuidle.h depend on it.
> 
> Not really, they are not guarded, the side effect of not having
> a CONFIG_CPU_IDLE guard is just a struct that is compiled in
> and freed after boot, I thought about that but I am tempted to leave
> it as is to avoid further ifdeffery, I am not fussed either way.

Whoops, I misread the gurards in arch/arm/include/asm/cpuidle.h. Sorry
for the noise!

Given the above, for this or a version with just psci.c:

Acked-by: Mark Rutland <mark.rutland@arm.com>

Thanks,
Mark.
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Catalin Marinas Oct. 12, 2015, 3:37 p.m. UTC | #4 
On Mon, Oct 12, 2015 at 12:17:08PM +0100, Lorenzo Pieralisi wrote:
> ARM64 PSCI kernel interfaces that initialize idle states and implement
> the suspend API to enter them are generic and can be shared with the
> ARM architecture.
> 
> To achieve that goal, this patch moves ARM64 PSCI idle management
> code to drivers/firmware by creating a file that contains PSCI
> helper functions implementing the common kernel interface required
> by ARM and ARM64 to share the PSCI idle management code.
> 
> The ARM generic CPUidle implementation also requires the definition of
> a cpuidle_ops section entry for the kernel to initialize the CPUidle
> operations at boot based on the enable-method (ie ARM64 has the
> statically initialized cpu_ops counterparts for that purpose); therefore
> this patch also adds the required section entry on CONFIG_ARM for PSCI so
> that the kernel can initialize the PSCI CPUidle back-end when PSCI is
> the probed enable-method.
> 
> On ARM64 this patch provides no functional change.
> 
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Sudeep Holla <sudeep.holla@arm.com>
> Cc: Russell King <linux@arm.linux.org.uk>
> Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Jisheng Zhang <jszhang@marvell.com>
> ---
>  arch/arm64/kernel/psci.c       |  99 +-----------------------------
>  drivers/firmware/Makefile      |   2 +-
>  drivers/firmware/psci_cpuops.c | 133 +++++++++++++++++++++++++++++++++++++++++
>  include/linux/psci.h           |   3 +

For the arch/arm64 part:

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
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diff mbox

Patch

diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c
index f67f35b..42816be 100644
--- a/arch/arm64/kernel/psci.c
+++ b/arch/arm64/kernel/psci.c
@@ -20,7 +20,6 @@ 
 #include <linux/smp.h>
 #include <linux/delay.h>
 #include <linux/psci.h>
-#include <linux/slab.h>
 
 #include <uapi/linux/psci.h>
 
@@ -28,73 +27,6 @@ 
 #include <asm/cpu_ops.h>
 #include <asm/errno.h>
 #include <asm/smp_plat.h>
-#include <asm/suspend.h>
-
-static DEFINE_PER_CPU_READ_MOSTLY(u32 *, psci_power_state);
-
-static int __maybe_unused cpu_psci_cpu_init_idle(unsigned int cpu)
-{
-	int i, ret, count = 0;
-	u32 *psci_states;
-	struct device_node *state_node, *cpu_node;
-
-	cpu_node = of_get_cpu_node(cpu, NULL);
-	if (!cpu_node)
-		return -ENODEV;
-
-	/*
-	 * If the PSCI cpu_suspend function hook has not been initialized
-	 * idle states must not be enabled, so bail out
-	 */
-	if (!psci_ops.cpu_suspend)
-		return -EOPNOTSUPP;
-
-	/* Count idle states */
-	while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states",
-					      count))) {
-		count++;
-		of_node_put(state_node);
-	}
-
-	if (!count)
-		return -ENODEV;
-
-	psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
-	if (!psci_states)
-		return -ENOMEM;
-
-	for (i = 0; i < count; i++) {
-		u32 state;
-
-		state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
-
-		ret = of_property_read_u32(state_node,
-					   "arm,psci-suspend-param",
-					   &state);
-		if (ret) {
-			pr_warn(" * %s missing arm,psci-suspend-param property\n",
-				state_node->full_name);
-			of_node_put(state_node);
-			goto free_mem;
-		}
-
-		of_node_put(state_node);
-		pr_debug("psci-power-state %#x index %d\n", state, i);
-		if (!psci_power_state_is_valid(state)) {
-			pr_warn("Invalid PSCI power state %#x\n", state);
-			ret = -EINVAL;
-			goto free_mem;
-		}
-		psci_states[i] = state;
-	}
-	/* Idle states parsed correctly, initialize per-cpu pointer */
-	per_cpu(psci_power_state, cpu) = psci_states;
-	return 0;
-
-free_mem:
-	kfree(psci_states);
-	return ret;
-}
 
 static int __init cpu_psci_cpu_init(unsigned int cpu)
 {
@@ -178,38 +110,11 @@  static int cpu_psci_cpu_kill(unsigned int cpu)
 }
 #endif
 
-static int psci_suspend_finisher(unsigned long index)
-{
-	u32 *state = __this_cpu_read(psci_power_state);
-
-	return psci_ops.cpu_suspend(state[index - 1],
-				    virt_to_phys(cpu_resume));
-}
-
-static int __maybe_unused cpu_psci_cpu_suspend(unsigned long index)
-{
-	int ret;
-	u32 *state = __this_cpu_read(psci_power_state);
-	/*
-	 * idle state index 0 corresponds to wfi, should never be called
-	 * from the cpu_suspend operations
-	 */
-	if (WARN_ON_ONCE(!index))
-		return -EINVAL;
-
-	if (!psci_power_state_loses_context(state[index - 1]))
-		ret = psci_ops.cpu_suspend(state[index - 1], 0);
-	else
-		ret = cpu_suspend(index, psci_suspend_finisher);
-
-	return ret;
-}
-
 const struct cpu_operations cpu_psci_ops = {
 	.name		= "psci",
 #ifdef CONFIG_CPU_IDLE
-	.cpu_init_idle	= cpu_psci_cpu_init_idle,
-	.cpu_suspend	= cpu_psci_cpu_suspend,
+	.cpu_init_idle	= psci_cpu_init_idle,
+	.cpu_suspend	= psci_cpu_suspend_enter,
 #endif
 	.cpu_init	= cpu_psci_cpu_init,
 	.cpu_prepare	= cpu_psci_cpu_prepare,
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 000830f..77553ab 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -1,7 +1,7 @@ 
 #
 # Makefile for the linux kernel.
 #
-obj-$(CONFIG_ARM_PSCI_FW)	+= psci.o
+obj-$(CONFIG_ARM_PSCI_FW)	+= psci.o psci_cpuops.o
 obj-$(CONFIG_DMI)		+= dmi_scan.o
 obj-$(CONFIG_DMI_SYSFS)		+= dmi-sysfs.o
 obj-$(CONFIG_EDD)		+= edd.o
diff --git a/drivers/firmware/psci_cpuops.c b/drivers/firmware/psci_cpuops.c
new file mode 100644
index 0000000..f9e68ab
--- /dev/null
+++ b/drivers/firmware/psci_cpuops.c
@@ -0,0 +1,133 @@ 
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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.
+ *
+ * Copyright (C) 2015 ARM Limited
+ */
+#include <linux/cpuidle.h>
+#include <linux/of.h>
+#include <linux/psci.h>
+#include <linux/slab.h>
+
+#include <asm/cpuidle.h>
+#include <asm/suspend.h>
+
+static DEFINE_PER_CPU_READ_MOSTLY(u32 *, psci_power_state);
+
+static int psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu)
+{
+	int i, ret, count = 0;
+	u32 *psci_states;
+	struct device_node *state_node;
+
+	/*
+	 * If the PSCI cpu_suspend function hook has not been initialized
+	 * idle states must not be enabled, so bail out
+	 */
+	if (!psci_ops.cpu_suspend)
+		return -EOPNOTSUPP;
+
+	/* Count idle states */
+	while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states",
+					      count))) {
+		count++;
+		of_node_put(state_node);
+	}
+
+	if (!count)
+		return -ENODEV;
+
+	psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
+	if (!psci_states)
+		return -ENOMEM;
+
+	for (i = 0; i < count; i++) {
+		u32 state;
+
+		state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
+
+		ret = of_property_read_u32(state_node,
+					   "arm,psci-suspend-param",
+					   &state);
+		if (ret) {
+			pr_warn(" * %s missing arm,psci-suspend-param property\n",
+				state_node->full_name);
+			of_node_put(state_node);
+			goto free_mem;
+		}
+
+		of_node_put(state_node);
+		pr_debug("psci-power-state %#x index %d\n", state, i);
+		if (!psci_power_state_is_valid(state)) {
+			pr_warn("Invalid PSCI power state %#x\n", state);
+			ret = -EINVAL;
+			goto free_mem;
+		}
+		psci_states[i] = state;
+	}
+	/* Idle states parsed correctly, initialize per-cpu pointer */
+	per_cpu(psci_power_state, cpu) = psci_states;
+	return 0;
+
+free_mem:
+	kfree(psci_states);
+	return ret;
+}
+
+int psci_cpu_init_idle(unsigned int cpu)
+{
+	struct device_node *cpu_node;
+	int ret;
+
+	cpu_node = of_get_cpu_node(cpu, NULL);
+	if (!cpu_node)
+		return -ENODEV;
+
+	ret = psci_dt_cpu_init_idle(cpu_node, cpu);
+
+	of_node_put(cpu_node);
+
+	return ret;
+}
+
+static int psci_suspend_finisher(unsigned long index)
+{
+	u32 *state = __this_cpu_read(psci_power_state);
+
+	return psci_ops.cpu_suspend(state[index - 1],
+				    virt_to_phys(cpu_resume));
+}
+
+int psci_cpu_suspend_enter(unsigned long index)
+{
+	int ret;
+	u32 *state = __this_cpu_read(psci_power_state);
+	/*
+	 * idle state index 0 corresponds to wfi, should never be called
+	 * from the cpu_suspend operations
+	 */
+	if (WARN_ON_ONCE(!index))
+		return -EINVAL;
+
+	if (!psci_power_state_loses_context(state[index - 1]))
+		ret = psci_ops.cpu_suspend(state[index - 1], 0);
+	else
+		ret = cpu_suspend(index, psci_suspend_finisher);
+
+	return ret;
+}
+
+#ifdef CONFIG_ARM
+struct cpuidle_ops psci_cpuidle_ops __initdata = {
+	.suspend = psci_cpu_suspend_enter,
+	.init = psci_dt_cpu_init_idle,
+};
+
+CPUIDLE_METHOD_OF_DECLARE(psci, "arm,psci", &psci_cpuidle_ops);
+#endif
diff --git a/include/linux/psci.h b/include/linux/psci.h
index 12c4865..393efe2 100644
--- a/include/linux/psci.h
+++ b/include/linux/psci.h
@@ -24,6 +24,9 @@  bool psci_tos_resident_on(int cpu);
 bool psci_power_state_loses_context(u32 state);
 bool psci_power_state_is_valid(u32 state);
 
+int psci_cpu_init_idle(unsigned int cpu);
+int psci_cpu_suspend_enter(unsigned long index);
+
 struct psci_operations {
 	int (*cpu_suspend)(u32 state, unsigned long entry_point);
 	int (*cpu_off)(u32 state);