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[kvm-unit-tests,8/8] arm/arm64: psci: don't assume method is hvc

Message ID 20210407185918.371983-9-drjones@redhat.com (mailing list archive)
State New
Headers show
Series arm/arm64: Prepare for target-efi | expand

Commit Message

Andrew Jones April 7, 2021, 6:59 p.m. UTC
The method can also be smc and it will be when running on bare metal.

Signed-off-by: Andrew Jones <drjones@redhat.com>
---
 arm/selftest.c     | 34 +++++++---------------------------
 lib/arm/asm/psci.h |  9 +++++++--
 lib/arm/psci.c     | 17 +++++++++++++++--
 lib/arm/setup.c    | 22 ++++++++++++++++++++++
 4 files changed, 51 insertions(+), 31 deletions(-)

Comments

Nikos Nikoleris April 9, 2021, 5:46 p.m. UTC | #1
On 07/04/2021 19:59, Andrew Jones wrote:
> The method can also be smc and it will be when running on bare metal.
> 
> Signed-off-by: Andrew Jones <drjones@redhat.com>
> ---
>   arm/selftest.c     | 34 +++++++---------------------------
>   lib/arm/asm/psci.h |  9 +++++++--
>   lib/arm/psci.c     | 17 +++++++++++++++--
>   lib/arm/setup.c    | 22 ++++++++++++++++++++++
>   4 files changed, 51 insertions(+), 31 deletions(-)
> 
> diff --git a/arm/selftest.c b/arm/selftest.c
> index 4495b161cdd5..9f459ed3d571 100644
> --- a/arm/selftest.c
> +++ b/arm/selftest.c
> @@ -400,33 +400,13 @@ static void check_vectors(void *arg __unused)
>   	exit(report_summary());
>   }
>   
> -static bool psci_check(void)
> +static void psci_print(void)
>   {
> -	const struct fdt_property *method;
> -	int node, len, ver;
> -
> -	node = fdt_node_offset_by_compatible(dt_fdt(), -1, "arm,psci-0.2");
> -	if (node < 0) {
> -		printf("PSCI v0.2 compatibility required\n");
> -		return false;
> -	}
> -
> -	method = fdt_get_property(dt_fdt(), node, "method", &len);
> -	if (method == NULL) {
> -		printf("bad psci device tree node\n");
> -		return false;
> -	}
> -
> -	if (len < 4 || strcmp(method->data, "hvc") != 0) {
> -		printf("psci method must be hvc\n");
> -		return false;
> -	}
> -
> -	ver = psci_invoke(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
> -	printf("PSCI version %d.%d\n", PSCI_VERSION_MAJOR(ver),
> -				       PSCI_VERSION_MINOR(ver));
> -
> -	return true;
> +	int ver = psci_invoke(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
> +	report_info("PSCI version: %d.%d", PSCI_VERSION_MAJOR(ver),
> +					  PSCI_VERSION_MINOR(ver));
> +	report_info("PSCI method: %s", psci_invoke == psci_invoke_hvc ?
> +				       "hvc" : "smc");
>   }
>   
>   static void cpu_report(void *data __unused)
> @@ -465,7 +445,7 @@ int main(int argc, char **argv)
>   
>   	} else if (strcmp(argv[1], "smp") == 0) {
>   
> -		report(psci_check(), "PSCI version");
> +		psci_print();
>   		on_cpus(cpu_report, NULL);
>   		while (!cpumask_full(&ready))
>   			cpu_relax();
> diff --git a/lib/arm/asm/psci.h b/lib/arm/asm/psci.h
> index 7b956bf5987d..e385ce27f5d1 100644
> --- a/lib/arm/asm/psci.h
> +++ b/lib/arm/asm/psci.h
> @@ -3,8 +3,13 @@
>   #include <libcflat.h>
>   #include <linux/psci.h>
>   
> -extern int psci_invoke(unsigned long function_id, unsigned long arg0,
> -		       unsigned long arg1, unsigned long arg2);
> +typedef int (*psci_invoke_fn)(unsigned long function_id, unsigned long arg0,
> +			      unsigned long arg1, unsigned long arg2);
> +extern psci_invoke_fn psci_invoke;
> +extern int psci_invoke_hvc(unsigned long function_id, unsigned long arg0,
> +			   unsigned long arg1, unsigned long arg2);
> +extern int psci_invoke_smc(unsigned long function_id, unsigned long arg0,
> +			   unsigned long arg1, unsigned long arg2);
>   extern int psci_cpu_on(unsigned long cpuid, unsigned long entry_point);
>   extern void psci_system_reset(void);
>   extern int cpu_psci_cpu_boot(unsigned int cpu);
> diff --git a/lib/arm/psci.c b/lib/arm/psci.c
> index 936c83948b6a..46300f30822c 100644
> --- a/lib/arm/psci.c
> +++ b/lib/arm/psci.c
> @@ -11,9 +11,11 @@
>   #include <asm/page.h>
>   #include <asm/smp.h>
>   
> +psci_invoke_fn psci_invoke;
> +
>   __attribute__((noinline))
> -int psci_invoke(unsigned long function_id, unsigned long arg0,
> -		unsigned long arg1, unsigned long arg2)
> +int psci_invoke_hvc(unsigned long function_id, unsigned long arg0,
> +		    unsigned long arg1, unsigned long arg2)
>   {
>   	asm volatile(
>   		"hvc #0"
> @@ -22,6 +24,17 @@ int psci_invoke(unsigned long function_id, unsigned long arg0,
>   	return function_id;
>   }
>   
> +__attribute__((noinline))

Is noinline necessary? We shouldn't be calling psci_invoke_smc and 
psci_invoke_hmc directly, it's unlikely that the compiler will have a 
chance to inline them. But I might be missing something here because I 
don't see why it was there in psci_invoke either.

Otherwise Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>

Thanks,

Nikos

> +int psci_invoke_smc(unsigned long function_id, unsigned long arg0,
> +		    unsigned long arg1, unsigned long arg2)
> +{
> +	asm volatile(
> +		"smc #0"
> +	: "+r" (function_id)
> +	: "r" (arg0), "r" (arg1), "r" (arg2));
> +	return function_id;
> +}
> +
>   int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
>   {
>   #ifdef __arm__
> diff --git a/lib/arm/setup.c b/lib/arm/setup.c
> index 5cda2d919d2b..e595a9e5a167 100644
> --- a/lib/arm/setup.c
> +++ b/lib/arm/setup.c
> @@ -25,6 +25,7 @@
>   #include <asm/processor.h>
>   #include <asm/smp.h>
>   #include <asm/timer.h>
> +#include <asm/psci.h>
>   
>   #include "io.h"
>   
> @@ -55,6 +56,26 @@ int mpidr_to_cpu(uint64_t mpidr)
>   	return -1;
>   }
>   
> +static void psci_set_conduit(void)
> +{
> +	const void *fdt = dt_fdt();
> +	const struct fdt_property *method;
> +	int node, len;
> +
> +	node = fdt_node_offset_by_compatible(fdt, -1, "arm,psci-0.2");
> +	assert_msg(node >= 0, "PSCI v0.2 compatibility required");
> +
> +	method = fdt_get_property(fdt, node, "method", &len);
> +	assert(method != NULL && len == 4);
> +
> +	if (strcmp(method->data, "hvc") == 0)
> +		psci_invoke = psci_invoke_hvc;
> +	else if (strcmp(method->data, "smc") == 0)
> +		psci_invoke = psci_invoke_smc;
> +	else
> +		assert_msg(false, "Unknown PSCI conduit: %s", method->data);
> +}
> +
>   static void cpu_set(int fdtnode __unused, u64 regval, void *info __unused)
>   {
>   	int cpu = nr_cpus++;
> @@ -259,6 +280,7 @@ void setup(const void *fdt, phys_addr_t freemem_start)
>   	mem_regions_add_assumed();
>   	mem_init(PAGE_ALIGN((unsigned long)freemem));
>   
> +	psci_set_conduit();
>   	cpu_init();
>   
>   	/* cpu_init must be called before thread_info_init */
>
Andrew Jones April 14, 2021, 9:06 a.m. UTC | #2
On Fri, Apr 09, 2021 at 10:46:33AM -0700, Nikos Nikoleris wrote:
> On 07/04/2021 19:59, Andrew Jones wrote:
> > The method can also be smc and it will be when running on bare metal.
> > 
> > Signed-off-by: Andrew Jones <drjones@redhat.com>
> > ---
> >   arm/selftest.c     | 34 +++++++---------------------------
> >   lib/arm/asm/psci.h |  9 +++++++--
> >   lib/arm/psci.c     | 17 +++++++++++++++--
> >   lib/arm/setup.c    | 22 ++++++++++++++++++++++
> >   4 files changed, 51 insertions(+), 31 deletions(-)
> > 
> > diff --git a/arm/selftest.c b/arm/selftest.c
> > index 4495b161cdd5..9f459ed3d571 100644
> > --- a/arm/selftest.c
> > +++ b/arm/selftest.c
> > @@ -400,33 +400,13 @@ static void check_vectors(void *arg __unused)
> >   	exit(report_summary());
> >   }
> > -static bool psci_check(void)
> > +static void psci_print(void)
> >   {
> > -	const struct fdt_property *method;
> > -	int node, len, ver;
> > -
> > -	node = fdt_node_offset_by_compatible(dt_fdt(), -1, "arm,psci-0.2");
> > -	if (node < 0) {
> > -		printf("PSCI v0.2 compatibility required\n");
> > -		return false;
> > -	}
> > -
> > -	method = fdt_get_property(dt_fdt(), node, "method", &len);
> > -	if (method == NULL) {
> > -		printf("bad psci device tree node\n");
> > -		return false;
> > -	}
> > -
> > -	if (len < 4 || strcmp(method->data, "hvc") != 0) {
> > -		printf("psci method must be hvc\n");
> > -		return false;
> > -	}
> > -
> > -	ver = psci_invoke(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
> > -	printf("PSCI version %d.%d\n", PSCI_VERSION_MAJOR(ver),
> > -				       PSCI_VERSION_MINOR(ver));
> > -
> > -	return true;
> > +	int ver = psci_invoke(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
> > +	report_info("PSCI version: %d.%d", PSCI_VERSION_MAJOR(ver),
> > +					  PSCI_VERSION_MINOR(ver));
> > +	report_info("PSCI method: %s", psci_invoke == psci_invoke_hvc ?
> > +				       "hvc" : "smc");
> >   }
> >   static void cpu_report(void *data __unused)
> > @@ -465,7 +445,7 @@ int main(int argc, char **argv)
> >   	} else if (strcmp(argv[1], "smp") == 0) {
> > -		report(psci_check(), "PSCI version");
> > +		psci_print();
> >   		on_cpus(cpu_report, NULL);
> >   		while (!cpumask_full(&ready))
> >   			cpu_relax();
> > diff --git a/lib/arm/asm/psci.h b/lib/arm/asm/psci.h
> > index 7b956bf5987d..e385ce27f5d1 100644
> > --- a/lib/arm/asm/psci.h
> > +++ b/lib/arm/asm/psci.h
> > @@ -3,8 +3,13 @@
> >   #include <libcflat.h>
> >   #include <linux/psci.h>
> > -extern int psci_invoke(unsigned long function_id, unsigned long arg0,
> > -		       unsigned long arg1, unsigned long arg2);
> > +typedef int (*psci_invoke_fn)(unsigned long function_id, unsigned long arg0,
> > +			      unsigned long arg1, unsigned long arg2);
> > +extern psci_invoke_fn psci_invoke;
> > +extern int psci_invoke_hvc(unsigned long function_id, unsigned long arg0,
> > +			   unsigned long arg1, unsigned long arg2);
> > +extern int psci_invoke_smc(unsigned long function_id, unsigned long arg0,
> > +			   unsigned long arg1, unsigned long arg2);
> >   extern int psci_cpu_on(unsigned long cpuid, unsigned long entry_point);
> >   extern void psci_system_reset(void);
> >   extern int cpu_psci_cpu_boot(unsigned int cpu);
> > diff --git a/lib/arm/psci.c b/lib/arm/psci.c
> > index 936c83948b6a..46300f30822c 100644
> > --- a/lib/arm/psci.c
> > +++ b/lib/arm/psci.c
> > @@ -11,9 +11,11 @@
> >   #include <asm/page.h>
> >   #include <asm/smp.h>
> > +psci_invoke_fn psci_invoke;
> > +
> >   __attribute__((noinline))
> > -int psci_invoke(unsigned long function_id, unsigned long arg0,
> > -		unsigned long arg1, unsigned long arg2)
> > +int psci_invoke_hvc(unsigned long function_id, unsigned long arg0,
> > +		    unsigned long arg1, unsigned long arg2)
> >   {
> >   	asm volatile(
> >   		"hvc #0"
> > @@ -22,6 +24,17 @@ int psci_invoke(unsigned long function_id, unsigned long arg0,
> >   	return function_id;
> >   }
> > +__attribute__((noinline))
> 
> Is noinline necessary? We shouldn't be calling psci_invoke_smc and
> psci_invoke_hmc directly, it's unlikely that the compiler will have a chance
> to inline them. But I might be missing something here because I don't see
> why it was there in psci_invoke either.

The noinline ensures that function_id,arg0,arg1,arg2 are in r0-r3 without
us having to do something like

 "mov r0, %0"
 "mov r1, %1"
 "mov r2, %2"
 "mov r3, %3"

in the asm().

> 
> Otherwise Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>

Thanks!
drew
Alexandru Elisei April 19, 2021, 4:33 p.m. UTC | #3
Hi Drew,

On 4/7/21 7:59 PM, Andrew Jones wrote:
> The method can also be smc and it will be when running on bare metal.
>
> Signed-off-by: Andrew Jones <drjones@redhat.com>
> ---
>  arm/selftest.c     | 34 +++++++---------------------------
>  lib/arm/asm/psci.h |  9 +++++++--
>  lib/arm/psci.c     | 17 +++++++++++++++--
>  lib/arm/setup.c    | 22 ++++++++++++++++++++++
>  4 files changed, 51 insertions(+), 31 deletions(-)
>
> diff --git a/arm/selftest.c b/arm/selftest.c
> index 4495b161cdd5..9f459ed3d571 100644
> --- a/arm/selftest.c
> +++ b/arm/selftest.c
> @@ -400,33 +400,13 @@ static void check_vectors(void *arg __unused)
>  	exit(report_summary());
>  }
>  
> -static bool psci_check(void)
> +static void psci_print(void)
>  {
> -	const struct fdt_property *method;
> -	int node, len, ver;
> -
> -	node = fdt_node_offset_by_compatible(dt_fdt(), -1, "arm,psci-0.2");
> -	if (node < 0) {
> -		printf("PSCI v0.2 compatibility required\n");
> -		return false;
> -	}
> -
> -	method = fdt_get_property(dt_fdt(), node, "method", &len);
> -	if (method == NULL) {
> -		printf("bad psci device tree node\n");
> -		return false;
> -	}
> -
> -	if (len < 4 || strcmp(method->data, "hvc") != 0) {
> -		printf("psci method must be hvc\n");
> -		return false;
> -	}
> -
> -	ver = psci_invoke(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
> -	printf("PSCI version %d.%d\n", PSCI_VERSION_MAJOR(ver),
> -				       PSCI_VERSION_MINOR(ver));
> -
> -	return true;
> +	int ver = psci_invoke(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
> +	report_info("PSCI version: %d.%d", PSCI_VERSION_MAJOR(ver),
> +					  PSCI_VERSION_MINOR(ver));
> +	report_info("PSCI method: %s", psci_invoke == psci_invoke_hvc ?
> +				       "hvc" : "smc");
>  }
>  
>  static void cpu_report(void *data __unused)
> @@ -465,7 +445,7 @@ int main(int argc, char **argv)
>  
>  	} else if (strcmp(argv[1], "smp") == 0) {
>  
> -		report(psci_check(), "PSCI version");
> +		psci_print();
>  		on_cpus(cpu_report, NULL);
>  		while (!cpumask_full(&ready))
>  			cpu_relax();
> diff --git a/lib/arm/asm/psci.h b/lib/arm/asm/psci.h
> index 7b956bf5987d..e385ce27f5d1 100644
> --- a/lib/arm/asm/psci.h
> +++ b/lib/arm/asm/psci.h
> @@ -3,8 +3,13 @@
>  #include <libcflat.h>
>  #include <linux/psci.h>
>  
> -extern int psci_invoke(unsigned long function_id, unsigned long arg0,
> -		       unsigned long arg1, unsigned long arg2);
> +typedef int (*psci_invoke_fn)(unsigned long function_id, unsigned long arg0,

function_id is 32bits. sizeof(unsigned long) is 64 bits for arm64.

> +			      unsigned long arg1, unsigned long arg2);
> +extern psci_invoke_fn psci_invoke;
> +extern int psci_invoke_hvc(unsigned long function_id, unsigned long arg0,
> +			   unsigned long arg1, unsigned long arg2);
> +extern int psci_invoke_smc(unsigned long function_id, unsigned long arg0,
> +			   unsigned long arg1, unsigned long arg2);
>  extern int psci_cpu_on(unsigned long cpuid, unsigned long entry_point);
>  extern void psci_system_reset(void);
>  extern int cpu_psci_cpu_boot(unsigned int cpu);
> diff --git a/lib/arm/psci.c b/lib/arm/psci.c
> index 936c83948b6a..46300f30822c 100644
> --- a/lib/arm/psci.c
> +++ b/lib/arm/psci.c
> @@ -11,9 +11,11 @@
>  #include <asm/page.h>
>  #include <asm/smp.h>
>  
> +psci_invoke_fn psci_invoke;

In setup(), we set the conduit after we call assert() several time. If the asert()
fails, then psci_system_off() will end up calling a NULL function. Maybe there
should be some sort of check for that?

> +
>  __attribute__((noinline))
> -int psci_invoke(unsigned long function_id, unsigned long arg0,
> -		unsigned long arg1, unsigned long arg2)
> +int psci_invoke_hvc(unsigned long function_id, unsigned long arg0,
> +		    unsigned long arg1, unsigned long arg2)
>  {
>  	asm volatile(
>  		"hvc #0"
> @@ -22,6 +24,17 @@ int psci_invoke(unsigned long function_id, unsigned long arg0,
>  	return function_id;
>  }
>  
> +__attribute__((noinline))
> +int psci_invoke_smc(unsigned long function_id, unsigned long arg0,
> +		    unsigned long arg1, unsigned long arg2)
> +{
> +	asm volatile(
> +		"smc #0"
> +	: "+r" (function_id)
> +	: "r" (arg0), "r" (arg1), "r" (arg2));
> +	return function_id;

I haven't been able to figure out what prevents the compiler from shuffling the
arguments around before executing the inline assembly, such that x0-x3 doesn't
contain the arguments in the order we are expecting.

Some excerpts from the extended asm help page [1] that make me believe that the
compiler doesn't provide any guarantees:

"If you must use a specific register, but your Machine Constraints do not provide
sufficient control to select the specific register you want, local register
variables may provide a solution"

"Using the generic ‘r’ constraint instead of a constraint for a specific register
allows the compiler to pick the register to use, which can result in more
efficient code."

Same with psci_invoke_hvc(). Doing both in assembly (like Linux) should be
sufficient and fairly straightforward.

[1] https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Extended-Asm

> +}
> +
>  int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
>  {
>  #ifdef __arm__
> diff --git a/lib/arm/setup.c b/lib/arm/setup.c
> index 5cda2d919d2b..e595a9e5a167 100644
> --- a/lib/arm/setup.c
> +++ b/lib/arm/setup.c
> @@ -25,6 +25,7 @@
>  #include <asm/processor.h>
>  #include <asm/smp.h>
>  #include <asm/timer.h>
> +#include <asm/psci.h>
>  
>  #include "io.h"
>  
> @@ -55,6 +56,26 @@ int mpidr_to_cpu(uint64_t mpidr)
>  	return -1;
>  }
>  
> +static void psci_set_conduit(void)
> +{
> +	const void *fdt = dt_fdt();
> +	const struct fdt_property *method;
> +	int node, len;
> +
> +	node = fdt_node_offset_by_compatible(fdt, -1, "arm,psci-0.2");
> +	assert_msg(node >= 0, "PSCI v0.2 compatibility required");
> +
> +	method = fdt_get_property(fdt, node, "method", &len);
> +	assert(method != NULL && len == 4);
> +
> +	if (strcmp(method->data, "hvc") == 0)
> +		psci_invoke = psci_invoke_hvc;
> +	else if (strcmp(method->data, "smc") == 0)
> +		psci_invoke = psci_invoke_smc;
> +	else
> +		assert_msg(false, "Unknown PSCI conduit: %s", method->data);
> +}

Any particular reason for doing this here instead of in psci.c? This looks like
something that belongs to that file, but that might just be my personal preference.

Thanks,

Alex

> +
>  static void cpu_set(int fdtnode __unused, u64 regval, void *info __unused)
>  {
>  	int cpu = nr_cpus++;
> @@ -259,6 +280,7 @@ void setup(const void *fdt, phys_addr_t freemem_start)
>  	mem_regions_add_assumed();
>  	mem_init(PAGE_ALIGN((unsigned long)freemem));
>  
> +	psci_set_conduit();
>  	cpu_init();
>  
>  	/* cpu_init must be called before thread_info_init */
Andrew Jones April 19, 2021, 6:13 p.m. UTC | #4
On Mon, Apr 19, 2021 at 05:33:37PM +0100, Alexandru Elisei wrote:
> On 4/7/21 7:59 PM, Andrew Jones wrote:
> > +psci_invoke_fn psci_invoke;
> 
> In setup(), we set the conduit after we call assert() several time. If the asert()
> fails, then psci_system_off() will end up calling a NULL function. Maybe there
> should be some sort of check for that?

I can initialize psci_invoke to something that will fail in a more obvious
manner.

> 
> > +
> >  __attribute__((noinline))
> > -int psci_invoke(unsigned long function_id, unsigned long arg0,
> > -		unsigned long arg1, unsigned long arg2)
> > +int psci_invoke_hvc(unsigned long function_id, unsigned long arg0,
> > +		    unsigned long arg1, unsigned long arg2)
> >  {
> >  	asm volatile(
> >  		"hvc #0"
> > @@ -22,6 +24,17 @@ int psci_invoke(unsigned long function_id, unsigned long arg0,
> >  	return function_id;
> >  }
> >  
> > +__attribute__((noinline))
> > +int psci_invoke_smc(unsigned long function_id, unsigned long arg0,
> > +		    unsigned long arg1, unsigned long arg2)
> > +{
> > +	asm volatile(
> > +		"smc #0"
> > +	: "+r" (function_id)
> > +	: "r" (arg0), "r" (arg1), "r" (arg2));
> > +	return function_id;
> 
> I haven't been able to figure out what prevents the compiler from shuffling the
> arguments around before executing the inline assembly, such that x0-x3 doesn't
> contain the arguments in the order we are expecting.

We know the arguments will be in r0-r3 because of the noinline and that
shuffling them wouldn't make much sense, but I agree that this is in the
realm of [too] fragile assumptions.

> 
> Some excerpts from the extended asm help page [1] that make me believe that the
> compiler doesn't provide any guarantees:
> 
> "If you must use a specific register, but your Machine Constraints do not provide
> sufficient control to select the specific register you want, local register
> variables may provide a solution"
> 
> "Using the generic ‘r’ constraint instead of a constraint for a specific register
> allows the compiler to pick the register to use, which can result in more
> efficient code."
> 
> Same with psci_invoke_hvc(). Doing both in assembly (like Linux) should be
> sufficient and fairly straightforward.

OK, I'll just use assembly to avoid the assumptions.

> 
> [1] https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Extended-Asm
> 
> > +}
> > +
> >  int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
> >  {
> >  #ifdef __arm__
> > diff --git a/lib/arm/setup.c b/lib/arm/setup.c
> > index 5cda2d919d2b..e595a9e5a167 100644
> > --- a/lib/arm/setup.c
> > +++ b/lib/arm/setup.c
> > @@ -25,6 +25,7 @@
> >  #include <asm/processor.h>
> >  #include <asm/smp.h>
> >  #include <asm/timer.h>
> > +#include <asm/psci.h>
> >  
> >  #include "io.h"
> >  
> > @@ -55,6 +56,26 @@ int mpidr_to_cpu(uint64_t mpidr)
> >  	return -1;
> >  }
> >  
> > +static void psci_set_conduit(void)
> > +{
> > +	const void *fdt = dt_fdt();
> > +	const struct fdt_property *method;
> > +	int node, len;
> > +
> > +	node = fdt_node_offset_by_compatible(fdt, -1, "arm,psci-0.2");
> > +	assert_msg(node >= 0, "PSCI v0.2 compatibility required");
> > +
> > +	method = fdt_get_property(fdt, node, "method", &len);
> > +	assert(method != NULL && len == 4);
> > +
> > +	if (strcmp(method->data, "hvc") == 0)
> > +		psci_invoke = psci_invoke_hvc;
> > +	else if (strcmp(method->data, "smc") == 0)
> > +		psci_invoke = psci_invoke_smc;
> > +	else
> > +		assert_msg(false, "Unknown PSCI conduit: %s", method->data);
> > +}
> 
> Any particular reason for doing this here instead of in psci.c? This looks like
> something that belongs to that file, but that might just be my personal preference.

I don't have a strong preference on this, so I'll move it.

Thanks,
drew
diff mbox series

Patch

diff --git a/arm/selftest.c b/arm/selftest.c
index 4495b161cdd5..9f459ed3d571 100644
--- a/arm/selftest.c
+++ b/arm/selftest.c
@@ -400,33 +400,13 @@  static void check_vectors(void *arg __unused)
 	exit(report_summary());
 }
 
-static bool psci_check(void)
+static void psci_print(void)
 {
-	const struct fdt_property *method;
-	int node, len, ver;
-
-	node = fdt_node_offset_by_compatible(dt_fdt(), -1, "arm,psci-0.2");
-	if (node < 0) {
-		printf("PSCI v0.2 compatibility required\n");
-		return false;
-	}
-
-	method = fdt_get_property(dt_fdt(), node, "method", &len);
-	if (method == NULL) {
-		printf("bad psci device tree node\n");
-		return false;
-	}
-
-	if (len < 4 || strcmp(method->data, "hvc") != 0) {
-		printf("psci method must be hvc\n");
-		return false;
-	}
-
-	ver = psci_invoke(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
-	printf("PSCI version %d.%d\n", PSCI_VERSION_MAJOR(ver),
-				       PSCI_VERSION_MINOR(ver));
-
-	return true;
+	int ver = psci_invoke(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
+	report_info("PSCI version: %d.%d", PSCI_VERSION_MAJOR(ver),
+					  PSCI_VERSION_MINOR(ver));
+	report_info("PSCI method: %s", psci_invoke == psci_invoke_hvc ?
+				       "hvc" : "smc");
 }
 
 static void cpu_report(void *data __unused)
@@ -465,7 +445,7 @@  int main(int argc, char **argv)
 
 	} else if (strcmp(argv[1], "smp") == 0) {
 
-		report(psci_check(), "PSCI version");
+		psci_print();
 		on_cpus(cpu_report, NULL);
 		while (!cpumask_full(&ready))
 			cpu_relax();
diff --git a/lib/arm/asm/psci.h b/lib/arm/asm/psci.h
index 7b956bf5987d..e385ce27f5d1 100644
--- a/lib/arm/asm/psci.h
+++ b/lib/arm/asm/psci.h
@@ -3,8 +3,13 @@ 
 #include <libcflat.h>
 #include <linux/psci.h>
 
-extern int psci_invoke(unsigned long function_id, unsigned long arg0,
-		       unsigned long arg1, unsigned long arg2);
+typedef int (*psci_invoke_fn)(unsigned long function_id, unsigned long arg0,
+			      unsigned long arg1, unsigned long arg2);
+extern psci_invoke_fn psci_invoke;
+extern int psci_invoke_hvc(unsigned long function_id, unsigned long arg0,
+			   unsigned long arg1, unsigned long arg2);
+extern int psci_invoke_smc(unsigned long function_id, unsigned long arg0,
+			   unsigned long arg1, unsigned long arg2);
 extern int psci_cpu_on(unsigned long cpuid, unsigned long entry_point);
 extern void psci_system_reset(void);
 extern int cpu_psci_cpu_boot(unsigned int cpu);
diff --git a/lib/arm/psci.c b/lib/arm/psci.c
index 936c83948b6a..46300f30822c 100644
--- a/lib/arm/psci.c
+++ b/lib/arm/psci.c
@@ -11,9 +11,11 @@ 
 #include <asm/page.h>
 #include <asm/smp.h>
 
+psci_invoke_fn psci_invoke;
+
 __attribute__((noinline))
-int psci_invoke(unsigned long function_id, unsigned long arg0,
-		unsigned long arg1, unsigned long arg2)
+int psci_invoke_hvc(unsigned long function_id, unsigned long arg0,
+		    unsigned long arg1, unsigned long arg2)
 {
 	asm volatile(
 		"hvc #0"
@@ -22,6 +24,17 @@  int psci_invoke(unsigned long function_id, unsigned long arg0,
 	return function_id;
 }
 
+__attribute__((noinline))
+int psci_invoke_smc(unsigned long function_id, unsigned long arg0,
+		    unsigned long arg1, unsigned long arg2)
+{
+	asm volatile(
+		"smc #0"
+	: "+r" (function_id)
+	: "r" (arg0), "r" (arg1), "r" (arg2));
+	return function_id;
+}
+
 int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
 {
 #ifdef __arm__
diff --git a/lib/arm/setup.c b/lib/arm/setup.c
index 5cda2d919d2b..e595a9e5a167 100644
--- a/lib/arm/setup.c
+++ b/lib/arm/setup.c
@@ -25,6 +25,7 @@ 
 #include <asm/processor.h>
 #include <asm/smp.h>
 #include <asm/timer.h>
+#include <asm/psci.h>
 
 #include "io.h"
 
@@ -55,6 +56,26 @@  int mpidr_to_cpu(uint64_t mpidr)
 	return -1;
 }
 
+static void psci_set_conduit(void)
+{
+	const void *fdt = dt_fdt();
+	const struct fdt_property *method;
+	int node, len;
+
+	node = fdt_node_offset_by_compatible(fdt, -1, "arm,psci-0.2");
+	assert_msg(node >= 0, "PSCI v0.2 compatibility required");
+
+	method = fdt_get_property(fdt, node, "method", &len);
+	assert(method != NULL && len == 4);
+
+	if (strcmp(method->data, "hvc") == 0)
+		psci_invoke = psci_invoke_hvc;
+	else if (strcmp(method->data, "smc") == 0)
+		psci_invoke = psci_invoke_smc;
+	else
+		assert_msg(false, "Unknown PSCI conduit: %s", method->data);
+}
+
 static void cpu_set(int fdtnode __unused, u64 regval, void *info __unused)
 {
 	int cpu = nr_cpus++;
@@ -259,6 +280,7 @@  void setup(const void *fdt, phys_addr_t freemem_start)
 	mem_regions_add_assumed();
 	mem_init(PAGE_ALIGN((unsigned long)freemem));
 
+	psci_set_conduit();
 	cpu_init();
 
 	/* cpu_init must be called before thread_info_init */