On Wed, Aug 10, 2016 at 11:59:36AM +1000, Suraj Jitindar Singh wrote:
> Add the lib/powerpc/smp.c file and associated header files as a place
> to implement generic smp functionality for inclusion in tests.
>
> Add functions start_all_cpus(), start_cpu() and start_thread() to start
> all stopped threads of all cpus, all stopped threads of a single cpu or a
> single stopped thread of a guest at a given execution location,
> respectively.
>
> Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@xxxxxxxxx>
> ---
> lib/powerpc/asm/smp.h | 15 +++++++
> lib/powerpc/smp.c | 115 ++++++++++++++++++++++++++++++++++++++++++++++++
> lib/ppc64/asm/smp.h | 1 +
> powerpc/Makefile.common | 1 +
> 4 files changed, 132 insertions(+)
> create mode 100644 lib/powerpc/asm/smp.h
> create mode 100644 lib/powerpc/smp.c
> create mode 100644 lib/ppc64/asm/smp.h
>
> diff --git a/lib/powerpc/asm/smp.h b/lib/powerpc/asm/smp.h
> new file mode 100644
> index 0000000..a4f3e7f
> --- /dev/null
> +++ b/lib/powerpc/asm/smp.h
> @@ -0,0 +1,15 @@
> +#ifndef _ASMPOWERPC_SMP_H_
> +#define _ASMPOWERPC_SMP_H_
> +
> +#include <libcflat.h>
> +#include <stdint.h>
nit: no need to include stdint.h, libcflat.h already does, so most
files neglect it.
> +
> +typedef void (*secondary_entry_fn)(void);
> +
> +extern void halt(void);
> +
> +bool start_thread(int cpu_id, secondary_entry_fn entry, uint32_t r3);
> +bool start_cpu(int cpu_node, secondary_entry_fn entry, uint32_t r3);
> +bool start_all_cpus(secondary_entry_fn entry, uint32_t r3);
nit: kvm-unit-tests likes to use 'extern' on function declarations
> +
> +#endif /* _ASMPOWERPC_SMP_H_ */
> diff --git a/lib/powerpc/smp.c b/lib/powerpc/smp.c
> new file mode 100644
> index 0000000..8968907
> --- /dev/null
> +++ b/lib/powerpc/smp.c
> @@ -0,0 +1,115 @@
> +/*
> + * Secondary cpu support
> + *
> + * Copyright 2016 Suraj Jitindar Singh, IBM.
> + *
> + * This work is licensed under the terms of the GNU LGPL, version 2.
> + */
> +
> +#include <stdint.h>
same nit as above
> +#include <libfdt/libfdt.h>
> +#include <libfdt/fdt.h>
nit: only need libfdt/libfdt.h, as that includes fdt.h
> +#include <devicetree.h>
> +#include <libcflat.h>
> +#include <string.h>
> +#include <asm/rtas.h>
> +#include <asm/smp.h>
> +
> +struct secondary_entry_data {
> + secondary_entry_fn entry;
> + uint64_t r3;
> + bool init_failed;
> +};
> +
> +/*
> + * Start stopped thread cpu_id at entry
> + * Returns: 1 on success or cpu not in stopped state
> + * 0 on failure to start stopped cpu
Returns: TRUE ...
FALSE ...
> + *
> + * Note: This function returns 1 on success in starting a stopped cpu or if the
returns true
> + * given cpu was not in the stopped state. Thus this can be called on a
> + * list of cpus and all the stopped ones will be started while false
> + * won't be returned if some cpus in that list were already running. Thus
> + * the user should check that cpus passed to this function are already in
> + * the stopped state if they want to guarantee that a return value of
> + * true corresponds to the given cpu now executing at entry. This
> + * function checks again however as calling cpu-start on a not stopped
> + * cpu results in undefined behaviour.
> + */
> +bool start_thread(int cpu_id, secondary_entry_fn entry, uint32_t r3)
> +{
> + int query_token, start_token, outputs[1], ret;
> +
> + query_token = rtas_token("query-cpu-stopped-state");
> + start_token = rtas_token("start-cpu");
> + assert(query_token != RTAS_UNKNOWN_SERVICE &&
> + start_token != RTAS_UNKNOWN_SERVICE);
> +
> + ret = rtas_call(query_token, 1, 2, outputs, cpu_id);
> + if (ret) {
> + printf("query-cpu-stopped-state failed for cpu %d\n", cpu_id);
> + return false;
> + }
> +
> + if (!outputs[0]) { /* cpu in stopped state */
> + ret = rtas_call(start_token, 3, 1, NULL, cpu_id, entry, r3);
> + if (ret) {
> + printf("failed to start cpu %d\n", cpu_id);
> + return false;
> + }
> + }
> +
> + return true;
> +}
> +
> +/*
> + * Start all stopped threads (vcpus) on cpu_node
> + * Returns: 1 on success
> + * 0 on failure
TRUE/FALSE, but I'd actually change the return type to struct start_threads;
struct start_threads {
int nr_threads;
int nr_started;
};
Then...
> + */
> +bool start_cpu(int cpu_node, secondary_entry_fn entry, uint32_t r3)
> +{
> + const struct fdt_property *prop;
> + int len, nr_cpu, cpu;
> + u32 *cpus;
> + bool ret = true;
> +
> + /* Get the id array of threads on this cpu_node */
> + prop = fdt_get_property(dt_fdt(), cpu_node,
> + "ibm,ppc-interrupt-server#s", &len);
> + assert(prop);
> +
> + nr_cpu = len >> 2; /* Divide by 4 since 4 bytes per cpu */
> + cpus = (u32 *)prop->data; /* Array of valid cpu numbers */
> +
> + for (cpu = 0; cpu < nr_cpu && ret; cpu++)
> + ret = start_thread(fdt32_to_cpu(cpus[cpu]), entry, r3);
> + return ret;
...change this to
nr_threads = len >> 2; /* Divide by 4 since 4 bytes per cpu */
cpus = (u32 *)prop->data; /* Array of valid cpu numbers */
for (cpu = 0; cpu < nr_threads; cpu++)
nr_started += start_thread(fdt32_to_cpu(cpus[cpu]), entry, r3);
return (struct start_threads){ nr_threads, nr_started };
and...
> +}
> +
> +static void start_each_secondary(int fdtnode, u32 regval __unused, void *info)
> +{
> + struct secondary_entry_data *datap = info;
> +
> + datap->init_failed |= !start_cpu(fdtnode, datap->entry, datap->r3);
> +}
...change init_failed to nr_started
start_threads = start_cpu(fdtnode, datap->entry, datap->r3);
nr_cpus += start_threads.nr_threads; // nr_cpus is global like ARM has
datap->nr_started += start_threads.nr_started;
and below just check that datap->nr_started == nr_cpus.
> +
> +/*
> + * Start all stopped cpus on the guest at entry with register 3 set to r3
> + * Returns: 1 on success
> + * 0 on failure
TRUE/FALSE
> + */
> +bool start_all_cpus(secondary_entry_fn entry, uint32_t r3)
> +{
> + struct secondary_entry_data data = {
> + entry,
> + r3,
> + false
> + };
> + int ret;
> +
> + ret = dt_for_each_cpu_node(&start_each_secondary, (void *) &data);
assert(ret == 0)
> +
> + return !(ret || data.init_failed);
See comment above about setting nr_cpus, and then just confirming they all
started here instead.
> +}
> diff --git a/lib/ppc64/asm/smp.h b/lib/ppc64/asm/smp.h
> new file mode 100644
> index 0000000..67ced75
> --- /dev/null
> +++ b/lib/ppc64/asm/smp.h
> @@ -0,0 +1 @@
> +#include "../../powerpc/asm/smp.h"
> diff --git a/powerpc/Makefile.common b/powerpc/Makefile.common
> index 404194b..677030a 100644
> --- a/powerpc/Makefile.common
> +++ b/powerpc/Makefile.common
> @@ -37,6 +37,7 @@ cflatobjs += lib/powerpc/setup.o
> cflatobjs += lib/powerpc/rtas.o
> cflatobjs += lib/powerpc/processor.o
> cflatobjs += lib/powerpc/handlers.o
> +cflatobjs += lib/powerpc/smp.o
>
> FLATLIBS = $(libcflat) $(LIBFDT_archive)
> %.elf: CFLAGS += $(arch_CFLAGS)
> --
> 2.5.5
Thanks,
drew
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