Messages in this thread | | | From | Michael Ellerman <> | Subject | Re: [PATCH v7 2/5] powerpc/hv-24x7: Add rtas call in hv-24x7 driver to get processor details | Date | Wed, 29 Apr 2020 21:31:54 +1000 |
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Hi Kajol,
Some comments inline ...
Kajol Jain <kjain@linux.ibm.com> writes: > For hv_24x7 socket/chip level events, specific chip-id to which > the data requested should be added as part of pmu events. > But number of chips/socket in the system details are not exposed. > > Patch implements read_sys_info_pseries() to get system > parameter values like number of sockets and chips per socket. > Rtas_call with token "PROCESSOR_MODULE_INFO" > is used to get these values. > > Sub-sequent patch exports these values via sysfs. > > Patch also make these parameters default to 1. > > Signed-off-by: Kajol Jain <kjain@linux.ibm.com> > --- > arch/powerpc/perf/hv-24x7.c | 72 ++++++++++++++++++++++++ > arch/powerpc/platforms/pseries/pseries.h | 3 + > 2 files changed, 75 insertions(+) > > diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c > index 48e8f4b17b91..9ae00f29bd21 100644 > --- a/arch/powerpc/perf/hv-24x7.c > +++ b/arch/powerpc/perf/hv-24x7.c > @@ -20,6 +20,11 @@ > #include <asm/io.h> > #include <linux/byteorder/generic.h> > > +#ifdef CONFIG_PPC_RTAS
This driver can only be build on pseries, and pseries always selects RTAS. So the ifdef is unncessary.
> +#include <asm/rtas.h> > +#include <../../platforms/pseries/pseries.h> > +#endif
That's not really what the platform header is intended for.
You should put the extern in arch/powerpc/include/asm somewhere.
Maybe rtas.h
> @@ -57,6 +62,69 @@ static bool is_physical_domain(unsigned domain) > } > } > > +#ifdef CONFIG_PPC_RTAS
Not needed.
> +#define PROCESSOR_MODULE_INFO 43
Please document where these come from, presumably LoPAPR somewhere?
> +#define PROCESSOR_MAX_LENGTH (8 * 1024) > + > +static int strbe16toh(const char *buf, int offset) > +{ > + return (buf[offset] << 8) + buf[offset + 1]; > +}
I'm confused by this. "str" implies string, a string is an array of bytes and has no endian. But then be16 implies it's an array of __be16, in which case buf should be a __be16 *.
> + > +static u32 physsockets; /* Physical sockets */ > +static u32 physchips; /* Physical chips */
No tabs there please.
> + > +/* > + * Function read_sys_info_pseries() make a rtas_call which require > + * data buffer of size 8K. As standard 'rtas_data_buf' is of size > + * 4K, we are adding new local buffer 'rtas_local_data_buf'. > + */ > +char rtas_local_data_buf[PROCESSOR_MAX_LENGTH] __cacheline_aligned;
static?
> +/* > + * read_sys_info_pseries() > + * Retrieve the number of sockets and chips per socket details > + * through the get-system-parameter rtas call. > + */ > +void read_sys_info_pseries(void) > +{ > + int call_status, len, ntypes; > + > + /* > + * Making system parameter: chips and sockets default to 1. > + */ > + physsockets = 1; > + physchips = 1; > + memset(rtas_local_data_buf, 0, PROCESSOR_MAX_LENGTH); > + spin_lock(&rtas_data_buf_lock);
You're not using the rtas_data_buf, so why are you taking the rtas_data_buf_lock?
> + call_status = rtas_call(rtas_token("ibm,get-system-parameter"), 3, 1, > + NULL, > + PROCESSOR_MODULE_INFO, > + __pa(rtas_local_data_buf), > + PROCESSOR_MAX_LENGTH); > + > + spin_unlock(&rtas_data_buf_lock); > + > + if (call_status != 0) { > + pr_info("%s %s Error calling get-system-parameter (0x%x)\n", > + __FILE__, __func__, call_status);
pr_err(), don't use __FILE__, this file already uses pr_fmt(). Not sure __func__ is really necessary either.
return;
Then you can deindent the next block.
> + } else { > + rtas_local_data_buf[PROCESSOR_MAX_LENGTH - 1] = '\0'; > + len = strbe16toh(rtas_local_data_buf, 0);
Why isn't the buffer a __be16 array, and then you just use be16_to_cpu() ?
> + if (len < 6) > + return; > + > + ntypes = strbe16toh(rtas_local_data_buf, 2); > + > + if (!ntypes) > + return;
What is ntypes?
> + physsockets = strbe16toh(rtas_local_data_buf, 4); > + physchips = strbe16toh(rtas_local_data_buf, 6); > + } > +} > +#endif /* CONFIG_PPC_RTAS */ > + > /* Domains for which more than one result element are returned for each event. */ > static bool domain_needs_aggregation(unsigned int domain) > { > @@ -1605,6 +1673,10 @@ static int hv_24x7_init(void) > if (r) > return r; > > +#ifdef CONFIG_PPC_RTAS > + read_sys_info_pseries(); > +#endif
> + > return 0; > } > > diff --git a/arch/powerpc/platforms/pseries/pseries.h b/arch/powerpc/platforms/pseries/pseries.h > index 13fa370a87e4..1727559ce304 100644 > --- a/arch/powerpc/platforms/pseries/pseries.h > +++ b/arch/powerpc/platforms/pseries/pseries.h > @@ -19,6 +19,9 @@ extern void request_event_sources_irqs(struct device_node *np, > struct pt_regs; > > extern int pSeries_system_reset_exception(struct pt_regs *regs); > +#ifdef CONFIG_PPC_RTAS > +extern void read_sys_info_pseries(void); > +#endif > extern int pSeries_machine_check_exception(struct pt_regs *regs); > extern long pseries_machine_check_realmode(struct pt_regs *regs);
cheers
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