Identifying the underlying RISC-V implementation can be important
for some of the user space applications. For example, the perf tool
uses arch specific CPU implementation id (i.e. CPUID) to select a
JSON file describing custom perf events on a CPU.
Currently, there is no way to identify RISC-V implementation so we
add mvendorid, marchid, and mimpid to /proc/cpuinfo output.
Signed-off-by: Anup Patel <[email protected]>
---
arch/riscv/kernel/cpu.c | 51 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 51 insertions(+)
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index fba9e9f46a8c..c037b8691bbb 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -3,10 +3,13 @@
* Copyright (C) 2012 Regents of the University of California
*/
+#include <linux/cpu.h>
#include <linux/init.h>
#include <linux/seq_file.h>
#include <linux/of.h>
+#include <asm/csr.h>
#include <asm/hwcap.h>
+#include <asm/sbi.h>
#include <asm/smp.h>
#include <asm/pgtable.h>
@@ -64,6 +67,50 @@ int riscv_of_parent_hartid(struct device_node *node)
}
#ifdef CONFIG_PROC_FS
+
+struct riscv_cpuinfo {
+ unsigned long mvendorid;
+ unsigned long marchid;
+ unsigned long mimpid;
+};
+static DEFINE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
+
+static int riscv_cpuinfo_starting(unsigned int cpu)
+{
+ struct riscv_cpuinfo *ci = this_cpu_ptr(&riscv_cpuinfo);
+
+#if defined(CONFIG_RISCV_SBI)
+ ci->mvendorid = sbi_spec_is_0_1() ? 0 : sbi_get_mvendorid();
+ ci->marchid = sbi_spec_is_0_1() ? 0 : sbi_get_marchid();
+ ci->mimpid = sbi_spec_is_0_1() ? 0 : sbi_get_mimpid();
+#elif defined(CONFIG_RISCV_M_MODE)
+ ci->mvendorid = csr_read(CSR_MVENDORID);
+ ci->marchid = csr_read(CSR_MARCHID);
+ ci->mimpid = csr_read(CSR_MIMPID);
+#else
+ ci->mvendorid = 0;
+ ci->marchid = 0;
+ ci->mimpid = 0;
+#endif
+
+ return 0;
+}
+
+static int __init riscv_cpuinfo_init(void)
+{
+ int ret;
+
+ ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "riscv/cpuinfo:starting",
+ riscv_cpuinfo_starting, NULL);
+ if (ret < 0) {
+ pr_err("cpuinfo: failed to register hotplug callbacks.\n");
+ return ret;
+ }
+
+ return 0;
+}
+device_initcall(riscv_cpuinfo_init);
+
#define __RISCV_ISA_EXT_DATA(UPROP, EXTID) \
{ \
.uprop = #UPROP, \
@@ -178,6 +225,7 @@ static int c_show(struct seq_file *m, void *v)
{
unsigned long cpu_id = (unsigned long)v - 1;
struct device_node *node = of_get_cpu_node(cpu_id, NULL);
+ struct riscv_cpuinfo *ci = per_cpu_ptr(&riscv_cpuinfo, cpu_id);
const char *compat, *isa;
seq_printf(m, "processor\t: %lu\n", cpu_id);
@@ -188,6 +236,9 @@ static int c_show(struct seq_file *m, void *v)
if (!of_property_read_string(node, "compatible", &compat)
&& strcmp(compat, "riscv"))
seq_printf(m, "uarch\t\t: %s\n", compat);
+ seq_printf(m, "mvendorid\t: 0x%lx\n", ci->mvendorid);
+ seq_printf(m, "marchid\t\t: 0x%lx\n", ci->marchid);
+ seq_printf(m, "mimpid\t\t: 0x%lx\n", ci->mimpid);
seq_puts(m, "\n");
of_node_put(node);
--
2.34.1
On 6/20/22 13:55, Anup Patel wrote:
> Identifying the underlying RISC-V implementation can be important
> for some of the user space applications. For example, the perf tool
> uses arch specific CPU implementation id (i.e. CPUID) to select a
> JSON file describing custom perf events on a CPU.
>
> Currently, there is no way to identify RISC-V implementation so we
> add mvendorid, marchid, and mimpid to /proc/cpuinfo output.
>
> Signed-off-by: Anup Patel <[email protected]>
Looks good to me. I only tested on QEMU where all values default to 0.
Reviewed-by: Heinrich Schuchardt <[email protected]>
> ---
> arch/riscv/kernel/cpu.c | 51 +++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 51 insertions(+)
>
> diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> index fba9e9f46a8c..c037b8691bbb 100644
> --- a/arch/riscv/kernel/cpu.c
> +++ b/arch/riscv/kernel/cpu.c
> @@ -3,10 +3,13 @@
> * Copyright (C) 2012 Regents of the University of California
> */
>
> +#include <linux/cpu.h>
> #include <linux/init.h>
> #include <linux/seq_file.h>
> #include <linux/of.h>
> +#include <asm/csr.h>
> #include <asm/hwcap.h>
> +#include <asm/sbi.h>
> #include <asm/smp.h>
> #include <asm/pgtable.h>
>
> @@ -64,6 +67,50 @@ int riscv_of_parent_hartid(struct device_node *node)
> }
>
> #ifdef CONFIG_PROC_FS
> +
> +struct riscv_cpuinfo {
> + unsigned long mvendorid;
> + unsigned long marchid;
> + unsigned long mimpid;
> +};
> +static DEFINE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
> +
> +static int riscv_cpuinfo_starting(unsigned int cpu)
> +{
> + struct riscv_cpuinfo *ci = this_cpu_ptr(&riscv_cpuinfo);
> +
> +#if defined(CONFIG_RISCV_SBI)
> + ci->mvendorid = sbi_spec_is_0_1() ? 0 : sbi_get_mvendorid();
> + ci->marchid = sbi_spec_is_0_1() ? 0 : sbi_get_marchid();
> + ci->mimpid = sbi_spec_is_0_1() ? 0 : sbi_get_mimpid();
> +#elif defined(CONFIG_RISCV_M_MODE)
> + ci->mvendorid = csr_read(CSR_MVENDORID);
> + ci->marchid = csr_read(CSR_MARCHID);
> + ci->mimpid = csr_read(CSR_MIMPID);
> +#else
> + ci->mvendorid = 0;
> + ci->marchid = 0;
> + ci->mimpid = 0;
> +#endif
> +
> + return 0;
> +}
> +
> +static int __init riscv_cpuinfo_init(void)
> +{
> + int ret;
> +
> + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "riscv/cpuinfo:starting",
> + riscv_cpuinfo_starting, NULL);
> + if (ret < 0) {
> + pr_err("cpuinfo: failed to register hotplug callbacks.\n");
> + return ret;
> + }
> +
> + return 0;
> +}
> +device_initcall(riscv_cpuinfo_init);
> +
> #define __RISCV_ISA_EXT_DATA(UPROP, EXTID) \
> { \
> .uprop = #UPROP, \
> @@ -178,6 +225,7 @@ static int c_show(struct seq_file *m, void *v)
> {
> unsigned long cpu_id = (unsigned long)v - 1;
> struct device_node *node = of_get_cpu_node(cpu_id, NULL);
> + struct riscv_cpuinfo *ci = per_cpu_ptr(&riscv_cpuinfo, cpu_id);
> const char *compat, *isa;
>
> seq_printf(m, "processor\t: %lu\n", cpu_id);
> @@ -188,6 +236,9 @@ static int c_show(struct seq_file *m, void *v)
> if (!of_property_read_string(node, "compatible", &compat)
> && strcmp(compat, "riscv"))
> seq_printf(m, "uarch\t\t: %s\n", compat);
> + seq_printf(m, "mvendorid\t: 0x%lx\n", ci->mvendorid);
> + seq_printf(m, "marchid\t\t: 0x%lx\n", ci->marchid);
> + seq_printf(m, "mimpid\t\t: 0x%lx\n", ci->mimpid);
> seq_puts(m, "\n");
> of_node_put(node);
>
Hey Anup,
Tested it & got back the (sadly boring) 0s that are set in
my hardware.
Two comments below.
Thanks,
Conor.
On 20/06/2022 12:55, Anup Patel wrote:
> Identifying the underlying RISC-V implementation can be important
> for some of the user space applications. For example, the perf tool
> uses arch specific CPU implementation id (i.e. CPUID) to select a
> JSON file describing custom perf events on a CPU.
>
> Currently, there is no way to identify RISC-V implementation so we
> add mvendorid, marchid, and mimpid to /proc/cpuinfo output.
>
> Signed-off-by: Anup Patel <[email protected]>
> ---
> arch/riscv/kernel/cpu.c | 51 +++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 51 insertions(+)
>
> diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> index fba9e9f46a8c..c037b8691bbb 100644
> --- a/arch/riscv/kernel/cpu.c
> +++ b/arch/riscv/kernel/cpu.c
> @@ -3,10 +3,13 @@
> * Copyright (C) 2012 Regents of the University of California
> */
>
> +#include <linux/cpu.h>
> #include <linux/init.h>
> #include <linux/seq_file.h>
> #include <linux/of.h>
> +#include <asm/csr.h>
> #include <asm/hwcap.h>
> +#include <asm/sbi.h>
> #include <asm/smp.h>
> #include <asm/pgtable.h>
>
> @@ -64,6 +67,50 @@ int riscv_of_parent_hartid(struct device_node *node)
> }
>
> #ifdef CONFIG_PROC_FS
> +
> +struct riscv_cpuinfo {
> + unsigned long mvendorid;
> + unsigned long marchid;
> + unsigned long mimpid;
> +};
> +static DEFINE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
> +
> +static int riscv_cpuinfo_starting(unsigned int cpu)
> +{
> + struct riscv_cpuinfo *ci = this_cpu_ptr(&riscv_cpuinfo);
> +
> +#if defined(CONFIG_RISCV_SBI)
This should be #if IS_ENABLED(CONFIG_RISCV_SBI) to match the
other users
> + ci->mvendorid = sbi_spec_is_0_1() ? 0 : sbi_get_mvendorid();
> + ci->marchid = sbi_spec_is_0_1() ? 0 : sbi_get_marchid();
> + ci->mimpid = sbi_spec_is_0_1() ? 0 : sbi_get_mimpid();
> +#elif defined(CONFIG_RISCV_M_MODE)
Ditto
> + ci->mvendorid = csr_read(CSR_MVENDORID);
> + ci->marchid = csr_read(CSR_MARCHID);
> + ci->mimpid = csr_read(CSR_MIMPID);
> +#else
> + ci->mvendorid = 0;
> + ci->marchid = 0;
> + ci->mimpid = 0;
> +#endif
> +
> + return 0;
> +}
> +
> +static int __init riscv_cpuinfo_init(void)
> +{
> + int ret;
> +
> + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "riscv/cpuinfo:starting",
> + riscv_cpuinfo_starting, NULL);
> + if (ret < 0) {
> + pr_err("cpuinfo: failed to register hotplug callbacks.\n");
> + return ret;
> + }
> +
> + return 0;
> +}
> +device_initcall(riscv_cpuinfo_init);
> +
> #define __RISCV_ISA_EXT_DATA(UPROP, EXTID) \
> { \
> .uprop = #UPROP, \
> @@ -178,6 +225,7 @@ static int c_show(struct seq_file *m, void *v)
> {
> unsigned long cpu_id = (unsigned long)v - 1;
> struct device_node *node = of_get_cpu_node(cpu_id, NULL);
> + struct riscv_cpuinfo *ci = per_cpu_ptr(&riscv_cpuinfo, cpu_id);
> const char *compat, *isa;
>
> seq_printf(m, "processor\t: %lu\n", cpu_id);
> @@ -188,6 +236,9 @@ static int c_show(struct seq_file *m, void *v)
> if (!of_property_read_string(node, "compatible", &compat)
> && strcmp(compat, "riscv"))
> seq_printf(m, "uarch\t\t: %s\n", compat);
> + seq_printf(m, "mvendorid\t: 0x%lx\n", ci->mvendorid);
> + seq_printf(m, "marchid\t\t: 0x%lx\n", ci->marchid);
> + seq_printf(m, "mimpid\t\t: 0x%lx\n", ci->mimpid);
> seq_puts(m, "\n");
> of_node_put(node);
>
Hello Anup!
On Mon, 20 Jun 2022 17:25:49 +0530
Anup Patel <[email protected]> wrote:
> Identifying the underlying RISC-V implementation can be important
> for some of the user space applications. For example, the perf tool
> uses arch specific CPU implementation id (i.e. CPUID) to select a
> JSON file describing custom perf events on a CPU.
>
> Currently, there is no way to identify RISC-V implementation so we
> add mvendorid, marchid, and mimpid to /proc/cpuinfo output.
Tested on Sifive Unmatched:
localhost / # cat /proc/cpuinfo
processor : 0
hart : 4
isa : rv64imafdc
mmu : sv39
uarch : sifive,bullet0
mvendorid : 0x489
marchid : 0x8000000000000007
mimpid : 0x20181004
processor : 1
hart : 1
isa : rv64imafdc
mmu : sv39
uarch : sifive,bullet0
mvendorid : 0x489
marchid : 0x8000000000000007
mimpid : 0x20181004
processor : 2
hart : 2
isa : rv64imafdc
mmu : sv39
uarch : sifive,bullet0
mvendorid : 0x489
marchid : 0x8000000000000007
mimpid : 0x20181004
processor : 3
hart : 3
isa : rv64imafdc
mmu : sv39
uarch : sifive,bullet0
mvendorid : 0x489
marchid : 0x8000000000000007
mimpid : 0x20181004
mvendorid, marchid values match the register description in u74 manual.
mimpid seems to be ok, through i can't find exact in U74/Unmatched docs.
Tested-by: Nikita Shubin <[email protected]>
>
> Signed-off-by: Anup Patel <[email protected]>
> ---
> arch/riscv/kernel/cpu.c | 51
> +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51
> insertions(+)
>
> diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> index fba9e9f46a8c..c037b8691bbb 100644
> --- a/arch/riscv/kernel/cpu.c
> +++ b/arch/riscv/kernel/cpu.c
> @@ -3,10 +3,13 @@
> * Copyright (C) 2012 Regents of the University of California
> */
>
> +#include <linux/cpu.h>
> #include <linux/init.h>
> #include <linux/seq_file.h>
> #include <linux/of.h>
> +#include <asm/csr.h>
> #include <asm/hwcap.h>
> +#include <asm/sbi.h>
> #include <asm/smp.h>
> #include <asm/pgtable.h>
>
> @@ -64,6 +67,50 @@ int riscv_of_parent_hartid(struct device_node
> *node) }
>
> #ifdef CONFIG_PROC_FS
> +
> +struct riscv_cpuinfo {
> + unsigned long mvendorid;
> + unsigned long marchid;
> + unsigned long mimpid;
> +};
> +static DEFINE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
> +
> +static int riscv_cpuinfo_starting(unsigned int cpu)
> +{
> + struct riscv_cpuinfo *ci = this_cpu_ptr(&riscv_cpuinfo);
> +
> +#if defined(CONFIG_RISCV_SBI)
> + ci->mvendorid = sbi_spec_is_0_1() ? 0 : sbi_get_mvendorid();
> + ci->marchid = sbi_spec_is_0_1() ? 0 : sbi_get_marchid();
> + ci->mimpid = sbi_spec_is_0_1() ? 0 : sbi_get_mimpid();
> +#elif defined(CONFIG_RISCV_M_MODE)
> + ci->mvendorid = csr_read(CSR_MVENDORID);
> + ci->marchid = csr_read(CSR_MARCHID);
> + ci->mimpid = csr_read(CSR_MIMPID);
> +#else
> + ci->mvendorid = 0;
> + ci->marchid = 0;
> + ci->mimpid = 0;
> +#endif
> +
> + return 0;
> +}
> +
> +static int __init riscv_cpuinfo_init(void)
> +{
> + int ret;
> +
> + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
> "riscv/cpuinfo:starting",
> + riscv_cpuinfo_starting, NULL);
> + if (ret < 0) {
> + pr_err("cpuinfo: failed to register hotplug
> callbacks.\n");
> + return ret;
> + }
> +
> + return 0;
> +}
> +device_initcall(riscv_cpuinfo_init);
> +
> #define __RISCV_ISA_EXT_DATA(UPROP, EXTID) \
> { \
> .uprop = #UPROP, \
> @@ -178,6 +225,7 @@ static int c_show(struct seq_file *m, void *v)
> {
> unsigned long cpu_id = (unsigned long)v - 1;
> struct device_node *node = of_get_cpu_node(cpu_id, NULL);
> + struct riscv_cpuinfo *ci = per_cpu_ptr(&riscv_cpuinfo,
> cpu_id); const char *compat, *isa;
>
> seq_printf(m, "processor\t: %lu\n", cpu_id);
> @@ -188,6 +236,9 @@ static int c_show(struct seq_file *m, void *v)
> if (!of_property_read_string(node, "compatible", &compat)
> && strcmp(compat, "riscv"))
> seq_printf(m, "uarch\t\t: %s\n", compat);
> + seq_printf(m, "mvendorid\t: 0x%lx\n", ci->mvendorid);
> + seq_printf(m, "marchid\t\t: 0x%lx\n", ci->marchid);
> + seq_printf(m, "mimpid\t\t: 0x%lx\n", ci->mimpid);
> seq_puts(m, "\n");
> of_node_put(node);
>
On Tue, Jun 21, 2022 at 10:53 AM Nikita Shubin
<[email protected]> wrote:
>
> Hello Anup!
>
> On Mon, 20 Jun 2022 17:25:49 +0530
> Anup Patel <[email protected]> wrote:
>
> > Identifying the underlying RISC-V implementation can be important
> > for some of the user space applications. For example, the perf tool
> > uses arch specific CPU implementation id (i.e. CPUID) to select a
> > JSON file describing custom perf events on a CPU.
> >
> > Currently, there is no way to identify RISC-V implementation so we
> > add mvendorid, marchid, and mimpid to /proc/cpuinfo output.
>
> Tested on Sifive Unmatched:
>
> localhost / # cat /proc/cpuinfo
> processor : 0
> hart : 4
> isa : rv64imafdc
> mmu : sv39
> uarch : sifive,bullet0
> mvendorid : 0x489
> marchid : 0x8000000000000007
> mimpid : 0x20181004
>
> processor : 1
> hart : 1
> isa : rv64imafdc
> mmu : sv39
> uarch : sifive,bullet0
> mvendorid : 0x489
> marchid : 0x8000000000000007
> mimpid : 0x20181004
>
> processor : 2
> hart : 2
> isa : rv64imafdc
> mmu : sv39
> uarch : sifive,bullet0
> mvendorid : 0x489
> marchid : 0x8000000000000007
> mimpid : 0x20181004
>
> processor : 3
> hart : 3
> isa : rv64imafdc
> mmu : sv39
> uarch : sifive,bullet0
> mvendorid : 0x489
> marchid : 0x8000000000000007
> mimpid : 0x20181004
>
> mvendorid, marchid values match the register description in u74 manual.
>
> mimpid seems to be ok, through i can't find exact in U74/Unmatched docs.
SiFive main website -> Products -> Documentation -> U74-MC Core
Complex Manual -> Page 274: B.2 Machine Implementation ID Register
(mimpid).
This mimpid value is not in the table thus it's most likely not part
of a particular U74 generator release. Looking at this value we could
assume that U74 cores within FU740 predates the general availability.
Cheers,
david
>
> Tested-by: Nikita Shubin <[email protected]>
>
> >
> > Signed-off-by: Anup Patel <[email protected]>
> > ---
> > arch/riscv/kernel/cpu.c | 51
> > +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51
> > insertions(+)
> >
> > diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> > index fba9e9f46a8c..c037b8691bbb 100644
> > --- a/arch/riscv/kernel/cpu.c
> > +++ b/arch/riscv/kernel/cpu.c
> > @@ -3,10 +3,13 @@
> > * Copyright (C) 2012 Regents of the University of California
> > */
> >
> > +#include <linux/cpu.h>
> > #include <linux/init.h>
> > #include <linux/seq_file.h>
> > #include <linux/of.h>
> > +#include <asm/csr.h>
> > #include <asm/hwcap.h>
> > +#include <asm/sbi.h>
> > #include <asm/smp.h>
> > #include <asm/pgtable.h>
> >
> > @@ -64,6 +67,50 @@ int riscv_of_parent_hartid(struct device_node
> > *node) }
> >
> > #ifdef CONFIG_PROC_FS
> > +
> > +struct riscv_cpuinfo {
> > + unsigned long mvendorid;
> > + unsigned long marchid;
> > + unsigned long mimpid;
> > +};
> > +static DEFINE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
> > +
> > +static int riscv_cpuinfo_starting(unsigned int cpu)
> > +{
> > + struct riscv_cpuinfo *ci = this_cpu_ptr(&riscv_cpuinfo);
> > +
> > +#if defined(CONFIG_RISCV_SBI)
> > + ci->mvendorid = sbi_spec_is_0_1() ? 0 : sbi_get_mvendorid();
> > + ci->marchid = sbi_spec_is_0_1() ? 0 : sbi_get_marchid();
> > + ci->mimpid = sbi_spec_is_0_1() ? 0 : sbi_get_mimpid();
> > +#elif defined(CONFIG_RISCV_M_MODE)
> > + ci->mvendorid = csr_read(CSR_MVENDORID);
> > + ci->marchid = csr_read(CSR_MARCHID);
> > + ci->mimpid = csr_read(CSR_MIMPID);
> > +#else
> > + ci->mvendorid = 0;
> > + ci->marchid = 0;
> > + ci->mimpid = 0;
> > +#endif
> > +
> > + return 0;
> > +}
> > +
> > +static int __init riscv_cpuinfo_init(void)
> > +{
> > + int ret;
> > +
> > + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
> > "riscv/cpuinfo:starting",
> > + riscv_cpuinfo_starting, NULL);
> > + if (ret < 0) {
> > + pr_err("cpuinfo: failed to register hotplug
> > callbacks.\n");
> > + return ret;
> > + }
> > +
> > + return 0;
> > +}
> > +device_initcall(riscv_cpuinfo_init);
> > +
> > #define __RISCV_ISA_EXT_DATA(UPROP, EXTID) \
> > { \
> > .uprop = #UPROP, \
> > @@ -178,6 +225,7 @@ static int c_show(struct seq_file *m, void *v)
> > {
> > unsigned long cpu_id = (unsigned long)v - 1;
> > struct device_node *node = of_get_cpu_node(cpu_id, NULL);
> > + struct riscv_cpuinfo *ci = per_cpu_ptr(&riscv_cpuinfo,
> > cpu_id); const char *compat, *isa;
> >
> > seq_printf(m, "processor\t: %lu\n", cpu_id);
> > @@ -188,6 +236,9 @@ static int c_show(struct seq_file *m, void *v)
> > if (!of_property_read_string(node, "compatible", &compat)
> > && strcmp(compat, "riscv"))
> > seq_printf(m, "uarch\t\t: %s\n", compat);
> > + seq_printf(m, "mvendorid\t: 0x%lx\n", ci->mvendorid);
> > + seq_printf(m, "marchid\t\t: 0x%lx\n", ci->marchid);
> > + seq_printf(m, "mimpid\t\t: 0x%lx\n", ci->mimpid);
> > seq_puts(m, "\n");
> > of_node_put(node);
> >
>
>
> _______________________________________________
> linux-riscv mailing list
> [email protected]
> http://lists.infradead.org/mailman/listinfo/linux-riscv
Hi Palmer,
On Mon, Jun 20, 2022 at 5:26 PM Anup Patel <[email protected]> wrote:
>
> Identifying the underlying RISC-V implementation can be important
> for some of the user space applications. For example, the perf tool
> uses arch specific CPU implementation id (i.e. CPUID) to select a
> JSON file describing custom perf events on a CPU.
>
> Currently, there is no way to identify RISC-V implementation so we
> add mvendorid, marchid, and mimpid to /proc/cpuinfo output.
>
> Signed-off-by: Anup Patel <[email protected]>
Can this patch be considered for 5.20 ?
Regards,
Anup
> ---
> arch/riscv/kernel/cpu.c | 51 +++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 51 insertions(+)
>
> diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> index fba9e9f46a8c..c037b8691bbb 100644
> --- a/arch/riscv/kernel/cpu.c
> +++ b/arch/riscv/kernel/cpu.c
> @@ -3,10 +3,13 @@
> * Copyright (C) 2012 Regents of the University of California
> */
>
> +#include <linux/cpu.h>
> #include <linux/init.h>
> #include <linux/seq_file.h>
> #include <linux/of.h>
> +#include <asm/csr.h>
> #include <asm/hwcap.h>
> +#include <asm/sbi.h>
> #include <asm/smp.h>
> #include <asm/pgtable.h>
>
> @@ -64,6 +67,50 @@ int riscv_of_parent_hartid(struct device_node *node)
> }
>
> #ifdef CONFIG_PROC_FS
> +
> +struct riscv_cpuinfo {
> + unsigned long mvendorid;
> + unsigned long marchid;
> + unsigned long mimpid;
> +};
> +static DEFINE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
> +
> +static int riscv_cpuinfo_starting(unsigned int cpu)
> +{
> + struct riscv_cpuinfo *ci = this_cpu_ptr(&riscv_cpuinfo);
> +
> +#if defined(CONFIG_RISCV_SBI)
> + ci->mvendorid = sbi_spec_is_0_1() ? 0 : sbi_get_mvendorid();
> + ci->marchid = sbi_spec_is_0_1() ? 0 : sbi_get_marchid();
> + ci->mimpid = sbi_spec_is_0_1() ? 0 : sbi_get_mimpid();
> +#elif defined(CONFIG_RISCV_M_MODE)
> + ci->mvendorid = csr_read(CSR_MVENDORID);
> + ci->marchid = csr_read(CSR_MARCHID);
> + ci->mimpid = csr_read(CSR_MIMPID);
> +#else
> + ci->mvendorid = 0;
> + ci->marchid = 0;
> + ci->mimpid = 0;
> +#endif
> +
> + return 0;
> +}
> +
> +static int __init riscv_cpuinfo_init(void)
> +{
> + int ret;
> +
> + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "riscv/cpuinfo:starting",
> + riscv_cpuinfo_starting, NULL);
> + if (ret < 0) {
> + pr_err("cpuinfo: failed to register hotplug callbacks.\n");
> + return ret;
> + }
> +
> + return 0;
> +}
> +device_initcall(riscv_cpuinfo_init);
> +
> #define __RISCV_ISA_EXT_DATA(UPROP, EXTID) \
> { \
> .uprop = #UPROP, \
> @@ -178,6 +225,7 @@ static int c_show(struct seq_file *m, void *v)
> {
> unsigned long cpu_id = (unsigned long)v - 1;
> struct device_node *node = of_get_cpu_node(cpu_id, NULL);
> + struct riscv_cpuinfo *ci = per_cpu_ptr(&riscv_cpuinfo, cpu_id);
> const char *compat, *isa;
>
> seq_printf(m, "processor\t: %lu\n", cpu_id);
> @@ -188,6 +236,9 @@ static int c_show(struct seq_file *m, void *v)
> if (!of_property_read_string(node, "compatible", &compat)
> && strcmp(compat, "riscv"))
> seq_printf(m, "uarch\t\t: %s\n", compat);
> + seq_printf(m, "mvendorid\t: 0x%lx\n", ci->mvendorid);
> + seq_printf(m, "marchid\t\t: 0x%lx\n", ci->marchid);
> + seq_printf(m, "mimpid\t\t: 0x%lx\n", ci->mimpid);
> seq_puts(m, "\n");
> of_node_put(node);
>
> --
> 2.34.1
>
On Tue, Jul 26, 2022 at 7:10 PM <[email protected]> wrote:
>
> Hey Anup,
>
> On 26/07/2022 12:57, Anup Patel wrote:
> > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> >
> > Hi Palmer,
> >
> > On Mon, Jun 20, 2022 at 5:26 PM Anup Patel <[email protected]> wrote:
> >>
> >> Identifying the underlying RISC-V implementation can be important
> >> for some of the user space applications. For example, the perf tool
> >> uses arch specific CPU implementation id (i.e. CPUID) to select a
> >> JSON file describing custom perf events on a CPU.
> >>
> >> Currently, there is no way to identify RISC-V implementation so we
> >> add mvendorid, marchid, and mimpid to /proc/cpuinfo output.
> >>
> >> Signed-off-by: Anup Patel <[email protected]>
> >
> > Can this patch be considered for 5.20 ?
>
> iirc I mentioned the consistency of using defined() for
> CONFIG_RISCV_SBI versus IS_ENABLED() elsewhere in arch/riscv/
> but I don't recall a response.
Sorry, I missed your comment. I will address and send v2 soon.
Regards,
Anup
>
> Thanks,
> Conor.
Hey Anup,
On 26/07/2022 12:57, Anup Patel wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> Hi Palmer,
>
> On Mon, Jun 20, 2022 at 5:26 PM Anup Patel <[email protected]> wrote:
>>
>> Identifying the underlying RISC-V implementation can be important
>> for some of the user space applications. For example, the perf tool
>> uses arch specific CPU implementation id (i.e. CPUID) to select a
>> JSON file describing custom perf events on a CPU.
>>
>> Currently, there is no way to identify RISC-V implementation so we
>> add mvendorid, marchid, and mimpid to /proc/cpuinfo output.
>>
>> Signed-off-by: Anup Patel <[email protected]>
>
> Can this patch be considered for 5.20 ?
iirc I mentioned the consistency of using defined() for
CONFIG_RISCV_SBI versus IS_ENABLED() elsewhere in arch/riscv/
but I don't recall a response.
Thanks,
Conor.