diff mbox series

[7/8] riscv: Use pgtable_l4_enabled to output mmu type in cpuinfo

Message ID 20200524091008.25587-8-alex@ghiti.fr (mailing list archive)
State New, archived
Headers show
Series Introduce sv48 support | expand

Commit Message

Alexandre Ghiti May 24, 2020, 9:10 a.m. UTC
Now that the mmu type is determined at runtime using SATP
characteristic, use the global variable pgtable_l4_enabled to output
mmu type of the processor through /proc/cpuinfo instead of relying on
device tree infos.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
---
 arch/riscv/boot/dts/sifive/fu540-c000.dtsi |  4 ----
 arch/riscv/kernel/cpu.c                    | 24 ++++++++++++----------
 2 files changed, 13 insertions(+), 15 deletions(-)

Comments

Anup Patel May 25, 2020, 6:21 a.m. UTC | #1
On Sun, May 24, 2020 at 2:47 PM Alexandre Ghiti <alex@ghiti.fr> wrote:
>
> Now that the mmu type is determined at runtime using SATP
> characteristic, use the global variable pgtable_l4_enabled to output
> mmu type of the processor through /proc/cpuinfo instead of relying on
> device tree infos.
>
> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
> Reviewed-by: Anup Patel <anup@brainfault.org>
> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
> ---
>  arch/riscv/boot/dts/sifive/fu540-c000.dtsi |  4 ----
>  arch/riscv/kernel/cpu.c                    | 24 ++++++++++++----------
>  2 files changed, 13 insertions(+), 15 deletions(-)
>
> diff --git a/arch/riscv/boot/dts/sifive/fu540-c000.dtsi b/arch/riscv/boot/dts/sifive/fu540-c000.dtsi
> index 7db861053483..6138590a2229 100644
> --- a/arch/riscv/boot/dts/sifive/fu540-c000.dtsi
> +++ b/arch/riscv/boot/dts/sifive/fu540-c000.dtsi
> @@ -50,7 +50,6 @@
>                         i-cache-size = <32768>;
>                         i-tlb-sets = <1>;
>                         i-tlb-size = <32>;
> -                       mmu-type = "riscv,sv39";
>                         reg = <1>;
>                         riscv,isa = "rv64imafdc";
>                         tlb-split;
> @@ -74,7 +73,6 @@
>                         i-cache-size = <32768>;
>                         i-tlb-sets = <1>;
>                         i-tlb-size = <32>;
> -                       mmu-type = "riscv,sv39";
>                         reg = <2>;
>                         riscv,isa = "rv64imafdc";
>                         tlb-split;
> @@ -98,7 +96,6 @@
>                         i-cache-size = <32768>;
>                         i-tlb-sets = <1>;
>                         i-tlb-size = <32>;
> -                       mmu-type = "riscv,sv39";
>                         reg = <3>;
>                         riscv,isa = "rv64imafdc";
>                         tlb-split;
> @@ -122,7 +119,6 @@
>                         i-cache-size = <32768>;
>                         i-tlb-sets = <1>;
>                         i-tlb-size = <32>;
> -                       mmu-type = "riscv,sv39";
>                         reg = <4>;
>                         riscv,isa = "rv64imafdc";
>                         tlb-split;

Your PATCH6 is already doing the right thing by skipping CPU DT
nodes that don't have "mmu-type" DT property.

The "mmu-type" DT property is very critical for RUNTIME M-mode
firmware (OpenSBI) because it tells whether a given CPU has MMU
(or not). This is also in agreement with the current DT bindings
document for RISC-V CPUs.

I suggest to drop the change in sifive/fu540-c000.dtsi and rest of
the patch is fine so my Reviewed-by still holds.

Regards,
Anup

> diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> index 40a3c442ac5f..38a699b997a8 100644
> --- a/arch/riscv/kernel/cpu.c
> +++ b/arch/riscv/kernel/cpu.c
> @@ -8,6 +8,8 @@
>  #include <linux/of.h>
>  #include <asm/smp.h>
>
> +extern bool pgtable_l4_enabled;
> +
>  /*
>   * Returns the hart ID of the given device tree node, or -ENODEV if the node
>   * isn't an enabled and valid RISC-V hart node.
> @@ -54,18 +56,19 @@ static void print_isa(struct seq_file *f, const char *isa)
>         seq_puts(f, "\n");
>  }
>
> -static void print_mmu(struct seq_file *f, const char *mmu_type)
> +static void print_mmu(struct seq_file *f)
>  {
> +       char sv_type[16];
> +
>  #if defined(CONFIG_32BIT)
> -       if (strcmp(mmu_type, "riscv,sv32") != 0)
> -               return;
> +       strncpy(sv_type, "sv32", 5);
>  #elif defined(CONFIG_64BIT)
> -       if (strcmp(mmu_type, "riscv,sv39") != 0 &&
> -           strcmp(mmu_type, "riscv,sv48") != 0)
> -               return;
> +       if (pgtable_l4_enabled)
> +               strncpy(sv_type, "sv48", 5);
> +       else
> +               strncpy(sv_type, "sv39", 5);
>  #endif
> -
> -       seq_printf(f, "mmu\t\t: %s\n", mmu_type+6);
> +       seq_printf(f, "mmu\t\t: %s\n", sv_type);
>  }
>
>  static void *c_start(struct seq_file *m, loff_t *pos)
> @@ -90,14 +93,13 @@ 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);
> -       const char *compat, *isa, *mmu;
> +       const char *compat, *isa;
>
>         seq_printf(m, "processor\t: %lu\n", cpu_id);
>         seq_printf(m, "hart\t\t: %lu\n", cpuid_to_hartid_map(cpu_id));
>         if (!of_property_read_string(node, "riscv,isa", &isa))
>                 print_isa(m, isa);
> -       if (!of_property_read_string(node, "mmu-type", &mmu))
> -               print_mmu(m, mmu);
> +       print_mmu(m);
>         if (!of_property_read_string(node, "compatible", &compat)
>             && strcmp(compat, "riscv"))
>                 seq_printf(m, "uarch\t\t: %s\n", compat);
> --
> 2.20.1
>
Alexandre Ghiti May 26, 2020, 4:26 p.m. UTC | #2
Hi Anup,

Le 5/25/20 à 2:21 AM, Anup Patel a écrit :
> On Sun, May 24, 2020 at 2:47 PM Alexandre Ghiti <alex@ghiti.fr> wrote:
>> Now that the mmu type is determined at runtime using SATP
>> characteristic, use the global variable pgtable_l4_enabled to output
>> mmu type of the processor through /proc/cpuinfo instead of relying on
>> device tree infos.
>>
>> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
>> Reviewed-by: Anup Patel <anup@brainfault.org>
>> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
>> ---
>>   arch/riscv/boot/dts/sifive/fu540-c000.dtsi |  4 ----
>>   arch/riscv/kernel/cpu.c                    | 24 ++++++++++++----------
>>   2 files changed, 13 insertions(+), 15 deletions(-)
>>
>> diff --git a/arch/riscv/boot/dts/sifive/fu540-c000.dtsi b/arch/riscv/boot/dts/sifive/fu540-c000.dtsi
>> index 7db861053483..6138590a2229 100644
>> --- a/arch/riscv/boot/dts/sifive/fu540-c000.dtsi
>> +++ b/arch/riscv/boot/dts/sifive/fu540-c000.dtsi
>> @@ -50,7 +50,6 @@
>>                          i-cache-size = <32768>;
>>                          i-tlb-sets = <1>;
>>                          i-tlb-size = <32>;
>> -                       mmu-type = "riscv,sv39";
>>                          reg = <1>;
>>                          riscv,isa = "rv64imafdc";
>>                          tlb-split;
>> @@ -74,7 +73,6 @@
>>                          i-cache-size = <32768>;
>>                          i-tlb-sets = <1>;
>>                          i-tlb-size = <32>;
>> -                       mmu-type = "riscv,sv39";
>>                          reg = <2>;
>>                          riscv,isa = "rv64imafdc";
>>                          tlb-split;
>> @@ -98,7 +96,6 @@
>>                          i-cache-size = <32768>;
>>                          i-tlb-sets = <1>;
>>                          i-tlb-size = <32>;
>> -                       mmu-type = "riscv,sv39";
>>                          reg = <3>;
>>                          riscv,isa = "rv64imafdc";
>>                          tlb-split;
>> @@ -122,7 +119,6 @@
>>                          i-cache-size = <32768>;
>>                          i-tlb-sets = <1>;
>>                          i-tlb-size = <32>;
>> -                       mmu-type = "riscv,sv39";
>>                          reg = <4>;
>>                          riscv,isa = "rv64imafdc";
>>                          tlb-split;
> Your PATCH6 is already doing the right thing by skipping CPU DT
> nodes that don't have "mmu-type" DT property.
>
> The "mmu-type" DT property is very critical for RUNTIME M-mode
> firmware (OpenSBI) because it tells whether a given CPU has MMU
> (or not). This is also in agreement with the current DT bindings
> document for RISC-V CPUs.
>
> I suggest to drop the change in sifive/fu540-c000.dtsi and rest of
> the patch is fine so my Reviewed-by still holds.


Ok I'll do that in v2, thanks.


Alex


> Regards,
> Anup
>
>> diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
>> index 40a3c442ac5f..38a699b997a8 100644
>> --- a/arch/riscv/kernel/cpu.c
>> +++ b/arch/riscv/kernel/cpu.c
>> @@ -8,6 +8,8 @@
>>   #include <linux/of.h>
>>   #include <asm/smp.h>
>>
>> +extern bool pgtable_l4_enabled;
>> +
>>   /*
>>    * Returns the hart ID of the given device tree node, or -ENODEV if the node
>>    * isn't an enabled and valid RISC-V hart node.
>> @@ -54,18 +56,19 @@ static void print_isa(struct seq_file *f, const char *isa)
>>          seq_puts(f, "\n");
>>   }
>>
>> -static void print_mmu(struct seq_file *f, const char *mmu_type)
>> +static void print_mmu(struct seq_file *f)
>>   {
>> +       char sv_type[16];
>> +
>>   #if defined(CONFIG_32BIT)
>> -       if (strcmp(mmu_type, "riscv,sv32") != 0)
>> -               return;
>> +       strncpy(sv_type, "sv32", 5);
>>   #elif defined(CONFIG_64BIT)
>> -       if (strcmp(mmu_type, "riscv,sv39") != 0 &&
>> -           strcmp(mmu_type, "riscv,sv48") != 0)
>> -               return;
>> +       if (pgtable_l4_enabled)
>> +               strncpy(sv_type, "sv48", 5);
>> +       else
>> +               strncpy(sv_type, "sv39", 5);
>>   #endif
>> -
>> -       seq_printf(f, "mmu\t\t: %s\n", mmu_type+6);
>> +       seq_printf(f, "mmu\t\t: %s\n", sv_type);
>>   }
>>
>>   static void *c_start(struct seq_file *m, loff_t *pos)
>> @@ -90,14 +93,13 @@ 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);
>> -       const char *compat, *isa, *mmu;
>> +       const char *compat, *isa;
>>
>>          seq_printf(m, "processor\t: %lu\n", cpu_id);
>>          seq_printf(m, "hart\t\t: %lu\n", cpuid_to_hartid_map(cpu_id));
>>          if (!of_property_read_string(node, "riscv,isa", &isa))
>>                  print_isa(m, isa);
>> -       if (!of_property_read_string(node, "mmu-type", &mmu))
>> -               print_mmu(m, mmu);
>> +       print_mmu(m);
>>          if (!of_property_read_string(node, "compatible", &compat)
>>              && strcmp(compat, "riscv"))
>>                  seq_printf(m, "uarch\t\t: %s\n", compat);
>> --
>> 2.20.1
>>
diff mbox series

Patch

diff --git a/arch/riscv/boot/dts/sifive/fu540-c000.dtsi b/arch/riscv/boot/dts/sifive/fu540-c000.dtsi
index 7db861053483..6138590a2229 100644
--- a/arch/riscv/boot/dts/sifive/fu540-c000.dtsi
+++ b/arch/riscv/boot/dts/sifive/fu540-c000.dtsi
@@ -50,7 +50,6 @@ 
 			i-cache-size = <32768>;
 			i-tlb-sets = <1>;
 			i-tlb-size = <32>;
-			mmu-type = "riscv,sv39";
 			reg = <1>;
 			riscv,isa = "rv64imafdc";
 			tlb-split;
@@ -74,7 +73,6 @@ 
 			i-cache-size = <32768>;
 			i-tlb-sets = <1>;
 			i-tlb-size = <32>;
-			mmu-type = "riscv,sv39";
 			reg = <2>;
 			riscv,isa = "rv64imafdc";
 			tlb-split;
@@ -98,7 +96,6 @@ 
 			i-cache-size = <32768>;
 			i-tlb-sets = <1>;
 			i-tlb-size = <32>;
-			mmu-type = "riscv,sv39";
 			reg = <3>;
 			riscv,isa = "rv64imafdc";
 			tlb-split;
@@ -122,7 +119,6 @@ 
 			i-cache-size = <32768>;
 			i-tlb-sets = <1>;
 			i-tlb-size = <32>;
-			mmu-type = "riscv,sv39";
 			reg = <4>;
 			riscv,isa = "rv64imafdc";
 			tlb-split;
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index 40a3c442ac5f..38a699b997a8 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -8,6 +8,8 @@ 
 #include <linux/of.h>
 #include <asm/smp.h>
 
+extern bool pgtable_l4_enabled;
+
 /*
  * Returns the hart ID of the given device tree node, or -ENODEV if the node
  * isn't an enabled and valid RISC-V hart node.
@@ -54,18 +56,19 @@  static void print_isa(struct seq_file *f, const char *isa)
 	seq_puts(f, "\n");
 }
 
-static void print_mmu(struct seq_file *f, const char *mmu_type)
+static void print_mmu(struct seq_file *f)
 {
+	char sv_type[16];
+
 #if defined(CONFIG_32BIT)
-	if (strcmp(mmu_type, "riscv,sv32") != 0)
-		return;
+	strncpy(sv_type, "sv32", 5);
 #elif defined(CONFIG_64BIT)
-	if (strcmp(mmu_type, "riscv,sv39") != 0 &&
-	    strcmp(mmu_type, "riscv,sv48") != 0)
-		return;
+	if (pgtable_l4_enabled)
+		strncpy(sv_type, "sv48", 5);
+	else
+		strncpy(sv_type, "sv39", 5);
 #endif
-
-	seq_printf(f, "mmu\t\t: %s\n", mmu_type+6);
+	seq_printf(f, "mmu\t\t: %s\n", sv_type);
 }
 
 static void *c_start(struct seq_file *m, loff_t *pos)
@@ -90,14 +93,13 @@  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);
-	const char *compat, *isa, *mmu;
+	const char *compat, *isa;
 
 	seq_printf(m, "processor\t: %lu\n", cpu_id);
 	seq_printf(m, "hart\t\t: %lu\n", cpuid_to_hartid_map(cpu_id));
 	if (!of_property_read_string(node, "riscv,isa", &isa))
 		print_isa(m, isa);
-	if (!of_property_read_string(node, "mmu-type", &mmu))
-		print_mmu(m, mmu);
+	print_mmu(m);
 	if (!of_property_read_string(node, "compatible", &compat)
 	    && strcmp(compat, "riscv"))
 		seq_printf(m, "uarch\t\t: %s\n", compat);