| Message ID | 20220502125015.1345312-3-niklas.cassel@wdc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | riscv mmu-type minor fixes | expand |
On Mon, May 2, 2022 at 6:20 PM Niklas Cassel <niklas.cassel@wdc.com> wrote: > > Currently on a 64-bit kernel built without CONFIG_MMU, /proc/cpuinfo will > show the current MMU mode as sv57. > > While the device tree property "mmu-type" does have a value "riscv,none" to > describe a CPU without a MMU, since commit 73c7c8f68e72 ("riscv: Use > pgtable_l4_enabled to output mmu_type in cpuinfo"), we no longer rely on > device tree to output the MMU mode. (Not even for CONFIG_32BIT.) > > Therefore, instead of readding code to look at the "mmu-type" device tree > property, let's continue with the existing convention to use fixed values > for configurations where we don't determine the MMU mode at runtime. > > Add a new fixed value for !CONFIG_MMU in order to output the correct > MMU mode in cpuinfo. > > Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com> Looks good to me. Reviewed-by: Anup Patel <anup@brainfault.org> Regards, Anup > --- > arch/riscv/kernel/cpu.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c > index ccb617791e56..ecfb3e85ffb2 100644 > --- a/arch/riscv/kernel/cpu.c > +++ b/arch/riscv/kernel/cpu.c > @@ -138,6 +138,7 @@ static void print_mmu(struct seq_file *f) > { > char sv_type[16]; > > +#ifdef CONFIG_MMU > #if defined(CONFIG_32BIT) > strncpy(sv_type, "sv32", 5); > #elif defined(CONFIG_64BIT) > @@ -148,6 +149,9 @@ static void print_mmu(struct seq_file *f) > else > strncpy(sv_type, "sv39", 5); > #endif > +#else > + strncpy(sv_type, "none", 5); > +#endif /* CONFIG_MMU */ > seq_printf(f, "mmu\t\t: %s\n", sv_type); > } > > -- > 2.35.1 > > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c index ccb617791e56..ecfb3e85ffb2 100644 --- a/arch/riscv/kernel/cpu.c +++ b/arch/riscv/kernel/cpu.c @@ -138,6 +138,7 @@ static void print_mmu(struct seq_file *f) { char sv_type[16]; +#ifdef CONFIG_MMU #if defined(CONFIG_32BIT) strncpy(sv_type, "sv32", 5); #elif defined(CONFIG_64BIT) @@ -148,6 +149,9 @@ static void print_mmu(struct seq_file *f) else strncpy(sv_type, "sv39", 5); #endif +#else + strncpy(sv_type, "none", 5); +#endif /* CONFIG_MMU */ seq_printf(f, "mmu\t\t: %s\n", sv_type); }
Currently on a 64-bit kernel built without CONFIG_MMU, /proc/cpuinfo will show the current MMU mode as sv57. While the device tree property "mmu-type" does have a value "riscv,none" to describe a CPU without a MMU, since commit 73c7c8f68e72 ("riscv: Use pgtable_l4_enabled to output mmu_type in cpuinfo"), we no longer rely on device tree to output the MMU mode. (Not even for CONFIG_32BIT.) Therefore, instead of readding code to look at the "mmu-type" device tree property, let's continue with the existing convention to use fixed values for configurations where we don't determine the MMU mode at runtime. Add a new fixed value for !CONFIG_MMU in order to output the correct MMU mode in cpuinfo. Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com> --- arch/riscv/kernel/cpu.c | 4 ++++ 1 file changed, 4 insertions(+)