On Wed, Apr 03, 2024 at 04:34:50PM -0700, Deepak Gupta wrote: > Defines a base default value for envcfg per task. By default all tasks > should have cache zeroing capability. Any future base capabilities that > apply to all tasks can be turned on same way. > > Signed-off-by: Deepak Gupta <debug@xxxxxxxxxxxx> > --- > arch/riscv/include/asm/csr.h | 2 ++ > arch/riscv/kernel/process.c | 6 ++++++ > 2 files changed, 8 insertions(+) > > diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h > index 2468c55933cd..bbd2207adb39 100644 > --- a/arch/riscv/include/asm/csr.h > +++ b/arch/riscv/include/asm/csr.h > @@ -202,6 +202,8 @@ > #define ENVCFG_CBIE_FLUSH _AC(0x1, UL) > #define ENVCFG_CBIE_INV _AC(0x3, UL) > #define ENVCFG_FIOM _AC(0x1, UL) > +/* by default all threads should be able to zero cache */ > +#define ENVCFG_BASE ENVCFG_CBZE > > /* Smstateen bits */ > #define SMSTATEEN0_AIA_IMSIC_SHIFT 58 > diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c > index 92922dbd5b5c..d3109557f951 100644 > --- a/arch/riscv/kernel/process.c > +++ b/arch/riscv/kernel/process.c > @@ -152,6 +152,12 @@ void start_thread(struct pt_regs *regs, unsigned long pc, > else > regs->status |= SR_UXL_64; > #endif > + /* > + * read current envcfg settings, AND it with base settings applicable > + * for all the tasks. Base settings should've been set up during CPU > + * bring up. > + */ > + current->thread_info.envcfg = csr_read(CSR_ENVCFG) & ENVCFG_BASE; This needs to be gated on xlinuxenvcfg. - Charlie > } > > void flush_thread(void) > -- > 2.43.2 >
