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Subject: [RFC PATCH v1 03/28] riscv: define default value for envcfg
Date: Wed, 24 Jan 2024 22:21:28 -0800
Message-ID: <20240125062739.1339782-4-debug@rivosinc.com>
In-Reply-To: <20240125062739.1339782-1-debug@rivosinc.com>
References: <20240125062739.1339782-1-debug@rivosinc.com>
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From: Deepak Gupta <debug@rivosinc.com>

Defines a base default value for envcfg per task. By default all tasks
should have cache zeroing capability. Any future capabilities can be
turned on.

Signed-off-by: Deepak Gupta <debug@rivosinc.com>
---
 arch/riscv/include/asm/csr.h | 2 ++
 arch/riscv/kernel/process.c  | 1 +
 2 files changed, 3 insertions(+)

diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
index b3400517b0a9..01ba87954da2 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 4f21d970a129..2420123444c4 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -152,6 +152,7 @@ void start_thread(struct pt_regs *regs, unsigned long pc,
 	else
 		regs->status |= SR_UXL_64;
 #endif
+	current->thread_info.envcfg = ENVCFG_BASE;
 }
 
 void flush_thread(void)
-- 
2.43.0