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From: Greentime Hu <greentime.hu@sifive.com>
To: greentime.hu@sifive.com, linux-riscv@lists.infradead.org,
	linux-kernel@vger.kernel.org, aou@eecs.berkeley.edu,
	palmer@dabbelt.com, paul.walmsley@sifive.com
Cc: Vincent Chen <vincent.chen@sifive.com>
Subject: [RFC PATCH v7 20/21] riscv: Allocate space for vector registers in start_thread()
Date: Thu, 10 Sep 2020 16:12:15 +0800	[thread overview]
Message-ID: <1b09427788749bf7b5e35c771657661bd7165348.1599719352.git.greentime.hu@sifive.com> (raw)
In-Reply-To: <cover.1599719352.git.greentime.hu@sifive.com>

It allocates memory space for vector registers in start_thread() instead of
allocating in vstate_restore() in this patch. We can allocate memory here
so that it will be more readable.

Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
---
 arch/riscv/include/asm/switch_to.h | 7 +------
 arch/riscv/kernel/process.c        | 8 ++++++++
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/arch/riscv/include/asm/switch_to.h b/arch/riscv/include/asm/switch_to.h
index d33a86a48f0d..58898d33bf28 100644
--- a/arch/riscv/include/asm/switch_to.h
+++ b/arch/riscv/include/asm/switch_to.h
@@ -98,12 +98,6 @@ static inline void vstate_restore(struct task_struct *task,
 {
 	if ((regs->status & SR_VS) != SR_VS_OFF) {
 		struct __riscv_v_state *vstate = &(task->thread.vstate);
-
-		/* Allocate space for vector registers. */
-		if (!vstate->datap) {
-			vstate->datap = kzalloc(riscv_vsize, GFP_ATOMIC);
-			vstate->size = riscv_vsize;
-		}
 		__vstate_restore(vstate, vstate->datap);
 		__vstate_clean(regs);
 	}
@@ -122,6 +116,7 @@ static inline void __switch_to_vector(struct task_struct *prev,
 
 #else
 #define has_vector false
+#define riscv_vsize (0)
 #define vstate_save(task, regs) do { } while (0)
 #define vstate_restore(task, regs) do { } while (0)
 #define __switch_to_vector(__prev, __next) do { } while (0)
diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index fb485c9bceee..009ab4849fce 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -84,7 +84,15 @@ void start_thread(struct pt_regs *regs, unsigned long pc,
 	}
 
 	if (has_vector) {
+		struct __riscv_v_state *vstate = &(current->thread.vstate);
+
+		/* Enable vector and allocate memory for vector registers. */
+		vstate->datap = kzalloc(riscv_vsize, GFP_KERNEL);
+		if (WARN_ON(!vstate->datap))
+			return;
+		vstate->size = riscv_vsize;
 		regs->status |= SR_VS_INITIAL;
+
 		/*
 		 * Restore the initial value to the vector register
 		 * before starting the user program.
-- 
2.28.0


  parent reply	other threads:[~2020-09-10  8:25 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-10  8:11 [RFC PATCH v7 00/21] riscv: Add vector ISA support Greentime Hu
2020-09-10  8:11 ` [RFC PATCH v7 01/21] riscv: Separate patch for cflags and aflags Greentime Hu
2020-09-10  8:11 ` [RFC PATCH v7 02/21] riscv: Rename __switch_to_aux -> fpu Greentime Hu
2020-09-10  8:11 ` [RFC PATCH v7 03/21] riscv: Extending cpufeature.c to detect V-extension Greentime Hu
2020-09-10  8:11 ` [RFC PATCH v7 04/21] riscv: Add new csr defines related to vector extension Greentime Hu
2020-09-10  8:12 ` [RFC PATCH v7 05/21] riscv: Add vector feature to compile Greentime Hu
2020-09-10  8:12 ` [RFC PATCH v7 06/21] riscv: Add has_vector/riscv_vsize to save vector features Greentime Hu
2020-09-10  8:12 ` [RFC PATCH v7 07/21] riscv: Reset vector register Greentime Hu
2020-09-10  8:12 ` [RFC PATCH v7 08/21] riscv: Add vector struct and assembler definitions Greentime Hu
2020-09-10  8:12 ` [RFC PATCH v7 09/21] riscv: Add task switch support for vector Greentime Hu
2020-09-10  8:12 ` [RFC PATCH v7 10/21] " Greentime Hu
2020-09-10  8:12 ` [RFC PATCH v7 11/21] riscv: Add ptrace vector support Greentime Hu
2020-09-10  8:12 ` [RFC PATCH v7 12/21] riscv: Add sigcontext save/restore for vector Greentime Hu
2020-09-10  8:12 ` [RFC PATCH v7 13/21] riscv: signal: Report signal frame size to userspace via auxv Greentime Hu
2020-09-10  8:12 ` [RFC PATCH v7 14/21] riscv: Add support for kernel mode vector Greentime Hu
2020-09-10  8:12 ` [RFC PATCH v7 15/21] riscv: Use CSR_STATUS to replace sstatus in vector.S Greentime Hu
2020-09-10  8:12 ` [RFC PATCH v7 16/21] riscv: Add vector extension XOR implementation Greentime Hu
2020-09-10  8:12 ` [RFC PATCH v7 17/21] riscv: Initialize vector registers with proper vsetvli then it can work normally Greentime Hu
2020-09-10  8:12 ` [RFC PATCH v7 18/21] riscv: Optimize vector registers initialization Greentime Hu
2020-09-10  8:12 ` [RFC PATCH v7 19/21] riscv: Fix an illegal instruction exception when accessing vlenb without enable vector first Greentime Hu
2020-09-10  8:12 ` Greentime Hu [this message]
2020-09-10  8:12 ` [RFC PATCH v7 21/21] riscv: Optimize task switch codes of vector Greentime Hu

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