Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Greentime Hu <greentime.hu@sifive.com>
To:     greentime.hu@sifive.com, guoren@linux.alibaba.com,
        vincent.chen@sifive.com, paul.walmsley@sifive.com,
        palmerdabbelt@google.com, linux-riscv@lists.infradead.org,
        linux-kernel@vger.kernel.org, oleg@redhat.com
Subject: [RFC PATCH v4 07/13] riscv: Add has_vector/riscv_vsize to save vector features.
Date:   Tue, 26 May 2020 15:02:36 +0800
Message-Id: <e896db91e3303f64ac401021f848e536e9d42aaa.1590474856.git.greentime.hu@sifive.com>
In-Reply-To: <cover.1590474856.git.greentime.hu@sifive.com>
References: <cover.1590474856.git.greentime.hu@sifive.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Guo Ren <guoren@linux.alibaba.com>

This patch is used to detect vector support status of CPU and use
riscv_vsize to save the size of all the vector registers. It assumes
all harts has the same capabilities in SMP system.

[greentime.hu@sifive.com: add support for dynamic vlen]
Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
---
 arch/riscv/kernel/cpufeature.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index c8527d770c98..5a68a926da68 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -16,6 +16,10 @@ unsigned long elf_hwcap __read_mostly;
 #ifdef CONFIG_FPU
 bool has_fpu __read_mostly;
 #endif
+#ifdef CONFIG_VECTOR
+bool has_vector __read_mostly;
+unsigned long riscv_vsize __read_mostly;
+#endif
 
 void riscv_fill_hwcap(void)
 {
@@ -73,4 +77,11 @@ void riscv_fill_hwcap(void)
 	if (elf_hwcap & (COMPAT_HWCAP_ISA_F | COMPAT_HWCAP_ISA_D))
 		has_fpu = true;
 #endif
+
+#ifdef CONFIG_VECTOR
+	if (elf_hwcap & COMPAT_HWCAP_ISA_V) {
+		has_vector = true;
+		riscv_vsize = csr_read(CSR_VLENB) * 32;
+	}
+#endif
 }
-- 
2.26.2