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From: Charlie Jenkins <charlie@rivosinc.com>
To: "Conor Dooley" <conor@kernel.org>,
	"Rob Herring" <robh@kernel.org>,
	"Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>,
	"Paul Walmsley" <paul.walmsley@sifive.com>,
	"Palmer Dabbelt" <palmer@dabbelt.com>,
	"Albert Ou" <aou@eecs.berkeley.edu>,
	"Guo Ren" <guoren@kernel.org>,
	"Conor Dooley" <conor+dt@kernel.org>,
	"Chen-Yu Tsai" <wens@csie.org>,
	"Jernej Skrabec" <jernej.skrabec@gmail.com>,
	"Samuel Holland" <samuel@sholland.org>,
	"Conor Dooley" <conor.dooley@microchip.com>,
	"Evan Green" <evan@rivosinc.com>,
	"Clément Léger" <cleger@rivosinc.com>,
	"Jonathan Corbet" <corbet@lwn.net>,
	"Shuah Khan" <shuah@kernel.org>
Cc: linux-riscv@lists.infradead.org, devicetree@vger.kernel.org,
	 linux-kernel@vger.kernel.org,
	Palmer Dabbelt <palmer@rivosinc.com>,
	 linux-arm-kernel@lists.infradead.org,
	linux-sunxi@lists.linux.dev,  linux-doc@vger.kernel.org,
	linux-kselftest@vger.kernel.org,
	 Charlie Jenkins <charlie@rivosinc.com>
Subject: [PATCH v3 04/17] riscv: vector: Use vlenb from DT
Date: Sat, 20 Apr 2024 18:04:36 -0700	[thread overview]
Message-ID: <20240420-dev-charlie-support_thead_vector_6_9-v3-4-67cff4271d1d@rivosinc.com> (raw)
In-Reply-To: <20240420-dev-charlie-support_thead_vector_6_9-v3-0-67cff4271d1d@rivosinc.com>

If vlenb is provided in the device tree, prefer that over reading the
vlenb csr.

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
---
 arch/riscv/include/asm/cpufeature.h |  2 ++
 arch/riscv/kernel/cpufeature.c      | 26 ++++++++++++++++++++++++++
 arch/riscv/kernel/vector.c          | 13 +++++++++----
 3 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h
index 347805446151..809f61ffb667 100644
--- a/arch/riscv/include/asm/cpufeature.h
+++ b/arch/riscv/include/asm/cpufeature.h
@@ -31,6 +31,8 @@ DECLARE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
 /* Per-cpu ISA extensions. */
 extern struct riscv_isainfo hart_isa[NR_CPUS];
 
+extern u32 riscv_vlenb_dt[NR_CPUS];
+
 void riscv_user_isa_enable(void);
 
 #if defined(CONFIG_RISCV_MISALIGNED)
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index c6e27b45e192..48874aac4871 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -35,6 +35,8 @@ static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly;
 /* Per-cpu ISA extensions. */
 struct riscv_isainfo hart_isa[NR_CPUS];
 
+u32 riscv_vlenb_dt[NR_CPUS];
+
 /**
  * riscv_isa_extension_base() - Get base extension word
  *
@@ -656,6 +658,28 @@ static int __init riscv_isa_fallback_setup(char *__unused)
 early_param("riscv_isa_fallback", riscv_isa_fallback_setup);
 #endif
 
+static void riscv_set_vlenb_from_dt(void)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu) {
+		struct device_node *cpu_node;
+
+		cpu_node = of_cpu_device_node_get(cpu);
+		if (!cpu_node) {
+			pr_warn("Unable to find cpu node\n");
+			continue;
+		}
+
+		if (!of_property_read_u32(cpu_node, "riscv,vlenb", &riscv_vlenb_dt[cpu])) {
+			of_node_put(cpu_node);
+			continue;
+		}
+
+		of_node_put(cpu_node);
+	}
+}
+
 void __init riscv_fill_hwcap(void)
 {
 	char print_str[NUM_ALPHA_EXTS + 1];
@@ -675,6 +699,8 @@ void __init riscv_fill_hwcap(void)
 	} else {
 		int ret = riscv_fill_hwcap_from_ext_list(isa2hwcap);
 
+		riscv_set_vlenb_from_dt();
+
 		if (ret && riscv_isa_fallback) {
 			pr_info("Falling back to deprecated \"riscv,isa\"\n");
 			riscv_fill_hwcap_from_isa_string(isa2hwcap);
diff --git a/arch/riscv/kernel/vector.c b/arch/riscv/kernel/vector.c
index 6727d1d3b8f2..fb7f3ca80d9e 100644
--- a/arch/riscv/kernel/vector.c
+++ b/arch/riscv/kernel/vector.c
@@ -32,11 +32,16 @@ EXPORT_SYMBOL_GPL(riscv_v_vsize);
 int riscv_v_setup_vsize(void)
 {
 	unsigned long this_vsize;
+	int cpu = smp_processor_id();
 
-	/* There are 32 vector registers with vlenb length. */
-	riscv_v_enable();
-	this_vsize = csr_read(CSR_VLENB) * 32;
-	riscv_v_disable();
+	if (riscv_vlenb_dt[cpu]) {
+		this_vsize = riscv_vlenb_dt[cpu];
+	} else {
+		/* There are 32 vector registers with vlenb length. */
+		riscv_v_enable();
+		this_vsize = csr_read(CSR_VLENB) * 32;
+		riscv_v_disable();
+	}
 
 	if (!riscv_v_vsize) {
 		riscv_v_vsize = this_vsize;

-- 
2.44.0


  parent reply	other threads:[~2024-04-21  1:04 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-21  1:04 [PATCH v3 00/17] riscv: Support vendor extensions and xtheadvector Charlie Jenkins
2024-04-21  1:04 ` [PATCH v3 01/17] riscv: cpufeature: Fix thead vector hwcap removal Charlie Jenkins
2024-04-26  8:15   ` Guo Ren
2024-04-21  1:04 ` [PATCH v3 02/17] dt-bindings: riscv: Add xtheadvector ISA extension description Charlie Jenkins
2024-04-21  1:04 ` [PATCH v3 03/17] dt-bindings: riscv: cpus: add a vlen register length property Charlie Jenkins
2024-04-21  1:04 ` Charlie Jenkins [this message]
2024-04-26 15:17   ` [PATCH v3 04/17] riscv: vector: Use vlenb from DT Conor Dooley
2024-04-26 16:21     ` Conor Dooley
2024-04-26 17:03       ` Charlie Jenkins
2024-04-21  1:04 ` [PATCH v3 05/17] riscv: dts: allwinner: Add xtheadvector to the D1/D1s devicetree Charlie Jenkins
2024-04-21  1:04 ` [PATCH v3 06/17] riscv: Fix extension subset checking Charlie Jenkins
2024-04-24 14:22   ` Alexandre Ghiti
2024-04-24 14:51     ` Conor Dooley
2024-04-24 15:13       ` Charlie Jenkins
2024-04-24 15:21         ` Conor Dooley
2024-04-24 15:36           ` Charlie Jenkins
2024-04-21  1:04 ` [PATCH v3 07/17] riscv: Extend cpufeature.c to detect vendor extensions Charlie Jenkins
2024-04-26 16:00   ` Conor Dooley
2024-04-26 18:00     ` Charlie Jenkins
2024-04-21  1:04 ` [PATCH v3 08/17] riscv: Introduce vendor variants of extension helpers Charlie Jenkins
2024-04-26 16:19   ` Conor Dooley
2024-04-26 20:01     ` Charlie Jenkins
2024-04-26 20:37       ` Conor Dooley
2024-04-21  1:04 ` [PATCH v3 09/17] riscv: drivers: Convert xandespmu to use the vendor extension framework Charlie Jenkins
2024-04-26 16:25   ` Conor Dooley
2024-04-26 20:34     ` Charlie Jenkins
2024-04-26 20:46       ` Conor Dooley
2024-04-21  1:04 ` [PATCH v3 10/17] RISC-V: define the elements of the VCSR vector CSR Charlie Jenkins
2024-04-21  1:04 ` [PATCH v3 11/17] riscv: csr: Add CSR encodings for VCSR_VXRM/VCSR_VXSAT Charlie Jenkins
2024-04-21  1:04 ` [PATCH v3 12/17] riscv: Add xtheadvector instruction definitions Charlie Jenkins
2024-04-21  1:04 ` [PATCH v3 13/17] riscv: vector: Support xtheadvector save/restore Charlie Jenkins
2024-04-21  1:04 ` [PATCH v3 14/17] riscv: hwprobe: Add thead vendor extension probing Charlie Jenkins
2024-04-21  1:04 ` [PATCH v3 15/17] riscv: hwprobe: Document thead vendor extensions and xtheadvector extension Charlie Jenkins
2024-04-21  1:04 ` [PATCH v3 16/17] selftests: riscv: Fix vector tests Charlie Jenkins
2024-04-21  1:04 ` [PATCH v3 17/17] selftests: riscv: Support xtheadvector in " Charlie Jenkins

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