From 01573e231f18eb2d99162747186f59511f56b64d Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 08 Dec 2023 10:40:48 +0000
Subject: [PATCH] 移去rt
---
kernel/arch/riscv/kernel/cpufeature.c | 144 +++++++++++++++++++++++++++++++++++++++---------
1 files changed, 117 insertions(+), 27 deletions(-)
diff --git a/kernel/arch/riscv/kernel/cpufeature.c b/kernel/arch/riscv/kernel/cpufeature.c
index 17011a8..ac202f4 100644
--- a/kernel/arch/riscv/kernel/cpufeature.c
+++ b/kernel/arch/riscv/kernel/cpufeature.c
@@ -1,33 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Copied from arch/arm64/kernel/cpufeature.c
*
* Copyright (C) 2015 ARM Ltd.
* Copyright (C) 2017 SiFive
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <linux/bitmap.h>
#include <linux/of.h>
#include <asm/processor.h>
#include <asm/hwcap.h>
+#include <asm/smp.h>
+#include <asm/switch_to.h>
unsigned long elf_hwcap __read_mostly;
+
+/* Host ISA bitmap */
+static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly;
+
+#ifdef CONFIG_FPU
+bool has_fpu __read_mostly;
+#endif
+
+/**
+ * riscv_isa_extension_base() - Get base extension word
+ *
+ * @isa_bitmap: ISA bitmap to use
+ * Return: base extension word as unsigned long value
+ *
+ * NOTE: If isa_bitmap is NULL then Host ISA bitmap will be used.
+ */
+unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap)
+{
+ if (!isa_bitmap)
+ return riscv_isa[0];
+ return isa_bitmap[0];
+}
+EXPORT_SYMBOL_GPL(riscv_isa_extension_base);
+
+/**
+ * __riscv_isa_extension_available() - Check whether given extension
+ * is available or not
+ *
+ * @isa_bitmap: ISA bitmap to use
+ * @bit: bit position of the desired extension
+ * Return: true or false
+ *
+ * NOTE: If isa_bitmap is NULL then Host ISA bitmap will be used.
+ */
+bool __riscv_isa_extension_available(const unsigned long *isa_bitmap, int bit)
+{
+ const unsigned long *bmap = (isa_bitmap) ? isa_bitmap : riscv_isa;
+
+ if (bit >= RISCV_ISA_EXT_MAX)
+ return false;
+
+ return test_bit(bit, bmap) ? true : false;
+}
+EXPORT_SYMBOL_GPL(__riscv_isa_extension_available);
void riscv_fill_hwcap(void)
{
struct device_node *node;
const char *isa;
- size_t i;
+ char print_str[BITS_PER_LONG + 1];
+ size_t i, j, isa_len;
static unsigned long isa2hwcap[256] = {0};
isa2hwcap['i'] = isa2hwcap['I'] = COMPAT_HWCAP_ISA_I;
@@ -39,23 +76,76 @@
elf_hwcap = 0;
- /*
- * We don't support running Linux on hertergenous ISA systems. For
- * now, we just check the ISA of the first processor.
- */
- node = of_find_node_by_type(NULL, "cpu");
- if (!node) {
- pr_warning("Unable to find \"cpu\" devicetree entry");
- return;
+ bitmap_zero(riscv_isa, RISCV_ISA_EXT_MAX);
+
+ for_each_of_cpu_node(node) {
+ unsigned long this_hwcap = 0;
+ unsigned long this_isa = 0;
+
+ if (riscv_of_processor_hartid(node) < 0)
+ continue;
+
+ if (of_property_read_string(node, "riscv,isa", &isa)) {
+ pr_warn("Unable to find \"riscv,isa\" devicetree entry\n");
+ continue;
+ }
+
+ i = 0;
+ isa_len = strlen(isa);
+#if IS_ENABLED(CONFIG_32BIT)
+ if (!strncmp(isa, "rv32", 4))
+ i += 4;
+#elif IS_ENABLED(CONFIG_64BIT)
+ if (!strncmp(isa, "rv64", 4))
+ i += 4;
+#endif
+ for (; i < isa_len; ++i) {
+ this_hwcap |= isa2hwcap[(unsigned char)(isa[i])];
+ /*
+ * TODO: X, Y and Z extension parsing for Host ISA
+ * bitmap will be added in-future.
+ */
+ if ('a' <= isa[i] && isa[i] < 'x')
+ this_isa |= (1UL << (isa[i] - 'a'));
+ }
+
+ /*
+ * All "okay" hart should have same isa. Set HWCAP based on
+ * common capabilities of every "okay" hart, in case they don't
+ * have.
+ */
+ if (elf_hwcap)
+ elf_hwcap &= this_hwcap;
+ else
+ elf_hwcap = this_hwcap;
+
+ if (riscv_isa[0])
+ riscv_isa[0] &= this_isa;
+ else
+ riscv_isa[0] = this_isa;
}
- if (of_property_read_string(node, "riscv,isa", &isa)) {
- pr_warning("Unable to find \"riscv,isa\" devicetree entry");
- return;
+ /* We don't support systems with F but without D, so mask those out
+ * here. */
+ if ((elf_hwcap & COMPAT_HWCAP_ISA_F) && !(elf_hwcap & COMPAT_HWCAP_ISA_D)) {
+ pr_info("This kernel does not support systems with F but not D\n");
+ elf_hwcap &= ~COMPAT_HWCAP_ISA_F;
}
- for (i = 0; i < strlen(isa); ++i)
- elf_hwcap |= isa2hwcap[(unsigned char)(isa[i])];
+ memset(print_str, 0, sizeof(print_str));
+ for (i = 0, j = 0; i < BITS_PER_LONG; i++)
+ if (riscv_isa[0] & BIT_MASK(i))
+ print_str[j++] = (char)('a' + i);
+ pr_info("riscv: ISA extensions %s\n", print_str);
- pr_info("elf_hwcap is 0x%lx", elf_hwcap);
+ memset(print_str, 0, sizeof(print_str));
+ for (i = 0, j = 0; i < BITS_PER_LONG; i++)
+ if (elf_hwcap & BIT_MASK(i))
+ print_str[j++] = (char)('a' + i);
+ pr_info("riscv: ELF capabilities %s\n", print_str);
+
+#ifdef CONFIG_FPU
+ if (elf_hwcap & (COMPAT_HWCAP_ISA_F | COMPAT_HWCAP_ISA_D))
+ has_fpu = true;
+#endif
}
--
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