[PATCH 2/5] riscv: Add basic support for SBI v0.2

Pragnesh Patel pragnesh.patel at sifive.com
Wed Mar 11 10:07:09 CET 2020


Hi Bin,

>-----Original Message-----
>From: U-Boot <u-boot-bounces at lists.denx.de> On Behalf Of Bin Meng
>Sent: 10 March 2020 08:05
>To: Rick Chen <rick at andestech.com>; Anup Patel <anup.patel at wdc.com>;
>Atish Patra <atish.patra at wdc.com>; Lukas Auer
><lukas.auer at aisec.fraunhofer.de>; U-Boot Mailing List <u-
>boot at lists.denx.de>
>Subject: [PATCH 2/5] riscv: Add basic support for SBI v0.2
>
>The SBI v0.2 introduces a base extension which is backward compatible with
>v0.1. Implement all helper functions and minimum required SBI calls from
>v0.2 for now. All other base extension function will be added later as per
>need.
>
>As v0.2 calling convention is backward compatible with v0.1, remove the v0.1
>helper functions and just use v0.2 calling convention.
>
>Add a new Kconfig options CONFIG_SBI for the new SBI v0.2 codes, and let
>CONFIG_SBI_IPI depend on it.
>
>This commit is inspired from Linux kernel patch:
>https://patchwork.kernel.org/patch/11407363/
>
>Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
>---
>
> arch/riscv/Kconfig           |   5 ++
> arch/riscv/include/asm/sbi.h | 135 +++++++++++++-------------------
> arch/riscv/lib/Makefile      |   1 +
> arch/riscv/lib/sbi.c         | 181
>+++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 243 insertions(+), 79 deletions(-)  create mode 100644
>arch/riscv/lib/sbi.c
>
>diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 3338b78..09fff05
>100644
>--- a/arch/riscv/Kconfig
>+++ b/arch/riscv/Kconfig
>@@ -210,8 +210,13 @@ config NR_CPUS
> 	  Stack memory is pre-allocated. U-Boot must therefore know the
> 	  maximum number of CPUs that may be present.
>
>+config SBI
>+	bool
>+	default y if RISCV_SMODE || SPL_RISCV_SMODE
>+
> config SBI_IPI
> 	bool
>+	depends on SBI
> 	default y if RISCV_SMODE || SPL_RISCV_SMODE
> 	depends on SMP
>
>diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h index
>187ca58..fc8637c 100644
>--- a/arch/riscv/include/asm/sbi.h
>+++ b/arch/riscv/include/asm/sbi.h
>@@ -11,91 +11,68 @@
>
> #include <linux/types.h>
>
>-#define SBI_EXT_0_1_SET_TIMER 0x0
>-#define SBI_EXT_0_1_CONSOLE_PUTCHAR 0x1 -#define
>SBI_EXT_0_1_CONSOLE_GETCHAR 0x2 -#define SBI_EXT_0_1_CLEAR_IPI 0x3 -
>#define SBI_EXT_0_1_SEND_IPI 0x4 -#define SBI_EXT_0_1_REMOTE_FENCE_I
>0x5 -#define SBI_EXT_0_1_REMOTE_SFENCE_VMA 0x6 -#define
>SBI_EXT_0_1_REMOTE_SFENCE_VMA_ASID 0x7 -#define
>SBI_EXT_0_1_SHUTDOWN 0x8
>+enum sbi_ext_id {
>+	SBI_EXT_0_1_SET_TIMER = 0x0,
>+	SBI_EXT_0_1_CONSOLE_PUTCHAR = 0x1,
>+	SBI_EXT_0_1_CONSOLE_GETCHAR = 0x2,
>+	SBI_EXT_0_1_CLEAR_IPI = 0x3,
>+	SBI_EXT_0_1_SEND_IPI = 0x4,
>+	SBI_EXT_0_1_REMOTE_FENCE_I = 0x5,
>+	SBI_EXT_0_1_REMOTE_SFENCE_VMA = 0x6,
>+	SBI_EXT_0_1_REMOTE_SFENCE_VMA_ASID = 0x7,
>+	SBI_EXT_0_1_SHUTDOWN = 0x8,
>+	SBI_EXT_BASE = 0x10,
>+};
>
>-#define SBI_CALL(which, arg0, arg1, arg2, arg3) ({		\
>-	register uintptr_t a0 asm ("a0") = (uintptr_t)(arg0);	\
>-	register uintptr_t a1 asm ("a1") = (uintptr_t)(arg1);	\
>-	register uintptr_t a2 asm ("a2") = (uintptr_t)(arg2);	\
>-	register uintptr_t a3 asm ("a3") = (uintptr_t)(arg3);	\
>-	register uintptr_t a7 asm ("a7") = (uintptr_t)(which);	\
>-	asm volatile ("ecall"					\
>-		      : "+r" (a0)				\
>-		      : "r" (a1), "r" (a2), "r" (a3), "r" (a7)	\
>-		      : "memory");				\
>-	a0;							\
>-})
>+enum sbi_ext_base_fid {
>+	SBI_EXT_BASE_GET_SPEC_VERSION = 0,
>+	SBI_EXT_BASE_GET_IMP_ID,
>+	SBI_EXT_BASE_GET_IMP_VERSION,
>+	SBI_EXT_BASE_PROBE_EXT,
>+	SBI_EXT_BASE_GET_MVENDORID,
>+	SBI_EXT_BASE_GET_MARCHID,
>+	SBI_EXT_BASE_GET_MIMPID,
>+};
>
>-/* Lazy implementations until SBI is finalized */ -#define SBI_CALL_0(which)
>SBI_CALL(which, 0, 0, 0, 0) -#define SBI_CALL_1(which, arg0) SBI_CALL(which,
>arg0, 0, 0, 0) -#define SBI_CALL_2(which, arg0, arg1) SBI_CALL(which, arg0,
>arg1, 0, 0) -#define SBI_CALL_3(which, arg0, arg1, arg2) \
>-		SBI_CALL(which, arg0, arg1, arg2, 0)
>-#define SBI_CALL_4(which, arg0, arg1, arg2, arg3) \
>-		SBI_CALL(which, arg0, arg1, arg2, arg3)
>+#define SBI_SPEC_VERSION_DEFAULT	0x1
>+#define SBI_SPEC_VERSION_MAJOR_SHIFT	24
>+#define SBI_SPEC_VERSION_MAJOR_MASK	0x7f
>+#define SBI_SPEC_VERSION_MINOR_MASK	0xffffff
>
>-static inline void sbi_console_putchar(int ch) -{
>-	SBI_CALL_1(SBI_EXT_0_1_CONSOLE_PUTCHAR, ch);
>-}
>+/* SBI return error codes */
>+#define SBI_SUCCESS			0
>+#define SBI_ERR_FAILURE			-1
>+#define SBI_ERR_NOT_SUPPORTED		-2
>+#define SBI_ERR_INVALID_PARAM		-3
>+#define SBI_ERR_DENIED			-4
>+#define SBI_ERR_INVALID_ADDRESS		-5
>
>-static inline int sbi_console_getchar(void) -{
>-	return SBI_CALL_0(SBI_EXT_0_1_CONSOLE_GETCHAR);
>-}
>+extern unsigned long sbi_spec_version;
>+struct sbiret {
>+	long error;
>+	long value;
>+};
>
>-static inline void sbi_set_timer(uint64_t stime_value) -{ -#if __riscv_xlen == 32
>-	SBI_CALL_2(SBI_EXT_0_1_SET_TIMER, stime_value, stime_value >>
>32);
>-#else
>-	SBI_CALL_1(SBI_EXT_0_1_SET_TIMER, stime_value);
>-#endif
>-}
>-
>-static inline void sbi_shutdown(void)
>-{
>-	SBI_CALL_0(SBI_EXT_0_1_SHUTDOWN);
>-}
>-
>-static inline void sbi_clear_ipi(void)
>-{
>-	SBI_CALL_0(SBI_EXT_0_1_CLEAR_IPI);
>-}
>-
>-static inline void sbi_send_ipi(const unsigned long *hart_mask) -{
>-	SBI_CALL_1(SBI_EXT_0_1_SEND_IPI, hart_mask);
>-}
>-
>-static inline void sbi_remote_fence_i(const unsigned long *hart_mask) -{
>-	SBI_CALL_1(SBI_EXT_0_1_REMOTE_FENCE_I, hart_mask);
>-}
>+struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
>+			unsigned long arg1, unsigned long arg2,
>+			unsigned long arg3, unsigned long arg4,
>+			unsigned long arg5);
>
>-static inline void sbi_remote_sfence_vma(const unsigned long *hart_mask,
>-					 unsigned long start,
>-					 unsigned long size)
>-{
>-	SBI_CALL_3(SBI_EXT_0_1_REMOTE_SFENCE_VMA, hart_mask, start,
>size);
>-}
>+void sbi_console_putchar(int ch);
>+int sbi_console_getchar(void);
>+void sbi_clear_ipi(void);
>+void sbi_shutdown(void);
>+void sbi_set_timer(uint64_t stime_value); void sbi_send_ipi(const
>+unsigned long *hart_mask); void sbi_remote_fence_i(const unsigned long
>+*hart_mask); void sbi_remote_sfence_vma(const unsigned long *hart_mask,
>+			   unsigned long start,
>+			   unsigned long size);
>+void sbi_remote_sfence_vma_asid(const unsigned long *hart_mask,
>+				unsigned long start,
>+				unsigned long size,
>+				unsigned long asid);
>
>-static inline void sbi_remote_sfence_vma_asid(const unsigned long
>*hart_mask,
>-					      unsigned long start,
>-					      unsigned long size,
>-					      unsigned long asid)
>-{
>-	SBI_CALL_4(SBI_EXT_0_1_REMOTE_SFENCE_VMA_ASID, hart_mask,
>-		   start, size, asid);
>-}
>+int sbi_probe_extension(int ext);
>
> #endif
>diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile index
>c9179a5..adadbf4 100644
>--- a/arch/riscv/lib/Makefile
>+++ b/arch/riscv/lib/Makefile
>@@ -16,6 +16,7 @@ obj-$(CONFIG_ANDES_PLIC) += andes_plic.o
> obj-$(CONFIG_ANDES_PLMT) += andes_plmt.o  else
> obj-$(CONFIG_RISCV_RDTIME) += rdtime.o
>+obj-$(CONFIG_SBI) += sbi.o
> obj-$(CONFIG_SBI_IPI) += sbi_ipi.o
> endif
> obj-y	+= interrupts.o
>diff --git a/arch/riscv/lib/sbi.c b/arch/riscv/lib/sbi.c new file mode 100644
>index 0000000..4b6a9e0
>--- /dev/null
>+++ b/arch/riscv/lib/sbi.c
>@@ -0,0 +1,181 @@
>+// SPDX-License-Identifier: GPL-2.0-only
>+/*
>+ * SBI initialilization and all extension implementation.
>+ *
>+ * Copyright (c) 2020 Western Digital Corporation or its affiliates.
>+ *
>+ * Taken from Linux arch/riscv/kernel/sbi.c  */
>+
>+#include <common.h>
>+#include <asm/encoding.h>
>+#include <asm/sbi.h>
>+
>+/* default SBI version is 0.1 */
>+unsigned long sbi_spec_version = SBI_SPEC_VERSION_DEFAULT;
>+
>+struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
>+			unsigned long arg1, unsigned long arg2,
>+			unsigned long arg3, unsigned long arg4,
>+			unsigned long arg5)
>+{
>+	struct sbiret ret;
>+
>+	register uintptr_t a0 asm ("a0") = (uintptr_t)(arg0);
>+	register uintptr_t a1 asm ("a1") = (uintptr_t)(arg1);
>+	register uintptr_t a2 asm ("a2") = (uintptr_t)(arg2);
>+	register uintptr_t a3 asm ("a3") = (uintptr_t)(arg3);
>+	register uintptr_t a4 asm ("a4") = (uintptr_t)(arg4);
>+	register uintptr_t a5 asm ("a5") = (uintptr_t)(arg5);
>+	register uintptr_t a6 asm ("a6") = (uintptr_t)(fid);
>+	register uintptr_t a7 asm ("a7") = (uintptr_t)(ext);
>+	asm volatile ("ecall"
>+		      : "+r" (a0), "+r" (a1)
>+		      : "r" (a2), "r" (a3), "r" (a4), "r" (a5), "r" (a6), "r" (a7)
>+		      : "memory");
>+	ret.error = a0;
>+	ret.value = a1;
>+
>+	return ret;
>+}
>+
>+/**
>+ * sbi_console_putchar() - Writes given character to the console device.
>+ * @ch: The data to be written to the console.
>+ *
>+ * Return: None
>+ */
>+void sbi_console_putchar(int ch)
>+{
>+	sbi_ecall(SBI_EXT_0_1_CONSOLE_PUTCHAR, 0, ch, 0, 0, 0, 0, 0); }
>+
>+/**
>+ * sbi_console_getchar() - Reads a byte from console device.
>+ *
>+ * Returns the value read from console.
>+ */
>+int sbi_console_getchar(void)
>+{
>+	struct sbiret ret;
>+
>+	ret = sbi_ecall(SBI_EXT_0_1_CONSOLE_GETCHAR, 0, 0, 0, 0, 0, 0, 0);
>+
>+	return ret.error;
>+}
>+
>+/**
>+ * sbi_clear_ipi() - Clear any pending IPIs for the calling hart.
>+ *
>+ * Return: None
>+ */
>+void sbi_clear_ipi(void)
>+{
>+	sbi_ecall(SBI_EXT_0_1_CLEAR_IPI, 0, 0, 0, 0, 0, 0, 0); }
>+
>+/**
>+ * sbi_shutdown() - Remove all the harts from executing supervisor code.
>+ *
>+ * Return: None
>+ */
>+void sbi_shutdown(void)
>+{
>+	sbi_ecall(SBI_EXT_0_1_SHUTDOWN, 0, 0, 0, 0, 0, 0, 0); }
>+
>+/**
>+ * sbi_set_timer() - Program the timer for next timer event.
>+ * @stime_value: The value after which next timer event should fire.
>+ *
>+ * Return: None
>+ */
>+void sbi_set_timer(uint64_t stime_value) { #if __riscv_xlen == 32
>+	sbi_ecall(SBI_EXT_0_1_SET_TIMER, 0, stime_value,
>+		  stime_value >> 32, 0, 0, 0, 0);
>+#else
>+	sbi_ecall(SBI_EXT_0_1_SET_TIMER, 0, stime_value, 0, 0, 0, 0, 0);
>+#endif }
>+
>+/**
>+ * sbi_send_ipi() - Send an IPI to any hart.
>+ * @hart_mask: A cpu mask containing all the target harts.
>+ *
>+ * Return: None
>+ */
>+void sbi_send_ipi(const unsigned long *hart_mask) {
>+	sbi_ecall(SBI_EXT_0_1_SEND_IPI, 0, (unsigned long)hart_mask,
>+		  0, 0, 0, 0, 0);
>+}
>+
>+/**
>+ * sbi_remote_fence_i() - Execute FENCE.I instruction on given remote harts.
>+ * @hart_mask: A cpu mask containing all the target harts.
>+ *
>+ * Return: None
>+ */
>+void sbi_remote_fence_i(const unsigned long *hart_mask) {
>+	sbi_ecall(SBI_EXT_0_1_REMOTE_FENCE_I, 0, (unsigned
>long)hart_mask,
>+		  0, 0, 0, 0, 0);
>+}
>+
>+/**
>+ * sbi_remote_sfence_vma() - Execute SFENCE.VMA instructions on given
>remote
>+ *			     harts for the specified virtual address range.
>+ * @hart_mask: A cpu mask containing all the target harts.
>+ * @start: Start of the virtual address
>+ * @size: Total size of the virtual address range.
>+ *
>+ * Return: None
>+ */
>+void sbi_remote_sfence_vma(const unsigned long *hart_mask,
>+			   unsigned long start,
>+			   unsigned long size)
>+{
>+	sbi_ecall(SBI_EXT_0_1_REMOTE_SFENCE_VMA, 0,
>+		  (unsigned long)hart_mask, start, size, 0, 0, 0); }
>+
>+/**
>+ * sbi_remote_sfence_vma_asid() - Execute SFENCE.VMA instructions on
>+given
>+ * remote harts for a virtual address range belonging to a specific ASID.
>+ *
>+ * @hart_mask: A cpu mask containing all the target harts.
>+ * @start: Start of the virtual address
>+ * @size: Total size of the virtual address range.
>+ * @asid: The value of address space identifier (ASID).
>+ *
>+ * Return: None
>+ */
>+void sbi_remote_sfence_vma_asid(const unsigned long *hart_mask,
>+				unsigned long start,
>+				unsigned long size,
>+				unsigned long asid)
>+{
>+	sbi_ecall(SBI_EXT_0_1_REMOTE_SFENCE_VMA_ASID, 0,
>+		  (unsigned long)hart_mask, start, size, asid, 0, 0); }
>+
>+/**
>+ * sbi_probe_extension() - Check if an SBI extension ID is supported or not.
>+ * @extid: The extension ID to be probed.
>+ *
>+ * Return: Extension specific nonzero value f yes, -ENOTSUPP otherwise.
>+ */
>+int sbi_probe_extension(int extid)
>+{
>+	struct sbiret ret;
>+
>+	ret = sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_PROBE_EXT, extid,
>+			0, 0, 0, 0, 0);
>+	if (!ret.error)
>+		if (ret.value)
>+			return ret.value;
>+
>+	return -ENOTSUPP;
>+}

Reviewed-by: Pragnesh Patel <pragnesh.patel at sifive.com>

>--
>2.7.4



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