[PATCH v3 0/4] Add support for SBI v0.2

[PATCH v3 0/4] Add support for SBI v0.2

[Atish Patra]

The Supervisor Binary Interface(SBI) specification[1] now defines a
base extension that provides extendability to add future extensions
while maintaining backward compatibility with previous versions.
The new version is defined as 0.2 and older version is marked as 0.1.

This series adds support v0.2 and a unified calling convention
implementation between 0.1 and 0.2. It also adds minimal SBI functions
from 0.2 as well to keep the series lean. 

[1] https://github.com/riscv/riscv-sbi-doc/blob/master/riscv-sbi.adoc

The base support for SBI v0.2 is already available in OpenSBI v0.5.
This series needs following additional patches in OpenSBI. 

http://lists.infradead.org/pipermail/opensbi/2019-November/000704.html

Tested on both BBL, OpenSBI with/without the above patch series. 

Changes from v2->v3.
1. Moved v0.1 extensions to a new config.
2. Added support for relacement extensions of v0.1 extensions.

Changes from v1->v2
1. Removed the legacy calling convention.
2. Moved all SBI related calls to sbi.c.
3. Moved all SBI related macros to uapi.

Atish Patra (4):
RISC-V: Mark existing SBI as 0.1 SBI.
RISC-V: Add basic support for SBI v0.2
RISC-V: Introduce a new config for SBI v0.1
RISC-V: Implement SBI v0.2 replacement extensions

arch/riscv/Kconfig           |   6 +
arch/riscv/include/asm/sbi.h | 163 +++++++++--------
arch/riscv/kernel/Makefile   |   1 +
arch/riscv/kernel/sbi.c      | 330 +++++++++++++++++++++++++++++++++++
arch/riscv/kernel/setup.c    |   2 +
5 files changed, 431 insertions(+), 71 deletions(-)
create mode 100644 arch/riscv/kernel/sbi.c

--
2.23.0

[PATCH v3 1/4] RISC-V: Mark existing SBI as 0.1 SBI.

[Atish Patra]

As per the new SBI specification, current SBI implementation version
is defined as 0.1 and will be removed/replaced in future. Each of the
function call in 0.1 is defined as a separate extension which makes
easier to replace them one at a time.

Rename existing implementation to reflect that. This patch is just
a preparatory patch for SBI v0.2 and doesn't introduce any functional
changes.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 arch/riscv/include/asm/sbi.h | 43 +++++++++++++++++++-----------------
 1 file changed, 23 insertions(+), 20 deletions(-)

diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
index 21134b3ef404..2147f384fad0 100644
--- a/arch/riscv/include/asm/sbi.h
+++ b/arch/riscv/include/asm/sbi.h
@@ -8,17 +8,17 @@
 
 #include <linux/types.h>
 
-#define SBI_SET_TIMER 0
-#define SBI_CONSOLE_PUTCHAR 1
-#define SBI_CONSOLE_GETCHAR 2
-#define SBI_CLEAR_IPI 3
-#define SBI_SEND_IPI 4
-#define SBI_REMOTE_FENCE_I 5
-#define SBI_REMOTE_SFENCE_VMA 6
-#define SBI_REMOTE_SFENCE_VMA_ASID 7
-#define SBI_SHUTDOWN 8
+#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
 
-#define SBI_CALL(which, arg0, arg1, arg2, arg3) ({		\
+#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);	\
@@ -42,48 +42,50 @@
 
 static inline void sbi_console_putchar(int ch)
 {
-	SBI_CALL_1(SBI_CONSOLE_PUTCHAR, ch);
+	SBI_CALL_1(SBI_EXT_0_1_CONSOLE_PUTCHAR, ch);
 }
 
 static inline int sbi_console_getchar(void)
 {
-	return SBI_CALL_0(SBI_CONSOLE_GETCHAR);
+	return SBI_CALL_0(SBI_EXT_0_1_CONSOLE_GETCHAR);
 }
 
 static inline void sbi_set_timer(uint64_t stime_value)
 {
 #if __riscv_xlen == 32
-	SBI_CALL_2(SBI_SET_TIMER, stime_value, stime_value >> 32);
+	SBI_CALL_2(SBI_EXT_0_1_SET_TIMER, stime_value,
+			  stime_value >> 32);
 #else
-	SBI_CALL_1(SBI_SET_TIMER, stime_value);
+	SBI_CALL_1(SBI_EXT_0_1_SET_TIMER, stime_value);
 #endif
 }
 
 static inline void sbi_shutdown(void)
 {
-	SBI_CALL_0(SBI_SHUTDOWN);
+	SBI_CALL_0(SBI_EXT_0_1_SHUTDOWN);
 }
 
 static inline void sbi_clear_ipi(void)
 {
-	SBI_CALL_0(SBI_CLEAR_IPI);
+	SBI_CALL_0(SBI_EXT_0_1_CLEAR_IPI);
 }
 
 static inline void sbi_send_ipi(const unsigned long *hart_mask)
 {
-	SBI_CALL_1(SBI_SEND_IPI, 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_REMOTE_FENCE_I, hart_mask);
+	SBI_CALL_1(SBI_EXT_0_1_REMOTE_FENCE_I, hart_mask);
 }
 
 static inline void sbi_remote_sfence_vma(const unsigned long *hart_mask,
 					 unsigned long start,
 					 unsigned long size)
 {
-	SBI_CALL_3(SBI_REMOTE_SFENCE_VMA, hart_mask, start, size);
+	SBI_CALL_3(SBI_EXT_0_1_REMOTE_SFENCE_VMA, hart_mask,
+			  start, size);
 }
 
 static inline void sbi_remote_sfence_vma_asid(const unsigned long *hart_mask,
@@ -91,7 +93,8 @@ static inline void sbi_remote_sfence_vma_asid(const unsigned long *hart_mask,
 					      unsigned long size,
 					      unsigned long asid)
 {
-	SBI_CALL_4(SBI_REMOTE_SFENCE_VMA_ASID, hart_mask, start, size, asid);
+	SBI_CALL_4(SBI_EXT_0_1_REMOTE_SFENCE_VMA_ASID, hart_mask,
+			  start, size, asid);
 }
 
 #endif
-- 
2.23.0

[PATCH v3 2/4] RISC-V: Add basic support for SBI v0.2

[Atish Patra]

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.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 arch/riscv/include/asm/sbi.h | 140 ++++++++++----------
 arch/riscv/kernel/Makefile   |   1 +
 arch/riscv/kernel/sbi.c      | 244 +++++++++++++++++++++++++++++++++++
 arch/riscv/kernel/setup.c    |   2 +
 4 files changed, 315 insertions(+), 72 deletions(-)
 create mode 100644 arch/riscv/kernel/sbi.c

diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
index 2147f384fad0..75ad7a190b1b 100644
--- a/arch/riscv/include/asm/sbi.h
+++ b/arch/riscv/include/asm/sbi.h
@@ -8,93 +8,89 @@
 
 #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_BASE_GET_SPEC_VERSION = 0,
+	SBI_BASE_GET_IMP_ID,
+	SBI_BASE_GET_IMP_VERSION,
+	SBI_BASE_PROBE_EXT,
+	SBI_BASE_GET_MVENDORID,
+	SBI_BASE_GET_MARCHID,
+	SBI_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_OFFSET	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);
-}
-
-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
-}
+extern unsigned long sbi_spec_version;
+struct sbiret {
+	long error;
+	long value;
+};
 
-static inline void sbi_shutdown(void)
-{
-	SBI_CALL_0(SBI_EXT_0_1_SHUTDOWN);
-}
+void sbi_init(void);
+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);
+int sbi_err_map_linux_errorno(int err);
 
-static inline void sbi_clear_ipi(void)
-{
-	SBI_CALL_0(SBI_EXT_0_1_CLEAR_IPI);
-}
+void sbi_console_putchar(int ch);
+int sbi_console_getchar(void);
+void sbi_set_timer(uint64_t stime_value);
+void sbi_shutdown(void);
+void sbi_clear_ipi(void);
+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);
 
-static inline void sbi_send_ipi(const unsigned long *hart_mask)
-{
-	SBI_CALL_1(SBI_EXT_0_1_SEND_IPI, hart_mask);
-}
+void sbi_remote_sfence_vma_asid(const unsigned long *hart_mask,
+				unsigned long start,
+				unsigned long size,
+				unsigned long asid);
+int sbi_probe_extension(long ext);
 
-static inline void sbi_remote_fence_i(const unsigned long *hart_mask)
+/* Check if current SBI specification version is 0.1 or not */
+static inline int sbi_spec_is_0_1(void)
 {
-	SBI_CALL_1(SBI_EXT_0_1_REMOTE_FENCE_I, hart_mask);
+	return (sbi_spec_version == SBI_SPEC_VERSION_DEFAULT) ? 1 : 0;
 }
 
-static inline void sbi_remote_sfence_vma(const unsigned long *hart_mask,
-					 unsigned long start,
-					 unsigned long size)
+/* Get the major version of SBI */
+static inline unsigned long sbi_major_version(void)
 {
-	SBI_CALL_3(SBI_EXT_0_1_REMOTE_SFENCE_VMA, hart_mask,
-			  start, size);
+	return (sbi_spec_version >> SBI_SPEC_VERSION_MAJOR_OFFSET) &
+		SBI_SPEC_VERSION_MAJOR_MASK;
 }
 
-static inline void sbi_remote_sfence_vma_asid(const unsigned long *hart_mask,
-					      unsigned long start,
-					      unsigned long size,
-					      unsigned long asid)
+/* Get the minor version of SBI */
+static inline unsigned long sbi_minor_version(void)
 {
-	SBI_CALL_4(SBI_EXT_0_1_REMOTE_SFENCE_VMA_ASID, hart_mask,
-			  start, size, asid);
+	return sbi_spec_version & SBI_SPEC_VERSION_MINOR_MASK;
 }
 
 #endif
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index 696020ff72db..aef457607295 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -17,6 +17,7 @@ obj-y	+= irq.o
 obj-y	+= process.o
 obj-y	+= ptrace.o
 obj-y	+= reset.o
+obj-y	+= sbi.o
 obj-y	+= setup.o
 obj-y	+= signal.o
 obj-y	+= syscall_table.o
diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c
new file mode 100644
index 000000000000..1cee3ef009bb
--- /dev/null
+++ b/arch/riscv/kernel/sbi.c
@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2019 Western Digital Corporation or its affiliates.
+ */
+
+#include <asm/sbi.h>
+#include <linux/sched.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;
+}
+
+int sbi_err_map_linux_errno(int err)
+{
+	switch (err) {
+	case SBI_SUCCESS:
+		return 0;
+	case SBI_ERR_DENIED:
+		return -EPERM;
+	case SBI_ERR_INVALID_PARAM:
+		return -EINVAL;
+	case SBI_ERR_INVALID_ADDRESS:
+		return -EFAULT;
+	case SBI_ERR_NOT_SUPPORTED:
+	case SBI_ERR_FAILURE:
+	default:
+		return -ENOTSUPP;
+	};
+}
+
+/**
+ * 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_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_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_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_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(long extid)
+{
+	struct sbiret ret;
+
+	ret = sbi_ecall(SBI_EXT_BASE, SBI_BASE_PROBE_EXT, 0, 0, 0, 0, 0, 0);
+	if (!ret.error)
+		if (ret.value)
+			return ret.value;
+
+	return -ENOTSUPP;
+}
+
+static long sbi_get_spec_version(void)
+{
+	struct sbiret ret;
+
+	ret = sbi_ecall(SBI_EXT_BASE, SBI_BASE_GET_SPEC_VERSION,
+			       0, 0, 0, 0, 0, 0);
+	if (!ret.error)
+		return ret.value;
+	else
+		return ret.error;
+}
+
+static long sbi_get_firmware_id(void)
+{
+	struct sbiret ret;
+
+	ret = sbi_ecall(SBI_EXT_BASE, SBI_BASE_GET_IMP_ID,
+			       0, 0, 0, 0, 0, 0);
+	if (!ret.error)
+		return ret.value;
+	else
+		return sbi_err_map_linux_errno(ret.error);
+}
+
+static long sbi_get_firmware_version(void)
+{
+	struct sbiret ret;
+
+	ret = sbi_ecall(SBI_EXT_BASE, SBI_BASE_GET_IMP_VERSION,
+			       0, 0, 0, 0, 0, 0);
+	if (!ret.error)
+		return ret.value;
+	else
+		return sbi_err_map_linux_errno(ret.error);
+}
+
+void sbi_init(void)
+{
+	int ret;
+
+	ret = sbi_get_spec_version();
+	if (ret > 0)
+		sbi_spec_version = ret;
+
+	pr_info("SBI specification v%lu.%lu detected\n",
+		sbi_major_version(), sbi_minor_version());
+	if (!sbi_spec_is_0_1())
+		pr_info("SBI implementation ID=0x%lx Version=0x%lx\n",
+			sbi_get_firmware_id(), sbi_get_firmware_version());
+}
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 845ae0e12115..1aadae86ab02 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -21,6 +21,7 @@
 #include <asm/sections.h>
 #include <asm/pgtable.h>
 #include <asm/smp.h>
+#include <asm/sbi.h>
 #include <asm/tlbflush.h>
 #include <asm/thread_info.h>
 
@@ -72,6 +73,7 @@ void __init setup_arch(char **cmdline_p)
 	swiotlb_init(1);
 #endif
 
+	sbi_init();
 #ifdef CONFIG_SMP
 	setup_smp();
 #endif
-- 
2.23.0

[PATCH v3 3/4] RISC-V: Introduce a new config for SBI v0.1

[Atish Patra]

We now have SBI v0.2 which is more scalable and extendable to handle
future needs for RISC-V supervisor interfaces.

Introduce a new config and move all SBI v0.1 code under that config.
This allows to implement the new replacement SBI extensions cleanly
and remove v0.1 extensions easily in future. Currently, the config
is enabled by default. Once all M-mode software with v0.1 are no
longer in use, this config option and all relevant code can be easily
removed.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 arch/riscv/Kconfig      |  6 ++++
 arch/riscv/kernel/sbi.c | 69 +++++++++++++++++++++++++++++------------
 2 files changed, 55 insertions(+), 20 deletions(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 8eebbc8860bb..4881b87d0d14 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -272,6 +272,12 @@ menu "Kernel features"
 
 source "kernel/Kconfig.hz"
 
+config RISCV_SBI_V01
+	bool "SBI v0.1 support"
+	default y
+	help
+	  This config allows kernel to use SBI v0.1 APIs. This will be
+	  deprecated in future once legacy M-mode software are no longer in use.
 endmenu
 
 menu "Boot options"
diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c
index 1cee3ef009bb..6c864fd7fb95 100644
--- a/arch/riscv/kernel/sbi.c
+++ b/arch/riscv/kernel/sbi.c
@@ -52,6 +52,7 @@ int sbi_err_map_linux_errno(int err)
 	};
 }
 
+#ifdef CONFIG_RISCV_SBI_V01
 /**
  * sbi_console_putchar() - Writes given character to the console device.
  * @ch: The data to be written to the console.
@@ -78,39 +79,47 @@ int sbi_console_getchar(void)
 }
 
 /**
- * sbi_set_timer() - Program the timer for next timer event.
- * @stime_value: The value after which next timer event should fire.
+ * sbi_shutdown() - Remove all the harts from executing supervisor code.
  *
  * Return: None
  */
-void sbi_set_timer(uint64_t stime_value)
+void sbi_shutdown(void)
 {
-#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_ecall(SBI_EXT_0_1_SHUTDOWN, 0, 0, 0, 0, 0, 0, 0);
 }
 
 /**
- * sbi_shutdown() - Remove all the harts from executing supervisor code.
+ * sbi_clear_ipi() - Clear any pending IPIs for the calling hart.
  *
  * Return: None
  */
-void sbi_shutdown(void)
+void sbi_clear_ipi(void)
 {
-	sbi_ecall(SBI_EXT_0_1_SHUTDOWN, 0, 0, 0, 0, 0, 0, 0);
+	sbi_ecall(SBI_EXT_0_1_CLEAR_IPI, 0, 0, 0, 0, 0, 0, 0);
 }
 
+#endif
+
 /**
- * sbi_clear_ipi() - Clear any pending IPIs for the calling hart.
+ * 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_clear_ipi(void)
+void sbi_set_timer(uint64_t stime_value)
 {
-	sbi_ecall(SBI_EXT_0_1_CLEAR_IPI, 0, 0, 0, 0, 0, 0, 0);
+#ifdef CONFIG_RISCV_SBI_V01
+	if (sbi_spec_is_0_1()) {
+#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
+		return;
+	}
+#endif
+
 }
 
 /**
@@ -121,8 +130,13 @@ void sbi_clear_ipi(void)
  */
 void sbi_send_ipi(const unsigned long *hart_mask)
 {
-	sbi_ecall(SBI_EXT_0_1_SEND_IPI, 0, (unsigned long)hart_mask,
+#ifdef CONFIG_RISCV_SBI_V01
+	if (sbi_spec_is_0_1()) {
+		sbi_ecall(SBI_EXT_0_1_SEND_IPI, 0, (unsigned long)hart_mask,
 			0, 0, 0, 0, 0);
+		return;
+	}
+#endif
 }
 
 /**
@@ -133,8 +147,13 @@ void sbi_send_ipi(const unsigned long *hart_mask)
  */
 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);
+#ifdef CONFIG_RISCV_SBI_V01
+	if (sbi_spec_is_0_1()) {
+		sbi_ecall(SBI_EXT_0_1_REMOTE_FENCE_I, 0,
+			 (unsigned long)hart_mask, 0, 0, 0, 0, 0);
+		return;
+	}
+#endif
 }
 
 /**
@@ -150,8 +169,13 @@ 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,
+#ifdef CONFIG_RISCV_SBI_V01
+	if (sbi_spec_is_0_1()) {
+		sbi_ecall(SBI_EXT_0_1_REMOTE_SFENCE_VMA, 0,
 			(unsigned long)hart_mask, start, size, 0, 0, 0);
+		return;
+	}
+#endif
 }
 
 /**
@@ -170,8 +194,13 @@ void sbi_remote_sfence_vma_asid(const unsigned long *hart_mask,
 					      unsigned long size,
 					      unsigned long asid)
 {
-	sbi_ecall(SBI_EXT_0_1_REMOTE_SFENCE_VMA_ASID, 0,
+#ifdef CONFIG_RISCV_SBI_V01
+	if (sbi_spec_is_0_1()) {
+		sbi_ecall(SBI_EXT_0_1_REMOTE_SFENCE_VMA_ASID, 0,
 			(unsigned long)hart_mask, start, size, asid, 0, 0);
+		return;
+	}
+#endif
 }
 
 /**
-- 
2.23.0

[PATCH v3 4/4] RISC-V: Implement SBI v0.2 replacement extensions

[Atish Patra]

Few v0.1 SBI calls are being replaced by new SBI calls that follows
v0.2 calling convention. The specification changes can be found at

https://github.com/riscv/riscv-sbi-doc/pull/27

Implement the replacement extensions that makes way for a better SBI
interface in future.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
---
 arch/riscv/include/asm/sbi.h | 22 ++++++++++++++
 arch/riscv/kernel/sbi.c      | 57 ++++++++++++++++++++++++++++++++++++
 2 files changed, 79 insertions(+)

diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
index 75ad7a190b1b..09beb0bfa3b4 100644
--- a/arch/riscv/include/asm/sbi.h
+++ b/arch/riscv/include/asm/sbi.h
@@ -19,6 +19,10 @@ enum sbi_ext_id {
 	SBI_EXT_0_1_REMOTE_SFENCE_VMA_ASID = 0x7,
 	SBI_EXT_0_1_SHUTDOWN = 0x8,
 	SBI_EXT_BASE = 0x10,
+	SBI_EXT_TIME = 0x54494D45,
+	SBI_EXT_IPI = 0x735049,
+	SBI_EXT_RFENCE = 0x52464E43,
+
 };
 
 enum sbi_ext_base_fid {
@@ -31,6 +35,24 @@ enum sbi_ext_base_fid {
 	SBI_BASE_GET_MIMPID,
 };
 
+enum sbi_ext_time_fid {
+	SBI_EXT_TIME_SET_TIMER = 0,
+};
+
+enum sbi_ext_ipi_fid {
+	SBI_EXT_IPI_SEND_IPI = 0,
+};
+
+enum sbi_ext_rfence_fid {
+	SBI_EXT_RFENCE_REMOTE_FENCE_I = 0,
+	SBI_EXT_RFENCE_REMOTE_SFENCE_VMA,
+	SBI_EXT_RFENCE_REMOTE_SFENCE_VMA_ASID,
+	SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA,
+	SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA_VMID,
+	SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA,
+	SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA_ASID,
+};
+
 #define SBI_SPEC_VERSION_DEFAULT	0x1
 #define SBI_SPEC_VERSION_MAJOR_OFFSET	24
 #define SBI_SPEC_VERSION_MAJOR_MASK	0x7f
diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c
index 6c864fd7fb95..02e7bf581183 100644
--- a/arch/riscv/kernel/sbi.c
+++ b/arch/riscv/kernel/sbi.c
@@ -120,6 +120,14 @@ void sbi_set_timer(uint64_t stime_value)
 	}
 #endif
 
+#if __riscv_xlen == 32
+	sbi_ecall(SBI_EXT_TIME, SBI_EXT_TIME_SET_TIMER, stime_value,
+			  stime_value >> 32, 0, 0, 0, 0);
+#else
+	sbi_ecall(SBI_EXT_TIME, SBI_EXT_TIME_SET_TIMER, stime_value, 0,
+		  0, 0, 0, 0);
+#endif
+
 }
 
 /**
@@ -130,6 +138,8 @@ void sbi_set_timer(uint64_t stime_value)
  */
 void sbi_send_ipi(const unsigned long *hart_mask)
 {
+	unsigned long hmask_val;
+	struct sbiret ret;
 #ifdef CONFIG_RISCV_SBI_V01
 	if (sbi_spec_is_0_1()) {
 		sbi_ecall(SBI_EXT_0_1_SEND_IPI, 0, (unsigned long)hart_mask,
@@ -137,6 +147,16 @@ void sbi_send_ipi(const unsigned long *hart_mask)
 		return;
 	}
 #endif
+	if (!hart_mask)
+		hmask_val = *(cpumask_bits(cpu_online_mask));
+	else
+		hmask_val = *hart_mask;
+
+	ret = sbi_ecall(SBI_EXT_IPI, SBI_EXT_IPI_SEND_IPI, *hart_mask,
+		  0, 0, 0, 0, 0);
+	if (ret.error)
+		pr_err("%s: failed with error [%d]\n", __func__,
+			sbi_err_map_linux_errno(ret.error));
 }
 
 /**
@@ -147,6 +167,8 @@ void sbi_send_ipi(const unsigned long *hart_mask)
  */
 void sbi_remote_fence_i(const unsigned long *hart_mask)
 {
+	unsigned long hmask_val;
+	struct sbiret ret;
 #ifdef CONFIG_RISCV_SBI_V01
 	if (sbi_spec_is_0_1()) {
 		sbi_ecall(SBI_EXT_0_1_REMOTE_FENCE_I, 0,
@@ -154,6 +176,16 @@ void sbi_remote_fence_i(const unsigned long *hart_mask)
 		return;
 	}
 #endif
+	if (!hart_mask)
+		hmask_val = *(cpumask_bits(cpu_online_mask));
+	else
+		hmask_val = *hart_mask;
+
+	ret = sbi_ecall(SBI_EXT_RFENCE, SBI_EXT_RFENCE_REMOTE_FENCE_I,
+			hmask_val, 0, 0, 0, 0, 0);
+	if (ret.error)
+		pr_err("%s: failed with error [%d]\n", __func__,
+			sbi_err_map_linux_errno(ret.error));
 }
 
 /**
@@ -169,6 +201,8 @@ void sbi_remote_sfence_vma(const unsigned long *hart_mask,
 					 unsigned long start,
 					 unsigned long size)
 {
+	unsigned long hmask_val;
+	struct sbiret ret;
 #ifdef CONFIG_RISCV_SBI_V01
 	if (sbi_spec_is_0_1()) {
 		sbi_ecall(SBI_EXT_0_1_REMOTE_SFENCE_VMA, 0,
@@ -176,6 +210,17 @@ void sbi_remote_sfence_vma(const unsigned long *hart_mask,
 		return;
 	}
 #endif
+	if (!hart_mask)
+		hmask_val = *(cpumask_bits(cpu_online_mask));
+	else
+		hmask_val = *hart_mask;
+
+	ret = sbi_ecall(SBI_EXT_RFENCE, SBI_EXT_RFENCE_REMOTE_SFENCE_VMA,
+		  hmask_val, 0, start, size, 0, 0);
+
+	if (ret.error)
+		pr_err("%s: failed with error [%d]\n", __func__,
+			sbi_err_map_linux_errno(ret.error));
 }
 
 /**
@@ -194,6 +239,8 @@ void sbi_remote_sfence_vma_asid(const unsigned long *hart_mask,
 					      unsigned long size,
 					      unsigned long asid)
 {
+	struct sbiret ret;
+	unsigned long hmask_val;
 #ifdef CONFIG_RISCV_SBI_V01
 	if (sbi_spec_is_0_1()) {
 		sbi_ecall(SBI_EXT_0_1_REMOTE_SFENCE_VMA_ASID, 0,
@@ -201,6 +248,16 @@ void sbi_remote_sfence_vma_asid(const unsigned long *hart_mask,
 		return;
 	}
 #endif
+	if (!hart_mask)
+		hmask_val = *(cpumask_bits(cpu_online_mask));
+	else
+		hmask_val = *hart_mask;
+
+	ret = sbi_ecall(SBI_EXT_RFENCE, SBI_EXT_RFENCE_REMOTE_SFENCE_VMA_ASID,
+		  hmask_val, 0, start, size, asid, 0);
+	if (ret.error)
+		pr_err("%s: failed with error [%d]\n", __func__,
+			sbi_err_map_linux_errno(ret.error));
 }
 
 /**
-- 
2.23.0

Re: [PATCH v3 0/4] Add support for SBI v0.2

[Paul Walmsley]

Hi Atish,

On Mon, 18 Nov 2019, Atish Patra wrote:

> The Supervisor Binary Interface(SBI) specification[1] now defines a
> base extension that provides extendability to add future extensions
> while maintaining backward compatibility with previous versions.
> The new version is defined as 0.2 and older version is marked as 0.1.
> 
> This series adds support v0.2 and a unified calling convention
> implementation between 0.1 and 0.2. It also adds minimal SBI functions
> from 0.2 as well to keep the series lean. 
> 
> [1] https://github.com/riscv/riscv-sbi-doc/blob/master/riscv-sbi.adoc
> 
> The base support for SBI v0.2 is already available in OpenSBI v0.5.
> This series needs following additional patches in OpenSBI. 
> 
> http://lists.infradead.org/pipermail/opensbi/2019-November/000704.html
> 
> Tested on both BBL, OpenSBI with/without the above patch series. 

Just based on a quick look:

All of the patches in this series add warnings reported by 
'scripts/checkpatch.pl --strict'.  Could you please fix and repost?

Also: could you rebase these patches on top of the current RISC-V for-next 
branch?  There are some significant conflicts after Christoph's nommu 
work.

We'll wait to send these upstream until the SBI v0.2 spec is frozen, but 
in the meantime, it'll be good to get these into the experimental branch.

thanks,

- Paul

Re: [PATCH v3 0/4] Add support for SBI v0.2

[Atish Patra]

On Tue, 2019-11-19 at 23:51 -0800, Paul Walmsley wrote:
> Hi Atish,
> 
> On Mon, 18 Nov 2019, Atish Patra wrote:
> 
> > The Supervisor Binary Interface(SBI) specification[1] now defines a
> > base extension that provides extendability to add future extensions
> > while maintaining backward compatibility with previous versions.
> > The new version is defined as 0.2 and older version is marked as
> > 0.1.
> > 
> > This series adds support v0.2 and a unified calling convention
> > implementation between 0.1 and 0.2. It also adds minimal SBI
> > functions
> > from 0.2 as well to keep the series lean. 
> > 
> > [1] 
> > https://github.com/riscv/riscv-sbi-doc/blob/master/riscv-sbi.adoc
> > 
> > The base support for SBI v0.2 is already available in OpenSBI v0.5.
> > This series needs following additional patches in OpenSBI. 
> > 
> > http://lists.infradead.org/pipermail/opensbi/2019-November/000704.html
> > 
> > Tested on both BBL, OpenSBI with/without the above patch series. 
> 
> Just based on a quick look:
> 
> All of the patches in this series add warnings reported by 
> 'scripts/checkpatch.pl --strict'.  Could you please fix and repost?
> 

Yeah sure. I will do that.

> Also: could you rebase these patches on top of the current RISC-V
> for-next 
> branch?  There are some significant conflicts after Christoph's
> nommu 
> work.
> 

ok. I will rebase on top of for-next.

> We'll wait to send these upstream until the SBI v0.2 spec is frozen,
> but 
> in the meantime, it'll be good to get these into the experimental
> branch.
> 
> thanks,
> 
> - Paul

-- 
Regards,
Atish