RISC-V: Device, timer, IRQs, and the SBI

This patch contains code that interfaces with devices that are mandated
by the RISC-V supervisor specification and that don't have explicit
drivers anywhere else in the tree.  This includes the staticly defined
interrupts, the CSR-mapped timer, and virtualized SBI devices.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>

1 files changed, 100 insertions, 0 deletions

diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
new file mode 100644
index 000000000000..b6bb10b92fe2
--- /dev/null
+++ b/arch/riscv/include/asm/sbi.h
@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2015 Regents of the University of California
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   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.
+ */
+
+#ifndef _ASM_RISCV_SBI_H
+#define _ASM_RISCV_SBI_H
+
+#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_CALL(which, arg0, arg1, arg2) ({			\
+	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 a7 asm ("a7") = (uintptr_t)(which);	\
+	asm volatile ("ecall"					\
+		      : "+r" (a0)				\
+		      : "r" (a1), "r" (a2), "r" (a7)		\
+		      : "memory");				\
+	a0;							\
+})
+
+/* Lazy implementations until SBI is finalized */
+#define SBI_CALL_0(which) SBI_CALL(which, 0, 0, 0)
+#define SBI_CALL_1(which, arg0) SBI_CALL(which, arg0, 0, 0)
+#define SBI_CALL_2(which, arg0, arg1) SBI_CALL(which, arg0, arg1, 0)
+
+static inline void sbi_console_putchar(int ch)
+{
+	SBI_CALL_1(SBI_CONSOLE_PUTCHAR, ch);
+}
+
+static inline int sbi_console_getchar(void)
+{
+	return SBI_CALL_0(SBI_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);
+#else
+	SBI_CALL_1(SBI_SET_TIMER, stime_value);
+#endif
+}
+
+static inline void sbi_shutdown(void)
+{
+	SBI_CALL_0(SBI_SHUTDOWN);
+}
+
+static inline void sbi_clear_ipi(void)
+{
+	SBI_CALL_0(SBI_CLEAR_IPI);
+}
+
+static inline void sbi_send_ipi(const unsigned long *hart_mask)
+{
+	SBI_CALL_1(SBI_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);
+}
+
+static inline void sbi_remote_sfence_vma(const unsigned long *hart_mask,
+					 unsigned long start,
+					 unsigned long size)
+{
+	SBI_CALL_1(SBI_REMOTE_SFENCE_VMA, hart_mask);
+}
+
+static inline void sbi_remote_sfence_vma_asid(const unsigned long *hart_mask,
+					      unsigned long start,
+					      unsigned long size,
+					      unsigned long asid)
+{
+	SBI_CALL_1(SBI_REMOTE_SFENCE_VMA_ASID, hart_mask);
+}
+
+#endif