lib: sbi: Implement SBI SSE extension

The SBI SSE extension defines a set of function that can be called to
register and handle supervisor sofwtare events. This patch implements
all of the functionality defined in the specification.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Himanshu Chauhan <hchauhan@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

Author: clementleger

lib/sbi/Kconfig

@@ -54,4 +54,8 @@ config SBIUNIT
 	bool "Enable SBIUNIT tests"
 	default n
 
+config SBI_ECALL_SSE
+	bool "SSE extension"
+	default y
+
 endmenu

lib/sbi/objects.mk

@@ -55,6 +55,9 @@ libsbi-objs-$(CONFIG_SBI_ECALL_VENDOR) += sbi_ecall_vendor.o
 carray-sbi_ecall_exts-$(CONFIG_SBI_ECALL_DBTR) += ecall_dbtr
 libsbi-objs-$(CONFIG_SBI_ECALL_DBTR) += sbi_ecall_dbtr.o
 
+carray-sbi_ecall_exts-$(CONFIG_SBI_ECALL_SSE) += ecall_sse
+libsbi-objs-$(CONFIG_SBI_ECALL_SSE) += sbi_ecall_sse.o
+
 libsbi-objs-y += sbi_bitmap.o
 libsbi-objs-y += sbi_bitops.o
 libsbi-objs-y += sbi_console.o

lib/sbi/sbi_ecall_sse.c

@@ -0,0 +1,57 @@
+#include <sbi/sbi_error.h>
+#include <sbi/sbi_ecall.h>
+#include <sbi/sbi_trap.h>
+#include <sbi/sbi_sse.h>
+
+static int sbi_ecall_sse_handler(unsigned long extid, unsigned long funcid,
+				  struct sbi_trap_regs *regs,
+				  struct sbi_ecall_return *out)
+{
+	int ret;
+
+	switch (funcid) {
+	case SBI_EXT_SSE_READ_ATTR:
+		ret = sbi_sse_read_attrs(regs->a0, regs->a1, regs->a2,
+					 regs->a3, regs->a4);
+		break;
+	case SBI_EXT_SSE_WRITE_ATTR:
+		ret = sbi_sse_write_attrs(regs->a0, regs->a1, regs->a2,
+					 regs->a3, regs->a4);
+		break;
+	case SBI_EXT_SSE_REGISTER:
+		ret = sbi_sse_register(regs->a0, regs->a1, regs->a2);
+		break;
+	case SBI_EXT_SSE_UNREGISTER:
+		ret = sbi_sse_unregister(regs->a0);
+		break;
+	case SBI_EXT_SSE_ENABLE:
+		ret = sbi_sse_enable(regs->a0);
+		break;
+	case SBI_EXT_SSE_DISABLE:
+		ret = sbi_sse_disable(regs->a0);
+		break;
+	case SBI_EXT_SSE_COMPLETE:
+		ret = sbi_sse_complete(regs, out);
+		break;
+	case SBI_EXT_SSE_INJECT:
+		ret = sbi_sse_inject_from_ecall(regs->a0, regs->a1, out);
+		break;
+	default:
+		ret = SBI_ENOTSUPP;
+	}
+	return ret;
+}
+
+struct sbi_ecall_extension ecall_sse;
+
+static int sbi_ecall_sse_register_extensions(void)
+{
+	return sbi_ecall_register_extension(&ecall_sse);
+}
+
+struct sbi_ecall_extension ecall_sse = {
+	.extid_start		= SBI_EXT_SSE,
+	.extid_end		= SBI_EXT_SSE,
+	.register_extensions	= sbi_ecall_sse_register_extensions,
+	.handle			= sbi_ecall_sse_handler,
+};