Merge tag 'riscv-for-linus-4.21-rc2-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux

Pull RISC-V updates from Palmer Dabbelt:
 "This tag contains a handful of updates that slipped through the cracks
  during the merge window due to the holidays. The fixes are mostly
  independent, with the exception of one larger audit-related branch.

  Core RISC-V updates:

   - The BSS has been moved, which shrinks flat images.

   - A fix to test-bpf so it compiles on RV64I-based systems.

   - A fix to respect the kernel commandline when there is no device
     tree.

   - A fix to prevent CPUs from trying to put themselves to sleep when
     bringing down the system.

   - Support for MODULE_SECTIONS on RV32I-based systems.

   - [new in v2] The addition of an SBI earlycon driver. This is
     definately a new feature, but I'd like to include it now because I
     dropped this patch when submitting the merge window PR that removed
     our EARLY_PRINTK support.

  RISC-V audit updates:

   - The addition of NR_syscalls into unistd.h, which is necessary for
     CONFIG_FTRACE_SYSCALLS.

   - The definition of CREATE_TRACE_POINTS so __tracepoint_sys_{enter,exit}
     get defined.

   - A fix for trace_sys_exit() so we can enable HAVE_SYSCALL_TRACEPOINTS

  As usual, I've tested this by booting a Fedora-based image on a recent
  QEMU (this time just whatever I had lying around).

* tag 'riscv-for-linus-4.21-rc2-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux:
  tty/serial: Add RISC-V SBI earlycon support
  riscv: add HAVE_SYSCALL_TRACEPOINTS to Kconfig
  riscv: fix trace_sys_exit hook
  riscv: define CREATE_TRACE_POINTS in ptrace.c
  riscv: define NR_syscalls in unistd.h
  riscv: audit: add audit hook in do_syscall_trace_enter/exit()
  riscv: add audit support
  RISC-V: Support MODULE_SECTIONS mechanism on RV32
  MAINTAINERS: SiFive drivers: add myself as a SiFive driver maintainer
  MAINTAINERS: SiFive drivers: change the git tree to a SiFive git tree
  riscv: don't stop itself in smp_send_stop
  arch: riscv: support kernel command line forcing when no DTB passed
  tools uapi: fix RISC-V 64-bit support
  RISC-V: Make BSS section as the last section in vmlinux.lds.S

3 files changed, 41 insertions, 0 deletions

diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 67b9bf3b500e..089a6f285d5e 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -85,6 +85,18 @@ config SERIAL_EARLYCON_ARM_SEMIHOST
 	  with "earlycon=smh" on the kernel command line. The console is
 	  enabled when early_param is processed.
 
+config SERIAL_EARLYCON_RISCV_SBI
+	bool "Early console using RISC-V SBI"
+	depends on RISCV
+	select SERIAL_CORE
+	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
+	help
+	  Support for early debug console using RISC-V SBI. This enables
+	  the console before standard serial driver is probed. This is enabled
+	  with "earlycon=sbi" on the kernel command line. The console is
+	  enabled when early_param is processed.
+
 config SERIAL_SB1250_DUART
 	tristate "BCM1xxx on-chip DUART serial support"
 	depends on SIBYTE_SB1xxx_SOC=y
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index 8c303736b7e8..1511e8a9f856 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_SERIAL_CORE) += serial_core.o
 
 obj-$(CONFIG_SERIAL_EARLYCON) += earlycon.o
 obj-$(CONFIG_SERIAL_EARLYCON_ARM_SEMIHOST) += earlycon-arm-semihost.o
+obj-$(CONFIG_SERIAL_EARLYCON_RISCV_SBI) += earlycon-riscv-sbi.o
 
 # These Sparc drivers have to appear before others such as 8250
 # which share ttySx minor node space.  Otherwise console device
diff --git a/drivers/tty/serial/earlycon-riscv-sbi.c b/drivers/tty/serial/earlycon-riscv-sbi.c
new file mode 100644
index 000000000000..e1a551aae336
--- /dev/null
+++ b/drivers/tty/serial/earlycon-riscv-sbi.c
@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RISC-V SBI based earlycon
+ *
+ * Copyright (C) 2018 Anup Patel <anup@brainfault.org>
+ */
+#include <linux/kernel.h>
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/serial_core.h>
+#include <asm/sbi.h>
+
+static void sbi_console_write(struct console *con,
+			      const char *s, unsigned int n)
+{
+	int i;
+
+	for (i = 0; i < n; ++i)
+		sbi_console_putchar(s[i]);
+}
+
+static int __init early_sbi_setup(struct earlycon_device *device,
+				  const char *opt)
+{
+	device->con->write = sbi_console_write;
+	return 0;
+}
+EARLYCON_DECLARE(sbi, early_sbi_setup);