On Wed, Nov 22, 2023 at 4:11 AM Samuel Holland
[off-list ref] wrote:

Hi Anup,

On 2023-11-17 9:38 PM, Anup Patel wrote:

quoted

We extend the existing RISC-V SBI earlycon support to use the new
RISC-V SBI debug console extension.

Signed-off-by: Anup Patel <redacted>
Reviewed-by: Andrew Jones <redacted>
---
 drivers/tty/serial/Kconfig              |  2 +-
 drivers/tty/serial/earlycon-riscv-sbi.c | 24 ++++++++++++++++++++----
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 732c893c8d16..1f2594b8ab9d 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig

@@ -87,7 +87,7 @@ config SERIAL_EARLYCON_SEMIHOST

 config SERIAL_EARLYCON_RISCV_SBI
      bool "Early console using RISC-V SBI"
-     depends on RISCV_SBI_V01
+     depends on RISCV_SBI
      select SERIAL_CORE
      select SERIAL_CORE_CONSOLE
      select SERIAL_EARLYCON

diff --git a/drivers/tty/serial/earlycon-riscv-sbi.c b/drivers/tty/serial/earlycon-riscv-sbi.c
index 27afb0b74ea7..5351e1e31f45 100644
--- a/drivers/tty/serial/earlycon-riscv-sbi.c
+++ b/drivers/tty/serial/earlycon-riscv-sbi.c

@@ -15,17 +15,33 @@ static void sbi_putc(struct uart_port *port, unsigned char c)
      sbi_console_putchar(c);
 }

-static void sbi_console_write(struct console *con,
-                           const char *s, unsigned n)
+static void sbi_0_1_console_write(struct console *con,
+                               const char *s, unsigned int n)
 {
      struct earlycon_device *dev = con->data;
      uart_console_write(&dev->port, s, n, sbi_putc);
 }

+static void sbi_dbcn_console_write(struct console *con,
+                                const char *s, unsigned int n)
+{
+     sbi_debug_console_write(n, __pa(s));

This only works for strings in the linear mapping or the kernel mapping (not
vmalloc, which includes the stack). So I don't think we can use __pa() here.

In which case, we need extend sbi_debug_console_write() to
do the va-to-pa conversion for both earlycon-riscv-sbi.c and
hvc_riscv_sbi.c

quoted

+}
+
 static int __init early_sbi_setup(struct earlycon_device *device,
                                const char *opt)
 {
-     device->con->write = sbi_console_write;
-     return 0;
+     int ret = 0;
+
+     if (sbi_debug_console_available) {
+             device->con->write = sbi_dbcn_console_write;
+     } else {
+             if (IS_ENABLED(CONFIG_RISCV_SBI_V01))

"else if", no need for the extra block/indentation.

Okay, I will update.

Regards,
Samuel

quoted

+                     device->con->write = sbi_0_1_console_write;
+             else
+                     ret = -ENODEV;
+     }
+
+     return ret;
 }
 EARLYCON_DECLARE(sbi, early_sbi_setup);

Regards,
Anup