Re: [PATCH 01/16] xen: arm64: Add 8250 earlyprintk support

[Julien Grall <julien.grall@linaro.org>]

On 11/20/2013 02:48 PM, Ian Campbell wrote:
> From: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
> 
> Extracted from "Basic Platform support for APM X-Gene Storm."
> 
> Signed-off-by: Anup Patel <anup.patel@linaro.org>
> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
> 
> Reworked into generic 8250 driver, use EARLY_UART_REG_SHIFT.
> 
> While there observe a missing shift in the arm32 version (UART_THR is zero so
> it doesn't really matter). Changed for consistency.
> 
> Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
> ---
>  xen/arch/arm/Rules.mk             |    6 +++++
>  xen/arch/arm/arm64/debug-8250.inc |   52 +++++++++++++++++++++++++++++++++++++
>  2 files changed, 58 insertions(+)
>  create mode 100644 xen/arch/arm/arm64/debug-8250.inc
> 
> diff --git a/xen/arch/arm/Rules.mk b/xen/arch/arm/Rules.mk
> index c27c2eb..aaa203e 100644
> --- a/xen/arch/arm/Rules.mk
> +++ b/xen/arch/arm/Rules.mk
> @@ -82,6 +82,12 @@ EARLY_PRINTK_INC := 8250
>  EARLY_UART_BASE_ADDRESS := 0xF0406B00
>  EARLY_UART_REG_SHIFT := 2
>  endif
> +ifeq ($(CONFIG_EARLY_PRINTK), xgene-storm)
> +EARLY_PRINTK_INC := 8250
> +EARLY_PRINTK_BAUD := 115200
> +EARLY_UART_BASE_ADDRESS := 0x1c020000
> +EARLY_UART_REG_SHIFT := 2
> +endif
>  
>  ifneq ($(EARLY_PRINTK_INC),)
>  EARLY_PRINTK := y
> diff --git a/xen/arch/arm/arm64/debug-8250.inc b/xen/arch/arm/arm64/debug-8250.inc
> new file mode 100644
> index 0000000..5858354
> --- /dev/null
> +++ b/xen/arch/arm/arm64/debug-8250.inc
> @@ -0,0 +1,52 @@
> +/*
> + * xen/arch/arm/arm64/debug-8250.inc
> + *
> + * 8250 specific debug code
> + *
> + * Copyright (c) 2013 Applied Micro.
> + *
> + * 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; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * 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.
> + */
> +
> +#include <xen/8250-uart.h>
> +
> +/* UART initialization
> + * rb: register which contains the UART base address
> + * rc: scratch register 1
> + * rd: scratch register 2 */
> +.macro early_uart_init rb rc rd
> +.endm

You don't need to define early_uart_init. This macro is only used if
EARLY_PRINTK_INIT_UART is defined, which it's not the case here.

-- 
Julien Grall