[U-Boot] [PATCH v2] vexpress: disable cci ace slave ports when booting in non-sec/hyp mode

[Jon Medhurst (Tixy)]

On Fri, 2016-09-23 at 17:38 +0100, Sudeep Holla wrote:
> Commit f225d39d3093 ("vexpress: Check TC2 firmware support before defaulting
> to nonsec booting") added support to check if the firmware on TC2  is
> configured appropriately before booting in nonsec/hyp mode.
> 
> However when booting in non-secure/hyp mode, CCI control must be done in
> secure firmware and can't  be done in non-secure/hyp mode. In order to
> ensure that, this patch disables the cci slave port inteface so that it
> is not accessed at all.
> 
> Cc: Jon Medhurst <tixy at linaro.org>
> Acked-by: Marc Zyngier <marc.zyngier at arm.com>
> Signed-off-by: Sudeep Holla <sudeep.holla at arm.com>
> ---

Acked-by: Jon Medhurst <tixy at linaro.org>
Tested-by: Jon Medhurst <tixy at linaro.org>

>  board/armltd/vexpress/vexpress_tc2.c | 52 ++++++++++++++++++++++++++++++++++++
>  configs/vexpress_ca15_tc2_defconfig  |  1 +
>  2 files changed, 53 insertions(+)
> 
> Hi,
> 
> This change is needed to avoid the kernel panic while attempting to access
> CCI ports when booting in non-sec/HYP mode. The kernel patches to fix
> this are available @[1]
> 
> Regards,
> Sudeep
> 
> v1->v2:
> 	- Fix compilation with !CONFIG_ARMV7_NONSEC(Thanks to Tixy)
> 
> [1] http://www.spinics.net/lists/arm-kernel/msg533715.html
> 
> diff --git a/board/armltd/vexpress/vexpress_tc2.c b/board/armltd/vexpress/vexpress_tc2.c
> index ebb41a8833ab..c7adf950f579 100644
> --- a/board/armltd/vexpress/vexpress_tc2.c
> +++ b/board/armltd/vexpress/vexpress_tc2.c
> @@ -7,7 +7,11 @@
>   * SPDX-License-Identifier:	GPL-2.0+
>   */
> 
> +#include <asm/armv7.h>
>  #include <asm/io.h>
> +#include <asm/u-boot.h>
> +#include <common.h>
> +#include <libfdt.h>
> 
>  #define SCC_BASE	0x7fff0000
> 
> @@ -31,3 +35,51 @@ bool armv7_boot_nonsec_default(void)
>  	return (readl((u32 *)(SCC_BASE + 0x700)) & ((1 << 12) | (1 << 13))) == 0;
>  #endif
>  }
> +
> +#ifdef CONFIG_OF_BOARD_SETUP
> +int ft_board_setup(void *fdt, bd_t *bd)
> +{
> +	int offset, tmp, len;
> +	const struct fdt_property *prop;
> +	const char *cci_compatible = "arm,cci-400-ctrl-if";
> +
> +#ifdef CONFIG_ARMV7_NONSEC
> +	if (!armv7_boot_nonsec())
> +		return 0;
> +#else
> +	return 0;
> +#endif
> +	/* Booting in nonsec mode, disable CCI access */
> +	offset = fdt_path_offset(fdt, "/cpus");
> +	if (offset < 0) {
> +		printf("couldn't find /cpus\n");
> +		return offset;
> +	}
> +
> +	/* delete cci-control-port in each cpu node */
> +	for (tmp = fdt_first_subnode(fdt, offset); tmp >= 0;
> +	     tmp = fdt_next_subnode(fdt, tmp))
> +		fdt_delprop(fdt, tmp, "cci-control-port");
> +
> +	/* disable all ace cci slave ports */
> +	offset = fdt_node_offset_by_prop_value(fdt, offset, "compatible",
> +					       cci_compatible, 20);
> +	while (offset > 0) {
> +		prop = fdt_get_property(fdt, offset, "interface-type",
> +					&len);
> +		if (!prop)
> +			continue;
> +		if (len < 4)
> +			continue;
> +		if (strcmp(prop->data, "ace"))
> +			continue;
> +
> +		fdt_setprop_string(fdt, offset, "status", "disabled");
> +
> +		offset = fdt_node_offset_by_prop_value(fdt, offset, "compatible",
> +						       cci_compatible, 20);
> +	}
> +
> +	return 0;
> +}
> +#endif /* CONFIG_OF_BOARD_SETUP */
> diff --git a/configs/vexpress_ca15_tc2_defconfig b/configs/vexpress_ca15_tc2_defconfig
> index 2f141dda06c6..5154803b7c65 100644
> --- a/configs/vexpress_ca15_tc2_defconfig
> +++ b/configs/vexpress_ca15_tc2_defconfig
> @@ -1,5 +1,6 @@
>  CONFIG_ARM=y
>  CONFIG_TARGET_VEXPRESS_CA15_TC2=y
> +CONFIG_OF_BOARD_SETUP=y
>  CONFIG_HUSH_PARSER=y
>  # CONFIG_CMD_CONSOLE is not set
>  # CONFIG_CMD_BOOTD is not set
> --
> 2.7.4
>