[PATCH 4/4] sunxi: move arch timer setup out of board/ directory

[Samuel Holland]

Hi Andre,

On 12/13/22 18:22, Andre Przywara wrote:
> At the moment we have an #ifdef-protected routine in
> board/sunxi/board.c, which sets up the arch timer CNTFRQ register, if
> that hasn't been done already.
> This only applies to ARMv7 SoCs running in secure state, and so is
> much better located in the arch/arm/mach-sunxi directory.
> 
> Move that routine into a separate function and file in said directory,
> which also allows to trigger the compilation for ARMv7 in the Makefile.
> Also move the call to it into the arch/arm version of board.c.
> 
> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
> ---
>  arch/arm/mach-sunxi/Makefile     |  4 ++++
>  arch/arm/mach-sunxi/arch_timer.c | 39 ++++++++++++++++++++++++++++++++
>  arch/arm/mach-sunxi/board.c      | 14 ++++++++----
>  board/sunxi/board.c              | 34 +---------------------------
>  4 files changed, 54 insertions(+), 37 deletions(-)
>  create mode 100644 arch/arm/mach-sunxi/arch_timer.c
> 
> diff --git a/arch/arm/mach-sunxi/Makefile b/arch/arm/mach-sunxi/Makefile
> index 58f807cb82d..335c44476e9 100644
> --- a/arch/arm/mach-sunxi/Makefile
> +++ b/arch/arm/mach-sunxi/Makefile
> @@ -26,8 +26,12 @@ obj-$(CONFIG_MACH_SUN8I)	+= clock_sun6i.o
>  endif
>  obj-$(CONFIG_MACH_SUN9I)	+= clock_sun9i.o gtbus_sun9i.o
>  obj-$(CONFIG_SUN50I_GEN_H6)	+= clock_sun50i_h6.o
> +
>  ifndef CONFIG_ARM64
>  obj-y	+= timer.o
> +ifndef CONFIG_MACH_SUNIV

Probably Allwinner will not release any new ARMv5 SoC, but would it be
more future-proof (and a bit more meaningful) to condition this on
CONFIG_CPU_V7A?

Alternatively, would it make sense to put this code inside
arch/arm/cpu/armv7/arch_timer.c? I don't know why we wouldn't want to
enable CONFIG_SYS_ARCH_TIMER on sunxi SoCs where it is available. And
making this generic could eventually remove the need for the version in
arch/arm/cpu/armv7/nonsec_virt.S. But this patch is still an improvement
as-is.

Tested-by: Samuel Holland <samuel at sholland.org>

> +obj-y	+= arch_timer.o
> +endif
>  endif
>  
>  ifdef CONFIG_SPL_BUILD
> diff --git a/arch/arm/mach-sunxi/arch_timer.c b/arch/arm/mach-sunxi/arch_timer.c
> new file mode 100644
> index 00000000000..c0e4310741f
> --- /dev/null
> +++ b/arch/arm/mach-sunxi/arch_timer.c
> @@ -0,0 +1,39 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * ARM Generic Timer CNTFRQ setup
> + *
> + * (C) Copyright 2013 Oliver Schinagl <oliver at schinagl.nl>

`git blame` points to cba69eeeaa67d3fb93ec6f3abab1f653abf895a9 and
d96ebc468d0dff6eb6f069bba03b3f0e33aa22de as the source for this code, so
this authorship is incorrect.

> + */
> +
> +#include <stdint.h>

This does not do what you expect, or really anything at all. The comment
there suggests using linux/types.h.

Regards,
Samuel

> +#include <log.h>
> +#include <asm/armv7.h>
> +
> +void setup_arch_timer(void)
> +{
> +	uint32_t id_pfr1, freq;
> +
> +	asm volatile("mrc p15, 0, %0, c0, c1, 1" : "=r"(id_pfr1));
> +	debug("id_pfr1: 0x%08x\n", id_pfr1);
> +	/* Generic Timer Extension available? */
> +	if (((id_pfr1 >> CPUID_ARM_GENTIMER_SHIFT) & 0xf) == 0)
> +		return;
> +
> +	/*
> +	 * CNTFRQ is a secure register, so we will crash if we try to
> +	 * write this from the non-secure world (read is OK, though).
> +	 * In case some bootcode has already set the correct value,
> +	 * we avoid the risk of writing to it.
> +	 */
> +	asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r"(freq));
> +	if (freq == CONFIG_COUNTER_FREQUENCY)
> +		return;
> +
> +	debug("arch timer frequency is %d Hz, should be %d, fixing ...\n",
> +	      freq, CONFIG_COUNTER_FREQUENCY);
> +	if (IS_ENABLED(CONFIG_NON_SECURE))
> +		printf("arch timer frequency is wrong, but cannot adjust it\n");
> +	else
> +		asm volatile("mcr p15, 0, %0, c14, c0, 0"
> +			     : : "r"(CONFIG_COUNTER_FREQUENCY));
> +}
> diff --git a/arch/arm/mach-sunxi/board.c b/arch/arm/mach-sunxi/board.c
> index 0c4b6dd1ca3..943f89eaa78 100644
> --- a/arch/arm/mach-sunxi/board.c
> +++ b/arch/arm/mach-sunxi/board.c
> @@ -347,10 +347,6 @@ u32 spl_boot_device(void)
>  	return sunxi_get_boot_device();
>  }
>  
> -__weak void sunxi_sram_init(void)
> -{
> -}
> -
>  /*
>   * When booting from an eMMC boot partition, the SPL puts the same boot
>   * source code into SRAM A1 as when loading the SPL from the normal
> @@ -434,10 +430,20 @@ u32 spl_mmc_boot_mode(struct mmc *mmc, const u32 boot_device)
>  	return result;
>  }
>  
> +__weak void sunxi_sram_init(void)
> +{
> +}
> +
> +__weak void setup_arch_timer(void)
> +{
> +}
> +
>  void board_init_f(ulong dummy)
>  {
>  	sunxi_sram_init();
>  
> +	setup_arch_timer();
> +
>  #if defined CONFIG_MACH_SUN6I || defined CONFIG_MACH_SUN8I_H3
>  	/* Enable non-secure access to some peripherals */
>  	tzpc_init();
> diff --git a/board/sunxi/board.c b/board/sunxi/board.c
> index 827e545032e..55501fafc38 100644
> --- a/board/sunxi/board.c
> +++ b/board/sunxi/board.c
> @@ -34,9 +34,6 @@
>  #include <asm/global_data.h>
>  #include <linux/delay.h>
>  #include <u-boot/crc.h>
> -#ifndef CONFIG_ARM64
> -#include <asm/armv7.h>
> -#endif
>  #include <asm/gpio.h>
>  #include <asm/io.h>
>  #include <u-boot/crc.h>
> @@ -187,39 +184,10 @@ enum env_location env_get_location(enum env_operation op, int prio)
>  /* add board specific code here */
>  int board_init(void)
>  {
> -	__maybe_unused int id_pfr1, ret, satapwr_pin, macpwr_pin;
> +	int ret, satapwr_pin, macpwr_pin;
>  
>  	gd->bd->bi_boot_params = (PHYS_SDRAM_0 + 0x100);
>  
> -#if !defined(CONFIG_ARM64) && !defined(CONFIG_MACH_SUNIV)
> -	asm volatile("mrc p15, 0, %0, c0, c1, 1" : "=r"(id_pfr1));
> -	debug("id_pfr1: 0x%08x\n", id_pfr1);
> -	/* Generic Timer Extension available? */
> -	if ((id_pfr1 >> CPUID_ARM_GENTIMER_SHIFT) & 0xf) {
> -		uint32_t freq;
> -
> -		debug("Setting CNTFRQ\n");
> -
> -		/*
> -		 * CNTFRQ is a secure register, so we will crash if we try to
> -		 * write this from the non-secure world (read is OK, though).
> -		 * In case some bootcode has already set the correct value,
> -		 * we avoid the risk of writing to it.
> -		 */
> -		asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r"(freq));
> -		if (freq != CONFIG_COUNTER_FREQUENCY) {
> -			debug("arch timer frequency is %d Hz, should be %d, fixing ...\n",
> -			      freq, CONFIG_COUNTER_FREQUENCY);
> -#ifdef CONFIG_NON_SECURE
> -			printf("arch timer frequency is wrong, but cannot adjust it\n");
> -#else
> -			asm volatile("mcr p15, 0, %0, c14, c0, 0"
> -				     : : "r"(CONFIG_COUNTER_FREQUENCY));
> -#endif
> -		}
> -	}
> -#endif /* !CONFIG_ARM64 && !CONFIG_MACH_SUNIV */
> -
>  	ret = axp_gpio_init();
>  	if (ret)
>  		return ret;