[U-Boot,1/2] arm: Replace test for CONFIG_ARMV7 with CONFIG_CPU_V7

The arch/arm/lib/cache-cp15.c checks for CONFIG_ARMV7 and if this macro is
set, it configures TTBR0 register. This register must be configured for the
cache on ARMv7 to operate correctly.

The problem is that noone actually sets the CONFIG_ARMV7 macro and thus the
TTBR0 is not configured at all. On SoCFPGA, this produces all sorts of minor
issues which are hard to replicate, for example certain USB sticks are not
detected or QSPI NOR sometimes fails to write pages completely.

The solution is to replace CONFIG_ARMV7 test with CONFIG_CPU_V7 one. This is
correct because the code which added the test(s) for CONFIG_ARMV7 was added
shortly after CONFIG_ARMV7 was replaced by CONFIG_CPU_V7 and this code was
not adjusted correctly to reflect that change.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Tom Rini <trini@konsulko.com>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Cc: Simon Glass <sjg@chromium.org>
---
 arch/arm/include/asm/system.h | 4 ++--
 arch/arm/lib/cache-cp15.c     | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

Hello Marek,

On Tue, 29 Dec 2015 19:44:01 +0100, Marek Vasut <marex@denx.de> wrote:
> The arch/arm/lib/cache-cp15.c checks for CONFIG_ARMV7 and if this macro is
> set, it configures TTBR0 register. This register must be configured for the
> cache on ARMv7 to operate correctly.
> 
> The problem is that noone actually sets the CONFIG_ARMV7 macro and thus the
> TTBR0 is not configured at all. On SoCFPGA, this produces all sorts of minor
> issues which are hard to replicate, for example certain USB sticks are not
> detected or QSPI NOR sometimes fails to write pages completely.
> 
> The solution is to replace CONFIG_ARMV7 test with CONFIG_CPU_V7 one. This is
> correct because the code which added the test(s) for CONFIG_ARMV7 was added
> shortly after CONFIG_ARMV7 was replaced by CONFIG_CPU_V7 and this code was
> not adjusted correctly to reflect that change.

Analysis of the series shows that:

- it does not change the values of DCACHE_OFF, DCACHE_WRITETHROUGH and
  DCACHE_WRITEBACK;

- it does change the value of DCACHE_WRITEALLOC from 0x16 to 0x101E, but
  DCACHE_WRITEALLOC is only used when CONFIG_SYS_ARM_CACHE_WRITEALLOC is
  defined, which does not happen throughout U-Boot, as shown by a search
  for "WRITEALLOC".

- it sets inner and outer region cache control bits in TTBR0, to match
  the cacheability of the DDR in which the MMU table resides.

Marek performed tests of patch 1/2 only (with the S bit set) and of
the whole series (wih the S bit clear). With patch 1/2 only, Marek could
witness the performance hit described by Stefan Roese; with the whole
series, Marek saw no performance hit any more.

I will therefore take this patch series in, since it fixes an obvious
issue in the U-Boot code and does not show any adverse effect.

Amicalement,

Hello Marek,

On Tue, 29 Dec 2015 19:44:01 +0100, Marek Vasut <marex@denx.de> wrote:
> The arch/arm/lib/cache-cp15.c checks for CONFIG_ARMV7 and if this macro is
> set, it configures TTBR0 register. This register must be configured for the
> cache on ARMv7 to operate correctly.
> 
> The problem is that noone actually sets the CONFIG_ARMV7 macro and thus the
> TTBR0 is not configured at all. On SoCFPGA, this produces all sorts of minor
> issues which are hard to replicate, for example certain USB sticks are not
> detected or QSPI NOR sometimes fails to write pages completely.
> 
> The solution is to replace CONFIG_ARMV7 test with CONFIG_CPU_V7 one. This is
> correct because the code which added the test(s) for CONFIG_ARMV7 was added
> shortly after CONFIG_ARMV7 was replaced by CONFIG_CPU_V7 and this code was
> not adjusted correctly to reflect that change.
> 
> Signed-off-by: Marek Vasut <marex@denx.de>
> Cc: Tom Rini <trini@konsulko.com>
> Cc: Albert Aribaud <albert.u.boot@aribaud.net>
> Cc: Simon Glass <sjg@chromium.org>
> ---
>  arch/arm/include/asm/system.h | 4 ++--
>  arch/arm/lib/cache-cp15.c     | 2 +-
>  2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
> index 71b3108..dec83c7 100644
> --- a/arch/arm/include/asm/system.h
> +++ b/arch/arm/include/asm/system.h
> @@ -220,7 +220,7 @@ static inline void set_dacr(unsigned int val)
>  	isb();
>  }
>  
> -#ifdef CONFIG_ARMV7
> +#ifdef CONFIG_CPU_V7
>  /* Short-Descriptor Translation Table Level 1 Bits */
>  #define TTB_SECT_NS_MASK	(1 << 19)
>  #define TTB_SECT_NG_MASK	(1 << 17)
> @@ -257,7 +257,7 @@ enum {
>  	MMU_SECTION_SIZE	= 1 << MMU_SECTION_SHIFT,
>  };
>  
> -#ifdef CONFIG_ARMV7
> +#ifdef CONFIG_CPU_V7
>  /* TTBR0 bits */
>  #define TTBR0_BASE_ADDR_MASK	0xFFFFC000
>  #define TTBR0_RGN_NC			(0 << 3)
> diff --git a/arch/arm/lib/cache-cp15.c b/arch/arm/lib/cache-cp15.c
> index c65e068..8e18538 100644
> --- a/arch/arm/lib/cache-cp15.c
> +++ b/arch/arm/lib/cache-cp15.c
> @@ -96,7 +96,7 @@ static inline void mmu_setup(void)
>  		dram_bank_mmu_setup(i);
>  	}
>  
> -#ifdef CONFIG_ARMV7
> +#ifdef CONFIG_CPU_V7
>  	/* Set TTBR0 */
>  	reg = gd->arch.tlb_addr & TTBR0_BASE_ADDR_MASK;
>  #if defined(CONFIG_SYS_ARM_CACHE_WRITETHROUGH)
> -- 
> 2.1.4
> 

Series applied to u-boot-arm/master, thanks!

Amicalement,