[PATCH 3/4] ARM: L2 : Errata 588369: Clean & Invalidate do not invalidate clean lines

[Tony Lindgren]

Hi,

* Santosh Shilimkar <santosh.shilimkar at ti.com> [091209 10:42]:
> This patch implements the work-around for the errata 588369. The secure API
> is used to alter L2 debug regsiter because of trust-zone.

This one should be queued via Russell's patch system. It should
be also acked by Catalin.

Regards,

Tony

 
> Signed-off-by: Santosh Shilimkar <santosh.shilimkar at ti.com>
> ---
>  arch/arm/Kconfig         |   13 +++++++++++++
>  arch/arm/mm/cache-l2x0.c |   32 ++++++++++++++++++++++++++++++++
>  2 files changed, 45 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index cf8a99f..388d1e3 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -916,6 +916,19 @@ config ARM_ERRATA_460075
>  	  ACTLR register. Note that setting specific bits in the ACTLR register
>  	  may not be available in non-secure mode.
>  
> +config PL310_ERRATA_588369
> +	bool "Clean & Invalidate maintenance operations do not invalidate clean lines"
> +	depends on CACHE_L2X0
> +	default n
> +	help
> +	   The PL310 L2 cache controller implements three types of Clean &
> +	   Invalidate maintenance operations: by Physical Address
> +	   (offset 0x7F0), by Index/Way (0x7F8) and by Way (0x7FC).
> +	   They are architecturally defined to behave as the execution of a
> +	   clean operation followed immediately by an invalidate operation,
> +	   both performing to the same memory location. This functionality
> +	   is not correctly implemented in PL310 as clean lines are not
> +	   invalidated as a result of these operations
>  endmenu
>  
>  source "arch/arm/common/Kconfig"
> diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
> index 747f9a9..c3905a9 100644
> --- a/arch/arm/mm/cache-l2x0.c
> +++ b/arch/arm/mm/cache-l2x0.c
> @@ -88,8 +88,40 @@ static void l2x0_flush_range(unsigned long start, unsigned long end)
>  	unsigned long addr;
>  
>  	start &= ~(CACHE_LINE_SIZE - 1);
> +#ifdef CONFIG_PL310_ERRATA_588369
> +	/*
> +	 * Disable Write-Back and Cache Linefill (set bits [1:0] of the Debug
> +	 * Control Register)
> +	 */
> +	__asm__ __volatile__(
> +	"stmfd r13!, {r0-r12, r14}\n"
> +	"mov r0, #3\n"
> +	"ldr r12, =0x100\n"
> +	"dsb\n"
> +	"smc\n"
> +	"ldmfd r13!, {r0-r12, r14}");
> +
> +	/* Clean by PA followed by Invalidate by PA */
> +	for (addr = start; addr < end; addr += CACHE_LINE_SIZE) {
> +		sync_writel(addr, L2X0_CLEAN_LINE_PA, 1);
> +		sync_writel(addr, L2X0_INV_LINE_PA, 1);
> +	}
> +
> +	/*
> +	 * Enable Write-Back and Cache Linefill (set bits [1:0] of the Debug
> +	 * Control Register)
> +	 */
> +	__asm__ __volatile__(
> +	"stmfd r13!, {r0-r12, r14}\n"
> +	"mov r0, #0\n"
> +	"ldr r12, =0x100\n"
> +	"dsb\n"
> +	"smc\n"
> +	"ldmfd r13!, {r0-r12, r14}");
> +#else
>  	for (addr = start; addr < end; addr += CACHE_LINE_SIZE)
>  		sync_writel(addr, L2X0_CLEAN_INV_LINE_PA, 1);
> +#endif
>  	cache_sync();
>  }
>  
> -- 
> 1.6.0.4
>