[PATCH 2/2] ARM: imx6: dh-imx6: Enable d-cache early in SPL

[Marek Vasut]

On 8/4/22 10:15, Philip Oberfichtner wrote:
> From: Marek Vasut <marex at denx.de>
> 
> Enable d-cache early in SPL right after DRAM is started up.
> This reduces U-Boot proper load time by 650ms when loaded
> from SPI NOR.
> 
> Signed-off-by: Marek Vasut <marex at denx.de>
> Signed-off-by: Philip Oberfichtner <pro at denx.de>
> 
> ---
> 
>   board/dhelectronics/dh_imx6/dh_imx6_spl.c | 27 +++++++++++++++++++++++
>   1 file changed, 27 insertions(+)
> 
> diff --git a/board/dhelectronics/dh_imx6/dh_imx6_spl.c b/board/dhelectronics/dh_imx6/dh_imx6_spl.c
> index e49e97724a..2c0ddc527a 100644
> --- a/board/dhelectronics/dh_imx6/dh_imx6_spl.c
> +++ b/board/dhelectronics/dh_imx6/dh_imx6_spl.c
> @@ -6,6 +6,7 @@
>    */
>   
>   #include <common.h>
> +#include <cpu_func.h>
>   #include <init.h>
>   #include <asm/arch/clock.h>
>   #include <asm/arch/crm_regs.h>
> @@ -14,11 +15,13 @@
>   #include <asm/arch/mx6-ddr.h>
>   #include <asm/arch/mx6-pins.h>
>   #include <asm/arch/sys_proto.h>
> +#include <asm/cache.h>
>   #include <asm/gpio.h>
>   #include <asm/mach-imx/boot_mode.h>
>   #include <asm/mach-imx/iomux-v3.h>
>   #include <asm/mach-imx/mxc_i2c.h>
>   #include <asm/io.h>
> +#include <asm/system.h>
>   #include <errno.h>
>   #include <fuse.h>
>   #include <fsl_esdhc_imx.h>
> @@ -610,6 +613,20 @@ static void dhcom_spl_dram_init(void)
>   	}
>   }
>   
> +void dram_bank_mmu_setup(int bank)
> +{
> +	int i;
> +
> +	set_section_dcache(ROMCP_ARB_BASE_ADDR >> MMU_SECTION_SHIFT, DCACHE_DEFAULT_OPTION);
> +	set_section_dcache(IRAM_BASE_ADDR >> MMU_SECTION_SHIFT, DCACHE_DEFAULT_OPTION);
> +
> +	for (i = MMDC0_ARB_BASE_ADDR >> MMU_SECTION_SHIFT;
> +			i < ((MMDC0_ARB_BASE_ADDR >> MMU_SECTION_SHIFT) +
> +			(SZ_1G >> MMU_SECTION_SHIFT));
> +			i++)
> +		set_section_dcache(i, DCACHE_DEFAULT_OPTION);
> +}
> +
>   void board_init_f(ulong dummy)
>   {
>   	/* setup AIPS and disable watchdog */
> @@ -636,9 +653,19 @@ void board_init_f(ulong dummy)
>   	/* DDR3 initialization */
>   	dhcom_spl_dram_init();
>   
> +	/* Set up early MMU tables at the beginning of DRAM and start d-cache */
> +	gd->arch.tlb_addr = MMDC0_ARB_BASE_ADDR + SZ_32M;
> +	gd->arch.tlb_size = PGTABLE_SIZE;
> +	enable_caches();
> +
>   	/* Clear the BSS. */
>   	memset(__bss_start, 0, __bss_end - __bss_start);
>   
>   	/* load/boot image from boot device */
>   	board_init_r(NULL, 0);
>   }
> +
> +void spl_board_prepare_for_boot(void)
> +{

An explanation why this is needed in a comment would be good to have.

> +	dcache_disable();
> +}