[U-Boot] [PATCH] arm: imx: common rework cache settings for imx6

[Peng Fan <b51431@freescale.com>]

Hi Adrian,

On Wed, Aug 26, 2015 at 06:27:42PM -0500, Adrian Alonso wrote:
>Rework cache settings for imx6, move cache configuration
>to imx-common/cache.c so it can be reused for newer SoC

Better not do this now.
See below comments.

>
>Signed-off-by: Adrian Alonso <aalonso@freescale.com>
>---
> arch/arm/cpu/armv7/mx6/soc.c |  95 ---------------------------------------
> arch/arm/imx-common/Makefile |   1 +
> arch/arm/imx-common/cache.c  | 103 +++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 104 insertions(+), 95 deletions(-)
> create mode 100644 arch/arm/imx-common/cache.c
>

[...]

> 
>-#ifndef CONFIG_SYS_DCACHE_OFF
>-void enable_caches(void)

Different imx SoCs have different implementation for this.

>-{
>-#if defined(CONFIG_SYS_ARM_CACHE_WRITETHROUGH)
>-	enum dcache_option option = DCACHE_WRITETHROUGH;
>-#else
>-	enum dcache_option option = DCACHE_WRITEBACK;
>-#endif
>-
>-	/* Avoid random hang when download by usb */
>-	invalidate_dcache_all();
>-
>-	/* Enable D-cache. I-cache is already enabled in start.S */
>-	dcache_enable();
>-
>-	/* Enable caching on OCRAM and ROM */
>-	mmu_set_region_dcache_behaviour(ROMCP_ARB_BASE_ADDR,
>-					ROMCP_ARB_END_ADDR,
>-					option);
>-	mmu_set_region_dcache_behaviour(IRAM_BASE_ADDR,
>-					IRAM_SIZE,
>-					option);
>-}
>-#endif
>-

From my understanding, only i.MX6 have this pl310 support.
There is no need to move the code to imx-common.

>-
>-#ifndef CONFIG_SYS_L2CACHE_OFF
>-#define IOMUXC_GPR11_L2CACHE_AS_OCRAM 0x00000002
>-void v7_outer_cache_enable(void)
>-{
>-	struct pl310_regs *const pl310 = (struct pl310_regs *)L2_PL310_BASE;
>-	unsigned int val;
>-
>-
>-	/*
>-	 * Set bit 22 in the auxiliary control register. If this bit
>-	 * is cleared, PL310 treats Normal Shared Non-cacheable
>-	 * accesses as Cacheable no-allocate.
>-	 */
>-	setbits_le32(&pl310->pl310_aux_ctrl, L310_SHARED_ATT_OVERRIDE_ENABLE);
>-
>-#if defined CONFIG_MX6SL
>-	struct iomuxc *iomux = (struct iomuxc *)IOMUXC_BASE_ADDR;
>-	val = readl(&iomux->gpr[11]);
>-	if (val & IOMUXC_GPR11_L2CACHE_AS_OCRAM) {
>-		/* L2 cache configured as OCRAM, reset it */
>-		val &= ~IOMUXC_GPR11_L2CACHE_AS_OCRAM;
>-		writel(val, &iomux->gpr[11]);
>-	}
>-#endif
>-
>-	/* Must disable the L2 before changing the latency parameters */
>-	clrbits_le32(&pl310->pl310_ctrl, L2X0_CTRL_EN);
>-
>-	writel(0x132, &pl310->pl310_tag_latency_ctrl);
>-	writel(0x132, &pl310->pl310_data_latency_ctrl);
>-
>-	val = readl(&pl310->pl310_prefetch_ctrl);
>-
>-	/* Turn on the L2 I/D prefetch */
>-	val |= 0x30000000;
>-
>-	/*
>-	 * The L2 cache controller(PL310) version on the i.MX6D/Q is r3p1-50rel0
>-	 * The L2 cache controller(PL310) version on the i.MX6DL/SOLO/SL is r3p2
>-	 * But according to ARM PL310 errata: 752271
>-	 * ID: 752271: Double linefill feature can cause data corruption
>-	 * Fault Status: Present in: r3p0, r3p1, r3p1-50rel0. Fixed in r3p2
>-	 * Workaround: The only workaround to this erratum is to disable the
>-	 * double linefill feature. This is the default behavior.
>-	 */
>-
>-#ifndef CONFIG_MX6Q
>-	val |= 0x40800000;
>-#endif
>-	writel(val, &pl310->pl310_prefetch_ctrl);
>-
>-	val = readl(&pl310->pl310_power_ctrl);
>-	val |= L2X0_DYNAMIC_CLK_GATING_EN;
>-	val |= L2X0_STNDBY_MODE_EN;
>-	writel(val, &pl310->pl310_power_ctrl);
>-
>-	setbits_le32(&pl310->pl310_ctrl, L2X0_CTRL_EN);
>-}
>-
>-void v7_outer_cache_disable(void)
>-{
>-	struct pl310_regs *const pl310 = (struct pl310_regs *)L2_PL310_BASE;
>-
>-	clrbits_le32(&pl310->pl310_ctrl, L2X0_CTRL_EN);
>-}
>-#endif /* !CONFIG_SYS_L2CACHE_OFF */
>diff --git a/arch/arm/imx-common/Makefile b/arch/arm/imx-common/Makefile
>index b9f1ca4..3b034e1 100644
>--- a/arch/arm/imx-common/Makefile
>+++ b/arch/arm/imx-common/Makefile
>@@ -19,6 +19,7 @@ obj-y	+= misc.o
> obj-$(CONFIG_SPL_BUILD)	+= spl.o
> endif
> ifeq ($(SOC),$(filter $(SOC),mx6))
>+obj-y 	+= cache.o

Only mx6. Then there is no need to move the code imx-common.
From the long run, we may move most code to saying arch/arm/mach-imx in
future. But now I think we let the code be there.

[...]

Regards,
Peng.
--