Re: [PATCH v4 13/18] memory: mtk-smi: Add bus_sel for mt8183

Nicolas Boichat
2018-12-21T04:47:08Z

On Sat, Dec 8, 2018 at 4:43 PM Yong Wu <yong.wu@mediatek.com> wrote:
>
> There are 2 mmu cells in a M4U HW. we could adjust some larbs entering
> mmu0 or mmu1 to balance the bandwidth via the smi-common register
> SMI_BUS_SEL(0x220)(Each larb occupy 2 bits).
>
> In mt8183, For better performance, we switch larb1/2/5/7 to enter
> mmu1 while the others still keep enter mmu0.
>
> In mt8173 and mt2712, we don't get the performance issue,
> Keep its default value(0x0), that means all the larbs enter mmu0.
>
> Signed-off-by: Yong Wu <yong.wu@mediatek.com>
> ---
> drivers/memory/mtk-smi.c | 22 ++++++++++++++++++++--
> 1 file changed, 20 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/memory/mtk-smi.c b/drivers/memory/mtk-smi.c
> index ee6165e..88eb61a 100644
> --- a/drivers/memory/mtk-smi.c
> +++ b/drivers/memory/mtk-smi.c
> @@ -49,6 +49,12 @@
> #define SMI_LARB_NONSEC_CON(id) (0x380 + ((id) * 4))
> #define F_MMU_EN BIT(0)
>
> +/* SMI COMMON */
> +#define SMI_BUS_SEL 0x220
> +#define SMI_BUS_LARB_SHIFT(larbid) ((larbid) << 1)
> +/* All are MMU0 defaultly. Only specialize mmu1 here. */
> +#define F_MMU1_LARB(larbid) (0x1 << SMI_BUS_LARB_SHIFT(larbid))
> +
> enum mtk_smi_gen {
> MTK_SMI_GEN1,
> MTK_SMI_GEN2
> @@ -57,6 +63,7 @@ enum mtk_smi_gen {
> struct mtk_smi_common_plat {
> enum mtk_smi_gen gen;
> bool has_gals;
> + u32 bus_sel; /* Balance some larbs to enter mmu0 or mmu1 */
> };
>
> struct mtk_smi_larb_gen {
> @@ -72,8 +79,8 @@ struct mtk_smi {
> struct clk *clk_apb, *clk_smi;
> struct clk *clk_gals0, *clk_gals1;
> struct clk *clk_async; /*only needed by mt2701*/
> - void __iomem *smi_ao_base;
> -
> + void __iomem *smi_ao_base; /* only for gen1 */
> + void __iomem *base; /* only for gen2 */
> const struct mtk_smi_common_plat *plat;
> };
>
> @@ -409,6 +416,8 @@ static int __maybe_unused mtk_smi_larb_suspend(struct device *dev)
> static const struct mtk_smi_common_plat mtk_smi_common_mt8183 = {
> .gen = MTK_SMI_GEN2,
> .has_gals = true,
> + .bus_sel = F_MMU1_LARB(1) | F_MMU1_LARB(2) | F_MMU1_LARB(5) |
> + F_MMU1_LARB(7),

Maybe it's ok for now, but I wonder if this is something that should
be specified in device tree? Maybe different applications will want
different larb split between MMU0 and MMU1?

> };
>
> static const struct of_device_id mtk_smi_common_of_ids[] = {
> @@ -481,6 +490,11 @@ static int mtk_smi_common_probe(struct platform_device *pdev)
> ret = clk_prepare_enable(common->clk_async);
> if (ret)
> return ret;
> + } else {
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + common->base = devm_ioremap_resource(dev, res);
> + if (IS_ERR(common->base))
> + return PTR_ERR(common->base);
> }
> pm_runtime_enable(dev);
> platform_set_drvdata(pdev, common);
> @@ -496,6 +510,7 @@ static int mtk_smi_common_remove(struct platform_device *pdev)
> static int __maybe_unused mtk_smi_common_resume(struct device *dev)
> {
> struct mtk_smi *common = dev_get_drvdata(dev);
> + u32 bus_sel = common->plat->bus_sel;
> int ret;
>
> ret = mtk_smi_clk_enable(common);
> @@ -503,6 +518,9 @@ static int __maybe_unused mtk_smi_common_resume(struct device *dev)
> dev_err(common->dev, "Failed to enable clock(%d).\n", ret);
> return ret;
> }
> +
> + if (common->plat->gen == MTK_SMI_GEN2 && bus_sel)
> + writel(bus_sel, common->base + SMI_BUS_SEL);
> return 0;
> }
>
> --
> 1.9.1
>