Re: [PATCH v5 16/20] memory: mtk-smi: Add bus_sel for mt8183

From: Evan Green
Date: Wed Jan 30 2019 - 14:07:58 EST


On Mon, Dec 31, 2018 at 7:59 PM Yong Wu <yong.wu@xxxxxxxxxxxx> 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.
>
> Note: smi gen1(mt2701/mt7623) don't have this bus_sel.
>
> CC: Matthias Brugger <matthias.bgg@xxxxxxxxx>
> Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
> ---
> 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 9790801..08cf40d 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;
> };
>
> @@ -410,6 +417,8 @@ 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),
> };
>
> static const struct of_device_id mtk_smi_common_of_ids[] = {
> @@ -482,6 +491,11 @@ 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);

So you split base and smi_ao_base because they're completely different
register regions, or because ->base is no longer "always on"? It's
tempting to recombine them because they appear to be mutually
exclusive, but if they're truly different register regions then I
understand.