Hi Jisheng, On Monday 14 November 2016 12:24 PM, Jisheng Zhang wrote: > > On Mon, 14 Nov 2016 14:12:51 +0800 Jisheng Zhang wrote: > >> Hi Pankaj, >>
<snip> >>> + * Helper API to get SCU base address >>> + * In case platform DT do not have SCU node, or iomap fails >>> + * this call will fallback and will try to map via call to >>> + * scu_a9_get_base. >>> + * This will return ownership of scu_base to the caller >>> + */ >>> +void __iomem *of_scu_get_base(void) >>> +{ >>> + unsigned long base = 0; >>> + struct device_node *np; >>> + void __iomem *scu_base; >>> + >>> + np = of_find_matching_node(NULL, scu_match); >> >> could we check np before calling of_iomap()? >> >>> + scu_base = of_iomap(np, 0); >>> + of_node_put(np); >>> + if (!scu_base) { >>> + pr_err("%s failed to map scu_base via DT\n", __func__); >> >> For non-ca5, non-ca9 based SoCs, we'll see this error msg. We understand >> what does it mean, but it may confuse normal users. In current version, >> berlin doesn't complain like this for non-ca9 SoCs > > oops, I just realized that the non-ca9 berlin arm SoC version isn't > upstreamed. > Below is the draft version I planed. Basically speaking, the code tries to > find "arm,cortex-a9-scu" node from DT, if can't, we think we don't need to > worry about SCU. Is there any elegant solution for my situation? > To adopt new generic API I have submitted a patch for Berlin (along with other various platforms) here: https://patchwork.kernel.org/patch/9426457/ Please review and if possible test and let me know feedback. Thanks, Pankaj Dubey > Thanks, > Jisheng > > > ------------8<------------------- > --- a/arch/arm/mach-berlin/platsmp.c > +++ b/arch/arm/mach-berlin/platsmp.c > @@ -56,22 +56,25 @@ static void __init berlin_smp_prepare_cpus(unsigned int > max_cpus) > void __iomem *vectors_base; > > np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu"); > - scu_base = of_iomap(np, 0); > - of_node_put(np); > - if (!scu_base) > - return; > + if (np) { > + scu_base = of_iomap(np, 0); > + of_node_put(np); > + if (!scu_base) > + return; > + scu_enable(scu_base); > + iounmap(scu_base); > + } > > np = of_find_compatible_node(NULL, NULL, "marvell,berlin-cpu-ctrl"); > cpu_ctrl = of_iomap(np, 0); > of_node_put(np); > if (!cpu_ctrl) > - goto unmap_scu; > + return; > > vectors_base = ioremap(CONFIG_VECTORS_BASE, SZ_32K); > if (!vectors_base) > - goto unmap_scu; > + return; > > - scu_enable(scu_base); > flush_cache_all(); > > /* > @@ -87,8 +90,6 @@ static void __init berlin_smp_prepare_cpus(unsigned int > max_cpus) > writel(virt_to_phys(secondary_startup), vectors_base + SW_RESET_ADDR); > > iounmap(vectors_base); > -unmap_scu: > - iounmap(scu_base); > } > > static struct smp_operations berlin_smp_ops __initdata = { > > >> >>> + if (scu_a9_has_base()) { >>> + base = scu_a9_get_base(); >>> + scu_base = ioremap(base, SZ_4K); >>> + } >>> + if (!scu_base) { >>> + pr_err("%s failed to map scu_base\n", __func__); >> >> ditto >> >>> + return IOMEM_ERR_PTR(-ENOMEM); >>> + } >>> + } >>> + return scu_base; >>> +} >>> + >>> +/* >>> + * Enable SCU via mapping scu_base DT >>> + * If scu_base mapped successfully scu will be enabled and in case of >>> + * failure if will return non-zero error code >>> + */ >>> +int of_scu_enable(void) >>> +{ >>> + void __iomem *scu_base; >>> + >>> + scu_base = of_scu_get_base(); >>> + if (!IS_ERR(scu_base)) { >>> + scu_enable(scu_base); >>> + iounmap(scu_base); >>> + return 0; >>> + } >>> + return PTR_ERR(scu_base); >>> +} >>> + >>> #endif >>> >>> /* >> >> >> _______________________________________________ >> linux-arm-kernel mailing list >> linux-arm-ker...@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > > > >