Re: [PATCH] ARM: shmobile: r8a7790 SMP prototype v2

[Arnd Bergmann <arnd@arndb.de>]

On Thursday 27 June 2013, Magnus Damm wrote:

> +#include <asm/cacheflush.h>
> +#include <asm/cp15.h>
> +#include <asm/smp_plat.h>
> +
> +#define SYSC	0xe6180000
> +#define SYSCSR  0x0000
> +
> +#define RST	0xe6160000
> +#define CA15BAR	0x6020
> +#define CA15RESCNT 0x0040
> +#define CA7BAR	0x4030
> +#define CA7RESCNT 0x0044
> +#define RESCNT	0x0050
> +
> +#define APMU	0xe6150000
> +#define CA15WUPCR 0x2010
> +#define CA7WUPCR 0x1010
> +
> +#define MERAM	0xe8080000

Please get the base addresses from device tree if you can,
using of_iomap().

> +#define r8a7790_clst_id(cpu) (cpu_logical_map((cpu)) >> 8)
> +#define r8a7790_cpu_id(cpu) (cpu_logical_map((cpu)) & 0xff)
> +
> +static void r8a7790_deassert_reset(unsigned int cpu)
> +{
> +	void __iomem *p, *carescnt;
> +	u32 bar, mask, magic;
> +	unsigned int clst_id = r8a7790_clst_id(cpu);
> +
> +	/* setup reset vectors */
> +	p = ioremap_nocache(RST, 0x7000);
> +	bar = (MERAM >> 8) & 0xfffffc00;
> +	__raw_writel(bar, p + r8a7790_clst[clst_id].cabar);
> +	__raw_writel(bar | 0x10, p + r8a7790_clst[clst_id].cabar);
> +
> +	/* enable clocks for cluster */
> +	if (r8a7790_clst[clst_id].use_count++ = 0) {
> +		mask = 1 << r8a7790_clst[clst_id].rescnt_bit;
> +		__raw_writel(__raw_readl(p + RESCNT) & ~mask, p + RESCNT);
> +	}

If you cannot use writel_relaxed() here, add a comment. Otherwise
change it to writel or writel_relaxed.

> +static void __init r8a7790_smp_prepare_cpus(unsigned int max_cpus)
> +{
> +	void __iomem *p;
> +	unsigned int k;
> +
> +	shmobile_boot_fn = virt_to_phys(shmobile_invalidate_start);
> +
> +	/* MERAM for jump stub, because BAR requires 256KB aligned address */
> +	p = ioremap_nocache(MERAM, 16);
> +	memcpy(p, shmobile_boot_vector, 16);
> +	iounmap(p);

On the other hand here you have to use __raw_writel() or
memcpy_toio() because memcpy cannot operate on __iomem tokens.

Also, if this is actually memory, you probably want to use ioremap_cached
or ioremap_writecombine.

	Arnd