Re: [PATCH V3 16/22] LoongArch: Add misc common routines

From: Christoph Hellwig
Date: Fri Sep 17 2021 - 02:13:01 EST


> +
> +/*
> + * Change "struct page" to physical address.
> + */
> +#define page_to_phys(page) ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT)

Why is this using a dma_addr_t? phys_addr_t would be the right type
here.

> +
> +extern void __init __iomem *early_ioremap(u64 phys_addr, unsigned long size);
> +extern void __init early_iounmap(void __iomem *addr, unsigned long size);
> +
> +#define early_memremap early_ioremap
> +#define early_memunmap early_iounmap
> +
> +static inline void __iomem *ioremap_prot(phys_addr_t offset, unsigned long size,
> + unsigned long prot_val)
> +{
> + if (prot_val == _CACHE_CC)
> + return (void __iomem *)(unsigned long)(CAC_BASE + offset);
> + else
> + return (void __iomem *)(unsigned long)(UNCAC_BASE + offset);
> +}

There is no real need for this ioremap_prot multiplexer

> +/*
> + * ioremap_cache - map bus memory into CPU space
> + * @offset: bus address of the memory
> + * @size: size of the resource to map
> + *
> + * ioremap_cache performs a platform specific sequence of operations to
> + * make bus memory CPU accessible via the readb/readw/readl/writeb/
> + * writew/writel functions and the other mmio helpers. The returned
> + * address is not guaranteed to be usable directly as a virtual
> + * address.
> + *
> + * This version of ioremap ensures that the memory is marked cachable by
> + * the CPU. Also enables full write-combining. Useful for some
> + * memory-like regions on I/O busses.
> + */
> +#define ioremap_cache(offset, size) \
> + ioremap_prot((offset), (size), _CACHE_CC)

Please don't add ioremap_cache to new ports.