Re: [RFC PATCH 1/2] asm-generic: io: Add exec versions of ioremap

From: Arnd Bergmann
Date: Wed Nov 26 2014 - 16:33:07 EST


On Wednesday 26 November 2014 15:14:00 Dave Gerlach wrote:
> @@ -66,6 +66,11 @@ extern void ioport_unmap(void __iomem *);
> #define ioremap_wc ioremap_nocache
> #endif
>
> +#ifndef ARCH_HAS_IOREMAP_EXEC
> +#define ioremap_exec ioremap
> +#define ioremap_exec_nocache ioremap_nocache
> +#endif
> +
> #ifdef CONFIG_PCI
> /* Destroy a virtual mapping cookie for a PCI BAR (memory or IO) */
> struct pci_dev;
>

ioremap and ioremap_nocache are the same, and there is no
architecture-independent interface to map an MMIO range as
cached because a lot of architectures can't do that.

Also, I think there are architectures that cannot execute
from uncached memory, so I think adding this as a generic
API is not a good idea.

Arnd
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