Commit be39cbcb authored Apr 05, 2018 by Greg Ungerer

m68k: fix ioremapping for internal ColdFire peripherals



The ColdFire SoC internal peripherals are mapped into virtual address
space using the ACR registers of the cache control unit. This means we
are using a 1:1 physical:virtual mapping for them that does not rely on
page table mappings. We can quickly determine if we are accessing an
internal peripheral device given the physical or vitrual address using
the same range check.

The implications of this mapping is that an ioremap should return the
physical address as the virtual mapping __iomem cookie as well. So fix
ioremap() to deal with this on ColdFire. Of course you need to take
care of this in the iounmap() path as well.

Reported-by: Angelo Dureghello <angelo@sysam.it>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
Reviewed-by: Angelo Dureghello <angelo@sysam.it>
Tested-by: Angelo Dureghello <angelo@sysam.it>

parent 4d530378

arch/m68k/mm/kmap.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -125,6 +125,10 @@ void __iomem *__ioremap(unsigned long physaddr, unsigned long size, int cachefla
		return (void __iomem *)physaddr;
		}
		#endif
		#ifdef CONFIG_COLDFIRE
		if (__cf_internalio(physaddr))
		return (void __iomem *) physaddr;
		#endif

		#ifdef DEBUG
		printk("ioremap: 0x%lx,0x%lx(%d) - ", physaddr, size, cacheflag);
		@@ -235,6 +239,10 @@ void iounmap(void __iomem *addr)
		((unsigned long)addr > 0x60000000)))
		free_io_area((__force void *)addr);
		#else
		#ifdef CONFIG_COLDFIRE
		if (cf_internalio(addr))
		return;
		#endif
		free_io_area((__force void *)addr);
		#endif
		}

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