Messages in this thread | | | Subject | Re: [PATCH 1/6] powerpc/mm/32: Use pfn_valid to check if pointer is in RAM | From | christophe leroy <> | Date | Tue, 20 Feb 2018 18:45:09 +0100 |
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Le 20/02/2018 à 17:14, Jonathan Neuschäfer a écrit : > The Nintendo Wii has a memory layout that places two chunks of RAM at > non-adjacent addresses, and MMIO between them. Currently, the allocation > of these MMIO areas is made possible by declaring the MMIO hole as > reserved memory and allowing reserved memory to be allocated (cf. > wii_memory_fixups). > > This patch is the first step towards proper support for discontiguous > memory on PPC32 by using pfn_valid to check if a pointer points into > RAM, rather than open-coding the check. It should result in no > functional difference. > > Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> > --- > arch/powerpc/mm/pgtable_32.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c > index d35d9ad3c1cd..b5c009893a44 100644 > --- a/arch/powerpc/mm/pgtable_32.c > +++ b/arch/powerpc/mm/pgtable_32.c > @@ -147,7 +147,7 @@ __ioremap_caller(phys_addr_t addr, unsigned long size, unsigned long flags, > * Don't allow anybody to remap normal RAM that we're using. > * mem_init() sets high_memory so only do the check after that. > */ > - if (slab_is_available() && (p < virt_to_phys(high_memory)) && > + if (slab_is_available() && pfn_valid(__phys_to_pfn(p)) &&
I'm not sure this is equivalent:
high_memory = (void *) __va(max_low_pfn * PAGE_SIZE); #define ARCH_PFN_OFFSET ((unsigned long)(MEMORY_START >> PAGE_SHIFT)) #define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && (pfn) < max_mapnr) set_max_mapnr(max_pfn);
So in the current implementation it checks against max_low_pfn while your patch checks against max_pfn
max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT; #ifdef CONFIG_HIGHMEM max_low_pfn = lowmem_end_addr >> PAGE_SHIFT; #endif
Christophe
> !(__allow_ioremap_reserved && memblock_is_region_reserved(p, size))) { > printk("__ioremap(): phys addr 0x%llx is RAM lr %ps\n", > (unsigned long long)p, __builtin_return_address(0)); >
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