Re: [PATCH 1/6] powerpc/mm/32: Use pfn_valid to check if pointer is in RAM
From: christophe leroy <hidden>
Date: 2018-02-20 17:45:20
Also in:
linux-mm, lkml
Le 20/02/2018 à 17:14, Jonathan Neuschäfer a écrit :
quoted hunk ↗ jump to hunk
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));--- L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast. https://www.avast.com/antivirus