From 2bbf63264ab2e8cbc740c738f66984b2aafa29c5 Mon Sep 17 00:00:00 2001 From: Jonathan Neuschäfer Date: Wed, 28 Mar 2018 02:25:42 +0200 Subject: powerpc/mm/32: Use page_is_ram to check for RAM On systems where there is MMIO space between different blocks of RAM in the physical address space, __ioremap_caller did not allow mapping these MMIO areas, because they were below the end RAM and thus considered RAM as well. Use the memblock-based page_is_ram function, which returns false for such MMIO holes. v2: Keep the check for p < virt_to_phys(high_memory). On 32-bit systems with high memory (memory above physical address 4GiB), the high memory is expected to be available though ioremap. The high_memory variable marks the end of low memory; comparing against it means that only ioremap requests for low RAM will be denied. Reported by Michael Ellerman. Signed-off-by: Jonathan Neuschäfer Signed-off-by: Michael Ellerman --- arch/powerpc/mm/pgtable_32.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/powerpc') diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c index d35d9ad3c1cd..6668ecc041ad 100644 --- a/arch/powerpc/mm/pgtable_32.c +++ b/arch/powerpc/mm/pgtable_32.c @@ -148,6 +148,7 @@ __ioremap_caller(phys_addr_t addr, unsigned long size, unsigned long flags, * mem_init() sets high_memory so only do the check after that. */ if (slab_is_available() && (p < virt_to_phys(high_memory)) && + page_is_ram(__phys_to_pfn(p)) && !(__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)); -- cgit v1.2.3-55-g7522