From 2dece445b6dbdaa3d94f38ef44aa1b63bc2a6bb9 Mon Sep 17 00:00:00 2001 From: Laura Abbott Date: Tue, 10 Jan 2017 13:35:41 -0800 Subject: [PATCH] mm/cma: Cleanup highmem check 6b101e2a3ce4 ("mm/CMA: fix boot regression due to physical address of high_memory") added checks to use __pa_nodebug on x86 since CONFIG_DEBUG_VIRTUAL complains about high_memory not being linearlly mapped. arm64 is now getting support for CONFIG_DEBUG_VIRTUAL as well. Rather than add an explosion of arches to the #ifdef, switch to an alternate method to calculate the physical start of highmem using the page before highmem starts. This avoids the need for the #ifdef and extra __pa_nodebug calls. Reviewed-by: Mark Rutland Tested-by: Mark Rutland Signed-off-by: Laura Abbott Signed-off-by: Will Deacon --- mm/cma.c | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-) diff --git a/mm/cma.c b/mm/cma.c index c960459eda7e..94b3460cd608 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -235,18 +235,13 @@ int __init cma_declare_contiguous(phys_addr_t base, phys_addr_t highmem_start; int ret = 0; -#ifdef CONFIG_X86 /* - * high_memory isn't direct mapped memory so retrieving its physical - * address isn't appropriate. But it would be useful to check the - * physical address of the highmem boundary so it's justifiable to get - * the physical address from it. On x86 there is a validation check for - * this case, so the following workaround is needed to avoid it. + * We can't use __pa(high_memory) directly, since high_memory + * isn't a valid direct map VA, and DEBUG_VIRTUAL will (validly) + * complain. Find the boundary by adding one to the last valid + * address. */ - highmem_start = __pa_nodebug(high_memory); -#else - highmem_start = __pa(high_memory); -#endif + highmem_start = __pa(high_memory - 1) + 1; pr_debug("%s(size %pa, base %pa, limit %pa alignment %pa)\n", __func__, &size, &base, &limit, &alignment); -- 2.20.1