ioremap: rework pXd_free_pYd_page() API
The recently merged API for ensuring break-before-make on page-table entries when installing huge mappings in the vmalloc/ioremap region is fairly counter-intuitive, resulting in the arch freeing functions (e.g. pmd_free_pte_page()) being called even on entries that aren't present. This resulted in a minor bug in the arm64 implementation, giving rise to spurious VM_WARN messages. This patch moves the pXd_present() checks out into the core code, refactoring the callsites at the same time so that we avoid the complex conjunctions when determining whether or not we can put down a huge mapping. Link: http://lkml.kernel.org/r/1544120495-17438-2-git-send-email-will.deacon@arm.comSigned-off-by: NWill Deacon <will.deacon@arm.com> Reviewed-by: NToshi Kani <toshi.kani@hpe.com> Suggested-by: NLinus Torvalds <torvalds@linux-foundation.org> Cc: Chintan Pandya <cpandya@codeaurora.org> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Michal Hocko <mhocko@suse.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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