Mirror the physmap into the ASI pagetables, but with a maximum granularity that's guaranteed to allow changing pageblock sensitivity without having to allocate pagetables. Signed-off-by: Brendan Jackman <jackmanb@xxxxxxxxxx> --- arch/x86/mm/init_64.c | 30 ++++++++++++++++++++++++++++-- 1 file changed, 28 insertions(+), 2 deletions(-) diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 8f75274fddd96b8285aff48493ebad93e30daebe..4ca6bb419b9643b0e72cb5b6da6d905f2b2be84b 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -7,6 +7,7 @@ * Copyright (C) 2002,2003 Andi Kleen <ak@xxxxxxx> */ +#include <linux/asi.h> #include <linux/signal.h> #include <linux/sched.h> #include <linux/kernel.h> @@ -736,7 +737,8 @@ phys_pgd_init(pgd_t *pgd_page, unsigned long paddr_start, unsigned long paddr_en { unsigned long vaddr, vaddr_start, vaddr_end, vaddr_next, paddr_last; - *pgd_changed = false; + if (pgd_changed) + *pgd_changed = false; paddr_last = paddr_end; vaddr = (unsigned long)__va(paddr_start); @@ -770,9 +772,13 @@ phys_pgd_init(pgd_t *pgd_page, unsigned long paddr_start, unsigned long paddr_en (pud_t *) p4d, init); spin_unlock(&init_mm.page_table_lock); - *pgd_changed = true; + if (pgd_changed) + *pgd_changed = true; } + if (pgd_changed) + sync_global_pgds(vaddr_start, vaddr_end - 1); + return paddr_last; } @@ -784,9 +790,29 @@ __kernel_physical_mapping_init(unsigned long paddr_start, { bool pgd_changed; unsigned long paddr_last; + pgd_t *pgd_asi = asi_pgd(ASI_GLOBAL_NONSENSITIVE); paddr_last = phys_pgd_init(init_mm.pgd, paddr_start, paddr_end, page_size_mask, prot, init, &pgd_changed); + + /* + * Set up ASI's global-nonsensitive physmap. This needs to mapped at max + * 2M size so that regions can be mapped and unmapped at pageblock + * granularity without requiring allocations. + */ + if (pgd_asi) { + /* + * Since most memory is expected to end up sensitive, start with + * everything unmapped in this pagetable. The page allocator + * assumes that's the case. + */ + pgprot_t prot_np = __pgprot(pgprot_val(prot) & ~_PAGE_PRESENT); + + VM_BUG_ON((PAGE_SHIFT + pageblock_order) < page_level_shift(PG_LEVEL_2M)); + phys_pgd_init(pgd_asi, paddr_start, paddr_end, 1 << PG_LEVEL_2M, + prot_np, init, NULL); + } + if (pgd_changed) sync_global_pgds((unsigned long)__va(paddr_start), (unsigned long)__va(paddr_end) - 1); -- 2.49.0.rc1.451.g8f38331e32-goog