/* * This file contains the routines for TLB flushing. * On machines where the MMU does not use a hash table to store virtual to * physical translations (ie, SW loaded TLBs or Book3E compilant processors, * this does -not- include 603 however which shares the implementation with * hash based processors) * * -- BenH * * Copyright 2008,2009 Ben Herrenschmidt * IBM Corp. * * Derived from arch/ppc/mm/init.c: * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) * * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) * and Cort Dougan (PReP) (cort@cs.nmt.edu) * Copyright (C) 1996 Paul Mackerras * * Derived from "arch/i386/mm/init.c" * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * */ #include #include #include #include #include #include #include #include #include #include #include #include "mmu_decl.h" #ifdef CONFIG_PPC_BOOK3E struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = { [MMU_PAGE_4K] = { .shift = 12, .ind = 20, .enc = BOOK3E_PAGESZ_4K, }, [MMU_PAGE_16K] = { .shift = 14, .enc = BOOK3E_PAGESZ_16K, }, [MMU_PAGE_64K] = { .shift = 16, .ind = 28, .enc = BOOK3E_PAGESZ_64K, }, [MMU_PAGE_1M] = { .shift = 20, .enc = BOOK3E_PAGESZ_1M, }, [MMU_PAGE_16M] = { .shift = 24, .ind = 36, .enc = BOOK3E_PAGESZ_16M, }, [MMU_PAGE_256M] = { .shift = 28, .enc = BOOK3E_PAGESZ_256M, }, [MMU_PAGE_1G] = { .shift = 30, .enc = BOOK3E_PAGESZ_1GB, }, }; static inline int mmu_get_tsize(int psize) { return mmu_psize_defs[psize].enc; } #else static inline int mmu_get_tsize(int psize) { /* This isn't used on !Book3E for now */ return 0; } #endif /* The variables below are currently only used on 64-bit Book3E * though this will probably be made common with other nohash * implementations at some point */ #ifdef CONFIG_PPC64 int mmu_linear_psize; /* Page size used for the linear mapping */ int mmu_pte_psize; /* Page size used for PTE pages */ int mmu_vmemmap_psize; /* Page size used for the virtual mem map */ int book3e_htw_enabled; /* Is HW tablewalk enabled ? */ unsigned long linear_map_top; /* Top of linear mapping */ #endif /* CONFIG_PPC64 */ /* * Base TLB flushing operations: * * - flush_tlb_mm(mm) flushes the specified mm context TLB's * - flush_tlb_page(vma, vmaddr) flushes one page * - flush_tlb_range(vma, start, end) flushes a range of pages * - flush_tlb_kernel_range(start, end) flushes kernel pages * * - local_* variants of page and mm only apply to the current * processor */ /* * These are the base non-SMP variants of page and mm flushing */ void local_flush_tlb_mm(struct mm_struct *mm) { unsigned int pid; preempt_disable(); pid = mm->context.id; if (pid != MMU_NO_CONTEXT) _tlbil_pid(pid); preempt_enable(); } EXPORT_SYMBOL(local_flush_tlb_mm); void __local_flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr, int tsize, int ind) { unsigned int pid; preempt_disable(); pid = mm ? mm->context.id : 0; if (pid != MMU_NO_CONTEXT) _tlbil_va(vmaddr, pid, tsize, ind); preempt_enable(); } void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr) { __local_flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr, mmu_get_tsize(mmu_virtual_psize), 0); } EXPORT_SYMBOL(local_flush_tlb_page); /* * And here are the SMP non-local implementations */ #ifdef CONFIG_SMP static DEFINE_RAW_SPINLOCK(tlbivax_lock); static int mm_is_core_local(struct mm_struct *mm) { return cpumask_subset(mm_cpumask(mm), topology_thread_cpumask(smp_processor_id())); } struct tlb_flush_param { unsigned long addr; unsigned int pid; unsigned int tsize; unsigned int ind; }; static void do_flush_tlb_mm_ipi(void *param) { struct tlb_flush_param *p = param; _tlbil_pid(p ? p->pid : 0); } static void do_flush_tlb_page_ipi(void *param) { struct tlb_flush_param *p = param; _tlbil_va(p->addr, p->pid, p->tsize, p->ind); } /* Note on invalidations and PID: * * We snapshot the PID with preempt disabled. At this point, it can still * change either because: * - our context is being stolen (PID -> NO_CONTEXT) on another CPU * - we are invaliating some target that isn't currently running here * and is concurrently acquiring a new PID on another CPU * - some other CPU is re-acquiring a lost PID for this mm * etc... * * However, this shouldn't be a problem as we only guarantee * invalidation of TLB entries present prior to this call, so we * don't care about the PID changing, and invalidating a stale PID * is generally harmless. */ void flush_tlb_mm(struct mm_struct *mm) { unsigned int pid; preempt_disable(); pid = mm->context.id; if (unlikely(pid == MMU_NO_CONTEXT)) goto no_context; if (!mm_is_core_local(mm)) { struct tlb_flush_param p = { .pid = pid }; /* Ignores smp_processor_id() even if set. */ smp_call_function_many(mm_cpumask(mm), do_flush_tlb_mm_ipi, &p, 1); } _tlbil_pid(pid); no_context: preempt_enable(); } EXPORT_SYMBOL(flush_tlb_mm); void __flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr, int tsize, int ind) { struct cpumask *cpu_mask; unsigned int pid; preempt_disable(); pid = mm ? mm->context.id : 0; if (unlikely(pid == MMU_NO_CONTEXT)) goto bail; cpu_mask = mm_cpumask(mm); if (!mm_is_core_local(mm)) { /* If broadcast tlbivax is supported, use it */ if (mmu_has_feature(MMU_FTR_USE_TLBIVAX_BCAST)) { int lock = mmu_has_feature(MMU_FTR_LOCK_BCAST_INVAL); if (lock) raw_spin_lock(&tlbivax_lock); _tlbivax_bcast(vmaddr, pid, tsize, ind); if (lock) raw_spin_unlock(&tlbivax_lock); goto bail; } else { struct tlb_flush_param p = { .pid = pid, .addr = vmaddr, .tsize = tsize, .ind = ind, }; /* Ignores smp_processor_id() even if set in cpu_mask */ smp_call_function_many(cpu_mask, do_flush_tlb_page_ipi, &p, 1); } } _tlbil_va(vmaddr, pid, tsize, ind); bail: preempt_enable(); } void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr) { __flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr, mmu_get_tsize(mmu_virtual_psize), 0); } EXPORT_SYMBOL(flush_tlb_page); #endif /* CONFIG_SMP */ /* * Flush kernel TLB entries in the given range */ void flush_tlb_kernel_range(unsigned long start, unsigned long end) { #ifdef CONFIG_SMP preempt_disable(); smp_call_function(do_flush_tlb_mm_ipi, NULL, 1); _tlbil_pid(0); preempt_enable(); #else _tlbil_pid(0); #endif } EXPORT_SYMBOL(flush_tlb_kernel_range); /* * Currently, for range flushing, we just do a full mm flush. This should * be optimized based on a threshold on the size of the range, since * some implementation can stack multiple tlbivax before a tlbsync but * for now, we keep it that way */ void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end) { flush_tlb_mm(vma->vm_mm); } EXPORT_SYMBOL(flush_tlb_range); void tlb_flush(struct mmu_gather *tlb) { flush_tlb_mm(tlb->mm); /* Push out batch of freed page tables */ pte_free_finish(); } /* * Below are functions specific to the 64-bit variant of Book3E though that * may change in the future */ #ifdef CONFIG_PPC64 /* * Handling of virtual linear page tables or indirect TLB entries * flushing when PTE pages are freed */ void tlb_flush_pgtable(struct mmu_gather *tlb, unsigned long address) { int tsize = mmu_psize_defs[mmu_pte_psize].enc; if (book3e_htw_enabled) { unsigned long start = address & PMD_MASK; unsigned long end = address + PMD_SIZE; unsigned long size = 1UL << mmu_psize_defs[mmu_pte_psize].shift; /* This isn't the most optimal, ideally we would factor out the * while preempt & CPU mask mucking around, or even the IPI but * it will do for now */ while (start < end) { __flush_tlb_page(tlb->mm, start, tsize, 1); start += size; } } else { unsigned long rmask = 0xf000000000000000ul; unsigned long rid = (address & rmask) | 0x1000000000000000ul; unsigned long vpte = address & ~rmask; #ifdef CONFIG_PPC_64K_PAGES vpte = (vpte >> (PAGE_SHIFT - 4)) & ~0xfffful; #else vpte = (vpte >> (PAGE_SHIFT - 3)) & ~0xffful; #endif vpte |= rid; __flush_tlb_page(tlb->mm, vpte, tsize, 0); } } static void setup_page_sizes(void) { unsigned int tlb0cfg = mfspr(SPRN_TLB0CFG); unsigned int tlb0ps = mfspr(SPRN_TLB0PS); unsigned int eptcfg = mfspr(SPRN_EPTCFG); int i, psize; /* Look for supported direct sizes */ for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) { struct mmu_psize_def *def = &mmu_psize_defs[psize]; if (tlb0ps & (1U << (def->shift - 10))) def->flags |= MMU_PAGE_SIZE_DIRECT; } /* Indirect page sizes supported ? */ if ((tlb0cfg & TLBnCFG_IND) == 0) goto no_indirect; /* Now, we only deal with one IND page size for each * direct size. Hopefully all implementations today are * unambiguous, but we might want to be careful in the * future. */ for (i = 0; i < 3; i++) { unsigned int ps, sps; sps = eptcfg & 0x1f; eptcfg >>= 5; ps = eptcfg & 0x1f; eptcfg >>= 5; if (!ps || !sps) continue; for (psize = 0; psize < MMU_PAGE_COUNT; psize++) { struct mmu_psize_def *def = &mmu_psize_defs[psize]; if (ps == (def->shift - 10)) def->flags |= MMU_PAGE_SIZE_INDIRECT; if (sps == (def->shift - 10)) def->ind = ps + 10; } } no_indirect: /* Cleanup array and print summary */ pr_info("MMU: Supported page sizes\n"); for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) { struct mmu_psize_def *def = &mmu_psize_defs[psize]; const char *__page_type_names[] = { "unsupported", "direct", "indirect", "direct & indirect" }; if (def->flags == 0) { def->shift = 0; continue; } pr_info(" %8ld KB as %s\n", 1ul << (def->shift - 10), __page_type_names[def->flags & 0x3]); } } static void setup_mmu_htw(void) { extern unsigned int interrupt_base_book3e; extern unsigned int exc_data_tlb_miss_htw_book3e; extern unsigned int exc_instruction_tlb_miss_htw_book3e; unsigned int *ibase = &interrupt_base_book3e; /* Check if HW tablewalk is present, and if yes, enable it by: * * - patching the TLB miss handlers to branch to the * one dedicates to it * * - setting the global book3e_htw_enabled */ unsigned int tlb0cfg = mfspr(SPRN_TLB0CFG); if ((tlb0cfg & TLBnCFG_IND) && (tlb0cfg & TLBnCFG_PT)) { /* Our exceptions vectors start with a NOP and -then- a branch * to deal with single stepping from userspace which stops on * the second instruction. Thus we need to patch the second * instruction of the exception, not the first one */ patch_branch(ibase + (0x1c0 / 4) + 1, (unsigned long)&exc_data_tlb_miss_htw_book3e, 0); patch_branch(ibase + (0x1e0 / 4) + 1, (unsigned long)&exc_instruction_tlb_miss_htw_book3e, 0); book3e_htw_enabled = 1; } pr_info("MMU: Book3E Page Tables %s\n", book3e_htw_enabled ? "Enabled" : "Disabled"); } /* * Early initialization of the MMU TLB code */ static void __early_init_mmu(int boot_cpu) { unsigned int mas4; /* XXX This will have to be decided at runtime, but right * now our boot and TLB miss code hard wires it. Ideally * we should find out a suitable page size and patch the * TLB miss code (either that or use the PACA to store * the value we want) */ mmu_linear_psize = MMU_PAGE_1G; /* XXX This should be decided at runtime based on supported * page sizes in the TLB, but for now let's assume 16M is * always there and a good fit (which it probably is) */ mmu_vmemmap_psize = MMU_PAGE_16M; /* XXX This code only checks for TLB 0 capabilities and doesn't * check what page size combos are supported by the HW. It * also doesn't handle the case where a separate array holds * the IND entries from the array loaded by the PT. */ if (boot_cpu) { /* Look for supported page sizes */ setup_page_sizes(); /* Look for HW tablewalk support */ setup_mmu_htw(); } /* Set MAS4 based on page table setting */ mas4 = 0x4 << MAS4_WIMGED_SHIFT; if (book3e_htw_enabled) { mas4 |= mas4 | MAS4_INDD; #ifdef CONFIG_PPC_64K_PAGES mas4 |= BOOK3E_PAGESZ_256M << MAS4_TSIZED_SHIFT; mmu_pte_psize = MMU_PAGE_256M; #else mas4 |= BOOK3E_PAGESZ_1M << MAS4_TSIZED_SHIFT; mmu_pte_psize = MMU_PAGE_1M; #endif } else { #ifdef CONFIG_PPC_64K_PAGES mas4 |= BOOK3E_PAGESZ_64K << MAS4_TSIZED_SHIFT; #else mas4 |= BOOK3E_PAGESZ_4K << MAS4_TSIZED_SHIFT; #endif mmu_pte_psize = mmu_virtual_psize; } mtspr(SPRN_MAS4, mas4); /* Set the global containing the top of the linear mapping * for use by the TLB miss code */ linear_map_top = memblock_end_of_DRAM(); /* A sync won't hurt us after mucking around with * the MMU configuration */ mb(); memblock_set_current_limit(linear_map_top); } void __init early_init_mmu(void) { __early_init_mmu(1); } void __cpuinit early_init_mmu_secondary(void) { __early_init_mmu(0); } void setup_initial_memory_limit(phys_addr_t first_memblock_base, phys_addr_t first_memblock_size) { /* On Embedded 64-bit, we adjust the RMA size to match * the bolted TLB entry. We know for now that only 1G * entries are supported though that may eventually * change. We crop it to the size of the first MEMBLOCK to * avoid going over total available memory just in case... */ ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000); /* Finally limit subsequent allocations */ memblock_set_current_limit(ppc64_memblock_base + ppc64_rma_size); } #endif /* CONFIG_PPC64 */