diff options
Diffstat (limited to 'arch/powerpc/mm/nohash/tlb.c')
| -rw-r--r-- | arch/powerpc/mm/nohash/tlb.c | 795 |
1 files changed, 795 insertions, 0 deletions
diff --git a/arch/powerpc/mm/nohash/tlb.c b/arch/powerpc/mm/nohash/tlb.c new file mode 100644 index 000000000000..24f88efb05bf --- /dev/null +++ b/arch/powerpc/mm/nohash/tlb.c @@ -0,0 +1,795 @@ +/* + * 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 <benh@kernel.crashing.org> + * 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 <linux/kernel.h> +#include <linux/export.h> +#include <linux/mm.h> +#include <linux/init.h> +#include <linux/highmem.h> +#include <linux/pagemap.h> +#include <linux/preempt.h> +#include <linux/spinlock.h> +#include <linux/memblock.h> +#include <linux/of_fdt.h> +#include <linux/hugetlb.h> + +#include <asm/tlbflush.h> +#include <asm/tlb.h> +#include <asm/code-patching.h> +#include <asm/cputhreads.h> +#include <asm/hugetlb.h> +#include <asm/paca.h> + +#include <mm/mmu_decl.h> + +/* + * This struct lists the sw-supported page sizes. The hardawre MMU may support + * other sizes not listed here. The .ind field is only used on MMUs that have + * indirect page table entries. + */ +#if defined(CONFIG_PPC_BOOK3E_MMU) || defined(CONFIG_PPC_8xx) +#ifdef CONFIG_PPC_FSL_BOOK3E +struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = { + [MMU_PAGE_4K] = { + .shift = 12, + .enc = BOOK3E_PAGESZ_4K, + }, + [MMU_PAGE_2M] = { + .shift = 21, + .enc = BOOK3E_PAGESZ_2M, + }, + [MMU_PAGE_4M] = { + .shift = 22, + .enc = BOOK3E_PAGESZ_4M, + }, + [MMU_PAGE_16M] = { + .shift = 24, + .enc = BOOK3E_PAGESZ_16M, + }, + [MMU_PAGE_64M] = { + .shift = 26, + .enc = BOOK3E_PAGESZ_64M, + }, + [MMU_PAGE_256M] = { + .shift = 28, + .enc = BOOK3E_PAGESZ_256M, + }, + [MMU_PAGE_1G] = { + .shift = 30, + .enc = BOOK3E_PAGESZ_1GB, + }, +}; +#elif defined(CONFIG_PPC_8xx) +struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = { + /* we only manage 4k and 16k pages as normal pages */ +#ifdef CONFIG_PPC_4K_PAGES + [MMU_PAGE_4K] = { + .shift = 12, + }, +#else + [MMU_PAGE_16K] = { + .shift = 14, + }, +#endif + [MMU_PAGE_512K] = { + .shift = 19, + }, + [MMU_PAGE_8M] = { + .shift = 23, + }, +}; +#else +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, + }, +}; +#endif /* CONFIG_FSL_BOOKE */ + +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 /* CONFIG_PPC_BOOK3E_MMU */ + +/* 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_mode; /* HW tablewalk? Value is PPC_HTW_* */ +unsigned long linear_map_top; /* Top of linear mapping */ + + +/* + * Number of bytes to add to SPRN_SPRG_TLB_EXFRAME on crit/mcheck/debug + * exceptions. This is used for bolted and e6500 TLB miss handlers which + * do not modify this SPRG in the TLB miss code; for other TLB miss handlers, + * this is set to zero. + */ +int extlb_level_exc; + +#endif /* CONFIG_PPC64 */ + +#ifdef CONFIG_PPC_FSL_BOOK3E +/* next_tlbcam_idx is used to round-robin tlbcam entry assignment */ +DEFINE_PER_CPU(int, next_tlbcam_idx); +EXPORT_PER_CPU_SYMBOL(next_tlbcam_idx); +#endif + +/* + * 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); + +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; + + /* + * This function as well as __local_flush_tlb_page() must only be called + * for user contexts. + */ + if (WARN_ON(!mm)) + return; + + preempt_disable(); + pid = mm->context.id; + 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) +{ +#ifdef CONFIG_HUGETLB_PAGE + if (vma && is_vm_hugetlb_page(vma)) + flush_hugetlb_page(vma, vmaddr); +#endif + + __flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr, + mmu_get_tsize(mmu_virtual_psize), 0); +} +EXPORT_SYMBOL(flush_tlb_page); + +#endif /* CONFIG_SMP */ + +#ifdef CONFIG_PPC_47x +void __init early_init_mmu_47x(void) +{ +#ifdef CONFIG_SMP + unsigned long root = of_get_flat_dt_root(); + if (of_get_flat_dt_prop(root, "cooperative-partition", NULL)) + mmu_clear_feature(MMU_FTR_USE_TLBIVAX_BCAST); +#endif /* CONFIG_SMP */ +} +#endif /* CONFIG_PPC_47x */ + +/* + * 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) + +{ + if (end - start == PAGE_SIZE && !(start & ~PAGE_MASK)) + flush_tlb_page(vma, start); + else + flush_tlb_mm(vma->vm_mm); +} +EXPORT_SYMBOL(flush_tlb_range); + +void tlb_flush(struct mmu_gather *tlb) +{ + flush_tlb_mm(tlb->mm); +} + +/* + * 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_mode != PPC_HTW_NONE) { + 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; + + vpte = (vpte >> (PAGE_SHIFT - 3)) & ~0xffful; + vpte |= rid; + __flush_tlb_page(tlb->mm, vpte, tsize, 0); + } +} + +static void setup_page_sizes(void) +{ + unsigned int tlb0cfg; + unsigned int tlb0ps; + unsigned int eptcfg; + int i, psize; + +#ifdef CONFIG_PPC_FSL_BOOK3E + unsigned int mmucfg = mfspr(SPRN_MMUCFG); + int fsl_mmu = mmu_has_feature(MMU_FTR_TYPE_FSL_E); + + if (fsl_mmu && (mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V1) { + unsigned int tlb1cfg = mfspr(SPRN_TLB1CFG); + unsigned int min_pg, max_pg; + + min_pg = (tlb1cfg & TLBnCFG_MINSIZE) >> TLBnCFG_MINSIZE_SHIFT; + max_pg = (tlb1cfg & TLBnCFG_MAXSIZE) >> TLBnCFG_MAXSIZE_SHIFT; + + for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) { + struct mmu_psize_def *def; + unsigned int shift; + + def = &mmu_psize_defs[psize]; + shift = def->shift; + + if (shift == 0 || shift & 1) + continue; + + /* adjust to be in terms of 4^shift Kb */ + shift = (shift - 10) >> 1; + + if ((shift >= min_pg) && (shift <= max_pg)) + def->flags |= MMU_PAGE_SIZE_DIRECT; + } + + goto out; + } + + if (fsl_mmu && (mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V2) { + u32 tlb1cfg, tlb1ps; + + tlb0cfg = mfspr(SPRN_TLB0CFG); + tlb1cfg = mfspr(SPRN_TLB1CFG); + tlb1ps = mfspr(SPRN_TLB1PS); + eptcfg = mfspr(SPRN_EPTCFG); + + if ((tlb1cfg & TLBnCFG_IND) && (tlb0cfg & TLBnCFG_PT)) + book3e_htw_mode = PPC_HTW_E6500; + + /* + * We expect 4K subpage size and unrestricted indirect size. + * The lack of a restriction on indirect size is a Freescale + * extension, indicated by PSn = 0 but SPSn != 0. + */ + if (eptcfg != 2) + book3e_htw_mode = PPC_HTW_NONE; + + for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) { + struct mmu_psize_def *def = &mmu_psize_defs[psize]; + + if (!def->shift) + continue; + + if (tlb1ps & (1U << (def->shift - 10))) { + def->flags |= MMU_PAGE_SIZE_DIRECT; + + if (book3e_htw_mode && psize == MMU_PAGE_2M) + def->flags |= MMU_PAGE_SIZE_INDIRECT; + } + } + + goto out; + } +#endif + + tlb0cfg = mfspr(SPRN_TLB0CFG); + tlb0ps = mfspr(SPRN_TLB0PS); + eptcfg = mfspr(SPRN_EPTCFG); + + /* 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 || + (tlb0cfg & TLBnCFG_PT) == 0) + goto out; + + book3e_htw_mode = PPC_HTW_IBM; + + /* 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; + } + } + +out: + /* 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) +{ + /* + * If we want to use HW tablewalk, enable it by patching the TLB miss + * handlers to branch to the one dedicated to it. + */ + + switch (book3e_htw_mode) { + case PPC_HTW_IBM: + patch_exception(0x1c0, exc_data_tlb_miss_htw_book3e); + patch_exception(0x1e0, exc_instruction_tlb_miss_htw_book3e); + break; +#ifdef CONFIG_PPC_FSL_BOOK3E + case PPC_HTW_E6500: + extlb_level_exc = EX_TLB_SIZE; + patch_exception(0x1c0, exc_data_tlb_miss_e6500_book3e); + patch_exception(0x1e0, exc_instruction_tlb_miss_e6500_book3e); + break; +#endif + } + pr_info("MMU: Book3E HW tablewalk %s\n", + book3e_htw_mode != PPC_HTW_NONE ? "enabled" : "not supported"); +} + +/* + * Early initialization of the MMU TLB code + */ +static void early_init_this_mmu(void) +{ + unsigned int mas4; + + /* Set MAS4 based on page table setting */ + + mas4 = 0x4 << MAS4_WIMGED_SHIFT; + switch (book3e_htw_mode) { + case PPC_HTW_E6500: + mas4 |= MAS4_INDD; + mas4 |= BOOK3E_PAGESZ_2M << MAS4_TSIZED_SHIFT; + mas4 |= MAS4_TLBSELD(1); + mmu_pte_psize = MMU_PAGE_2M; + break; + + case PPC_HTW_IBM: + mas4 |= MAS4_INDD; + mas4 |= BOOK3E_PAGESZ_1M << MAS4_TSIZED_SHIFT; + mmu_pte_psize = MMU_PAGE_1M; + break; + + case PPC_HTW_NONE: + mas4 |= BOOK3E_PAGESZ_4K << MAS4_TSIZED_SHIFT; + mmu_pte_psize = mmu_virtual_psize; + break; + } + mtspr(SPRN_MAS4, mas4); + +#ifdef CONFIG_PPC_FSL_BOOK3E + if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) { + unsigned int num_cams; + int __maybe_unused cpu = smp_processor_id(); + bool map = true; + + /* use a quarter of the TLBCAM for bolted linear map */ + num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4; + + /* + * Only do the mapping once per core, or else the + * transient mapping would cause problems. + */ +#ifdef CONFIG_SMP + if (hweight32(get_tensr()) > 1) + map = false; +#endif + + if (map) + linear_map_top = map_mem_in_cams(linear_map_top, + num_cams, false); + } +#endif + + /* A sync won't hurt us after mucking around with + * the MMU configuration + */ + mb(); +} + +static void __init early_init_mmu_global(void) +{ + /* 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) + * + * Freescale booke only supports 4K pages in TLB0, so use that. + */ + if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) + mmu_vmemmap_psize = MMU_PAGE_4K; + else + 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. + */ + /* Look for supported page sizes */ + setup_page_sizes(); + + /* Look for HW tablewalk support */ + setup_mmu_htw(); + +#ifdef CONFIG_PPC_FSL_BOOK3E + if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) { + if (book3e_htw_mode == PPC_HTW_NONE) { + extlb_level_exc = EX_TLB_SIZE; + patch_exception(0x1c0, exc_data_tlb_miss_bolted_book3e); + patch_exception(0x1e0, + exc_instruction_tlb_miss_bolted_book3e); + } + } +#endif + + /* Set the global containing the top of the linear mapping + * for use by the TLB miss code + */ + linear_map_top = memblock_end_of_DRAM(); +} + +static void __init early_mmu_set_memory_limit(void) +{ +#ifdef CONFIG_PPC_FSL_BOOK3E + if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) { + /* + * Limit memory so we dont have linear faults. + * Unlike memblock_set_current_limit, which limits + * memory available during early boot, this permanently + * reduces the memory available to Linux. We need to + * do this because highmem is not supported on 64-bit. + */ + memblock_enforce_memory_limit(linear_map_top); + } +#endif + + memblock_set_current_limit(linear_map_top); +} + +/* boot cpu only */ +void __init early_init_mmu(void) +{ + early_init_mmu_global(); + early_init_this_mmu(); + early_mmu_set_memory_limit(); +} + +void early_init_mmu_secondary(void) +{ + early_init_this_mmu(); +} + +void setup_initial_memory_limit(phys_addr_t first_memblock_base, + phys_addr_t first_memblock_size) +{ + /* On non-FSL 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. + * + * on FSL Embedded 64-bit, usually all RAM is bolted, but with + * unusual memory sizes it's possible for some RAM to not be mapped + * (such RAM is not used at all by Linux, since we don't support + * highmem on 64-bit). We limit ppc64_rma_size to what would be + * mappable if this memblock is the only one. Additional memblocks + * can only increase, not decrease, the amount that ends up getting + * mapped. We still limit max to 1G even if we'll eventually map + * more. This is due to what the early init code is set up to do. + * + * We crop it to the size of the first MEMBLOCK to + * avoid going over total available memory just in case... + */ +#ifdef CONFIG_PPC_FSL_BOOK3E + if (early_mmu_has_feature(MMU_FTR_TYPE_FSL_E)) { + unsigned long linear_sz; + unsigned int num_cams; + + /* use a quarter of the TLBCAM for bolted linear map */ + num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4; + + linear_sz = map_mem_in_cams(first_memblock_size, num_cams, + true); + + ppc64_rma_size = min_t(u64, linear_sz, 0x40000000); + } else +#endif + ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000); + + /* Finally limit subsequent allocations */ + memblock_set_current_limit(first_memblock_base + ppc64_rma_size); +} +#else /* ! CONFIG_PPC64 */ +void __init early_init_mmu(void) +{ +#ifdef CONFIG_PPC_47x + early_init_mmu_47x(); +#endif + +#ifdef CONFIG_PPC_MM_SLICES + mm_ctx_set_slb_addr_limit(&init_mm.context, SLB_ADDR_LIMIT_DEFAULT); +#endif +} +#endif /* CONFIG_PPC64 */ |