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Diffstat (limited to '')
| -rw-r--r-- | arch/powerpc/mm/book3s64/hash_utils.c | 2282 |
1 files changed, 2282 insertions, 0 deletions
diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c new file mode 100644 index 0000000000..ad2afa08e6 --- /dev/null +++ b/arch/powerpc/mm/book3s64/hash_utils.c @@ -0,0 +1,2282 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * PowerPC64 port by Mike Corrigan and Dave Engebretsen + * {mikejc|engebret}@us.ibm.com + * + * Copyright (c) 2000 Mike Corrigan <mikejc@us.ibm.com> + * + * SMP scalability work: + * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM + * + * Module name: htab.c + * + * Description: + * PowerPC Hashed Page Table functions + */ + +#undef DEBUG +#undef DEBUG_LOW + +#define pr_fmt(fmt) "hash-mmu: " fmt +#include <linux/spinlock.h> +#include <linux/errno.h> +#include <linux/sched/mm.h> +#include <linux/proc_fs.h> +#include <linux/stat.h> +#include <linux/sysctl.h> +#include <linux/export.h> +#include <linux/ctype.h> +#include <linux/cache.h> +#include <linux/init.h> +#include <linux/signal.h> +#include <linux/memblock.h> +#include <linux/context_tracking.h> +#include <linux/libfdt.h> +#include <linux/pkeys.h> +#include <linux/hugetlb.h> +#include <linux/cpu.h> +#include <linux/pgtable.h> +#include <linux/debugfs.h> +#include <linux/random.h> +#include <linux/elf-randomize.h> +#include <linux/of_fdt.h> + +#include <asm/interrupt.h> +#include <asm/processor.h> +#include <asm/mmu.h> +#include <asm/mmu_context.h> +#include <asm/page.h> +#include <asm/types.h> +#include <linux/uaccess.h> +#include <asm/machdep.h> +#include <asm/io.h> +#include <asm/eeh.h> +#include <asm/tlb.h> +#include <asm/cacheflush.h> +#include <asm/cputable.h> +#include <asm/sections.h> +#include <asm/copro.h> +#include <asm/udbg.h> +#include <asm/code-patching.h> +#include <asm/fadump.h> +#include <asm/firmware.h> +#include <asm/tm.h> +#include <asm/trace.h> +#include <asm/ps3.h> +#include <asm/pte-walk.h> +#include <asm/asm-prototypes.h> +#include <asm/ultravisor.h> + +#include <mm/mmu_decl.h> + +#include "internal.h" + + +#ifdef DEBUG +#define DBG(fmt...) udbg_printf(fmt) +#else +#define DBG(fmt...) +#endif + +#ifdef DEBUG_LOW +#define DBG_LOW(fmt...) udbg_printf(fmt) +#else +#define DBG_LOW(fmt...) +#endif + +#define KB (1024) +#define MB (1024*KB) +#define GB (1024L*MB) + +/* + * Note: pte --> Linux PTE + * HPTE --> PowerPC Hashed Page Table Entry + * + * Execution context: + * htab_initialize is called with the MMU off (of course), but + * the kernel has been copied down to zero so it can directly + * reference global data. At this point it is very difficult + * to print debug info. + * + */ + +static unsigned long _SDR1; + +u8 hpte_page_sizes[1 << LP_BITS]; +EXPORT_SYMBOL_GPL(hpte_page_sizes); + +struct hash_pte *htab_address; +unsigned long htab_size_bytes; +unsigned long htab_hash_mask; +EXPORT_SYMBOL_GPL(htab_hash_mask); +int mmu_linear_psize = MMU_PAGE_4K; +EXPORT_SYMBOL_GPL(mmu_linear_psize); +int mmu_virtual_psize = MMU_PAGE_4K; +int mmu_vmalloc_psize = MMU_PAGE_4K; +EXPORT_SYMBOL_GPL(mmu_vmalloc_psize); +int mmu_io_psize = MMU_PAGE_4K; +int mmu_kernel_ssize = MMU_SEGSIZE_256M; +EXPORT_SYMBOL_GPL(mmu_kernel_ssize); +int mmu_highuser_ssize = MMU_SEGSIZE_256M; +u16 mmu_slb_size = 64; +EXPORT_SYMBOL_GPL(mmu_slb_size); +#ifdef CONFIG_PPC_64K_PAGES +int mmu_ci_restrictions; +#endif +static u8 *linear_map_hash_slots; +static unsigned long linear_map_hash_count; +struct mmu_hash_ops mmu_hash_ops; +EXPORT_SYMBOL(mmu_hash_ops); + +/* + * These are definitions of page sizes arrays to be used when none + * is provided by the firmware. + */ + +/* + * Fallback (4k pages only) + */ +static struct mmu_psize_def mmu_psize_defaults[] = { + [MMU_PAGE_4K] = { + .shift = 12, + .sllp = 0, + .penc = {[MMU_PAGE_4K] = 0, [1 ... MMU_PAGE_COUNT - 1] = -1}, + .avpnm = 0, + .tlbiel = 0, + }, +}; + +/* + * POWER4, GPUL, POWER5 + * + * Support for 16Mb large pages + */ +static struct mmu_psize_def mmu_psize_defaults_gp[] = { + [MMU_PAGE_4K] = { + .shift = 12, + .sllp = 0, + .penc = {[MMU_PAGE_4K] = 0, [1 ... MMU_PAGE_COUNT - 1] = -1}, + .avpnm = 0, + .tlbiel = 1, + }, + [MMU_PAGE_16M] = { + .shift = 24, + .sllp = SLB_VSID_L, + .penc = {[0 ... MMU_PAGE_16M - 1] = -1, [MMU_PAGE_16M] = 0, + [MMU_PAGE_16M + 1 ... MMU_PAGE_COUNT - 1] = -1 }, + .avpnm = 0x1UL, + .tlbiel = 0, + }, +}; + +static inline void tlbiel_hash_set_isa206(unsigned int set, unsigned int is) +{ + unsigned long rb; + + rb = (set << PPC_BITLSHIFT(51)) | (is << PPC_BITLSHIFT(53)); + + asm volatile("tlbiel %0" : : "r" (rb)); +} + +/* + * tlbiel instruction for hash, set invalidation + * i.e., r=1 and is=01 or is=10 or is=11 + */ +static __always_inline void tlbiel_hash_set_isa300(unsigned int set, unsigned int is, + unsigned int pid, + unsigned int ric, unsigned int prs) +{ + unsigned long rb; + unsigned long rs; + unsigned int r = 0; /* hash format */ + + rb = (set << PPC_BITLSHIFT(51)) | (is << PPC_BITLSHIFT(53)); + rs = ((unsigned long)pid << PPC_BITLSHIFT(31)); + + asm volatile(PPC_TLBIEL(%0, %1, %2, %3, %4) + : : "r"(rb), "r"(rs), "i"(ric), "i"(prs), "i"(r) + : "memory"); +} + + +static void tlbiel_all_isa206(unsigned int num_sets, unsigned int is) +{ + unsigned int set; + + asm volatile("ptesync": : :"memory"); + + for (set = 0; set < num_sets; set++) + tlbiel_hash_set_isa206(set, is); + + ppc_after_tlbiel_barrier(); +} + +static void tlbiel_all_isa300(unsigned int num_sets, unsigned int is) +{ + unsigned int set; + + asm volatile("ptesync": : :"memory"); + + /* + * Flush the partition table cache if this is HV mode. + */ + if (early_cpu_has_feature(CPU_FTR_HVMODE)) + tlbiel_hash_set_isa300(0, is, 0, 2, 0); + + /* + * Now invalidate the process table cache. UPRT=0 HPT modes (what + * current hardware implements) do not use the process table, but + * add the flushes anyway. + * + * From ISA v3.0B p. 1078: + * The following forms are invalid. + * * PRS=1, R=0, and RIC!=2 (The only process-scoped + * HPT caching is of the Process Table.) + */ + tlbiel_hash_set_isa300(0, is, 0, 2, 1); + + /* + * Then flush the sets of the TLB proper. Hash mode uses + * partition scoped TLB translations, which may be flushed + * in !HV mode. + */ + for (set = 0; set < num_sets; set++) + tlbiel_hash_set_isa300(set, is, 0, 0, 0); + + ppc_after_tlbiel_barrier(); + + asm volatile(PPC_ISA_3_0_INVALIDATE_ERAT "; isync" : : :"memory"); +} + +void hash__tlbiel_all(unsigned int action) +{ + unsigned int is; + + switch (action) { + case TLB_INVAL_SCOPE_GLOBAL: + is = 3; + break; + case TLB_INVAL_SCOPE_LPID: + is = 2; + break; + default: + BUG(); + } + + if (early_cpu_has_feature(CPU_FTR_ARCH_300)) + tlbiel_all_isa300(POWER9_TLB_SETS_HASH, is); + else if (early_cpu_has_feature(CPU_FTR_ARCH_207S)) + tlbiel_all_isa206(POWER8_TLB_SETS, is); + else if (early_cpu_has_feature(CPU_FTR_ARCH_206)) + tlbiel_all_isa206(POWER7_TLB_SETS, is); + else + WARN(1, "%s called on pre-POWER7 CPU\n", __func__); +} + +/* + * 'R' and 'C' update notes: + * - Under pHyp or KVM, the updatepp path will not set C, thus it *will* + * create writeable HPTEs without C set, because the hcall H_PROTECT + * that we use in that case will not update C + * - The above is however not a problem, because we also don't do that + * fancy "no flush" variant of eviction and we use H_REMOVE which will + * do the right thing and thus we don't have the race I described earlier + * + * - Under bare metal, we do have the race, so we need R and C set + * - We make sure R is always set and never lost + * - C is _PAGE_DIRTY, and *should* always be set for a writeable mapping + */ +unsigned long htab_convert_pte_flags(unsigned long pteflags, unsigned long flags) +{ + unsigned long rflags = 0; + + /* _PAGE_EXEC -> NOEXEC */ + if ((pteflags & _PAGE_EXEC) == 0) + rflags |= HPTE_R_N; + /* + * PPP bits: + * Linux uses slb key 0 for kernel and 1 for user. + * kernel RW areas are mapped with PPP=0b000 + * User area is mapped with PPP=0b010 for read/write + * or PPP=0b011 for read-only (including writeable but clean pages). + */ + if (pteflags & _PAGE_PRIVILEGED) { + /* + * Kernel read only mapped with ppp bits 0b110 + */ + if (!(pteflags & _PAGE_WRITE)) { + if (mmu_has_feature(MMU_FTR_KERNEL_RO)) + rflags |= (HPTE_R_PP0 | 0x2); + else + rflags |= 0x3; + } + } else { + if (pteflags & _PAGE_RWX) + rflags |= 0x2; + if (!((pteflags & _PAGE_WRITE) && (pteflags & _PAGE_DIRTY))) + rflags |= 0x1; + } + /* + * We can't allow hardware to update hpte bits. Hence always + * set 'R' bit and set 'C' if it is a write fault + */ + rflags |= HPTE_R_R; + + if (pteflags & _PAGE_DIRTY) + rflags |= HPTE_R_C; + /* + * Add in WIG bits + */ + + if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_TOLERANT) + rflags |= HPTE_R_I; + else if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_NON_IDEMPOTENT) + rflags |= (HPTE_R_I | HPTE_R_G); + else if ((pteflags & _PAGE_CACHE_CTL) == _PAGE_SAO) + rflags |= (HPTE_R_W | HPTE_R_I | HPTE_R_M); + else + /* + * Add memory coherence if cache inhibited is not set + */ + rflags |= HPTE_R_M; + + rflags |= pte_to_hpte_pkey_bits(pteflags, flags); + return rflags; +} + +int htab_bolt_mapping(unsigned long vstart, unsigned long vend, + unsigned long pstart, unsigned long prot, + int psize, int ssize) +{ + unsigned long vaddr, paddr; + unsigned int step, shift; + int ret = 0; + + shift = mmu_psize_defs[psize].shift; + step = 1 << shift; + + prot = htab_convert_pte_flags(prot, HPTE_USE_KERNEL_KEY); + + DBG("htab_bolt_mapping(%lx..%lx -> %lx (%lx,%d,%d)\n", + vstart, vend, pstart, prot, psize, ssize); + + /* Carefully map only the possible range */ + vaddr = ALIGN(vstart, step); + paddr = ALIGN(pstart, step); + vend = ALIGN_DOWN(vend, step); + + for (; vaddr < vend; vaddr += step, paddr += step) { + unsigned long hash, hpteg; + unsigned long vsid = get_kernel_vsid(vaddr, ssize); + unsigned long vpn = hpt_vpn(vaddr, vsid, ssize); + unsigned long tprot = prot; + bool secondary_hash = false; + + /* + * If we hit a bad address return error. + */ + if (!vsid) + return -1; + /* Make kernel text executable */ + if (overlaps_kernel_text(vaddr, vaddr + step)) + tprot &= ~HPTE_R_N; + + /* + * If relocatable, check if it overlaps interrupt vectors that + * are copied down to real 0. For relocatable kernel + * (e.g. kdump case) we copy interrupt vectors down to real + * address 0. Mark that region as executable. This is + * because on p8 system with relocation on exception feature + * enabled, exceptions are raised with MMU (IR=DR=1) ON. Hence + * in order to execute the interrupt handlers in virtual + * mode the vector region need to be marked as executable. + */ + if ((PHYSICAL_START > MEMORY_START) && + overlaps_interrupt_vector_text(vaddr, vaddr + step)) + tprot &= ~HPTE_R_N; + + hash = hpt_hash(vpn, shift, ssize); + hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP); + + BUG_ON(!mmu_hash_ops.hpte_insert); +repeat: + ret = mmu_hash_ops.hpte_insert(hpteg, vpn, paddr, tprot, + HPTE_V_BOLTED, psize, psize, + ssize); + if (ret == -1) { + /* + * Try to keep bolted entries in primary. + * Remove non bolted entries and try insert again + */ + ret = mmu_hash_ops.hpte_remove(hpteg); + if (ret != -1) + ret = mmu_hash_ops.hpte_insert(hpteg, vpn, paddr, tprot, + HPTE_V_BOLTED, psize, psize, + ssize); + if (ret == -1 && !secondary_hash) { + secondary_hash = true; + hpteg = ((~hash & htab_hash_mask) * HPTES_PER_GROUP); + goto repeat; + } + } + + if (ret < 0) + break; + + cond_resched(); + if (debug_pagealloc_enabled_or_kfence() && + (paddr >> PAGE_SHIFT) < linear_map_hash_count) + linear_map_hash_slots[paddr >> PAGE_SHIFT] = ret | 0x80; + } + return ret < 0 ? ret : 0; +} + +int htab_remove_mapping(unsigned long vstart, unsigned long vend, + int psize, int ssize) +{ + unsigned long vaddr, time_limit; + unsigned int step, shift; + int rc; + int ret = 0; + + shift = mmu_psize_defs[psize].shift; + step = 1 << shift; + + if (!mmu_hash_ops.hpte_removebolted) + return -ENODEV; + + /* Unmap the full range specificied */ + vaddr = ALIGN_DOWN(vstart, step); + time_limit = jiffies + HZ; + + for (;vaddr < vend; vaddr += step) { + rc = mmu_hash_ops.hpte_removebolted(vaddr, psize, ssize); + + /* + * For large number of mappings introduce a cond_resched() + * to prevent softlockup warnings. + */ + if (time_after(jiffies, time_limit)) { + cond_resched(); + time_limit = jiffies + HZ; + } + if (rc == -ENOENT) { + ret = -ENOENT; + continue; + } + if (rc < 0) + return rc; + } + + return ret; +} + +static bool disable_1tb_segments __ro_after_init; + +static int __init parse_disable_1tb_segments(char *p) +{ + disable_1tb_segments = true; + return 0; +} +early_param("disable_1tb_segments", parse_disable_1tb_segments); + +bool stress_hpt_enabled __initdata; + +static int __init parse_stress_hpt(char *p) +{ + stress_hpt_enabled = true; + return 0; +} +early_param("stress_hpt", parse_stress_hpt); + +__ro_after_init DEFINE_STATIC_KEY_FALSE(stress_hpt_key); + +/* + * per-CPU array allocated if we enable stress_hpt. + */ +#define STRESS_MAX_GROUPS 16 +struct stress_hpt_struct { + unsigned long last_group[STRESS_MAX_GROUPS]; +}; + +static inline int stress_nr_groups(void) +{ + /* + * LPAR H_REMOVE flushes TLB, so need some number > 1 of entries + * to allow practical forward progress. Bare metal returns 1, which + * seems to help uncover more bugs. + */ + if (firmware_has_feature(FW_FEATURE_LPAR)) + return STRESS_MAX_GROUPS; + else + return 1; +} + +static struct stress_hpt_struct *stress_hpt_struct; + +static int __init htab_dt_scan_seg_sizes(unsigned long node, + const char *uname, int depth, + void *data) +{ + const char *type = of_get_flat_dt_prop(node, "device_type", NULL); + const __be32 *prop; + int size = 0; + + /* We are scanning "cpu" nodes only */ + if (type == NULL || strcmp(type, "cpu") != 0) + return 0; + + prop = of_get_flat_dt_prop(node, "ibm,processor-segment-sizes", &size); + if (prop == NULL) + return 0; + for (; size >= 4; size -= 4, ++prop) { + if (be32_to_cpu(prop[0]) == 40) { + DBG("1T segment support detected\n"); + + if (disable_1tb_segments) { + DBG("1T segments disabled by command line\n"); + break; + } + + cur_cpu_spec->mmu_features |= MMU_FTR_1T_SEGMENT; + return 1; + } + } + cur_cpu_spec->mmu_features &= ~MMU_FTR_NO_SLBIE_B; + return 0; +} + +static int __init get_idx_from_shift(unsigned int shift) +{ + int idx = -1; + + switch (shift) { + case 0xc: + idx = MMU_PAGE_4K; + break; + case 0x10: + idx = MMU_PAGE_64K; + break; + case 0x14: + idx = MMU_PAGE_1M; + break; + case 0x18: + idx = MMU_PAGE_16M; + break; + case 0x22: + idx = MMU_PAGE_16G; + break; + } + return idx; +} + +static int __init htab_dt_scan_page_sizes(unsigned long node, + const char *uname, int depth, + void *data) +{ + const char *type = of_get_flat_dt_prop(node, "device_type", NULL); + const __be32 *prop; + int size = 0; + + /* We are scanning "cpu" nodes only */ + if (type == NULL || strcmp(type, "cpu") != 0) + return 0; + + prop = of_get_flat_dt_prop(node, "ibm,segment-page-sizes", &size); + if (!prop) + return 0; + + pr_info("Page sizes from device-tree:\n"); + size /= 4; + cur_cpu_spec->mmu_features &= ~(MMU_FTR_16M_PAGE); + while(size > 0) { + unsigned int base_shift = be32_to_cpu(prop[0]); + unsigned int slbenc = be32_to_cpu(prop[1]); + unsigned int lpnum = be32_to_cpu(prop[2]); + struct mmu_psize_def *def; + int idx, base_idx; + + size -= 3; prop += 3; + base_idx = get_idx_from_shift(base_shift); + if (base_idx < 0) { + /* skip the pte encoding also */ + prop += lpnum * 2; size -= lpnum * 2; + continue; + } + def = &mmu_psize_defs[base_idx]; + if (base_idx == MMU_PAGE_16M) + cur_cpu_spec->mmu_features |= MMU_FTR_16M_PAGE; + + def->shift = base_shift; + if (base_shift <= 23) + def->avpnm = 0; + else + def->avpnm = (1 << (base_shift - 23)) - 1; + def->sllp = slbenc; + /* + * We don't know for sure what's up with tlbiel, so + * for now we only set it for 4K and 64K pages + */ + if (base_idx == MMU_PAGE_4K || base_idx == MMU_PAGE_64K) + def->tlbiel = 1; + else + def->tlbiel = 0; + + while (size > 0 && lpnum) { + unsigned int shift = be32_to_cpu(prop[0]); + int penc = be32_to_cpu(prop[1]); + + prop += 2; size -= 2; + lpnum--; + + idx = get_idx_from_shift(shift); + if (idx < 0) + continue; + + if (penc == -1) + pr_err("Invalid penc for base_shift=%d " + "shift=%d\n", base_shift, shift); + + def->penc[idx] = penc; + pr_info("base_shift=%d: shift=%d, sllp=0x%04lx," + " avpnm=0x%08lx, tlbiel=%d, penc=%d\n", + base_shift, shift, def->sllp, + def->avpnm, def->tlbiel, def->penc[idx]); + } + } + + return 1; +} + +#ifdef CONFIG_HUGETLB_PAGE +/* + * Scan for 16G memory blocks that have been set aside for huge pages + * and reserve those blocks for 16G huge pages. + */ +static int __init htab_dt_scan_hugepage_blocks(unsigned long node, + const char *uname, int depth, + void *data) { + const char *type = of_get_flat_dt_prop(node, "device_type", NULL); + const __be64 *addr_prop; + const __be32 *page_count_prop; + unsigned int expected_pages; + long unsigned int phys_addr; + long unsigned int block_size; + + /* We are scanning "memory" nodes only */ + if (type == NULL || strcmp(type, "memory") != 0) + return 0; + + /* + * This property is the log base 2 of the number of virtual pages that + * will represent this memory block. + */ + page_count_prop = of_get_flat_dt_prop(node, "ibm,expected#pages", NULL); + if (page_count_prop == NULL) + return 0; + expected_pages = (1 << be32_to_cpu(page_count_prop[0])); + addr_prop = of_get_flat_dt_prop(node, "reg", NULL); + if (addr_prop == NULL) + return 0; + phys_addr = be64_to_cpu(addr_prop[0]); + block_size = be64_to_cpu(addr_prop[1]); + if (block_size != (16 * GB)) + return 0; + printk(KERN_INFO "Huge page(16GB) memory: " + "addr = 0x%lX size = 0x%lX pages = %d\n", + phys_addr, block_size, expected_pages); + if (phys_addr + block_size * expected_pages <= memblock_end_of_DRAM()) { + memblock_reserve(phys_addr, block_size * expected_pages); + pseries_add_gpage(phys_addr, block_size, expected_pages); + } + return 0; +} +#endif /* CONFIG_HUGETLB_PAGE */ + +static void __init mmu_psize_set_default_penc(void) +{ + int bpsize, apsize; + for (bpsize = 0; bpsize < MMU_PAGE_COUNT; bpsize++) + for (apsize = 0; apsize < MMU_PAGE_COUNT; apsize++) + mmu_psize_defs[bpsize].penc[apsize] = -1; +} + +#ifdef CONFIG_PPC_64K_PAGES + +static bool __init might_have_hea(void) +{ + /* + * The HEA ethernet adapter requires awareness of the + * GX bus. Without that awareness we can easily assume + * we will never see an HEA ethernet device. + */ +#ifdef CONFIG_IBMEBUS + return !cpu_has_feature(CPU_FTR_ARCH_207S) && + firmware_has_feature(FW_FEATURE_SPLPAR); +#else + return false; +#endif +} + +#endif /* #ifdef CONFIG_PPC_64K_PAGES */ + +static void __init htab_scan_page_sizes(void) +{ + int rc; + + /* se the invalid penc to -1 */ + mmu_psize_set_default_penc(); + + /* Default to 4K pages only */ + memcpy(mmu_psize_defs, mmu_psize_defaults, + sizeof(mmu_psize_defaults)); + + /* + * Try to find the available page sizes in the device-tree + */ + rc = of_scan_flat_dt(htab_dt_scan_page_sizes, NULL); + if (rc == 0 && early_mmu_has_feature(MMU_FTR_16M_PAGE)) { + /* + * Nothing in the device-tree, but the CPU supports 16M pages, + * so let's fallback on a known size list for 16M capable CPUs. + */ + memcpy(mmu_psize_defs, mmu_psize_defaults_gp, + sizeof(mmu_psize_defaults_gp)); + } + +#ifdef CONFIG_HUGETLB_PAGE + if (!hugetlb_disabled && !early_radix_enabled() ) { + /* Reserve 16G huge page memory sections for huge pages */ + of_scan_flat_dt(htab_dt_scan_hugepage_blocks, NULL); + } +#endif /* CONFIG_HUGETLB_PAGE */ +} + +/* + * Fill in the hpte_page_sizes[] array. + * We go through the mmu_psize_defs[] array looking for all the + * supported base/actual page size combinations. Each combination + * has a unique pagesize encoding (penc) value in the low bits of + * the LP field of the HPTE. For actual page sizes less than 1MB, + * some of the upper LP bits are used for RPN bits, meaning that + * we need to fill in several entries in hpte_page_sizes[]. + * + * In diagrammatic form, with r = RPN bits and z = page size bits: + * PTE LP actual page size + * rrrr rrrz >=8KB + * rrrr rrzz >=16KB + * rrrr rzzz >=32KB + * rrrr zzzz >=64KB + * ... + * + * The zzzz bits are implementation-specific but are chosen so that + * no encoding for a larger page size uses the same value in its + * low-order N bits as the encoding for the 2^(12+N) byte page size + * (if it exists). + */ +static void __init init_hpte_page_sizes(void) +{ + long int ap, bp; + long int shift, penc; + + for (bp = 0; bp < MMU_PAGE_COUNT; ++bp) { + if (!mmu_psize_defs[bp].shift) + continue; /* not a supported page size */ + for (ap = bp; ap < MMU_PAGE_COUNT; ++ap) { + penc = mmu_psize_defs[bp].penc[ap]; + if (penc == -1 || !mmu_psize_defs[ap].shift) + continue; + shift = mmu_psize_defs[ap].shift - LP_SHIFT; + if (shift <= 0) + continue; /* should never happen */ + /* + * For page sizes less than 1MB, this loop + * replicates the entry for all possible values + * of the rrrr bits. + */ + while (penc < (1 << LP_BITS)) { + hpte_page_sizes[penc] = (ap << 4) | bp; + penc += 1 << shift; + } + } + } +} + +static void __init htab_init_page_sizes(void) +{ + bool aligned = true; + init_hpte_page_sizes(); + + if (!debug_pagealloc_enabled_or_kfence()) { + /* + * Pick a size for the linear mapping. Currently, we only + * support 16M, 1M and 4K which is the default + */ + if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX) && + (unsigned long)_stext % 0x1000000) { + if (mmu_psize_defs[MMU_PAGE_16M].shift) + pr_warn("Kernel not 16M aligned, disabling 16M linear map alignment\n"); + aligned = false; + } + + if (mmu_psize_defs[MMU_PAGE_16M].shift && aligned) + mmu_linear_psize = MMU_PAGE_16M; + else if (mmu_psize_defs[MMU_PAGE_1M].shift) + mmu_linear_psize = MMU_PAGE_1M; + } + +#ifdef CONFIG_PPC_64K_PAGES + /* + * Pick a size for the ordinary pages. Default is 4K, we support + * 64K for user mappings and vmalloc if supported by the processor. + * We only use 64k for ioremap if the processor + * (and firmware) support cache-inhibited large pages. + * If not, we use 4k and set mmu_ci_restrictions so that + * hash_page knows to switch processes that use cache-inhibited + * mappings to 4k pages. + */ + if (mmu_psize_defs[MMU_PAGE_64K].shift) { + mmu_virtual_psize = MMU_PAGE_64K; + mmu_vmalloc_psize = MMU_PAGE_64K; + if (mmu_linear_psize == MMU_PAGE_4K) + mmu_linear_psize = MMU_PAGE_64K; + if (mmu_has_feature(MMU_FTR_CI_LARGE_PAGE)) { + /* + * When running on pSeries using 64k pages for ioremap + * would stop us accessing the HEA ethernet. So if we + * have the chance of ever seeing one, stay at 4k. + */ + if (!might_have_hea()) + mmu_io_psize = MMU_PAGE_64K; + } else + mmu_ci_restrictions = 1; + } +#endif /* CONFIG_PPC_64K_PAGES */ + +#ifdef CONFIG_SPARSEMEM_VMEMMAP + /* + * We try to use 16M pages for vmemmap if that is supported + * and we have at least 1G of RAM at boot + */ + if (mmu_psize_defs[MMU_PAGE_16M].shift && + memblock_phys_mem_size() >= 0x40000000) + mmu_vmemmap_psize = MMU_PAGE_16M; + else + mmu_vmemmap_psize = mmu_virtual_psize; +#endif /* CONFIG_SPARSEMEM_VMEMMAP */ + + printk(KERN_DEBUG "Page orders: linear mapping = %d, " + "virtual = %d, io = %d" +#ifdef CONFIG_SPARSEMEM_VMEMMAP + ", vmemmap = %d" +#endif + "\n", + mmu_psize_defs[mmu_linear_psize].shift, + mmu_psize_defs[mmu_virtual_psize].shift, + mmu_psize_defs[mmu_io_psize].shift +#ifdef CONFIG_SPARSEMEM_VMEMMAP + ,mmu_psize_defs[mmu_vmemmap_psize].shift +#endif + ); +} + +static int __init htab_dt_scan_pftsize(unsigned long node, + const char *uname, int depth, + void *data) +{ + const char *type = of_get_flat_dt_prop(node, "device_type", NULL); + const __be32 *prop; + + /* We are scanning "cpu" nodes only */ + if (type == NULL || strcmp(type, "cpu") != 0) + return 0; + + prop = of_get_flat_dt_prop(node, "ibm,pft-size", NULL); + if (prop != NULL) { + /* pft_size[0] is the NUMA CEC cookie */ + ppc64_pft_size = be32_to_cpu(prop[1]); + return 1; + } + return 0; +} + +unsigned htab_shift_for_mem_size(unsigned long mem_size) +{ + unsigned memshift = __ilog2(mem_size); + unsigned pshift = mmu_psize_defs[mmu_virtual_psize].shift; + unsigned pteg_shift; + + /* round mem_size up to next power of 2 */ + if ((1UL << memshift) < mem_size) + memshift += 1; + + /* aim for 2 pages / pteg */ + pteg_shift = memshift - (pshift + 1); + + /* + * 2^11 PTEGS of 128 bytes each, ie. 2^18 bytes is the minimum htab + * size permitted by the architecture. + */ + return max(pteg_shift + 7, 18U); +} + +static unsigned long __init htab_get_table_size(void) +{ + /* + * If hash size isn't already provided by the platform, we try to + * retrieve it from the device-tree. If it's not there neither, we + * calculate it now based on the total RAM size + */ + if (ppc64_pft_size == 0) + of_scan_flat_dt(htab_dt_scan_pftsize, NULL); + if (ppc64_pft_size) + return 1UL << ppc64_pft_size; + + return 1UL << htab_shift_for_mem_size(memblock_phys_mem_size()); +} + +#ifdef CONFIG_MEMORY_HOTPLUG +static int resize_hpt_for_hotplug(unsigned long new_mem_size) +{ + unsigned target_hpt_shift; + + if (!mmu_hash_ops.resize_hpt) + return 0; + + target_hpt_shift = htab_shift_for_mem_size(new_mem_size); + + /* + * To avoid lots of HPT resizes if memory size is fluctuating + * across a boundary, we deliberately have some hysterisis + * here: we immediately increase the HPT size if the target + * shift exceeds the current shift, but we won't attempt to + * reduce unless the target shift is at least 2 below the + * current shift + */ + if (target_hpt_shift > ppc64_pft_size || + target_hpt_shift < ppc64_pft_size - 1) + return mmu_hash_ops.resize_hpt(target_hpt_shift); + + return 0; +} + +int hash__create_section_mapping(unsigned long start, unsigned long end, + int nid, pgprot_t prot) +{ + int rc; + + if (end >= H_VMALLOC_START) { + pr_warn("Outside the supported range\n"); + return -1; + } + + resize_hpt_for_hotplug(memblock_phys_mem_size()); + + rc = htab_bolt_mapping(start, end, __pa(start), + pgprot_val(prot), mmu_linear_psize, + mmu_kernel_ssize); + + if (rc < 0) { + int rc2 = htab_remove_mapping(start, end, mmu_linear_psize, + mmu_kernel_ssize); + BUG_ON(rc2 && (rc2 != -ENOENT)); + } + return rc; +} + +int hash__remove_section_mapping(unsigned long start, unsigned long end) +{ + int rc = htab_remove_mapping(start, end, mmu_linear_psize, + mmu_kernel_ssize); + + if (resize_hpt_for_hotplug(memblock_phys_mem_size()) == -ENOSPC) + pr_warn("Hash collision while resizing HPT\n"); + + return rc; +} +#endif /* CONFIG_MEMORY_HOTPLUG */ + +static void __init hash_init_partition_table(phys_addr_t hash_table, + unsigned long htab_size) +{ + mmu_partition_table_init(); + + /* + * PS field (VRMA page size) is not used for LPID 0, hence set to 0. + * For now, UPRT is 0 and we have no segment table. + */ + htab_size = __ilog2(htab_size) - 18; + mmu_partition_table_set_entry(0, hash_table | htab_size, 0, false); + pr_info("Partition table %p\n", partition_tb); +} + +void hpt_clear_stress(void); +static struct timer_list stress_hpt_timer; +static void stress_hpt_timer_fn(struct timer_list *timer) +{ + int next_cpu; + + hpt_clear_stress(); + if (!firmware_has_feature(FW_FEATURE_LPAR)) + tlbiel_all(); + + next_cpu = cpumask_next(raw_smp_processor_id(), cpu_online_mask); + if (next_cpu >= nr_cpu_ids) + next_cpu = cpumask_first(cpu_online_mask); + stress_hpt_timer.expires = jiffies + msecs_to_jiffies(10); + add_timer_on(&stress_hpt_timer, next_cpu); +} + +static void __init htab_initialize(void) +{ + unsigned long table; + unsigned long pteg_count; + unsigned long prot; + phys_addr_t base = 0, size = 0, end; + u64 i; + + DBG(" -> htab_initialize()\n"); + + if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) { + mmu_kernel_ssize = MMU_SEGSIZE_1T; + mmu_highuser_ssize = MMU_SEGSIZE_1T; + printk(KERN_INFO "Using 1TB segments\n"); + } + + if (stress_slb_enabled) + static_branch_enable(&stress_slb_key); + + if (stress_hpt_enabled) { + unsigned long tmp; + static_branch_enable(&stress_hpt_key); + // Too early to use nr_cpu_ids, so use NR_CPUS + tmp = memblock_phys_alloc_range(sizeof(struct stress_hpt_struct) * NR_CPUS, + __alignof__(struct stress_hpt_struct), + 0, MEMBLOCK_ALLOC_ANYWHERE); + memset((void *)tmp, 0xff, sizeof(struct stress_hpt_struct) * NR_CPUS); + stress_hpt_struct = __va(tmp); + + timer_setup(&stress_hpt_timer, stress_hpt_timer_fn, 0); + stress_hpt_timer.expires = jiffies + msecs_to_jiffies(10); + add_timer(&stress_hpt_timer); + } + + /* + * Calculate the required size of the htab. We want the number of + * PTEGs to equal one half the number of real pages. + */ + htab_size_bytes = htab_get_table_size(); + pteg_count = htab_size_bytes >> 7; + + htab_hash_mask = pteg_count - 1; + + if (firmware_has_feature(FW_FEATURE_LPAR) || + firmware_has_feature(FW_FEATURE_PS3_LV1)) { + /* Using a hypervisor which owns the htab */ + htab_address = NULL; + _SDR1 = 0; +#ifdef CONFIG_FA_DUMP + /* + * If firmware assisted dump is active firmware preserves + * the contents of htab along with entire partition memory. + * Clear the htab if firmware assisted dump is active so + * that we dont end up using old mappings. + */ + if (is_fadump_active() && mmu_hash_ops.hpte_clear_all) + mmu_hash_ops.hpte_clear_all(); +#endif + } else { + unsigned long limit = MEMBLOCK_ALLOC_ANYWHERE; + +#ifdef CONFIG_PPC_CELL + /* + * Cell may require the hash table down low when using the + * Axon IOMMU in order to fit the dynamic region over it, see + * comments in cell/iommu.c + */ + if (fdt_subnode_offset(initial_boot_params, 0, "axon") > 0) { + limit = 0x80000000; + pr_info("Hash table forced below 2G for Axon IOMMU\n"); + } +#endif /* CONFIG_PPC_CELL */ + + table = memblock_phys_alloc_range(htab_size_bytes, + htab_size_bytes, + 0, limit); + if (!table) + panic("ERROR: Failed to allocate %pa bytes below %pa\n", + &htab_size_bytes, &limit); + + DBG("Hash table allocated at %lx, size: %lx\n", table, + htab_size_bytes); + + htab_address = __va(table); + + /* htab absolute addr + encoded htabsize */ + _SDR1 = table + __ilog2(htab_size_bytes) - 18; + + /* Initialize the HPT with no entries */ + memset((void *)table, 0, htab_size_bytes); + + if (!cpu_has_feature(CPU_FTR_ARCH_300)) + /* Set SDR1 */ + mtspr(SPRN_SDR1, _SDR1); + else + hash_init_partition_table(table, htab_size_bytes); + } + + prot = pgprot_val(PAGE_KERNEL); + + if (debug_pagealloc_enabled_or_kfence()) { + linear_map_hash_count = memblock_end_of_DRAM() >> PAGE_SHIFT; + linear_map_hash_slots = memblock_alloc_try_nid( + linear_map_hash_count, 1, MEMBLOCK_LOW_LIMIT, + ppc64_rma_size, NUMA_NO_NODE); + if (!linear_map_hash_slots) + panic("%s: Failed to allocate %lu bytes max_addr=%pa\n", + __func__, linear_map_hash_count, &ppc64_rma_size); + } + + /* create bolted the linear mapping in the hash table */ + for_each_mem_range(i, &base, &end) { + size = end - base; + base = (unsigned long)__va(base); + + DBG("creating mapping for region: %lx..%lx (prot: %lx)\n", + base, size, prot); + + if ((base + size) >= H_VMALLOC_START) { + pr_warn("Outside the supported range\n"); + continue; + } + + BUG_ON(htab_bolt_mapping(base, base + size, __pa(base), + prot, mmu_linear_psize, mmu_kernel_ssize)); + } + memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE); + + /* + * If we have a memory_limit and we've allocated TCEs then we need to + * explicitly map the TCE area at the top of RAM. We also cope with the + * case that the TCEs start below memory_limit. + * tce_alloc_start/end are 16MB aligned so the mapping should work + * for either 4K or 16MB pages. + */ + if (tce_alloc_start) { + tce_alloc_start = (unsigned long)__va(tce_alloc_start); + tce_alloc_end = (unsigned long)__va(tce_alloc_end); + + if (base + size >= tce_alloc_start) + tce_alloc_start = base + size + 1; + + BUG_ON(htab_bolt_mapping(tce_alloc_start, tce_alloc_end, + __pa(tce_alloc_start), prot, + mmu_linear_psize, mmu_kernel_ssize)); + } + + + DBG(" <- htab_initialize()\n"); +} +#undef KB +#undef MB + +void __init hash__early_init_devtree(void) +{ + /* Initialize segment sizes */ + of_scan_flat_dt(htab_dt_scan_seg_sizes, NULL); + + /* Initialize page sizes */ + htab_scan_page_sizes(); +} + +static struct hash_mm_context init_hash_mm_context; +void __init hash__early_init_mmu(void) +{ +#ifndef CONFIG_PPC_64K_PAGES + /* + * We have code in __hash_page_4K() and elsewhere, which assumes it can + * do the following: + * new_pte |= (slot << H_PAGE_F_GIX_SHIFT) & (H_PAGE_F_SECOND | H_PAGE_F_GIX); + * + * Where the slot number is between 0-15, and values of 8-15 indicate + * the secondary bucket. For that code to work H_PAGE_F_SECOND and + * H_PAGE_F_GIX must occupy four contiguous bits in the PTE, and + * H_PAGE_F_SECOND must be placed above H_PAGE_F_GIX. Assert that here + * with a BUILD_BUG_ON(). + */ + BUILD_BUG_ON(H_PAGE_F_SECOND != (1ul << (H_PAGE_F_GIX_SHIFT + 3))); +#endif /* CONFIG_PPC_64K_PAGES */ + + htab_init_page_sizes(); + + /* + * initialize page table size + */ + __pte_frag_nr = H_PTE_FRAG_NR; + __pte_frag_size_shift = H_PTE_FRAG_SIZE_SHIFT; + __pmd_frag_nr = H_PMD_FRAG_NR; + __pmd_frag_size_shift = H_PMD_FRAG_SIZE_SHIFT; + + __pte_index_size = H_PTE_INDEX_SIZE; + __pmd_index_size = H_PMD_INDEX_SIZE; + __pud_index_size = H_PUD_INDEX_SIZE; + __pgd_index_size = H_PGD_INDEX_SIZE; + __pud_cache_index = H_PUD_CACHE_INDEX; + __pte_table_size = H_PTE_TABLE_SIZE; + __pmd_table_size = H_PMD_TABLE_SIZE; + __pud_table_size = H_PUD_TABLE_SIZE; + __pgd_table_size = H_PGD_TABLE_SIZE; + /* + * 4k use hugepd format, so for hash set then to + * zero + */ + __pmd_val_bits = HASH_PMD_VAL_BITS; + __pud_val_bits = HASH_PUD_VAL_BITS; + __pgd_val_bits = HASH_PGD_VAL_BITS; + + __kernel_virt_start = H_KERN_VIRT_START; + __vmalloc_start = H_VMALLOC_START; + __vmalloc_end = H_VMALLOC_END; + __kernel_io_start = H_KERN_IO_START; + __kernel_io_end = H_KERN_IO_END; + vmemmap = (struct page *)H_VMEMMAP_START; + ioremap_bot = IOREMAP_BASE; + +#ifdef CONFIG_PCI + pci_io_base = ISA_IO_BASE; +#endif + + /* Select appropriate backend */ + if (firmware_has_feature(FW_FEATURE_PS3_LV1)) + ps3_early_mm_init(); + else if (firmware_has_feature(FW_FEATURE_LPAR)) + hpte_init_pseries(); + else if (IS_ENABLED(CONFIG_PPC_HASH_MMU_NATIVE)) + hpte_init_native(); + + if (!mmu_hash_ops.hpte_insert) + panic("hash__early_init_mmu: No MMU hash ops defined!\n"); + + /* + * Initialize the MMU Hash table and create the linear mapping + * of memory. Has to be done before SLB initialization as this is + * currently where the page size encoding is obtained. + */ + htab_initialize(); + + init_mm.context.hash_context = &init_hash_mm_context; + mm_ctx_set_slb_addr_limit(&init_mm.context, SLB_ADDR_LIMIT_DEFAULT); + + pr_info("Initializing hash mmu with SLB\n"); + /* Initialize SLB management */ + slb_initialize(); + + if (cpu_has_feature(CPU_FTR_ARCH_206) + && cpu_has_feature(CPU_FTR_HVMODE)) + tlbiel_all(); +} + +#ifdef CONFIG_SMP +void hash__early_init_mmu_secondary(void) +{ + /* Initialize hash table for that CPU */ + if (!firmware_has_feature(FW_FEATURE_LPAR)) { + + if (!cpu_has_feature(CPU_FTR_ARCH_300)) + mtspr(SPRN_SDR1, _SDR1); + else + set_ptcr_when_no_uv(__pa(partition_tb) | + (PATB_SIZE_SHIFT - 12)); + } + /* Initialize SLB */ + slb_initialize(); + + if (cpu_has_feature(CPU_FTR_ARCH_206) + && cpu_has_feature(CPU_FTR_HVMODE)) + tlbiel_all(); + +#ifdef CONFIG_PPC_MEM_KEYS + if (mmu_has_feature(MMU_FTR_PKEY)) + mtspr(SPRN_UAMOR, default_uamor); +#endif +} +#endif /* CONFIG_SMP */ + +/* + * Called by asm hashtable.S for doing lazy icache flush + */ +unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap) +{ + struct folio *folio; + + if (!pfn_valid(pte_pfn(pte))) + return pp; + + folio = page_folio(pte_page(pte)); + + /* page is dirty */ + if (!test_bit(PG_dcache_clean, &folio->flags) && + !folio_test_reserved(folio)) { + if (trap == INTERRUPT_INST_STORAGE) { + flush_dcache_icache_folio(folio); + set_bit(PG_dcache_clean, &folio->flags); + } else + pp |= HPTE_R_N; + } + return pp; +} + +static unsigned int get_paca_psize(unsigned long addr) +{ + unsigned char *psizes; + unsigned long index, mask_index; + + if (addr < SLICE_LOW_TOP) { + psizes = get_paca()->mm_ctx_low_slices_psize; + index = GET_LOW_SLICE_INDEX(addr); + } else { + psizes = get_paca()->mm_ctx_high_slices_psize; + index = GET_HIGH_SLICE_INDEX(addr); + } + mask_index = index & 0x1; + return (psizes[index >> 1] >> (mask_index * 4)) & 0xF; +} + + +/* + * Demote a segment to using 4k pages. + * For now this makes the whole process use 4k pages. + */ +#ifdef CONFIG_PPC_64K_PAGES +void demote_segment_4k(struct mm_struct *mm, unsigned long addr) +{ + if (get_slice_psize(mm, addr) == MMU_PAGE_4K) + return; + slice_set_range_psize(mm, addr, 1, MMU_PAGE_4K); + copro_flush_all_slbs(mm); + if ((get_paca_psize(addr) != MMU_PAGE_4K) && (current->mm == mm)) { + + copy_mm_to_paca(mm); + slb_flush_and_restore_bolted(); + } +} +#endif /* CONFIG_PPC_64K_PAGES */ + +#ifdef CONFIG_PPC_SUBPAGE_PROT +/* + * This looks up a 2-bit protection code for a 4k subpage of a 64k page. + * Userspace sets the subpage permissions using the subpage_prot system call. + * + * Result is 0: full permissions, _PAGE_RW: read-only, + * _PAGE_RWX: no access. + */ +static int subpage_protection(struct mm_struct *mm, unsigned long ea) +{ + struct subpage_prot_table *spt = mm_ctx_subpage_prot(&mm->context); + u32 spp = 0; + u32 **sbpm, *sbpp; + + if (!spt) + return 0; + + if (ea >= spt->maxaddr) + return 0; + if (ea < 0x100000000UL) { + /* addresses below 4GB use spt->low_prot */ + sbpm = spt->low_prot; + } else { + sbpm = spt->protptrs[ea >> SBP_L3_SHIFT]; + if (!sbpm) + return 0; + } + sbpp = sbpm[(ea >> SBP_L2_SHIFT) & (SBP_L2_COUNT - 1)]; + if (!sbpp) + return 0; + spp = sbpp[(ea >> PAGE_SHIFT) & (SBP_L1_COUNT - 1)]; + + /* extract 2-bit bitfield for this 4k subpage */ + spp >>= 30 - 2 * ((ea >> 12) & 0xf); + + /* + * 0 -> full permission + * 1 -> Read only + * 2 -> no access. + * We return the flag that need to be cleared. + */ + spp = ((spp & 2) ? _PAGE_RWX : 0) | ((spp & 1) ? _PAGE_WRITE : 0); + return spp; +} + +#else /* CONFIG_PPC_SUBPAGE_PROT */ +static inline int subpage_protection(struct mm_struct *mm, unsigned long ea) +{ + return 0; +} +#endif + +void hash_failure_debug(unsigned long ea, unsigned long access, + unsigned long vsid, unsigned long trap, + int ssize, int psize, int lpsize, unsigned long pte) +{ + if (!printk_ratelimit()) + return; + pr_info("mm: Hashing failure ! EA=0x%lx access=0x%lx current=%s\n", + ea, access, current->comm); + pr_info(" trap=0x%lx vsid=0x%lx ssize=%d base psize=%d psize %d pte=0x%lx\n", + trap, vsid, ssize, psize, lpsize, pte); +} + +static void check_paca_psize(unsigned long ea, struct mm_struct *mm, + int psize, bool user_region) +{ + if (user_region) { + if (psize != get_paca_psize(ea)) { + copy_mm_to_paca(mm); + slb_flush_and_restore_bolted(); + } + } else if (get_paca()->vmalloc_sllp != + mmu_psize_defs[mmu_vmalloc_psize].sllp) { + get_paca()->vmalloc_sllp = + mmu_psize_defs[mmu_vmalloc_psize].sllp; + slb_vmalloc_update(); + } +} + +/* + * Result code is: + * 0 - handled + * 1 - normal page fault + * -1 - critical hash insertion error + * -2 - access not permitted by subpage protection mechanism + */ +int hash_page_mm(struct mm_struct *mm, unsigned long ea, + unsigned long access, unsigned long trap, + unsigned long flags) +{ + bool is_thp; + pgd_t *pgdir; + unsigned long vsid; + pte_t *ptep; + unsigned hugeshift; + int rc, user_region = 0; + int psize, ssize; + + DBG_LOW("hash_page(ea=%016lx, access=%lx, trap=%lx\n", + ea, access, trap); + trace_hash_fault(ea, access, trap); + + /* Get region & vsid */ + switch (get_region_id(ea)) { + case USER_REGION_ID: + user_region = 1; + if (! mm) { + DBG_LOW(" user region with no mm !\n"); + rc = 1; + goto bail; + } + psize = get_slice_psize(mm, ea); + ssize = user_segment_size(ea); + vsid = get_user_vsid(&mm->context, ea, ssize); + break; + case VMALLOC_REGION_ID: + vsid = get_kernel_vsid(ea, mmu_kernel_ssize); + psize = mmu_vmalloc_psize; + ssize = mmu_kernel_ssize; + flags |= HPTE_USE_KERNEL_KEY; + break; + + case IO_REGION_ID: + vsid = get_kernel_vsid(ea, mmu_kernel_ssize); + psize = mmu_io_psize; + ssize = mmu_kernel_ssize; + flags |= HPTE_USE_KERNEL_KEY; + break; + default: + /* + * Not a valid range + * Send the problem up to do_page_fault() + */ + rc = 1; + goto bail; + } + DBG_LOW(" mm=%p, mm->pgdir=%p, vsid=%016lx\n", mm, mm->pgd, vsid); + + /* Bad address. */ + if (!vsid) { + DBG_LOW("Bad address!\n"); + rc = 1; + goto bail; + } + /* Get pgdir */ + pgdir = mm->pgd; + if (pgdir == NULL) { + rc = 1; + goto bail; + } + + /* Check CPU locality */ + if (user_region && mm_is_thread_local(mm)) + flags |= HPTE_LOCAL_UPDATE; + +#ifndef CONFIG_PPC_64K_PAGES + /* + * If we use 4K pages and our psize is not 4K, then we might + * be hitting a special driver mapping, and need to align the + * address before we fetch the PTE. + * + * It could also be a hugepage mapping, in which case this is + * not necessary, but it's not harmful, either. + */ + if (psize != MMU_PAGE_4K) + ea &= ~((1ul << mmu_psize_defs[psize].shift) - 1); +#endif /* CONFIG_PPC_64K_PAGES */ + + /* Get PTE and page size from page tables */ + ptep = find_linux_pte(pgdir, ea, &is_thp, &hugeshift); + if (ptep == NULL || !pte_present(*ptep)) { + DBG_LOW(" no PTE !\n"); + rc = 1; + goto bail; + } + + /* + * Add _PAGE_PRESENT to the required access perm. If there are parallel + * updates to the pte that can possibly clear _PAGE_PTE, catch that too. + * + * We can safely use the return pte address in rest of the function + * because we do set H_PAGE_BUSY which prevents further updates to pte + * from generic code. + */ + access |= _PAGE_PRESENT | _PAGE_PTE; + + /* + * Pre-check access permissions (will be re-checked atomically + * in __hash_page_XX but this pre-check is a fast path + */ + if (!check_pte_access(access, pte_val(*ptep))) { + DBG_LOW(" no access !\n"); + rc = 1; + goto bail; + } + + if (hugeshift) { + if (is_thp) + rc = __hash_page_thp(ea, access, vsid, (pmd_t *)ptep, + trap, flags, ssize, psize); +#ifdef CONFIG_HUGETLB_PAGE + else + rc = __hash_page_huge(ea, access, vsid, ptep, trap, + flags, ssize, hugeshift, psize); +#else + else { + /* + * if we have hugeshift, and is not transhuge with + * hugetlb disabled, something is really wrong. + */ + rc = 1; + WARN_ON(1); + } +#endif + if (current->mm == mm) + check_paca_psize(ea, mm, psize, user_region); + + goto bail; + } + +#ifndef CONFIG_PPC_64K_PAGES + DBG_LOW(" i-pte: %016lx\n", pte_val(*ptep)); +#else + DBG_LOW(" i-pte: %016lx %016lx\n", pte_val(*ptep), + pte_val(*(ptep + PTRS_PER_PTE))); +#endif + /* Do actual hashing */ +#ifdef CONFIG_PPC_64K_PAGES + /* If H_PAGE_4K_PFN is set, make sure this is a 4k segment */ + if ((pte_val(*ptep) & H_PAGE_4K_PFN) && psize == MMU_PAGE_64K) { + demote_segment_4k(mm, ea); + psize = MMU_PAGE_4K; + } + + /* + * If this PTE is non-cacheable and we have restrictions on + * using non cacheable large pages, then we switch to 4k + */ + if (mmu_ci_restrictions && psize == MMU_PAGE_64K && pte_ci(*ptep)) { + if (user_region) { + demote_segment_4k(mm, ea); + psize = MMU_PAGE_4K; + } else if (ea < VMALLOC_END) { + /* + * some driver did a non-cacheable mapping + * in vmalloc space, so switch vmalloc + * to 4k pages + */ + printk(KERN_ALERT "Reducing vmalloc segment " + "to 4kB pages because of " + "non-cacheable mapping\n"); + psize = mmu_vmalloc_psize = MMU_PAGE_4K; + copro_flush_all_slbs(mm); + } + } + +#endif /* CONFIG_PPC_64K_PAGES */ + + if (current->mm == mm) + check_paca_psize(ea, mm, psize, user_region); + +#ifdef CONFIG_PPC_64K_PAGES + if (psize == MMU_PAGE_64K) + rc = __hash_page_64K(ea, access, vsid, ptep, trap, + flags, ssize); + else +#endif /* CONFIG_PPC_64K_PAGES */ + { + int spp = subpage_protection(mm, ea); + if (access & spp) + rc = -2; + else + rc = __hash_page_4K(ea, access, vsid, ptep, trap, + flags, ssize, spp); + } + + /* + * Dump some info in case of hash insertion failure, they should + * never happen so it is really useful to know if/when they do + */ + if (rc == -1) + hash_failure_debug(ea, access, vsid, trap, ssize, psize, + psize, pte_val(*ptep)); +#ifndef CONFIG_PPC_64K_PAGES + DBG_LOW(" o-pte: %016lx\n", pte_val(*ptep)); +#else + DBG_LOW(" o-pte: %016lx %016lx\n", pte_val(*ptep), + pte_val(*(ptep + PTRS_PER_PTE))); +#endif + DBG_LOW(" -> rc=%d\n", rc); + +bail: + return rc; +} +EXPORT_SYMBOL_GPL(hash_page_mm); + +int hash_page(unsigned long ea, unsigned long access, unsigned long trap, + unsigned long dsisr) +{ + unsigned long flags = 0; + struct mm_struct *mm = current->mm; + + if ((get_region_id(ea) == VMALLOC_REGION_ID) || + (get_region_id(ea) == IO_REGION_ID)) + mm = &init_mm; + + if (dsisr & DSISR_NOHPTE) + flags |= HPTE_NOHPTE_UPDATE; + + return hash_page_mm(mm, ea, access, trap, flags); +} +EXPORT_SYMBOL_GPL(hash_page); + +DEFINE_INTERRUPT_HANDLER(do_hash_fault) +{ + unsigned long ea = regs->dar; + unsigned long dsisr = regs->dsisr; + unsigned long access = _PAGE_PRESENT | _PAGE_READ; + unsigned long flags = 0; + struct mm_struct *mm; + unsigned int region_id; + long err; + + if (unlikely(dsisr & (DSISR_BAD_FAULT_64S | DSISR_KEYFAULT))) { + hash__do_page_fault(regs); + return; + } + + region_id = get_region_id(ea); + if ((region_id == VMALLOC_REGION_ID) || (region_id == IO_REGION_ID)) + mm = &init_mm; + else + mm = current->mm; + + if (dsisr & DSISR_NOHPTE) + flags |= HPTE_NOHPTE_UPDATE; + + if (dsisr & DSISR_ISSTORE) + access |= _PAGE_WRITE; + /* + * We set _PAGE_PRIVILEGED only when + * kernel mode access kernel space. + * + * _PAGE_PRIVILEGED is NOT set + * 1) when kernel mode access user space + * 2) user space access kernel space. + */ + access |= _PAGE_PRIVILEGED; + if (user_mode(regs) || (region_id == USER_REGION_ID)) + access &= ~_PAGE_PRIVILEGED; + + if (TRAP(regs) == INTERRUPT_INST_STORAGE) + access |= _PAGE_EXEC; + + err = hash_page_mm(mm, ea, access, TRAP(regs), flags); + if (unlikely(err < 0)) { + // failed to insert a hash PTE due to an hypervisor error + if (user_mode(regs)) { + if (IS_ENABLED(CONFIG_PPC_SUBPAGE_PROT) && err == -2) + _exception(SIGSEGV, regs, SEGV_ACCERR, ea); + else + _exception(SIGBUS, regs, BUS_ADRERR, ea); + } else { + bad_page_fault(regs, SIGBUS); + } + err = 0; + + } else if (err) { + hash__do_page_fault(regs); + } +} + +static bool should_hash_preload(struct mm_struct *mm, unsigned long ea) +{ + int psize = get_slice_psize(mm, ea); + + /* We only prefault standard pages for now */ + if (unlikely(psize != mm_ctx_user_psize(&mm->context))) + return false; + + /* + * Don't prefault if subpage protection is enabled for the EA. + */ + if (unlikely((psize == MMU_PAGE_4K) && subpage_protection(mm, ea))) + return false; + + return true; +} + +static void hash_preload(struct mm_struct *mm, pte_t *ptep, unsigned long ea, + bool is_exec, unsigned long trap) +{ + unsigned long vsid; + pgd_t *pgdir; + int rc, ssize, update_flags = 0; + unsigned long access = _PAGE_PRESENT | _PAGE_READ | (is_exec ? _PAGE_EXEC : 0); + unsigned long flags; + + BUG_ON(get_region_id(ea) != USER_REGION_ID); + + if (!should_hash_preload(mm, ea)) + return; + + DBG_LOW("hash_preload(mm=%p, mm->pgdir=%p, ea=%016lx, access=%lx," + " trap=%lx\n", mm, mm->pgd, ea, access, trap); + + /* Get Linux PTE if available */ + pgdir = mm->pgd; + if (pgdir == NULL) + return; + + /* Get VSID */ + ssize = user_segment_size(ea); + vsid = get_user_vsid(&mm->context, ea, ssize); + if (!vsid) + return; + +#ifdef CONFIG_PPC_64K_PAGES + /* If either H_PAGE_4K_PFN or cache inhibited is set (and we are on + * a 64K kernel), then we don't preload, hash_page() will take + * care of it once we actually try to access the page. + * That way we don't have to duplicate all of the logic for segment + * page size demotion here + * Called with PTL held, hence can be sure the value won't change in + * between. + */ + if ((pte_val(*ptep) & H_PAGE_4K_PFN) || pte_ci(*ptep)) + return; +#endif /* CONFIG_PPC_64K_PAGES */ + + /* + * __hash_page_* must run with interrupts off, including PMI interrupts + * off, as it sets the H_PAGE_BUSY bit. + * + * It's otherwise possible for perf interrupts to hit at any time and + * may take a hash fault reading the user stack, which could take a + * hash miss and deadlock on the same H_PAGE_BUSY bit. + * + * Interrupts must also be off for the duration of the + * mm_is_thread_local test and update, to prevent preempt running the + * mm on another CPU (XXX: this may be racy vs kthread_use_mm). + */ + powerpc_local_irq_pmu_save(flags); + + /* Is that local to this CPU ? */ + if (mm_is_thread_local(mm)) + update_flags |= HPTE_LOCAL_UPDATE; + + /* Hash it in */ +#ifdef CONFIG_PPC_64K_PAGES + if (mm_ctx_user_psize(&mm->context) == MMU_PAGE_64K) + rc = __hash_page_64K(ea, access, vsid, ptep, trap, + update_flags, ssize); + else +#endif /* CONFIG_PPC_64K_PAGES */ + rc = __hash_page_4K(ea, access, vsid, ptep, trap, update_flags, + ssize, subpage_protection(mm, ea)); + + /* Dump some info in case of hash insertion failure, they should + * never happen so it is really useful to know if/when they do + */ + if (rc == -1) + hash_failure_debug(ea, access, vsid, trap, ssize, + mm_ctx_user_psize(&mm->context), + mm_ctx_user_psize(&mm->context), + pte_val(*ptep)); + + powerpc_local_irq_pmu_restore(flags); +} + +/* + * This is called at the end of handling a user page fault, when the + * fault has been handled by updating a PTE in the linux page tables. + * We use it to preload an HPTE into the hash table corresponding to + * the updated linux PTE. + * + * This must always be called with the pte lock held. + */ +void __update_mmu_cache(struct vm_area_struct *vma, unsigned long address, + pte_t *ptep) +{ + /* + * We don't need to worry about _PAGE_PRESENT here because we are + * called with either mm->page_table_lock held or ptl lock held + */ + unsigned long trap; + bool is_exec; + + /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */ + if (!pte_young(*ptep) || address >= TASK_SIZE) + return; + + /* + * We try to figure out if we are coming from an instruction + * access fault and pass that down to __hash_page so we avoid + * double-faulting on execution of fresh text. We have to test + * for regs NULL since init will get here first thing at boot. + * + * We also avoid filling the hash if not coming from a fault. + */ + + trap = current->thread.regs ? TRAP(current->thread.regs) : 0UL; + switch (trap) { + case 0x300: + is_exec = false; + break; + case 0x400: + is_exec = true; + break; + default: + return; + } + + hash_preload(vma->vm_mm, ptep, address, is_exec, trap); +} + +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM +static inline void tm_flush_hash_page(int local) +{ + /* + * Transactions are not aborted by tlbiel, only tlbie. Without, syncing a + * page back to a block device w/PIO could pick up transactional data + * (bad!) so we force an abort here. Before the sync the page will be + * made read-only, which will flush_hash_page. BIG ISSUE here: if the + * kernel uses a page from userspace without unmapping it first, it may + * see the speculated version. + */ + if (local && cpu_has_feature(CPU_FTR_TM) && current->thread.regs && + MSR_TM_ACTIVE(current->thread.regs->msr)) { + tm_enable(); + tm_abort(TM_CAUSE_TLBI); + } +} +#else +static inline void tm_flush_hash_page(int local) +{ +} +#endif + +/* + * Return the global hash slot, corresponding to the given PTE, which contains + * the HPTE. + */ +unsigned long pte_get_hash_gslot(unsigned long vpn, unsigned long shift, + int ssize, real_pte_t rpte, unsigned int subpg_index) +{ + unsigned long hash, gslot, hidx; + + hash = hpt_hash(vpn, shift, ssize); + hidx = __rpte_to_hidx(rpte, subpg_index); + if (hidx & _PTEIDX_SECONDARY) + hash = ~hash; + gslot = (hash & htab_hash_mask) * HPTES_PER_GROUP; + gslot += hidx & _PTEIDX_GROUP_IX; + return gslot; +} + +void flush_hash_page(unsigned long vpn, real_pte_t pte, int psize, int ssize, + unsigned long flags) +{ + unsigned long index, shift, gslot; + int local = flags & HPTE_LOCAL_UPDATE; + + DBG_LOW("flush_hash_page(vpn=%016lx)\n", vpn); + pte_iterate_hashed_subpages(pte, psize, vpn, index, shift) { + gslot = pte_get_hash_gslot(vpn, shift, ssize, pte, index); + DBG_LOW(" sub %ld: gslot=%lx\n", index, gslot); + /* + * We use same base page size and actual psize, because we don't + * use these functions for hugepage + */ + mmu_hash_ops.hpte_invalidate(gslot, vpn, psize, psize, + ssize, local); + } pte_iterate_hashed_end(); + + tm_flush_hash_page(local); +} + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +void flush_hash_hugepage(unsigned long vsid, unsigned long addr, + pmd_t *pmdp, unsigned int psize, int ssize, + unsigned long flags) +{ + int i, max_hpte_count, valid; + unsigned long s_addr; + unsigned char *hpte_slot_array; + unsigned long hidx, shift, vpn, hash, slot; + int local = flags & HPTE_LOCAL_UPDATE; + + s_addr = addr & HPAGE_PMD_MASK; + hpte_slot_array = get_hpte_slot_array(pmdp); + /* + * IF we try to do a HUGE PTE update after a withdraw is done. + * we will find the below NULL. This happens when we do + * split_huge_pmd + */ + if (!hpte_slot_array) + return; + + if (mmu_hash_ops.hugepage_invalidate) { + mmu_hash_ops.hugepage_invalidate(vsid, s_addr, hpte_slot_array, + psize, ssize, local); + goto tm_abort; + } + /* + * No bluk hpte removal support, invalidate each entry + */ + shift = mmu_psize_defs[psize].shift; + max_hpte_count = HPAGE_PMD_SIZE >> shift; + for (i = 0; i < max_hpte_count; i++) { + /* + * 8 bits per each hpte entries + * 000| [ secondary group (one bit) | hidx (3 bits) | valid bit] + */ + valid = hpte_valid(hpte_slot_array, i); + if (!valid) + continue; + hidx = hpte_hash_index(hpte_slot_array, i); + + /* get the vpn */ + addr = s_addr + (i * (1ul << shift)); + vpn = hpt_vpn(addr, vsid, ssize); + hash = hpt_hash(vpn, shift, ssize); + if (hidx & _PTEIDX_SECONDARY) + hash = ~hash; + + slot = (hash & htab_hash_mask) * HPTES_PER_GROUP; + slot += hidx & _PTEIDX_GROUP_IX; + mmu_hash_ops.hpte_invalidate(slot, vpn, psize, + MMU_PAGE_16M, ssize, local); + } +tm_abort: + tm_flush_hash_page(local); +} +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + +void flush_hash_range(unsigned long number, int local) +{ + if (mmu_hash_ops.flush_hash_range) + mmu_hash_ops.flush_hash_range(number, local); + else { + int i; + struct ppc64_tlb_batch *batch = + this_cpu_ptr(&ppc64_tlb_batch); + + for (i = 0; i < number; i++) + flush_hash_page(batch->vpn[i], batch->pte[i], + batch->psize, batch->ssize, local); + } +} + +long hpte_insert_repeating(unsigned long hash, unsigned long vpn, + unsigned long pa, unsigned long rflags, + unsigned long vflags, int psize, int ssize) +{ + unsigned long hpte_group; + long slot; + +repeat: + hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP; + + /* Insert into the hash table, primary slot */ + slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags, vflags, + psize, psize, ssize); + + /* Primary is full, try the secondary */ + if (unlikely(slot == -1)) { + hpte_group = (~hash & htab_hash_mask) * HPTES_PER_GROUP; + slot = mmu_hash_ops.hpte_insert(hpte_group, vpn, pa, rflags, + vflags | HPTE_V_SECONDARY, + psize, psize, ssize); + if (slot == -1) { + if (mftb() & 0x1) + hpte_group = (hash & htab_hash_mask) * + HPTES_PER_GROUP; + + mmu_hash_ops.hpte_remove(hpte_group); + goto repeat; + } + } + + return slot; +} + +void hpt_clear_stress(void) +{ + int cpu = raw_smp_processor_id(); + int g; + + for (g = 0; g < stress_nr_groups(); g++) { + unsigned long last_group; + last_group = stress_hpt_struct[cpu].last_group[g]; + + if (last_group != -1UL) { + int i; + for (i = 0; i < HPTES_PER_GROUP; i++) { + if (mmu_hash_ops.hpte_remove(last_group) == -1) + break; + } + stress_hpt_struct[cpu].last_group[g] = -1; + } + } +} + +void hpt_do_stress(unsigned long ea, unsigned long hpte_group) +{ + unsigned long last_group; + int cpu = raw_smp_processor_id(); + + last_group = stress_hpt_struct[cpu].last_group[stress_nr_groups() - 1]; + if (hpte_group == last_group) + return; + + if (last_group != -1UL) { + int i; + /* + * Concurrent CPUs might be inserting into this group, so + * give up after a number of iterations, to prevent a live + * lock. + */ + for (i = 0; i < HPTES_PER_GROUP; i++) { + if (mmu_hash_ops.hpte_remove(last_group) == -1) + break; + } + stress_hpt_struct[cpu].last_group[stress_nr_groups() - 1] = -1; + } + + if (ea >= PAGE_OFFSET) { + /* + * We would really like to prefetch to get the TLB loaded, then + * remove the PTE before returning from fault interrupt, to + * increase the hash fault rate. + * + * Unfortunately QEMU TCG does not model the TLB in a way that + * makes this possible, and systemsim (mambo) emulator does not + * bring in TLBs with prefetches (although loads/stores do + * work for non-CI PTEs). + * + * So remember this PTE and clear it on the next hash fault. + */ + memmove(&stress_hpt_struct[cpu].last_group[1], + &stress_hpt_struct[cpu].last_group[0], + (stress_nr_groups() - 1) * sizeof(unsigned long)); + stress_hpt_struct[cpu].last_group[0] = hpte_group; + } +} + +#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KFENCE) +static DEFINE_RAW_SPINLOCK(linear_map_hash_lock); + +static void kernel_map_linear_page(unsigned long vaddr, unsigned long lmi) +{ + unsigned long hash; + unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize); + unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize); + unsigned long mode = htab_convert_pte_flags(pgprot_val(PAGE_KERNEL), HPTE_USE_KERNEL_KEY); + long ret; + + hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize); + + /* Don't create HPTE entries for bad address */ + if (!vsid) + return; + + if (linear_map_hash_slots[lmi] & 0x80) + return; + + ret = hpte_insert_repeating(hash, vpn, __pa(vaddr), mode, + HPTE_V_BOLTED, + mmu_linear_psize, mmu_kernel_ssize); + + BUG_ON (ret < 0); + raw_spin_lock(&linear_map_hash_lock); + BUG_ON(linear_map_hash_slots[lmi] & 0x80); + linear_map_hash_slots[lmi] = ret | 0x80; + raw_spin_unlock(&linear_map_hash_lock); +} + +static void kernel_unmap_linear_page(unsigned long vaddr, unsigned long lmi) +{ + unsigned long hash, hidx, slot; + unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize); + unsigned long vpn = hpt_vpn(vaddr, vsid, mmu_kernel_ssize); + + hash = hpt_hash(vpn, PAGE_SHIFT, mmu_kernel_ssize); + raw_spin_lock(&linear_map_hash_lock); + if (!(linear_map_hash_slots[lmi] & 0x80)) { + raw_spin_unlock(&linear_map_hash_lock); + return; + } + hidx = linear_map_hash_slots[lmi] & 0x7f; + linear_map_hash_slots[lmi] = 0; + raw_spin_unlock(&linear_map_hash_lock); + if (hidx & _PTEIDX_SECONDARY) + hash = ~hash; + slot = (hash & htab_hash_mask) * HPTES_PER_GROUP; + slot += hidx & _PTEIDX_GROUP_IX; + mmu_hash_ops.hpte_invalidate(slot, vpn, mmu_linear_psize, + mmu_linear_psize, + mmu_kernel_ssize, 0); +} + +void hash__kernel_map_pages(struct page *page, int numpages, int enable) +{ + unsigned long flags, vaddr, lmi; + int i; + + local_irq_save(flags); + for (i = 0; i < numpages; i++, page++) { + vaddr = (unsigned long)page_address(page); + lmi = __pa(vaddr) >> PAGE_SHIFT; + if (lmi >= linear_map_hash_count) + continue; + if (enable) + kernel_map_linear_page(vaddr, lmi); + else + kernel_unmap_linear_page(vaddr, lmi); + } + local_irq_restore(flags); +} +#endif /* CONFIG_DEBUG_PAGEALLOC || CONFIG_KFENCE */ + +void hash__setup_initial_memory_limit(phys_addr_t first_memblock_base, + phys_addr_t first_memblock_size) +{ + /* + * We don't currently support the first MEMBLOCK not mapping 0 + * physical on those processors + */ + BUG_ON(first_memblock_base != 0); + + /* + * On virtualized systems the first entry is our RMA region aka VRMA, + * non-virtualized 64-bit hash MMU systems don't have a limitation + * on real mode access. + * + * For guests on platforms before POWER9, we clamp the it limit to 1G + * to avoid some funky things such as RTAS bugs etc... + * + * On POWER9 we limit to 1TB in case the host erroneously told us that + * the RMA was >1TB. Effective address bits 0:23 are treated as zero + * (meaning the access is aliased to zero i.e. addr = addr % 1TB) + * for virtual real mode addressing and so it doesn't make sense to + * have an area larger than 1TB as it can't be addressed. + */ + if (!early_cpu_has_feature(CPU_FTR_HVMODE)) { + ppc64_rma_size = first_memblock_size; + if (!early_cpu_has_feature(CPU_FTR_ARCH_300)) + ppc64_rma_size = min_t(u64, ppc64_rma_size, 0x40000000); + else + ppc64_rma_size = min_t(u64, ppc64_rma_size, + 1UL << SID_SHIFT_1T); + + /* Finally limit subsequent allocations */ + memblock_set_current_limit(ppc64_rma_size); + } else { + ppc64_rma_size = ULONG_MAX; + } +} + +#ifdef CONFIG_DEBUG_FS + +static int hpt_order_get(void *data, u64 *val) +{ + *val = ppc64_pft_size; + return 0; +} + +static int hpt_order_set(void *data, u64 val) +{ + int ret; + + if (!mmu_hash_ops.resize_hpt) + return -ENODEV; + + cpus_read_lock(); + ret = mmu_hash_ops.resize_hpt(val); + cpus_read_unlock(); + + return ret; +} + +DEFINE_DEBUGFS_ATTRIBUTE(fops_hpt_order, hpt_order_get, hpt_order_set, "%llu\n"); + +static int __init hash64_debugfs(void) +{ + debugfs_create_file("hpt_order", 0600, arch_debugfs_dir, NULL, + &fops_hpt_order); + return 0; +} +machine_device_initcall(pseries, hash64_debugfs); +#endif /* CONFIG_DEBUG_FS */ + +void __init print_system_hash_info(void) +{ + pr_info("ppc64_pft_size = 0x%llx\n", ppc64_pft_size); + + if (htab_hash_mask) + pr_info("htab_hash_mask = 0x%lx\n", htab_hash_mask); +} + +unsigned long arch_randomize_brk(struct mm_struct *mm) +{ + /* + * If we are using 1TB segments and we are allowed to randomise + * the heap, we can put it above 1TB so it is backed by a 1TB + * segment. Otherwise the heap will be in the bottom 1TB + * which always uses 256MB segments and this may result in a + * performance penalty. + */ + if (is_32bit_task()) + return randomize_page(mm->brk, SZ_32M); + else if (!radix_enabled() && mmu_highuser_ssize == MMU_SEGSIZE_1T) + return randomize_page(max_t(unsigned long, mm->brk, SZ_1T), SZ_1G); + else + return randomize_page(mm->brk, SZ_1G); +} |