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authorChristophe Leroy <christophe.leroy@c-s.fr>2019-03-29 10:00:00 +0000
committerMichael Ellerman <mpe@ellerman.id.au>2019-05-03 01:18:38 +1000
commit47d99948eee48a84a4b242c17915a4ff59a29b5d (patch)
tree93b4b14a4775dfc34c00cd38454672e4233280db /arch/powerpc/mm/slb.c
parent9d9f2cccde952126185e3336af0d4dc62eb254ad (diff)
powerpc/mm: Move book3s64 specifics in subdirectory mm/book3s64
Many files in arch/powerpc/mm are only for book3S64. This patch creates a subdirectory for them. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: Update the selftest sym links, shorten new filenames, cleanup some whitespace and formatting in the new files.] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/mm/slb.c')
-rw-r--r--arch/powerpc/mm/slb.c832
1 files changed, 0 insertions, 832 deletions
diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
deleted file mode 100644
index 89e4531de64b..000000000000
--- a/arch/powerpc/mm/slb.c
+++ /dev/null
@@ -1,832 +0,0 @@
-/*
- * PowerPC64 SLB support.
- *
- * Copyright (C) 2004 David Gibson <dwg@au.ibm.com>, IBM
- * Based on earlier code written by:
- * Dave Engebretsen and Mike Corrigan {engebret|mikejc}@us.ibm.com
- * Copyright (c) 2001 Dave Engebretsen
- * Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM
- *
- *
- * 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 <asm/asm-prototypes.h>
-#include <asm/pgtable.h>
-#include <asm/mmu.h>
-#include <asm/mmu_context.h>
-#include <asm/paca.h>
-#include <asm/ppc-opcode.h>
-#include <asm/cputable.h>
-#include <asm/cacheflush.h>
-#include <asm/smp.h>
-#include <linux/compiler.h>
-#include <linux/context_tracking.h>
-#include <linux/mm_types.h>
-
-#include <asm/udbg.h>
-#include <asm/code-patching.h>
-
-enum slb_index {
- LINEAR_INDEX = 0, /* Kernel linear map (0xc000000000000000) */
- KSTACK_INDEX = 1, /* Kernel stack map */
-};
-
-static long slb_allocate_user(struct mm_struct *mm, unsigned long ea);
-
-#define slb_esid_mask(ssize) \
- (((ssize) == MMU_SEGSIZE_256M)? ESID_MASK: ESID_MASK_1T)
-
-static inline unsigned long mk_esid_data(unsigned long ea, int ssize,
- enum slb_index index)
-{
- return (ea & slb_esid_mask(ssize)) | SLB_ESID_V | index;
-}
-
-static inline unsigned long __mk_vsid_data(unsigned long vsid, int ssize,
- unsigned long flags)
-{
- return (vsid << slb_vsid_shift(ssize)) | flags |
- ((unsigned long) ssize << SLB_VSID_SSIZE_SHIFT);
-}
-
-static inline unsigned long mk_vsid_data(unsigned long ea, int ssize,
- unsigned long flags)
-{
- return __mk_vsid_data(get_kernel_vsid(ea, ssize), ssize, flags);
-}
-
-static void assert_slb_presence(bool present, unsigned long ea)
-{
-#ifdef CONFIG_DEBUG_VM
- unsigned long tmp;
-
- WARN_ON_ONCE(mfmsr() & MSR_EE);
-
- if (!cpu_has_feature(CPU_FTR_ARCH_206))
- return;
-
- /*
- * slbfee. requires bit 24 (PPC bit 39) be clear in RB. Hardware
- * ignores all other bits from 0-27, so just clear them all.
- */
- ea &= ~((1UL << 28) - 1);
- asm volatile(__PPC_SLBFEE_DOT(%0, %1) : "=r"(tmp) : "r"(ea) : "cr0");
-
- WARN_ON(present == (tmp == 0));
-#endif
-}
-
-static inline void slb_shadow_update(unsigned long ea, int ssize,
- unsigned long flags,
- enum slb_index index)
-{
- struct slb_shadow *p = get_slb_shadow();
-
- /*
- * Clear the ESID first so the entry is not valid while we are
- * updating it. No write barriers are needed here, provided
- * we only update the current CPU's SLB shadow buffer.
- */
- WRITE_ONCE(p->save_area[index].esid, 0);
- WRITE_ONCE(p->save_area[index].vsid, cpu_to_be64(mk_vsid_data(ea, ssize, flags)));
- WRITE_ONCE(p->save_area[index].esid, cpu_to_be64(mk_esid_data(ea, ssize, index)));
-}
-
-static inline void slb_shadow_clear(enum slb_index index)
-{
- WRITE_ONCE(get_slb_shadow()->save_area[index].esid, cpu_to_be64(index));
-}
-
-static inline void create_shadowed_slbe(unsigned long ea, int ssize,
- unsigned long flags,
- enum slb_index index)
-{
- /*
- * Updating the shadow buffer before writing the SLB ensures
- * we don't get a stale entry here if we get preempted by PHYP
- * between these two statements.
- */
- slb_shadow_update(ea, ssize, flags, index);
-
- assert_slb_presence(false, ea);
- asm volatile("slbmte %0,%1" :
- : "r" (mk_vsid_data(ea, ssize, flags)),
- "r" (mk_esid_data(ea, ssize, index))
- : "memory" );
-}
-
-/*
- * Insert bolted entries into SLB (which may not be empty, so don't clear
- * slb_cache_ptr).
- */
-void __slb_restore_bolted_realmode(void)
-{
- struct slb_shadow *p = get_slb_shadow();
- enum slb_index index;
-
- /* No isync needed because realmode. */
- for (index = 0; index < SLB_NUM_BOLTED; index++) {
- asm volatile("slbmte %0,%1" :
- : "r" (be64_to_cpu(p->save_area[index].vsid)),
- "r" (be64_to_cpu(p->save_area[index].esid)));
- }
-
- assert_slb_presence(true, local_paca->kstack);
-}
-
-/*
- * Insert the bolted entries into an empty SLB.
- */
-void slb_restore_bolted_realmode(void)
-{
- __slb_restore_bolted_realmode();
- get_paca()->slb_cache_ptr = 0;
-
- get_paca()->slb_kern_bitmap = (1U << SLB_NUM_BOLTED) - 1;
- get_paca()->slb_used_bitmap = get_paca()->slb_kern_bitmap;
-}
-
-/*
- * This flushes all SLB entries including 0, so it must be realmode.
- */
-void slb_flush_all_realmode(void)
-{
- asm volatile("slbmte %0,%0; slbia" : : "r" (0));
-}
-
-/*
- * This flushes non-bolted entries, it can be run in virtual mode. Must
- * be called with interrupts disabled.
- */
-void slb_flush_and_restore_bolted(void)
-{
- struct slb_shadow *p = get_slb_shadow();
-
- BUILD_BUG_ON(SLB_NUM_BOLTED != 2);
-
- WARN_ON(!irqs_disabled());
-
- /*
- * We can't take a PMU exception in the following code, so hard
- * disable interrupts.
- */
- hard_irq_disable();
-
- asm volatile("isync\n"
- "slbia\n"
- "slbmte %0, %1\n"
- "isync\n"
- :: "r" (be64_to_cpu(p->save_area[KSTACK_INDEX].vsid)),
- "r" (be64_to_cpu(p->save_area[KSTACK_INDEX].esid))
- : "memory");
- assert_slb_presence(true, get_paca()->kstack);
-
- get_paca()->slb_cache_ptr = 0;
-
- get_paca()->slb_kern_bitmap = (1U << SLB_NUM_BOLTED) - 1;
- get_paca()->slb_used_bitmap = get_paca()->slb_kern_bitmap;
-}
-
-void slb_save_contents(struct slb_entry *slb_ptr)
-{
- int i;
- unsigned long e, v;
-
- /* Save slb_cache_ptr value. */
- get_paca()->slb_save_cache_ptr = get_paca()->slb_cache_ptr;
-
- if (!slb_ptr)
- return;
-
- for (i = 0; i < mmu_slb_size; i++) {
- asm volatile("slbmfee %0,%1" : "=r" (e) : "r" (i));
- asm volatile("slbmfev %0,%1" : "=r" (v) : "r" (i));
- slb_ptr->esid = e;
- slb_ptr->vsid = v;
- slb_ptr++;
- }
-}
-
-void slb_dump_contents(struct slb_entry *slb_ptr)
-{
- int i, n;
- unsigned long e, v;
- unsigned long llp;
-
- if (!slb_ptr)
- return;
-
- pr_err("SLB contents of cpu 0x%x\n", smp_processor_id());
- pr_err("Last SLB entry inserted at slot %d\n", get_paca()->stab_rr);
-
- for (i = 0; i < mmu_slb_size; i++) {
- e = slb_ptr->esid;
- v = slb_ptr->vsid;
- slb_ptr++;
-
- if (!e && !v)
- continue;
-
- pr_err("%02d %016lx %016lx\n", i, e, v);
-
- if (!(e & SLB_ESID_V)) {
- pr_err("\n");
- continue;
- }
- llp = v & SLB_VSID_LLP;
- if (v & SLB_VSID_B_1T) {
- pr_err(" 1T ESID=%9lx VSID=%13lx LLP:%3lx\n",
- GET_ESID_1T(e),
- (v & ~SLB_VSID_B) >> SLB_VSID_SHIFT_1T, llp);
- } else {
- pr_err(" 256M ESID=%9lx VSID=%13lx LLP:%3lx\n",
- GET_ESID(e),
- (v & ~SLB_VSID_B) >> SLB_VSID_SHIFT, llp);
- }
- }
- pr_err("----------------------------------\n");
-
- /* Dump slb cache entires as well. */
- pr_err("SLB cache ptr value = %d\n", get_paca()->slb_save_cache_ptr);
- pr_err("Valid SLB cache entries:\n");
- n = min_t(int, get_paca()->slb_save_cache_ptr, SLB_CACHE_ENTRIES);
- for (i = 0; i < n; i++)
- pr_err("%02d EA[0-35]=%9x\n", i, get_paca()->slb_cache[i]);
- pr_err("Rest of SLB cache entries:\n");
- for (i = n; i < SLB_CACHE_ENTRIES; i++)
- pr_err("%02d EA[0-35]=%9x\n", i, get_paca()->slb_cache[i]);
-}
-
-void slb_vmalloc_update(void)
-{
- /*
- * vmalloc is not bolted, so just have to flush non-bolted.
- */
- slb_flush_and_restore_bolted();
-}
-
-static bool preload_hit(struct thread_info *ti, unsigned long esid)
-{
- unsigned char i;
-
- for (i = 0; i < ti->slb_preload_nr; i++) {
- unsigned char idx;
-
- idx = (ti->slb_preload_tail + i) % SLB_PRELOAD_NR;
- if (esid == ti->slb_preload_esid[idx])
- return true;
- }
- return false;
-}
-
-static bool preload_add(struct thread_info *ti, unsigned long ea)
-{
- unsigned char idx;
- unsigned long esid;
-
- if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) {
- /* EAs are stored >> 28 so 256MB segments don't need clearing */
- if (ea & ESID_MASK_1T)
- ea &= ESID_MASK_1T;
- }
-
- esid = ea >> SID_SHIFT;
-
- if (preload_hit(ti, esid))
- return false;
-
- idx = (ti->slb_preload_tail + ti->slb_preload_nr) % SLB_PRELOAD_NR;
- ti->slb_preload_esid[idx] = esid;
- if (ti->slb_preload_nr == SLB_PRELOAD_NR)
- ti->slb_preload_tail = (ti->slb_preload_tail + 1) % SLB_PRELOAD_NR;
- else
- ti->slb_preload_nr++;
-
- return true;
-}
-
-static void preload_age(struct thread_info *ti)
-{
- if (!ti->slb_preload_nr)
- return;
- ti->slb_preload_nr--;
- ti->slb_preload_tail = (ti->slb_preload_tail + 1) % SLB_PRELOAD_NR;
-}
-
-void slb_setup_new_exec(void)
-{
- struct thread_info *ti = current_thread_info();
- struct mm_struct *mm = current->mm;
- unsigned long exec = 0x10000000;
-
- WARN_ON(irqs_disabled());
-
- /*
- * preload cache can only be used to determine whether a SLB
- * entry exists if it does not start to overflow.
- */
- if (ti->slb_preload_nr + 2 > SLB_PRELOAD_NR)
- return;
-
- hard_irq_disable();
-
- /*
- * We have no good place to clear the slb preload cache on exec,
- * flush_thread is about the earliest arch hook but that happens
- * after we switch to the mm and have aleady preloaded the SLBEs.
- *
- * For the most part that's probably okay to use entries from the
- * previous exec, they will age out if unused. It may turn out to
- * be an advantage to clear the cache before switching to it,
- * however.
- */
-
- /*
- * preload some userspace segments into the SLB.
- * Almost all 32 and 64bit PowerPC executables are linked at
- * 0x10000000 so it makes sense to preload this segment.
- */
- if (!is_kernel_addr(exec)) {
- if (preload_add(ti, exec))
- slb_allocate_user(mm, exec);
- }
-
- /* Libraries and mmaps. */
- if (!is_kernel_addr(mm->mmap_base)) {
- if (preload_add(ti, mm->mmap_base))
- slb_allocate_user(mm, mm->mmap_base);
- }
-
- /* see switch_slb */
- asm volatile("isync" : : : "memory");
-
- local_irq_enable();
-}
-
-void preload_new_slb_context(unsigned long start, unsigned long sp)
-{
- struct thread_info *ti = current_thread_info();
- struct mm_struct *mm = current->mm;
- unsigned long heap = mm->start_brk;
-
- WARN_ON(irqs_disabled());
-
- /* see above */
- if (ti->slb_preload_nr + 3 > SLB_PRELOAD_NR)
- return;
-
- hard_irq_disable();
-
- /* Userspace entry address. */
- if (!is_kernel_addr(start)) {
- if (preload_add(ti, start))
- slb_allocate_user(mm, start);
- }
-
- /* Top of stack, grows down. */
- if (!is_kernel_addr(sp)) {
- if (preload_add(ti, sp))
- slb_allocate_user(mm, sp);
- }
-
- /* Bottom of heap, grows up. */
- if (heap && !is_kernel_addr(heap)) {
- if (preload_add(ti, heap))
- slb_allocate_user(mm, heap);
- }
-
- /* see switch_slb */
- asm volatile("isync" : : : "memory");
-
- local_irq_enable();
-}
-
-
-/* Flush all user entries from the segment table of the current processor. */
-void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
-{
- struct thread_info *ti = task_thread_info(tsk);
- unsigned char i;
-
- /*
- * We need interrupts hard-disabled here, not just soft-disabled,
- * so that a PMU interrupt can't occur, which might try to access
- * user memory (to get a stack trace) and possible cause an SLB miss
- * which would update the slb_cache/slb_cache_ptr fields in the PACA.
- */
- hard_irq_disable();
- asm volatile("isync" : : : "memory");
- if (cpu_has_feature(CPU_FTR_ARCH_300)) {
- /*
- * SLBIA IH=3 invalidates all Class=1 SLBEs and their
- * associated lookaside structures, which matches what
- * switch_slb wants. So ARCH_300 does not use the slb
- * cache.
- */
- asm volatile(PPC_SLBIA(3));
- } else {
- unsigned long offset = get_paca()->slb_cache_ptr;
-
- if (!mmu_has_feature(MMU_FTR_NO_SLBIE_B) &&
- offset <= SLB_CACHE_ENTRIES) {
- unsigned long slbie_data = 0;
-
- for (i = 0; i < offset; i++) {
- unsigned long ea;
-
- ea = (unsigned long)
- get_paca()->slb_cache[i] << SID_SHIFT;
- /*
- * Could assert_slb_presence(true) here, but
- * hypervisor or machine check could have come
- * in and removed the entry at this point.
- */
-
- slbie_data = ea;
- slbie_data |= user_segment_size(slbie_data)
- << SLBIE_SSIZE_SHIFT;
- slbie_data |= SLBIE_C; /* user slbs have C=1 */
- asm volatile("slbie %0" : : "r" (slbie_data));
- }
-
- /* Workaround POWER5 < DD2.1 issue */
- if (!cpu_has_feature(CPU_FTR_ARCH_207S) && offset == 1)
- asm volatile("slbie %0" : : "r" (slbie_data));
-
- } else {
- struct slb_shadow *p = get_slb_shadow();
- unsigned long ksp_esid_data =
- be64_to_cpu(p->save_area[KSTACK_INDEX].esid);
- unsigned long ksp_vsid_data =
- be64_to_cpu(p->save_area[KSTACK_INDEX].vsid);
-
- asm volatile(PPC_SLBIA(1) "\n"
- "slbmte %0,%1\n"
- "isync"
- :: "r"(ksp_vsid_data),
- "r"(ksp_esid_data));
-
- get_paca()->slb_kern_bitmap = (1U << SLB_NUM_BOLTED) - 1;
- }
-
- get_paca()->slb_cache_ptr = 0;
- }
- get_paca()->slb_used_bitmap = get_paca()->slb_kern_bitmap;
-
- copy_mm_to_paca(mm);
-
- /*
- * We gradually age out SLBs after a number of context switches to
- * reduce reload overhead of unused entries (like we do with FP/VEC
- * reload). Each time we wrap 256 switches, take an entry out of the
- * SLB preload cache.
- */
- tsk->thread.load_slb++;
- if (!tsk->thread.load_slb) {
- unsigned long pc = KSTK_EIP(tsk);
-
- preload_age(ti);
- preload_add(ti, pc);
- }
-
- for (i = 0; i < ti->slb_preload_nr; i++) {
- unsigned char idx;
- unsigned long ea;
-
- idx = (ti->slb_preload_tail + i) % SLB_PRELOAD_NR;
- ea = (unsigned long)ti->slb_preload_esid[idx] << SID_SHIFT;
-
- slb_allocate_user(mm, ea);
- }
-
- /*
- * Synchronize slbmte preloads with possible subsequent user memory
- * address accesses by the kernel (user mode won't happen until
- * rfid, which is safe).
- */
- asm volatile("isync" : : : "memory");
-}
-
-void slb_set_size(u16 size)
-{
- mmu_slb_size = size;
-}
-
-void slb_initialize(void)
-{
- unsigned long linear_llp, vmalloc_llp, io_llp;
- unsigned long lflags;
- static int slb_encoding_inited;
-#ifdef CONFIG_SPARSEMEM_VMEMMAP
- unsigned long vmemmap_llp;
-#endif
-
- /* Prepare our SLB miss handler based on our page size */
- linear_llp = mmu_psize_defs[mmu_linear_psize].sllp;
- io_llp = mmu_psize_defs[mmu_io_psize].sllp;
- vmalloc_llp = mmu_psize_defs[mmu_vmalloc_psize].sllp;
- get_paca()->vmalloc_sllp = SLB_VSID_KERNEL | vmalloc_llp;
-#ifdef CONFIG_SPARSEMEM_VMEMMAP
- vmemmap_llp = mmu_psize_defs[mmu_vmemmap_psize].sllp;
-#endif
- if (!slb_encoding_inited) {
- slb_encoding_inited = 1;
- pr_devel("SLB: linear LLP = %04lx\n", linear_llp);
- pr_devel("SLB: io LLP = %04lx\n", io_llp);
-#ifdef CONFIG_SPARSEMEM_VMEMMAP
- pr_devel("SLB: vmemmap LLP = %04lx\n", vmemmap_llp);
-#endif
- }
-
- get_paca()->stab_rr = SLB_NUM_BOLTED - 1;
- get_paca()->slb_kern_bitmap = (1U << SLB_NUM_BOLTED) - 1;
- get_paca()->slb_used_bitmap = get_paca()->slb_kern_bitmap;
-
- lflags = SLB_VSID_KERNEL | linear_llp;
-
- /* Invalidate the entire SLB (even entry 0) & all the ERATS */
- asm volatile("isync":::"memory");
- asm volatile("slbmte %0,%0"::"r" (0) : "memory");
- asm volatile("isync; slbia; isync":::"memory");
- create_shadowed_slbe(PAGE_OFFSET, mmu_kernel_ssize, lflags, LINEAR_INDEX);
-
- /* For the boot cpu, we're running on the stack in init_thread_union,
- * which is in the first segment of the linear mapping, and also
- * get_paca()->kstack hasn't been initialized yet.
- * For secondary cpus, we need to bolt the kernel stack entry now.
- */
- slb_shadow_clear(KSTACK_INDEX);
- if (raw_smp_processor_id() != boot_cpuid &&
- (get_paca()->kstack & slb_esid_mask(mmu_kernel_ssize)) > PAGE_OFFSET)
- create_shadowed_slbe(get_paca()->kstack,
- mmu_kernel_ssize, lflags, KSTACK_INDEX);
-
- asm volatile("isync":::"memory");
-}
-
-static void slb_cache_update(unsigned long esid_data)
-{
- int slb_cache_index;
-
- if (cpu_has_feature(CPU_FTR_ARCH_300))
- return; /* ISAv3.0B and later does not use slb_cache */
-
- /*
- * Now update slb cache entries
- */
- slb_cache_index = local_paca->slb_cache_ptr;
- if (slb_cache_index < SLB_CACHE_ENTRIES) {
- /*
- * We have space in slb cache for optimized switch_slb().
- * Top 36 bits from esid_data as per ISA
- */
- local_paca->slb_cache[slb_cache_index++] = esid_data >> 28;
- local_paca->slb_cache_ptr++;
- } else {
- /*
- * Our cache is full and the current cache content strictly
- * doesn't indicate the active SLB conents. Bump the ptr
- * so that switch_slb() will ignore the cache.
- */
- local_paca->slb_cache_ptr = SLB_CACHE_ENTRIES + 1;
- }
-}
-
-static enum slb_index alloc_slb_index(bool kernel)
-{
- enum slb_index index;
-
- /*
- * The allocation bitmaps can become out of synch with the SLB
- * when the _switch code does slbie when bolting a new stack
- * segment and it must not be anywhere else in the SLB. This leaves
- * a kernel allocated entry that is unused in the SLB. With very
- * large systems or small segment sizes, the bitmaps could slowly
- * fill with these entries. They will eventually be cleared out
- * by the round robin allocator in that case, so it's probably not
- * worth accounting for.
- */
-
- /*
- * SLBs beyond 32 entries are allocated with stab_rr only
- * POWER7/8/9 have 32 SLB entries, this could be expanded if a
- * future CPU has more.
- */
- if (local_paca->slb_used_bitmap != U32_MAX) {
- index = ffz(local_paca->slb_used_bitmap);
- local_paca->slb_used_bitmap |= 1U << index;
- if (kernel)
- local_paca->slb_kern_bitmap |= 1U << index;
- } else {
- /* round-robin replacement of slb starting at SLB_NUM_BOLTED. */
- index = local_paca->stab_rr;
- if (index < (mmu_slb_size - 1))
- index++;
- else
- index = SLB_NUM_BOLTED;
- local_paca->stab_rr = index;
- if (index < 32) {
- if (kernel)
- local_paca->slb_kern_bitmap |= 1U << index;
- else
- local_paca->slb_kern_bitmap &= ~(1U << index);
- }
- }
- BUG_ON(index < SLB_NUM_BOLTED);
-
- return index;
-}
-
-static long slb_insert_entry(unsigned long ea, unsigned long context,
- unsigned long flags, int ssize, bool kernel)
-{
- unsigned long vsid;
- unsigned long vsid_data, esid_data;
- enum slb_index index;
-
- vsid = get_vsid(context, ea, ssize);
- if (!vsid)
- return -EFAULT;
-
- /*
- * There must not be a kernel SLB fault in alloc_slb_index or before
- * slbmte here or the allocation bitmaps could get out of whack with
- * the SLB.
- *
- * User SLB faults or preloads take this path which might get inlined
- * into the caller, so add compiler barriers here to ensure unsafe
- * memory accesses do not come between.
- */
- barrier();
-
- index = alloc_slb_index(kernel);
-
- vsid_data = __mk_vsid_data(vsid, ssize, flags);
- esid_data = mk_esid_data(ea, ssize, index);
-
- /*
- * No need for an isync before or after this slbmte. The exception
- * we enter with and the rfid we exit with are context synchronizing.
- * User preloads should add isync afterwards in case the kernel
- * accesses user memory before it returns to userspace with rfid.
- */
- assert_slb_presence(false, ea);
- asm volatile("slbmte %0, %1" : : "r" (vsid_data), "r" (esid_data));
-
- barrier();
-
- if (!kernel)
- slb_cache_update(esid_data);
-
- return 0;
-}
-
-static long slb_allocate_kernel(unsigned long ea, unsigned long id)
-{
- unsigned long context;
- unsigned long flags;
- int ssize;
-
- if (id == LINEAR_MAP_REGION_ID) {
-
- /* We only support upto MAX_PHYSMEM_BITS */
- if ((ea & EA_MASK) > (1UL << MAX_PHYSMEM_BITS))
- return -EFAULT;
-
- flags = SLB_VSID_KERNEL | mmu_psize_defs[mmu_linear_psize].sllp;
-
-#ifdef CONFIG_SPARSEMEM_VMEMMAP
- } else if (id == VMEMMAP_REGION_ID) {
-
- if (ea >= H_VMEMMAP_END)
- return -EFAULT;
-
- flags = SLB_VSID_KERNEL | mmu_psize_defs[mmu_vmemmap_psize].sllp;
-#endif
- } else if (id == VMALLOC_REGION_ID) {
-
- if (ea >= H_VMALLOC_END)
- return -EFAULT;
-
- flags = local_paca->vmalloc_sllp;
-
- } else if (id == IO_REGION_ID) {
-
- if (ea >= H_KERN_IO_END)
- return -EFAULT;
-
- flags = SLB_VSID_KERNEL | mmu_psize_defs[mmu_io_psize].sllp;
-
- } else {
- return -EFAULT;
- }
-
- ssize = MMU_SEGSIZE_1T;
- if (!mmu_has_feature(MMU_FTR_1T_SEGMENT))
- ssize = MMU_SEGSIZE_256M;
-
- context = get_kernel_context(ea);
-
- return slb_insert_entry(ea, context, flags, ssize, true);
-}
-
-static long slb_allocate_user(struct mm_struct *mm, unsigned long ea)
-{
- unsigned long context;
- unsigned long flags;
- int bpsize;
- int ssize;
-
- /*
- * consider this as bad access if we take a SLB miss
- * on an address above addr limit.
- */
- if (ea >= mm_ctx_slb_addr_limit(&mm->context))
- return -EFAULT;
-
- context = get_user_context(&mm->context, ea);
- if (!context)
- return -EFAULT;
-
- if (unlikely(ea >= H_PGTABLE_RANGE)) {
- WARN_ON(1);
- return -EFAULT;
- }
-
- ssize = user_segment_size(ea);
-
- bpsize = get_slice_psize(mm, ea);
- flags = SLB_VSID_USER | mmu_psize_defs[bpsize].sllp;
-
- return slb_insert_entry(ea, context, flags, ssize, false);
-}
-
-long do_slb_fault(struct pt_regs *regs, unsigned long ea)
-{
- unsigned long id = get_region_id(ea);
-
- /* IRQs are not reconciled here, so can't check irqs_disabled */
- VM_WARN_ON(mfmsr() & MSR_EE);
-
- if (unlikely(!(regs->msr & MSR_RI)))
- return -EINVAL;
-
- /*
- * SLB kernel faults must be very careful not to touch anything
- * that is not bolted. E.g., PACA and global variables are okay,
- * mm->context stuff is not.
- *
- * SLB user faults can access all of kernel memory, but must be
- * careful not to touch things like IRQ state because it is not
- * "reconciled" here. The difficulty is that we must use
- * fast_exception_return to return from kernel SLB faults without
- * looking at possible non-bolted memory. We could test user vs
- * kernel faults in the interrupt handler asm and do a full fault,
- * reconcile, ret_from_except for user faults which would make them
- * first class kernel code. But for performance it's probably nicer
- * if they go via fast_exception_return too.
- */
- if (id >= LINEAR_MAP_REGION_ID) {
- long err;
-#ifdef CONFIG_DEBUG_VM
- /* Catch recursive kernel SLB faults. */
- BUG_ON(local_paca->in_kernel_slb_handler);
- local_paca->in_kernel_slb_handler = 1;
-#endif
- err = slb_allocate_kernel(ea, id);
-#ifdef CONFIG_DEBUG_VM
- local_paca->in_kernel_slb_handler = 0;
-#endif
- return err;
- } else {
- struct mm_struct *mm = current->mm;
- long err;
-
- if (unlikely(!mm))
- return -EFAULT;
-
- err = slb_allocate_user(mm, ea);
- if (!err)
- preload_add(current_thread_info(), ea);
-
- return err;
- }
-}
-
-void do_bad_slb_fault(struct pt_regs *regs, unsigned long ea, long err)
-{
- if (err == -EFAULT) {
- if (user_mode(regs))
- _exception(SIGSEGV, regs, SEGV_BNDERR, ea);
- else
- bad_page_fault(regs, ea, SIGSEGV);
- } else if (err == -EINVAL) {
- unrecoverable_exception(regs);
- } else {
- BUG();
- }
-}