d7a5b2ffa1
Currently most callers of lmb_alloc() don't check if it worked or not, if it ever does weird bad things will probably happen. The few callers who do check just panic or BUG_ON. So make lmb_alloc() panic internally, to catch bugs at the source. The few callers who did check the result no longer need to. The only caller that did anything interesting with the return result was careful_allocation(). For it we create __lmb_alloc_base() which _doesn't_ panic automatically, a little messy, but passable. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
290 lines
7.4 KiB
C
290 lines
7.4 KiB
C
/*
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* PowerPC64 Segment Translation Support.
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*
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* Dave Engebretsen and Mike Corrigan {engebret|mikejc}@us.ibm.com
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* Copyright (c) 2001 Dave Engebretsen
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*
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* Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/config.h>
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#include <asm/pgtable.h>
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#include <asm/mmu.h>
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#include <asm/mmu_context.h>
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#include <asm/paca.h>
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#include <asm/cputable.h>
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#include <asm/lmb.h>
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#include <asm/abs_addr.h>
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#include <asm/firmware.h>
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struct stab_entry {
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unsigned long esid_data;
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unsigned long vsid_data;
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};
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#define NR_STAB_CACHE_ENTRIES 8
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DEFINE_PER_CPU(long, stab_cache_ptr);
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DEFINE_PER_CPU(long, stab_cache[NR_STAB_CACHE_ENTRIES]);
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/*
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* Create a segment table entry for the given esid/vsid pair.
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*/
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static int make_ste(unsigned long stab, unsigned long esid, unsigned long vsid)
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{
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unsigned long esid_data, vsid_data;
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unsigned long entry, group, old_esid, castout_entry, i;
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unsigned int global_entry;
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struct stab_entry *ste, *castout_ste;
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unsigned long kernel_segment = (esid << SID_SHIFT) >= PAGE_OFFSET;
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vsid_data = vsid << STE_VSID_SHIFT;
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esid_data = esid << SID_SHIFT | STE_ESID_KP | STE_ESID_V;
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if (! kernel_segment)
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esid_data |= STE_ESID_KS;
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/* Search the primary group first. */
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global_entry = (esid & 0x1f) << 3;
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ste = (struct stab_entry *)(stab | ((esid & 0x1f) << 7));
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/* Find an empty entry, if one exists. */
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for (group = 0; group < 2; group++) {
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for (entry = 0; entry < 8; entry++, ste++) {
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if (!(ste->esid_data & STE_ESID_V)) {
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ste->vsid_data = vsid_data;
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asm volatile("eieio":::"memory");
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ste->esid_data = esid_data;
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return (global_entry | entry);
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}
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}
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/* Now search the secondary group. */
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global_entry = ((~esid) & 0x1f) << 3;
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ste = (struct stab_entry *)(stab | (((~esid) & 0x1f) << 7));
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}
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/*
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* Could not find empty entry, pick one with a round robin selection.
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* Search all entries in the two groups.
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*/
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castout_entry = get_paca()->stab_rr;
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for (i = 0; i < 16; i++) {
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if (castout_entry < 8) {
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global_entry = (esid & 0x1f) << 3;
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ste = (struct stab_entry *)(stab | ((esid & 0x1f) << 7));
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castout_ste = ste + castout_entry;
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} else {
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global_entry = ((~esid) & 0x1f) << 3;
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ste = (struct stab_entry *)(stab | (((~esid) & 0x1f) << 7));
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castout_ste = ste + (castout_entry - 8);
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}
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/* Dont cast out the first kernel segment */
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if ((castout_ste->esid_data & ESID_MASK) != PAGE_OFFSET)
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break;
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castout_entry = (castout_entry + 1) & 0xf;
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}
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get_paca()->stab_rr = (castout_entry + 1) & 0xf;
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/* Modify the old entry to the new value. */
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/* Force previous translations to complete. DRENG */
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asm volatile("isync" : : : "memory");
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old_esid = castout_ste->esid_data >> SID_SHIFT;
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castout_ste->esid_data = 0; /* Invalidate old entry */
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asm volatile("sync" : : : "memory"); /* Order update */
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castout_ste->vsid_data = vsid_data;
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asm volatile("eieio" : : : "memory"); /* Order update */
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castout_ste->esid_data = esid_data;
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asm volatile("slbie %0" : : "r" (old_esid << SID_SHIFT));
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/* Ensure completion of slbie */
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asm volatile("sync" : : : "memory");
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return (global_entry | (castout_entry & 0x7));
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}
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/*
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* Allocate a segment table entry for the given ea and mm
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*/
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static int __ste_allocate(unsigned long ea, struct mm_struct *mm)
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{
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unsigned long vsid;
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unsigned char stab_entry;
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unsigned long offset;
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/* Kernel or user address? */
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if (is_kernel_addr(ea)) {
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vsid = get_kernel_vsid(ea);
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} else {
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if ((ea >= TASK_SIZE_USER64) || (! mm))
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return 1;
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vsid = get_vsid(mm->context.id, ea);
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}
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stab_entry = make_ste(get_paca()->stab_addr, GET_ESID(ea), vsid);
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if (!is_kernel_addr(ea)) {
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offset = __get_cpu_var(stab_cache_ptr);
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if (offset < NR_STAB_CACHE_ENTRIES)
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__get_cpu_var(stab_cache[offset++]) = stab_entry;
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else
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offset = NR_STAB_CACHE_ENTRIES+1;
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__get_cpu_var(stab_cache_ptr) = offset;
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/* Order update */
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asm volatile("sync":::"memory");
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}
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return 0;
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}
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int ste_allocate(unsigned long ea)
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{
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return __ste_allocate(ea, current->mm);
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}
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/*
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* Do the segment table work for a context switch: flush all user
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* entries from the table, then preload some probably useful entries
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* for the new task
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*/
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void switch_stab(struct task_struct *tsk, struct mm_struct *mm)
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{
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struct stab_entry *stab = (struct stab_entry *) get_paca()->stab_addr;
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struct stab_entry *ste;
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unsigned long offset = __get_cpu_var(stab_cache_ptr);
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unsigned long pc = KSTK_EIP(tsk);
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unsigned long stack = KSTK_ESP(tsk);
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unsigned long unmapped_base;
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/* Force previous translations to complete. DRENG */
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asm volatile("isync" : : : "memory");
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if (offset <= NR_STAB_CACHE_ENTRIES) {
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int i;
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for (i = 0; i < offset; i++) {
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ste = stab + __get_cpu_var(stab_cache[i]);
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ste->esid_data = 0; /* invalidate entry */
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}
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} else {
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unsigned long entry;
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/* Invalidate all entries. */
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ste = stab;
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/* Never flush the first entry. */
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ste += 1;
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for (entry = 1;
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entry < (HW_PAGE_SIZE / sizeof(struct stab_entry));
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entry++, ste++) {
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unsigned long ea;
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ea = ste->esid_data & ESID_MASK;
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if (!is_kernel_addr(ea)) {
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ste->esid_data = 0;
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}
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}
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}
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asm volatile("sync; slbia; sync":::"memory");
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__get_cpu_var(stab_cache_ptr) = 0;
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#ifdef CONFIG_PPC_64K_PAGES
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get_paca()->pgdir = mm->pgd;
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#endif /* CONFIG_PPC_64K_PAGES */
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/* Now preload some entries for the new task */
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if (test_tsk_thread_flag(tsk, TIF_32BIT))
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unmapped_base = TASK_UNMAPPED_BASE_USER32;
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else
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unmapped_base = TASK_UNMAPPED_BASE_USER64;
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__ste_allocate(pc, mm);
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if (GET_ESID(pc) == GET_ESID(stack))
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return;
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__ste_allocate(stack, mm);
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if ((GET_ESID(pc) == GET_ESID(unmapped_base))
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|| (GET_ESID(stack) == GET_ESID(unmapped_base)))
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return;
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__ste_allocate(unmapped_base, mm);
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/* Order update */
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asm volatile("sync" : : : "memory");
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}
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/*
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* Allocate segment tables for secondary CPUs. These must all go in
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* the first (bolted) segment, so that do_stab_bolted won't get a
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* recursive segment miss on the segment table itself.
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*/
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void stabs_alloc(void)
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{
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int cpu;
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if (cpu_has_feature(CPU_FTR_SLB))
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return;
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for_each_cpu(cpu) {
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unsigned long newstab;
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if (cpu == 0)
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continue; /* stab for CPU 0 is statically allocated */
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newstab = lmb_alloc_base(HW_PAGE_SIZE, HW_PAGE_SIZE,
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1<<SID_SHIFT);
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newstab = (unsigned long)__va(newstab);
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memset((void *)newstab, 0, HW_PAGE_SIZE);
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paca[cpu].stab_addr = newstab;
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paca[cpu].stab_real = virt_to_abs(newstab);
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printk(KERN_INFO "Segment table for CPU %d at 0x%lx "
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"virtual, 0x%lx absolute\n",
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cpu, paca[cpu].stab_addr, paca[cpu].stab_real);
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}
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}
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/*
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* Build an entry for the base kernel segment and put it into
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* the segment table or SLB. All other segment table or SLB
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* entries are faulted in.
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*/
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void stab_initialize(unsigned long stab)
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{
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unsigned long vsid = get_kernel_vsid(PAGE_OFFSET);
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unsigned long stabreal;
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asm volatile("isync; slbia; isync":::"memory");
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make_ste(stab, GET_ESID(PAGE_OFFSET), vsid);
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/* Order update */
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asm volatile("sync":::"memory");
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/* Set ASR */
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stabreal = get_paca()->stab_real | 0x1ul;
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#ifdef CONFIG_PPC_ISERIES
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if (firmware_has_feature(FW_FEATURE_ISERIES)) {
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HvCall1(HvCallBaseSetASR, stabreal);
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return;
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}
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#endif /* CONFIG_PPC_ISERIES */
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mtspr(SPRN_ASR, stabreal);
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}
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