![Paul Mundt](/assets/img/avatar_default.png)
This is the last remaining slab destructor in the kernel, which we kill off and move the resultant list tracking logic up to the pmb_alloc()/pmb_free() paths. As Christoph Lameter pointed out, it's potentially unsafe to be taking the list lock in the destructor anyways, so this is also more fundamentally correct. With this in place, we're all set for killing off slab destructors from the kernel entirely. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
398 lines
8.5 KiB
C
398 lines
8.5 KiB
C
/*
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* arch/sh/mm/pmb.c
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*
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* Privileged Space Mapping Buffer (PMB) Support.
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*
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* Copyright (C) 2005, 2006, 2007 Paul Mundt
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*
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* P1/P2 Section mapping definitions from map32.h, which was:
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*
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* Copyright 2003 (c) Lineo Solutions,Inc.
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/bitops.h>
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#include <linux/debugfs.h>
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#include <linux/fs.h>
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#include <linux/seq_file.h>
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#include <linux/err.h>
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#include <asm/system.h>
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#include <asm/uaccess.h>
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#include <asm/pgtable.h>
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#include <asm/mmu.h>
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#include <asm/io.h>
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#define NR_PMB_ENTRIES 16
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static struct kmem_cache *pmb_cache;
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static unsigned long pmb_map;
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static struct pmb_entry pmb_init_map[] = {
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/* vpn ppn flags (ub/sz/c/wt) */
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/* P1 Section Mappings */
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{ 0x80000000, 0x00000000, PMB_SZ_64M | PMB_C, },
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{ 0x84000000, 0x04000000, PMB_SZ_64M | PMB_C, },
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{ 0x88000000, 0x08000000, PMB_SZ_128M | PMB_C, },
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{ 0x90000000, 0x10000000, PMB_SZ_64M | PMB_C, },
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{ 0x94000000, 0x14000000, PMB_SZ_64M | PMB_C, },
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{ 0x98000000, 0x18000000, PMB_SZ_64M | PMB_C, },
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/* P2 Section Mappings */
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{ 0xa0000000, 0x00000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
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{ 0xa4000000, 0x04000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
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{ 0xa8000000, 0x08000000, PMB_UB | PMB_SZ_128M | PMB_WT, },
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{ 0xb0000000, 0x10000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
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{ 0xb4000000, 0x14000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
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{ 0xb8000000, 0x18000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
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};
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static inline unsigned long mk_pmb_entry(unsigned int entry)
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{
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return (entry & PMB_E_MASK) << PMB_E_SHIFT;
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}
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static inline unsigned long mk_pmb_addr(unsigned int entry)
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{
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return mk_pmb_entry(entry) | PMB_ADDR;
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}
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static inline unsigned long mk_pmb_data(unsigned int entry)
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{
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return mk_pmb_entry(entry) | PMB_DATA;
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}
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static DEFINE_SPINLOCK(pmb_list_lock);
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static struct pmb_entry *pmb_list;
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static inline void pmb_list_add(struct pmb_entry *pmbe)
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{
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struct pmb_entry **p, *tmp;
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p = &pmb_list;
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while ((tmp = *p) != NULL)
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p = &tmp->next;
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pmbe->next = tmp;
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*p = pmbe;
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}
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static inline void pmb_list_del(struct pmb_entry *pmbe)
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{
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struct pmb_entry **p, *tmp;
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for (p = &pmb_list; (tmp = *p); p = &tmp->next)
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if (tmp == pmbe) {
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*p = tmp->next;
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return;
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}
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}
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struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn,
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unsigned long flags)
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{
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struct pmb_entry *pmbe;
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pmbe = kmem_cache_alloc(pmb_cache, GFP_KERNEL);
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if (!pmbe)
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return ERR_PTR(-ENOMEM);
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pmbe->vpn = vpn;
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pmbe->ppn = ppn;
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pmbe->flags = flags;
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spin_lock_irq(&pmb_list_lock);
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pmb_list_add(pmbe);
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spin_unlock_irq(&pmb_list_lock);
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return pmbe;
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}
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void pmb_free(struct pmb_entry *pmbe)
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{
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spin_lock_irq(&pmb_list_lock);
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pmb_list_del(pmbe);
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spin_unlock_irq(&pmb_list_lock);
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kmem_cache_free(pmb_cache, pmbe);
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}
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/*
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* Must be in P2 for __set_pmb_entry()
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*/
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int __set_pmb_entry(unsigned long vpn, unsigned long ppn,
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unsigned long flags, int *entry)
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{
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unsigned int pos = *entry;
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if (unlikely(pos == PMB_NO_ENTRY))
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pos = find_first_zero_bit(&pmb_map, NR_PMB_ENTRIES);
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repeat:
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if (unlikely(pos > NR_PMB_ENTRIES))
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return -ENOSPC;
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if (test_and_set_bit(pos, &pmb_map)) {
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pos = find_first_zero_bit(&pmb_map, NR_PMB_ENTRIES);
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goto repeat;
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}
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ctrl_outl(vpn | PMB_V, mk_pmb_addr(pos));
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#ifdef CONFIG_SH_WRITETHROUGH
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/*
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* When we are in 32-bit address extended mode, CCR.CB becomes
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* invalid, so care must be taken to manually adjust cacheable
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* translations.
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*/
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if (likely(flags & PMB_C))
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flags |= PMB_WT;
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#endif
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ctrl_outl(ppn | flags | PMB_V, mk_pmb_data(pos));
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*entry = pos;
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return 0;
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}
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int set_pmb_entry(struct pmb_entry *pmbe)
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{
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int ret;
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jump_to_P2();
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ret = __set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, &pmbe->entry);
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back_to_P1();
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return ret;
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}
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void clear_pmb_entry(struct pmb_entry *pmbe)
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{
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unsigned int entry = pmbe->entry;
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unsigned long addr;
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/*
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* Don't allow clearing of wired init entries, P1 or P2 access
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* without a corresponding mapping in the PMB will lead to reset
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* by the TLB.
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*/
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if (unlikely(entry < ARRAY_SIZE(pmb_init_map) ||
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entry >= NR_PMB_ENTRIES))
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return;
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jump_to_P2();
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/* Clear V-bit */
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addr = mk_pmb_addr(entry);
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ctrl_outl(ctrl_inl(addr) & ~PMB_V, addr);
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addr = mk_pmb_data(entry);
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ctrl_outl(ctrl_inl(addr) & ~PMB_V, addr);
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back_to_P1();
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clear_bit(entry, &pmb_map);
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}
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static struct {
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unsigned long size;
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int flag;
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} pmb_sizes[] = {
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{ .size = 0x20000000, .flag = PMB_SZ_512M, },
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{ .size = 0x08000000, .flag = PMB_SZ_128M, },
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{ .size = 0x04000000, .flag = PMB_SZ_64M, },
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{ .size = 0x01000000, .flag = PMB_SZ_16M, },
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};
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long pmb_remap(unsigned long vaddr, unsigned long phys,
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unsigned long size, unsigned long flags)
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{
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struct pmb_entry *pmbp;
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unsigned long wanted;
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int pmb_flags, i;
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/* Convert typical pgprot value to the PMB equivalent */
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if (flags & _PAGE_CACHABLE) {
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if (flags & _PAGE_WT)
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pmb_flags = PMB_WT;
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else
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pmb_flags = PMB_C;
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} else
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pmb_flags = PMB_WT | PMB_UB;
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pmbp = NULL;
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wanted = size;
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again:
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for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++) {
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struct pmb_entry *pmbe;
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int ret;
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if (size < pmb_sizes[i].size)
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continue;
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pmbe = pmb_alloc(vaddr, phys, pmb_flags | pmb_sizes[i].flag);
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if (IS_ERR(pmbe))
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return PTR_ERR(pmbe);
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ret = set_pmb_entry(pmbe);
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if (ret != 0) {
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pmb_free(pmbe);
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return -EBUSY;
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}
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phys += pmb_sizes[i].size;
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vaddr += pmb_sizes[i].size;
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size -= pmb_sizes[i].size;
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/*
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* Link adjacent entries that span multiple PMB entries
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* for easier tear-down.
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*/
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if (likely(pmbp))
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pmbp->link = pmbe;
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pmbp = pmbe;
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}
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if (size >= 0x1000000)
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goto again;
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return wanted - size;
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}
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void pmb_unmap(unsigned long addr)
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{
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struct pmb_entry **p, *pmbe;
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for (p = &pmb_list; (pmbe = *p); p = &pmbe->next)
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if (pmbe->vpn == addr)
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break;
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if (unlikely(!pmbe))
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return;
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WARN_ON(!test_bit(pmbe->entry, &pmb_map));
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do {
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struct pmb_entry *pmblink = pmbe;
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clear_pmb_entry(pmbe);
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pmbe = pmblink->link;
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pmb_free(pmblink);
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} while (pmbe);
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}
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static void pmb_cache_ctor(void *pmb, struct kmem_cache *cachep,
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unsigned long flags)
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{
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struct pmb_entry *pmbe = pmb;
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memset(pmb, 0, sizeof(struct pmb_entry));
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pmbe->entry = PMB_NO_ENTRY;
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}
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static int __init pmb_init(void)
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{
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unsigned int nr_entries = ARRAY_SIZE(pmb_init_map);
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unsigned int entry;
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BUG_ON(unlikely(nr_entries >= NR_PMB_ENTRIES));
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pmb_cache = kmem_cache_create("pmb", sizeof(struct pmb_entry), 0,
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SLAB_PANIC, pmb_cache_ctor, NULL);
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jump_to_P2();
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/*
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* Ordering is important, P2 must be mapped in the PMB before we
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* can set PMB.SE, and P1 must be mapped before we jump back to
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* P1 space.
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*/
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for (entry = 0; entry < nr_entries; entry++) {
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struct pmb_entry *pmbe = pmb_init_map + entry;
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__set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, &entry);
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}
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ctrl_outl(0, PMB_IRMCR);
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/* PMB.SE and UB[7] */
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ctrl_outl((1 << 31) | (1 << 7), PMB_PASCR);
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back_to_P1();
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return 0;
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}
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arch_initcall(pmb_init);
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static int pmb_seq_show(struct seq_file *file, void *iter)
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{
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int i;
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seq_printf(file, "V: Valid, C: Cacheable, WT: Write-Through\n"
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"CB: Copy-Back, B: Buffered, UB: Unbuffered\n");
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seq_printf(file, "ety vpn ppn size flags\n");
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for (i = 0; i < NR_PMB_ENTRIES; i++) {
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unsigned long addr, data;
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unsigned int size;
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char *sz_str = NULL;
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addr = ctrl_inl(mk_pmb_addr(i));
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data = ctrl_inl(mk_pmb_data(i));
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size = data & PMB_SZ_MASK;
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sz_str = (size == PMB_SZ_16M) ? " 16MB":
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(size == PMB_SZ_64M) ? " 64MB":
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(size == PMB_SZ_128M) ? "128MB":
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"512MB";
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/* 02: V 0x88 0x08 128MB C CB B */
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seq_printf(file, "%02d: %c 0x%02lx 0x%02lx %s %c %s %s\n",
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i, ((addr & PMB_V) && (data & PMB_V)) ? 'V' : ' ',
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(addr >> 24) & 0xff, (data >> 24) & 0xff,
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sz_str, (data & PMB_C) ? 'C' : ' ',
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(data & PMB_WT) ? "WT" : "CB",
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(data & PMB_UB) ? "UB" : " B");
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}
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return 0;
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}
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static int pmb_debugfs_open(struct inode *inode, struct file *file)
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{
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return single_open(file, pmb_seq_show, NULL);
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}
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static const struct file_operations pmb_debugfs_fops = {
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.owner = THIS_MODULE,
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.open = pmb_debugfs_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = seq_release,
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};
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static int __init pmb_debugfs_init(void)
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{
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struct dentry *dentry;
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dentry = debugfs_create_file("pmb", S_IFREG | S_IRUGO,
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NULL, NULL, &pmb_debugfs_fops);
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if (IS_ERR(dentry))
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return PTR_ERR(dentry);
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return 0;
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}
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postcore_initcall(pmb_debugfs_init);
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