linux-sg2042/arch/sh/mm/pmb.c

405 lines
8.7 KiB
C

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