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sh: SH-4A Privileged Space Mapping Buffer (PMB) support.
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Add support for 32-bit physical addressing through the SH-4A
Privileged Space Mapping Buffer (PMB).

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
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Paul Mundt committed Sep 27, 2006
1 parent a09749d commit 0c7b1df
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Showing 3 changed files with 318 additions and 2 deletions.
3 changes: 2 additions & 1 deletion arch/sh/mm/Makefile
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Original file line number Diff line number Diff line change
Expand Up @@ -22,4 +22,5 @@ obj-$(CONFIG_CPU_SH4) += tlb-sh4.o ioremap.o
obj-$(CONFIG_SH7705_CACHE_32KB) += pg-sh7705.o
endif

obj-$(CONFIG_SH7705_CACHE_32KB) += cache-sh7705.o
obj-$(CONFIG_SH7705_CACHE_32KB) += cache-sh7705.o
obj-$(CONFIG_32BIT) += pmb.o
269 changes: 269 additions & 0 deletions arch/sh/mm/pmb.c
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Original file line number Diff line number Diff line change
@@ -0,0 +1,269 @@
/*
* arch/sh/mm/pmb.c
*
* Privileged Space Mapping Buffer (PMB) Support.
*
* Copyright (C) 2005 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/mmu.h>
#include <asm/io.h>

#define NR_PMB_ENTRIES 16

static kmem_cache_t *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;
}

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;

return pmbe;
}

void pmb_free(struct pmb_entry *pmbe)
{
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_SH_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;
}

void set_pmb_entry(struct pmb_entry *pmbe)
{
jump_to_P2();
__set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, &pmbe->entry);
back_to_P1();
}

void 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_P2();

/* 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_P1();

clear_bit(entry, &pmb_map);
}

static void pmb_cache_ctor(void *pmb, kmem_cache_t *cachep, unsigned long flags)
{
memset(pmb, 0, sizeof(struct pmb_entry));

((struct pmb_entry *)pmb)->entry = PMB_NO_ENTRY;
}

static int __init pmb_init(void)
{
unsigned int nr_entries = ARRAY_SIZE(pmb_init_map);
unsigned int entry;

BUG_ON(unlikely(nr_entries >= NR_PMB_ENTRIES));

pmb_cache = kmem_cache_create("pmb", sizeof(struct pmb_entry),
0, 0, pmb_cache_ctor, NULL);
BUG_ON(!pmb_cache);

jump_to_P2();

/*
* 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);

back_to_P1();

return 0;
}

arch_initcall(pmb_init);

#ifdef CONFIG_DEBUG_FS
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 struct file_operations pmb_debugfs_fops = {
.owner = THIS_MODULE,
.open = pmb_debugfs_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};

static int __init pmb_debugfs_init(void)
{
struct dentry *dentry;

dentry = debugfs_create_file("pmb", S_IFREG | S_IRUGO,
NULL, NULL, &pmb_debugfs_fops);
if (IS_ERR(dentry))
return PTR_ERR(dentry);

return 0;
}

postcore_initcall(pmb_debugfs_init);
#endif
48 changes: 47 additions & 1 deletion include/asm-sh/mmu.h
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Original file line number Diff line number Diff line change
Expand Up @@ -25,5 +25,51 @@ typedef struct {
typedef unsigned long mm_context_t;

#endif /* CONFIG_MMU */
#endif /* __MMH_H */

/*
* Privileged Space Mapping Buffer (PMB) definitions
*/
#define PMB_PASCR 0xff000070
#define PMB_IRMCR 0xff000078

#define PMB_ADDR 0xf6100000
#define PMB_DATA 0xf7100000
#define PMB_ENTRY_MAX 16
#define PMB_E_MASK 0x0000000f
#define PMB_E_SHIFT 8

#define PMB_SZ_16M 0x00000000
#define PMB_SZ_64M 0x00000010
#define PMB_SZ_128M 0x00000080
#define PMB_SZ_512M 0x00000090
#define PMB_SZ_MASK PMB_SZ_512M
#define PMB_C 0x00000008
#define PMB_WT 0x00000001
#define PMB_UB 0x00000200
#define PMB_V 0x00000100

#define PMB_NO_ENTRY (-1)

struct pmb_entry {
unsigned long vpn;
unsigned long ppn;
unsigned long flags;

/*
* 0 .. NR_PMB_ENTRIES for specific entry selection, or
* PMB_NO_ENTRY to search for a free one
*/
int entry;
};

/* arch/sh/mm/pmb.c */
int __set_pmb_entry(unsigned long vpn, unsigned long ppn,
unsigned long flags, int *entry);
void set_pmb_entry(struct pmb_entry *pmbe);
void clear_pmb_entry(struct pmb_entry *pmbe);
struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn,
unsigned long flags);
void pmb_free(struct pmb_entry *pmbe);

#endif /* __MMU_H */

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