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android_kernel_motorola_sm6225/arch/sh/mm/pmb.c
Matt Fleming 3d467676ab sh: Setup early PMB mappings. 
More and more boards are going to start shipping that boot with the MMU
in 32BIT mode by default. Previously we relied on the bootloader to
setup PMB mappings for use by the kernel but we also need to cater for
boards whose bootloaders don't set them up.

If CONFIG_PMB_LEGACY is not enabled we have full control over our PMB
mappings and can compress our address space. Usually, the distance
between the the cached and uncached mappings of RAM is always 512MB,
however we can compress the distance to be the amount of RAM on the
board.

pmb_init() now becomes much simpler. It no longer has to calculate any
mappings, it just has to synchronise the software PMB table with the
hardware.

Tested on SDK7786 and SH7785LCR.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-01-18 19:33:10 +09:00

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/*
* arch/sh/mm/pmb.c
*
* Privileged Space Mapping Buffer (PMB) Support.
*
* Copyright (C) 2005 - 2010 Paul Mundt
* Copyright (C) 2010 Matt Fleming
*
* 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/sysdev.h>
#include <linux/cpu.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 void __pmb_unmap(struct pmb_entry *);
static struct pmb_entry pmb_entry_list[NR_PMB_ENTRIES];
static unsigned long pmb_map;
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 int pmb_alloc_entry(void)
{
unsigned int pos;
repeat:
pos = find_first_zero_bit(&pmb_map, NR_PMB_ENTRIES);
if (unlikely(pos > NR_PMB_ENTRIES))
return -ENOSPC;
if (test_and_set_bit(pos, &pmb_map))
goto repeat;
return pos;
}
static struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn,
unsigned long flags, int entry)
{
struct pmb_entry *pmbe;
int pos;
if (entry == PMB_NO_ENTRY) {
pos = pmb_alloc_entry();
if (pos < 0)
return ERR_PTR(pos);
} else {
if (test_bit(entry, &pmb_map))
return ERR_PTR(-ENOSPC);
pos = entry;
}
pmbe = &pmb_entry_list[pos];
if (!pmbe)
return ERR_PTR(-ENOMEM);
pmbe->vpn = vpn;
pmbe->ppn = ppn;
pmbe->flags = flags;
pmbe->entry = pos;
return pmbe;
}
static void pmb_free(struct pmb_entry *pmbe)
{
int pos = pmbe->entry;
pmbe->vpn = 0;
pmbe->ppn = 0;
pmbe->flags = 0;
pmbe->entry = 0;
clear_bit(pos, &pmb_map);
}
/*
* Must be in P2 for __set_pmb_entry()
*/
static void __set_pmb_entry(unsigned long vpn, unsigned long ppn,
unsigned long flags, int pos)
{
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));
}
static void __uses_jump_to_uncached set_pmb_entry(struct pmb_entry *pmbe)
{
jump_to_uncached();
__set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, pmbe->entry);
back_to_cached();
}
static void __uses_jump_to_uncached clear_pmb_entry(struct pmb_entry *pmbe)
{
unsigned int entry = pmbe->entry;
unsigned long addr;
if (unlikely(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();
}
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, *pmbe;
unsigned long wanted;
int pmb_flags, i;
long err;
/* 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++) {
if (size < pmb_sizes[i].size)
continue;
pmbe = pmb_alloc(vaddr, phys, pmb_flags | pmb_sizes[i].flag,
PMB_NO_ENTRY);
if (IS_ERR(pmbe)) {
err = PTR_ERR(pmbe);
goto out;
}
set_pmb_entry(pmbe);
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;
/*
* Instead of trying smaller sizes on every iteration
* (even if we succeed in allocating space), try using
* pmb_sizes[i].size again.
*/
i--;
}
if (size >= 0x1000000)
goto again;
return wanted - size;
out:
if (pmbp)
__pmb_unmap(pmbp);
return err;
}
void pmb_unmap(unsigned long addr)
{
struct pmb_entry *pmbe = NULL;
int i;
for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
if (test_bit(i, &pmb_map)) {
pmbe = &pmb_entry_list[i];
if (pmbe->vpn == addr)
break;
}
}
if (unlikely(!pmbe))
return;
__pmb_unmap(pmbe);
}
static void __pmb_unmap(struct pmb_entry *pmbe)
{
BUG_ON(!test_bit(pmbe->entry, &pmb_map));
do {
struct pmb_entry *pmblink = pmbe;
/*
* We may be called before this pmb_entry has been
* entered into the PMB table via set_pmb_entry(), but
* that's OK because we've allocated a unique slot for
* this entry in pmb_alloc() (even if we haven't filled
* it yet).
*
* Therefore, calling clear_pmb_entry() is safe as no
* other mapping can be using that slot.
*/
clear_pmb_entry(pmbe);
pmbe = pmblink->link;
pmb_free(pmblink);
} while (pmbe);
}
#ifdef CONFIG_PMB_LEGACY
static inline unsigned int pmb_ppn_in_range(unsigned long ppn)
{
return ppn >= __MEMORY_START && ppn < __MEMORY_START + __MEMORY_SIZE;
}
static int pmb_apply_legacy_mappings(void)
{
unsigned int applied = 0;
int i;
pr_info("PMB: Preserving legacy mappings:\n");
/*
* The following entries are setup by the bootloader.
*
* Entry VPN PPN V SZ C UB
* --------------------------------------------------------
* 0 0xA0000000 0x00000000 1 64MB 0 0
* 1 0xA4000000 0x04000000 1 16MB 0 0
* 2 0xA6000000 0x08000000 1 16MB 0 0
* 9 0x88000000 0x48000000 1 128MB 1 1
* 10 0x90000000 0x50000000 1 128MB 1 1
* 11 0x98000000 0x58000000 1 128MB 1 1
* 13 0xA8000000 0x48000000 1 128MB 0 0
* 14 0xB0000000 0x50000000 1 128MB 0 0
* 15 0xB8000000 0x58000000 1 128MB 0 0
*
* The only entries the we need are the ones that map the kernel
* at the cached and uncached addresses.
*/
for (i = 0; i < PMB_ENTRY_MAX; i++) {
unsigned long addr, data;
unsigned long addr_val, data_val;
unsigned long ppn, vpn;
addr = mk_pmb_addr(i);
data = mk_pmb_data(i);
addr_val = __raw_readl(addr);
data_val = __raw_readl(data);
/*
* Skip over any bogus entries
*/
if (!(data_val & PMB_V) || !(addr_val & PMB_V))
continue;
ppn = data_val & PMB_PFN_MASK;
vpn = addr_val & PMB_PFN_MASK;
/*
* Only preserve in-range mappings.
*/
if (pmb_ppn_in_range(ppn)) {
unsigned int size;
char *sz_str = NULL;
size = data_val & PMB_SZ_MASK;
sz_str = (size == PMB_SZ_16M) ? " 16MB":
(size == PMB_SZ_64M) ? " 64MB":
(size == PMB_SZ_128M) ? "128MB":
"512MB";
pr_info("\t0x%08lx -> 0x%08lx [ %s %scached ]\n",
vpn >> PAGE_SHIFT, ppn >> PAGE_SHIFT, sz_str,
(data_val & PMB_C) ? "" : "un");
applied++;
} else {
/*
* Invalidate anything out of bounds.
*/
__raw_writel(addr_val & ~PMB_V, addr);
__raw_writel(data_val & ~PMB_V, data);
}
}
return (applied == 0);
}
#else
static inline int pmb_apply_legacy_mappings(void)
{
return 1;
}
#endif
int __uses_jump_to_uncached pmb_init(void)
{
int i;
unsigned long addr, data;
unsigned long ret;
jump_to_uncached();
/*
* Attempt to apply the legacy boot mappings if configured. If
* this is successful then we simply carry on with those and
* don't bother establishing additional memory mappings. Dynamic
* device mappings through pmb_remap() can still be bolted on
* after this.
*/
ret = pmb_apply_legacy_mappings();
if (ret == 0) {
back_to_cached();
return 0;
}
/*
* Sync our software copy of the PMB mappings with those in
* hardware. The mappings in the hardware PMB were either set up
* by the bootloader or very early on by the kernel.
*/
for (i = 0; i < PMB_ENTRY_MAX; i++) {
struct pmb_entry *pmbe;
unsigned long vpn, ppn, flags;
addr = PMB_DATA + (i << PMB_E_SHIFT);
data = ctrl_inl(addr);
if (!(data & PMB_V))
continue;
if (data & PMB_C) {
#if defined(CONFIG_CACHE_WRITETHROUGH)
data |= PMB_WT;
#elif defined(CONFIG_CACHE_WRITEBACK)
data &= ~PMB_WT;
#else
data &= ~(PMB_C | PMB_WT);
#endif
}
ctrl_outl(data, addr);
ppn = data & PMB_PFN_MASK;
flags = data & (PMB_C | PMB_WT | PMB_UB);
flags |= data & PMB_SZ_MASK;
addr = PMB_ADDR + (i << PMB_E_SHIFT);
data = ctrl_inl(addr);
vpn = data & PMB_PFN_MASK;
pmbe = pmb_alloc(vpn, ppn, flags, i);
WARN_ON(IS_ERR(pmbe));
}
ctrl_outl(0, PMB_IRMCR);
/* Flush out the TLB */
i = ctrl_inl(MMUCR);
i |= MMUCR_TI;
ctrl_outl(i, MMUCR);
back_to_cached();
return 0;
}
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);
#ifdef CONFIG_PM
static int pmb_sysdev_suspend(struct sys_device *dev, pm_message_t state)
{
static pm_message_t prev_state;
int i;
/* Restore the PMB after a resume from hibernation */
if (state.event == PM_EVENT_ON &&
prev_state.event == PM_EVENT_FREEZE) {
struct pmb_entry *pmbe;
for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
if (test_bit(i, &pmb_map)) {
pmbe = &pmb_entry_list[i];
set_pmb_entry(pmbe);
}
}
}
prev_state = state;
return 0;
}
static int pmb_sysdev_resume(struct sys_device *dev)
{
return pmb_sysdev_suspend(dev, PMSG_ON);
}
static struct sysdev_driver pmb_sysdev_driver = {
.suspend = pmb_sysdev_suspend,
.resume = pmb_sysdev_resume,
};
static int __init pmb_sysdev_init(void)
{
return sysdev_driver_register(&cpu_sysdev_class, &pmb_sysdev_driver);
}
subsys_initcall(pmb_sysdev_init);
#endif
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