linux_old1/arch/sh/mm/pmb.c

516 lines
11 KiB
C
Raw Normal View History

/*
* 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 <linux/io.h>
#include <asm/sizes.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/mmu.h>
#include <asm/mmu_context.h>
static void pmb_unmap_entry(struct pmb_entry *);
static struct pmb_entry pmb_entry_list[NR_PMB_ENTRIES];
static DECLARE_BITMAP(pmb_map, NR_PMB_ENTRIES);
static __always_inline unsigned long mk_pmb_entry(unsigned int entry)
{
return (entry & PMB_E_MASK) << PMB_E_SHIFT;
}
static __always_inline unsigned long mk_pmb_addr(unsigned int entry)
{
return mk_pmb_entry(entry) | PMB_ADDR;
}
static __always_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_and_set_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 run uncached.
*/
static void set_pmb_entry(struct pmb_entry *pmbe)
{
jump_to_uncached();
__raw_writel(pmbe->vpn | PMB_V, mk_pmb_addr(pmbe->entry));
#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(pmbe->flags & PMB_C))
pmbe->flags |= PMB_WT;
#endif
__raw_writel(pmbe->ppn | pmbe->flags | PMB_V, mk_pmb_data(pmbe->entry));
back_to_cached();
}
static void clear_pmb_entry(struct pmb_entry *pmbe)
{
unsigned int entry = pmbe->entry;
unsigned long addr;
jump_to_uncached();
/* Clear V-bit */
addr = mk_pmb_addr(entry);
__raw_writel(__raw_readl(addr) & ~PMB_V, addr);
addr = mk_pmb_data(entry);
__raw_writel(__raw_readl(addr) & ~PMB_V, addr);
back_to_cached();
}
static struct {
unsigned long size;
int flag;
} pmb_sizes[] = {
{ .size = SZ_512M, .flag = PMB_SZ_512M, },
{ .size = SZ_128M, .flag = PMB_SZ_128M, },
{ .size = SZ_64M, .flag = PMB_SZ_64M, },
{ .size = SZ_16M, .flag = PMB_SZ_16M, },
};
long pmb_remap(unsigned long vaddr, unsigned long phys,
unsigned long size, pgprot_t prot)
{
struct pmb_entry *pmbp, *pmbe;
unsigned long wanted;
int pmb_flags, i;
long err;
u64 flags;
flags = pgprot_val(prot);
/* 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:
pmb_unmap_entry(pmbp);
return err;
}
void pmb_unmap(unsigned long addr)
{
struct pmb_entry *pmbe;
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) {
pmb_unmap_entry(pmbe);
break;
}
}
}
}
static void pmb_unmap_entry(struct pmb_entry *pmbe)
{
if (unlikely(!pmbe))
return;
if (!test_bit(pmbe->entry, pmb_map)) {
WARN_ON(1);
return;
}
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);
}
static inline void
pmb_log_mapping(unsigned long data_val, unsigned long vpn, unsigned long ppn)
{
unsigned int size;
const char *sz_str;
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");
}
static inline unsigned int pmb_ppn_in_range(unsigned long ppn)
{
return ppn >= __pa(memory_start) && ppn < __pa(memory_end);
}
static int pmb_synchronize_mappings(void)
{
unsigned int applied = 0;
int i;
pr_info("PMB: boot mappings:\n");
/*
* Run through the initial boot mappings, log the established
* ones, and blow away anything that falls outside of the valid
* PPN range. Specifically, we only care about existing mappings
* that impact the cached/uncached sections.
*
* Note that touching these can be a bit of a minefield; the boot
* loader can establish multi-page mappings with the same caching
* attributes, so we need to ensure that we aren't modifying a
* mapping that we're presently executing from, or may execute
* from in the case of straddling page boundaries.
*
* In the future we will have to tidy up after the boot loader by
* jumping between the cached and uncached mappings and tearing
* down alternating mappings while executing from the other.
*/
for (i = 0; i < NR_PMB_ENTRIES; i++) {
unsigned long addr, data;
unsigned long addr_val, data_val;
unsigned long ppn, vpn, flags;
struct pmb_entry *pmbe;
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)) {
/*
* Invalidate anything out of bounds.
*/
__raw_writel(addr_val & ~PMB_V, addr);
__raw_writel(data_val & ~PMB_V, data);
continue;
}
/*
* Update the caching attributes if necessary
*/
if (data_val & PMB_C) {
#if defined(CONFIG_CACHE_WRITETHROUGH)
data_val |= PMB_WT;
#elif defined(CONFIG_CACHE_WRITEBACK)
data_val &= ~PMB_WT;
#else
data_val &= ~(PMB_C | PMB_WT);
#endif
__raw_writel(data_val, data);
}
flags = data_val & (PMB_SZ_MASK | PMB_CACHE_MASK);
pmbe = pmb_alloc(vpn, ppn, flags, i);
if (IS_ERR(pmbe)) {
WARN_ON_ONCE(1);
continue;
}
pmb_log_mapping(data_val, vpn, ppn);
applied++;
}
return (applied == 0);
}
int pmb_init(void)
{
int ret;
jump_to_uncached();
/*
* 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.
*/
ret = pmb_synchronize_mappings();
if (unlikely(ret == 0)) {
back_to_cached();
return 0;
}
__raw_writel(0, PMB_IRMCR);
/* Flush out the TLB */
__raw_writel(__raw_readl(MMUCR) | MMUCR_TI, MMUCR);
back_to_cached();
return 0;
}
bool __in_29bit_mode(void)
{
return (__raw_readl(PMB_PASCR) & PASCR_SE) == 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 = __raw_readl(mk_pmb_addr(i));
data = __raw_readl(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