linux/arch/sh/mm/pmb.c
Greg Kroah-Hartman 03eb2a08fc sh: no need to check return value of debugfs_create functions
When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: <linux-sh@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-03 15:39:40 +02:00

899 lines
18 KiB
C

/*
* arch/sh/mm/pmb.c
*
* Privileged Space Mapping Buffer (PMB) Support.
*
* Copyright (C) 2005 - 2011 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/syscore_ops.h>
#include <linux/cpu.h>
#include <linux/module.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 <linux/spinlock.h>
#include <linux/vmalloc.h>
#include <asm/cacheflush.h>
#include <linux/sizes.h>
#include <linux/uaccess.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/mmu.h>
#include <asm/mmu_context.h>
struct pmb_entry;
struct pmb_entry {
unsigned long vpn;
unsigned long ppn;
unsigned long flags;
unsigned long size;
raw_spinlock_t lock;
/*
* 0 .. NR_PMB_ENTRIES for specific entry selection, or
* PMB_NO_ENTRY to search for a free one
*/
int entry;
/* Adjacent entry link for contiguous multi-entry mappings */
struct pmb_entry *link;
};
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, },
};
static void pmb_unmap_entry(struct pmb_entry *, int depth);
static DEFINE_RWLOCK(pmb_rwlock);
static struct pmb_entry pmb_entry_list[NR_PMB_ENTRIES];
static DECLARE_BITMAP(pmb_map, NR_PMB_ENTRIES);
static unsigned int pmb_iomapping_enabled;
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 __always_inline unsigned int pmb_ppn_in_range(unsigned long ppn)
{
return ppn >= __pa(memory_start) && ppn < __pa(memory_end);
}
/*
* Ensure that the PMB entries match our cache configuration.
*
* When we are in 32-bit address extended mode, CCR.CB becomes
* invalid, so care must be taken to manually adjust cacheable
* translations.
*/
static __always_inline unsigned long pmb_cache_flags(void)
{
unsigned long flags = 0;
#if defined(CONFIG_CACHE_OFF)
flags |= PMB_WT | PMB_UB;
#elif defined(CONFIG_CACHE_WRITETHROUGH)
flags |= PMB_C | PMB_WT | PMB_UB;
#elif defined(CONFIG_CACHE_WRITEBACK)
flags |= PMB_C;
#endif
return flags;
}
/*
* Convert typical pgprot value to the PMB equivalent
*/
static inline unsigned long pgprot_to_pmb_flags(pgprot_t prot)
{
unsigned long pmb_flags = 0;
u64 flags = pgprot_val(prot);
if (flags & _PAGE_CACHABLE)
pmb_flags |= PMB_C;
if (flags & _PAGE_WT)
pmb_flags |= PMB_WT | PMB_UB;
return pmb_flags;
}
static inline bool pmb_can_merge(struct pmb_entry *a, struct pmb_entry *b)
{
return (b->vpn == (a->vpn + a->size)) &&
(b->ppn == (a->ppn + a->size)) &&
(b->flags == a->flags);
}
static bool pmb_mapping_exists(unsigned long vaddr, phys_addr_t phys,
unsigned long size)
{
int i;
read_lock(&pmb_rwlock);
for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
struct pmb_entry *pmbe, *iter;
unsigned long span;
if (!test_bit(i, pmb_map))
continue;
pmbe = &pmb_entry_list[i];
/*
* See if VPN and PPN are bounded by an existing mapping.
*/
if ((vaddr < pmbe->vpn) || (vaddr >= (pmbe->vpn + pmbe->size)))
continue;
if ((phys < pmbe->ppn) || (phys >= (pmbe->ppn + pmbe->size)))
continue;
/*
* Now see if we're in range of a simple mapping.
*/
if (size <= pmbe->size) {
read_unlock(&pmb_rwlock);
return true;
}
span = pmbe->size;
/*
* Finally for sizes that involve compound mappings, walk
* the chain.
*/
for (iter = pmbe->link; iter; iter = iter->link)
span += iter->size;
/*
* Nothing else to do if the range requirements are met.
*/
if (size <= span) {
read_unlock(&pmb_rwlock);
return true;
}
}
read_unlock(&pmb_rwlock);
return false;
}
static bool pmb_size_valid(unsigned long size)
{
int i;
for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++)
if (pmb_sizes[i].size == size)
return true;
return false;
}
static inline bool pmb_addr_valid(unsigned long addr, unsigned long size)
{
return (addr >= P1SEG && (addr + size - 1) < P3SEG);
}
static inline bool pmb_prot_valid(pgprot_t prot)
{
return (pgprot_val(prot) & _PAGE_USER) == 0;
}
static int pmb_size_to_flags(unsigned long size)
{
int i;
for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++)
if (pmb_sizes[i].size == size)
return pmb_sizes[i].flag;
return 0;
}
static int pmb_alloc_entry(void)
{
int pos;
pos = find_first_zero_bit(pmb_map, NR_PMB_ENTRIES);
if (pos >= 0 && pos < NR_PMB_ENTRIES)
__set_bit(pos, pmb_map);
else
pos = -ENOSPC;
return pos;
}
static struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn,
unsigned long flags, int entry)
{
struct pmb_entry *pmbe;
unsigned long irqflags;
void *ret = NULL;
int pos;
write_lock_irqsave(&pmb_rwlock, irqflags);
if (entry == PMB_NO_ENTRY) {
pos = pmb_alloc_entry();
if (unlikely(pos < 0)) {
ret = ERR_PTR(pos);
goto out;
}
} else {
if (__test_and_set_bit(entry, pmb_map)) {
ret = ERR_PTR(-ENOSPC);
goto out;
}
pos = entry;
}
write_unlock_irqrestore(&pmb_rwlock, irqflags);
pmbe = &pmb_entry_list[pos];
memset(pmbe, 0, sizeof(struct pmb_entry));
raw_spin_lock_init(&pmbe->lock);
pmbe->vpn = vpn;
pmbe->ppn = ppn;
pmbe->flags = flags;
pmbe->entry = pos;
return pmbe;
out:
write_unlock_irqrestore(&pmb_rwlock, irqflags);
return ret;
}
static void pmb_free(struct pmb_entry *pmbe)
{
__clear_bit(pmbe->entry, pmb_map);
pmbe->entry = PMB_NO_ENTRY;
pmbe->link = NULL;
}
/*
* Must be run uncached.
*/
static void __set_pmb_entry(struct pmb_entry *pmbe)
{
unsigned long addr, data;
addr = mk_pmb_addr(pmbe->entry);
data = mk_pmb_data(pmbe->entry);
jump_to_uncached();
/* Set V-bit */
__raw_writel(pmbe->vpn | PMB_V, addr);
__raw_writel(pmbe->ppn | pmbe->flags | PMB_V, data);
back_to_cached();
}
static void __clear_pmb_entry(struct pmb_entry *pmbe)
{
unsigned long addr, data;
unsigned long addr_val, data_val;
addr = mk_pmb_addr(pmbe->entry);
data = mk_pmb_data(pmbe->entry);
addr_val = __raw_readl(addr);
data_val = __raw_readl(data);
/* Clear V-bit */
writel_uncached(addr_val & ~PMB_V, addr);
writel_uncached(data_val & ~PMB_V, data);
}
#ifdef CONFIG_PM
static void set_pmb_entry(struct pmb_entry *pmbe)
{
unsigned long flags;
raw_spin_lock_irqsave(&pmbe->lock, flags);
__set_pmb_entry(pmbe);
raw_spin_unlock_irqrestore(&pmbe->lock, flags);
}
#endif /* CONFIG_PM */
int pmb_bolt_mapping(unsigned long vaddr, phys_addr_t phys,
unsigned long size, pgprot_t prot)
{
struct pmb_entry *pmbp, *pmbe;
unsigned long orig_addr, orig_size;
unsigned long flags, pmb_flags;
int i, mapped;
if (size < SZ_16M)
return -EINVAL;
if (!pmb_addr_valid(vaddr, size))
return -EFAULT;
if (pmb_mapping_exists(vaddr, phys, size))
return 0;
orig_addr = vaddr;
orig_size = size;
flush_tlb_kernel_range(vaddr, vaddr + size);
pmb_flags = pgprot_to_pmb_flags(prot);
pmbp = NULL;
do {
for (i = mapped = 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)) {
pmb_unmap_entry(pmbp, mapped);
return PTR_ERR(pmbe);
}
raw_spin_lock_irqsave(&pmbe->lock, flags);
pmbe->size = pmb_sizes[i].size;
__set_pmb_entry(pmbe);
phys += pmbe->size;
vaddr += pmbe->size;
size -= pmbe->size;
/*
* Link adjacent entries that span multiple PMB
* entries for easier tear-down.
*/
if (likely(pmbp)) {
raw_spin_lock_nested(&pmbp->lock,
SINGLE_DEPTH_NESTING);
pmbp->link = pmbe;
raw_spin_unlock(&pmbp->lock);
}
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--;
mapped++;
raw_spin_unlock_irqrestore(&pmbe->lock, flags);
}
} while (size >= SZ_16M);
flush_cache_vmap(orig_addr, orig_addr + orig_size);
return 0;
}
void __iomem *pmb_remap_caller(phys_addr_t phys, unsigned long size,
pgprot_t prot, void *caller)
{
unsigned long vaddr;
phys_addr_t offset, last_addr;
phys_addr_t align_mask;
unsigned long aligned;
struct vm_struct *area;
int i, ret;
if (!pmb_iomapping_enabled)
return NULL;
/*
* Small mappings need to go through the TLB.
*/
if (size < SZ_16M)
return ERR_PTR(-EINVAL);
if (!pmb_prot_valid(prot))
return ERR_PTR(-EINVAL);
for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++)
if (size >= pmb_sizes[i].size)
break;
last_addr = phys + size;
align_mask = ~(pmb_sizes[i].size - 1);
offset = phys & ~align_mask;
phys &= align_mask;
aligned = ALIGN(last_addr, pmb_sizes[i].size) - phys;
/*
* XXX: This should really start from uncached_end, but this
* causes the MMU to reset, so for now we restrict it to the
* 0xb000...0xc000 range.
*/
area = __get_vm_area_caller(aligned, VM_IOREMAP, 0xb0000000,
P3SEG, caller);
if (!area)
return NULL;
area->phys_addr = phys;
vaddr = (unsigned long)area->addr;
ret = pmb_bolt_mapping(vaddr, phys, size, prot);
if (unlikely(ret != 0))
return ERR_PTR(ret);
return (void __iomem *)(offset + (char *)vaddr);
}
int pmb_unmap(void __iomem *addr)
{
struct pmb_entry *pmbe = NULL;
unsigned long vaddr = (unsigned long __force)addr;
int i, found = 0;
read_lock(&pmb_rwlock);
for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
if (test_bit(i, pmb_map)) {
pmbe = &pmb_entry_list[i];
if (pmbe->vpn == vaddr) {
found = 1;
break;
}
}
}
read_unlock(&pmb_rwlock);
if (found) {
pmb_unmap_entry(pmbe, NR_PMB_ENTRIES);
return 0;
}
return -EINVAL;
}
static void __pmb_unmap_entry(struct pmb_entry *pmbe, int depth)
{
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);
flush_cache_vunmap(pmbe->vpn, pmbe->vpn + pmbe->size);
pmbe = pmblink->link;
pmb_free(pmblink);
} while (pmbe && --depth);
}
static void pmb_unmap_entry(struct pmb_entry *pmbe, int depth)
{
unsigned long flags;
if (unlikely(!pmbe))
return;
write_lock_irqsave(&pmb_rwlock, flags);
__pmb_unmap_entry(pmbe, depth);
write_unlock_irqrestore(&pmb_rwlock, flags);
}
static void __init pmb_notify(void)
{
int i;
pr_info("PMB: boot mappings:\n");
read_lock(&pmb_rwlock);
for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
struct pmb_entry *pmbe;
if (!test_bit(i, pmb_map))
continue;
pmbe = &pmb_entry_list[i];
pr_info(" 0x%08lx -> 0x%08lx [ %4ldMB %2scached ]\n",
pmbe->vpn >> PAGE_SHIFT, pmbe->ppn >> PAGE_SHIFT,
pmbe->size >> 20, (pmbe->flags & PMB_C) ? "" : "un");
}
read_unlock(&pmb_rwlock);
}
/*
* 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.
*/
static void __init pmb_synchronize(void)
{
struct pmb_entry *pmbp = NULL;
int i, j;
/*
* 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;
unsigned long irqflags;
unsigned int size;
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.
*/
writel_uncached(addr_val & ~PMB_V, addr);
writel_uncached(data_val & ~PMB_V, data);
continue;
}
/*
* Update the caching attributes if necessary
*/
if (data_val & PMB_C) {
data_val &= ~PMB_CACHE_MASK;
data_val |= pmb_cache_flags();
writel_uncached(data_val, data);
}
size = data_val & PMB_SZ_MASK;
flags = size | (data_val & PMB_CACHE_MASK);
pmbe = pmb_alloc(vpn, ppn, flags, i);
if (IS_ERR(pmbe)) {
WARN_ON_ONCE(1);
continue;
}
raw_spin_lock_irqsave(&pmbe->lock, irqflags);
for (j = 0; j < ARRAY_SIZE(pmb_sizes); j++)
if (pmb_sizes[j].flag == size)
pmbe->size = pmb_sizes[j].size;
if (pmbp) {
raw_spin_lock_nested(&pmbp->lock, SINGLE_DEPTH_NESTING);
/*
* Compare the previous entry against the current one to
* see if the entries span a contiguous mapping. If so,
* setup the entry links accordingly. Compound mappings
* are later coalesced.
*/
if (pmb_can_merge(pmbp, pmbe))
pmbp->link = pmbe;
raw_spin_unlock(&pmbp->lock);
}
pmbp = pmbe;
raw_spin_unlock_irqrestore(&pmbe->lock, irqflags);
}
}
static void __init pmb_merge(struct pmb_entry *head)
{
unsigned long span, newsize;
struct pmb_entry *tail;
int i = 1, depth = 0;
span = newsize = head->size;
tail = head->link;
while (tail) {
span += tail->size;
if (pmb_size_valid(span)) {
newsize = span;
depth = i;
}
/* This is the end of the line.. */
if (!tail->link)
break;
tail = tail->link;
i++;
}
/*
* The merged page size must be valid.
*/
if (!depth || !pmb_size_valid(newsize))
return;
head->flags &= ~PMB_SZ_MASK;
head->flags |= pmb_size_to_flags(newsize);
head->size = newsize;
__pmb_unmap_entry(head->link, depth);
__set_pmb_entry(head);
}
static void __init pmb_coalesce(void)
{
unsigned long flags;
int i;
write_lock_irqsave(&pmb_rwlock, flags);
for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
struct pmb_entry *pmbe;
if (!test_bit(i, pmb_map))
continue;
pmbe = &pmb_entry_list[i];
/*
* We're only interested in compound mappings
*/
if (!pmbe->link)
continue;
/*
* Nothing to do if it already uses the largest possible
* page size.
*/
if (pmbe->size == SZ_512M)
continue;
pmb_merge(pmbe);
}
write_unlock_irqrestore(&pmb_rwlock, flags);
}
#ifdef CONFIG_UNCACHED_MAPPING
static void __init pmb_resize(void)
{
int i;
/*
* If the uncached mapping was constructed by the kernel, it will
* already be a reasonable size.
*/
if (uncached_size == SZ_16M)
return;
read_lock(&pmb_rwlock);
for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
struct pmb_entry *pmbe;
unsigned long flags;
if (!test_bit(i, pmb_map))
continue;
pmbe = &pmb_entry_list[i];
if (pmbe->vpn != uncached_start)
continue;
/*
* Found it, now resize it.
*/
raw_spin_lock_irqsave(&pmbe->lock, flags);
pmbe->size = SZ_16M;
pmbe->flags &= ~PMB_SZ_MASK;
pmbe->flags |= pmb_size_to_flags(pmbe->size);
uncached_resize(pmbe->size);
__set_pmb_entry(pmbe);
raw_spin_unlock_irqrestore(&pmbe->lock, flags);
}
read_unlock(&pmb_rwlock);
}
#endif
static int __init early_pmb(char *p)
{
if (!p)
return 0;
if (strstr(p, "iomap"))
pmb_iomapping_enabled = 1;
return 0;
}
early_param("pmb", early_pmb);
void __init pmb_init(void)
{
/* Synchronize software state */
pmb_synchronize();
/* Attempt to combine compound mappings */
pmb_coalesce();
#ifdef CONFIG_UNCACHED_MAPPING
/* Resize initial mappings, if necessary */
pmb_resize();
#endif
/* Log them */
pmb_notify();
writel_uncached(0, PMB_IRMCR);
/* Flush out the TLB */
local_flush_tlb_all();
ctrl_barrier();
}
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)
{
debugfs_create_file("pmb", S_IFREG | S_IRUGO, arch_debugfs_dir, NULL,
&pmb_debugfs_fops);
return 0;
}
subsys_initcall(pmb_debugfs_init);
#ifdef CONFIG_PM
static void pmb_syscore_resume(void)
{
struct pmb_entry *pmbe;
int i;
read_lock(&pmb_rwlock);
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);
}
}
read_unlock(&pmb_rwlock);
}
static struct syscore_ops pmb_syscore_ops = {
.resume = pmb_syscore_resume,
};
static int __init pmb_sysdev_init(void)
{
register_syscore_ops(&pmb_syscore_ops);
return 0;
}
subsys_initcall(pmb_sysdev_init);
#endif