#include <asm/io.h>
#ifdef CONFIG_X86_PAT
-int __read_mostly pat_wc_enabled = 1;
+int __read_mostly pat_enabled = 1;
-void __init pat_disable(char *reason)
+void __cpuinit pat_disable(char *reason)
{
- pat_wc_enabled = 0;
+ pat_enabled = 0;
printk(KERN_INFO "%s\n", reason);
}
early_param("nopat", nopat);
#endif
+
+static int debug_enable;
+static int __init pat_debug_setup(char *str)
+{
+ debug_enable = 1;
+ return 0;
+}
+__setup("debugpat", pat_debug_setup);
+
+#define dprintk(fmt, arg...) \
+ do { if (debug_enable) printk(KERN_INFO fmt, ##arg); } while (0)
+
+
static u64 __read_mostly boot_pat_state;
enum {
PAT_UC_MINUS = 7, /* UC, but can be overriden by MTRR */
};
-#define PAT(x,y) ((u64)PAT_ ## y << ((x)*8))
+#define PAT(x, y) ((u64)PAT_ ## y << ((x)*8))
void pat_init(void)
{
u64 pat;
- if (!pat_wc_enabled)
+ if (!pat_enabled)
return;
/* Paranoia check. */
- if (!cpu_has_pat) {
- printk(KERN_ERR "PAT enabled, but CPU feature cleared\n");
+ if (!cpu_has_pat && boot_pat_state) {
/*
- * Panic if this happens on the secondary CPU, and we
+ * If this happens we are on a secondary CPU, but
* switched to PAT on the boot CPU. We have no way to
* undo PAT.
- */
- BUG_ON(boot_pat_state);
+ */
+ printk(KERN_ERR "PAT enabled, "
+ "but not supported by secondary CPU\n");
+ BUG();
}
/* Set PWT to Write-Combining. All other bits stay the same */
* 011 UC _PAGE_CACHE_UC
* PAT bit unused
*/
- pat = PAT(0,WB) | PAT(1,WC) | PAT(2,UC_MINUS) | PAT(3,UC) |
- PAT(4,WB) | PAT(5,WC) | PAT(6,UC_MINUS) | PAT(7,UC);
+ pat = PAT(0, WB) | PAT(1, WC) | PAT(2, UC_MINUS) | PAT(3, UC) |
+ PAT(4, WB) | PAT(5, WC) | PAT(6, UC_MINUS) | PAT(7, UC);
/* Boot CPU check */
if (!boot_pat_state)
static char *cattr_name(unsigned long flags)
{
switch (flags & _PAGE_CACHE_MASK) {
- case _PAGE_CACHE_UC: return "uncached";
- case _PAGE_CACHE_UC_MINUS: return "uncached-minus";
- case _PAGE_CACHE_WB: return "write-back";
- case _PAGE_CACHE_WC: return "write-combining";
- default: return "broken";
+ case _PAGE_CACHE_UC: return "uncached";
+ case _PAGE_CACHE_UC_MINUS: return "uncached-minus";
+ case _PAGE_CACHE_WB: return "write-back";
+ case _PAGE_CACHE_WC: return "write-combining";
+ default: return "broken";
}
}
unsigned long pat_type;
u8 mtrr_type;
- mtrr_type = mtrr_type_lookup(start, end);
- if (mtrr_type == 0xFF) { /* MTRR not enabled */
- *ret_prot = prot;
- return 0;
- }
- if (mtrr_type == 0xFE) { /* MTRR match error */
- *ret_prot = _PAGE_CACHE_UC;
- return -1;
- }
- if (mtrr_type != MTRR_TYPE_UNCACHABLE &&
- mtrr_type != MTRR_TYPE_WRBACK &&
- mtrr_type != MTRR_TYPE_WRCOMB) { /* MTRR type unhandled */
- *ret_prot = _PAGE_CACHE_UC;
- return -1;
- }
-
pat_type = prot & _PAGE_CACHE_MASK;
prot &= (~_PAGE_CACHE_MASK);
- /* Currently doing intersection by hand. Optimize it later. */
+ /*
+ * We return the PAT request directly for types where PAT takes
+ * precedence with respect to MTRR and for UC_MINUS.
+ * Consistency checks with other PAT requests is done later
+ * while going through memtype list.
+ */
if (pat_type == _PAGE_CACHE_WC) {
*ret_prot = prot | _PAGE_CACHE_WC;
+ return 0;
} else if (pat_type == _PAGE_CACHE_UC_MINUS) {
*ret_prot = prot | _PAGE_CACHE_UC_MINUS;
- } else if (pat_type == _PAGE_CACHE_UC ||
- mtrr_type == MTRR_TYPE_UNCACHABLE) {
+ return 0;
+ } else if (pat_type == _PAGE_CACHE_UC) {
+ *ret_prot = prot | _PAGE_CACHE_UC;
+ return 0;
+ }
+
+ /*
+ * Look for MTRR hint to get the effective type in case where PAT
+ * request is for WB.
+ */
+ mtrr_type = mtrr_type_lookup(start, end);
+
+ if (mtrr_type == MTRR_TYPE_UNCACHABLE) {
*ret_prot = prot | _PAGE_CACHE_UC;
} else if (mtrr_type == MTRR_TYPE_WRCOMB) {
*ret_prot = prot | _PAGE_CACHE_WC;
unsigned long actual_type;
int err = 0;
- /* Only track when pat_wc_enabled */
- if (!pat_wc_enabled) {
+ /* Only track when pat_enabled */
+ if (!pat_enabled) {
/* This is identical to page table setting without PAT */
if (ret_type) {
if (req_type == -1) {
if (req_type == -1) {
/*
- * Special case where caller wants to inherit from mtrr or
- * existing pat mapping, defaulting to UC_MINUS in case of
- * no match.
+ * Call mtrr_lookup to get the type hint. This is an
+ * optimization for /dev/mem mmap'ers into WB memory (BIOS
+ * tools and ACPI tools). Use WB request for WB memory and use
+ * UC_MINUS otherwise.
*/
u8 mtrr_type = mtrr_type_lookup(start, end);
- if (mtrr_type == 0xFE) { /* MTRR match error */
- err = -1;
- }
if (mtrr_type == MTRR_TYPE_WRBACK) {
req_type = _PAGE_CACHE_WB;
struct memtype *saved_ptr;
if (parse->start >= end) {
- pr_debug("New Entry\n");
+ dprintk("New Entry\n");
list_add(&new_entry->nd, parse->nd.prev);
new_entry = NULL;
break;
break;
}
- pr_debug("Overlap at 0x%Lx-0x%Lx\n",
+ dprintk("Overlap at 0x%Lx-0x%Lx\n",
saved_ptr->start, saved_ptr->end);
/* No conflict. Go ahead and add this new entry */
list_add(&new_entry->nd, saved_ptr->nd.prev);
break;
}
- pr_debug(KERN_INFO "Overlap at 0x%Lx-0x%Lx\n",
+ dprintk("Overlap at 0x%Lx-0x%Lx\n",
saved_ptr->start, saved_ptr->end);
/* No conflict. Go ahead and add this new entry */
list_add(&new_entry->nd, &saved_ptr->nd);
if (new_entry) {
/* No conflict. Not yet added to the list. Add to the tail */
list_add_tail(&new_entry->nd, &memtype_list);
- pr_debug("New Entry\n");
+ dprintk("New Entry\n");
}
if (ret_type) {
- pr_debug(
+ dprintk(
"reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s, ret %s\n",
start, end, cattr_name(actual_type),
cattr_name(req_type), cattr_name(*ret_type));
} else {
- pr_debug(
+ dprintk(
"reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s\n",
start, end, cattr_name(actual_type),
cattr_name(req_type));
struct memtype *ml;
int err = -EINVAL;
- /* Only track when pat_wc_enabled */
- if (!pat_wc_enabled) {
+ /* Only track when pat_enabled */
+ if (!pat_enabled) {
return 0;
}
current->comm, current->pid, start, end);
}
- pr_debug("free_memtype request 0x%Lx-0x%Lx\n", start, end);
+ dprintk("free_memtype request 0x%Lx-0x%Lx\n", start, end);
return err;
}
* caching for the high addresses through the KEN pin, but
* we maintain the tradition of paranoia in this code.
*/
- if (!pat_wc_enabled &&
- ! ( test_bit(X86_FEATURE_MTRR, boot_cpu_data.x86_capability) ||
- test_bit(X86_FEATURE_K6_MTRR, boot_cpu_data.x86_capability) ||
- test_bit(X86_FEATURE_CYRIX_ARR, boot_cpu_data.x86_capability) ||
- test_bit(X86_FEATURE_CENTAUR_MCR, boot_cpu_data.x86_capability)) &&
- (pfn << PAGE_SHIFT) >= __pa(high_memory)) {
+ if (!pat_enabled &&
+ !(boot_cpu_has(X86_FEATURE_MTRR) ||
+ boot_cpu_has(X86_FEATURE_K6_MTRR) ||
+ boot_cpu_has(X86_FEATURE_CYRIX_ARR) ||
+ boot_cpu_has(X86_FEATURE_CENTAUR_MCR)) &&
+ (pfn << PAGE_SHIFT) >= __pa(high_memory)) {
flags = _PAGE_CACHE_UC;
}
#endif
return 0;
if (pfn <= max_pfn_mapped &&
- ioremap_change_attr((unsigned long)__va(offset), size, flags) < 0) {
+ ioremap_change_attr((unsigned long)__va(offset), size, flags) < 0) {
free_memtype(offset, offset + size);
printk(KERN_INFO
"%s:%d /dev/mem ioremap_change_attr failed %s for %Lx-%Lx\n",
free_memtype(addr, addr + size);
}
-
projects / deliverable / linux.git / blobdiff