1 files changed, 230 insertions, 240 deletions

diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 06b7a1c90fb8..2fe30916d4b6 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -12,6 +12,8 @@
 #include <linux/gfp.h>
 #include <linux/fs.h>
 #include <linux/bootmem.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
 
 #include <asm/msr.h>
 #include <asm/tlbflush.h>
@@ -26,11 +28,11 @@
 #include <asm/io.h>
 
 #ifdef CONFIG_X86_PAT
-int __read_mostly pat_wc_enabled = 1;
+int __read_mostly pat_enabled = 1;
 
 void __cpuinit pat_disable(char *reason)
 {
-        pat_wc_enabled = 0;
+        pat_enabled = 0;
         printk(KERN_INFO "%s\n", reason);
 }
 
@@ -42,6 +44,19 @@ static int __init nopat(char *str)
 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 {
@@ -53,24 +68,25 @@ 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 */
@@ -86,8 +102,8 @@ void pat_init(void)
          *      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)
@@ -103,11 +119,11 @@ void pat_init(void)
 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";
         }
 }
 
@@ -145,47 +161,50 @@ static DEFINE_SPINLOCK(memtype_lock); 	/* protects memtype list */
  * The intersection is based on "Effective Memory Type" tables in IA-32
  * SDM vol 3a
  */
-static int pat_x_mtrr_type(u64 start, u64 end, unsigned long prot,
-                                unsigned long *ret_prot)
+static unsigned long pat_x_mtrr_type(u64 start, u64 end, unsigned long req_type)
 {
-        unsigned long pat_type;
-        u8 mtrr_type;
-
-        pat_type = prot & _PAGE_CACHE_MASK;
-        prot &= (~_PAGE_CACHE_MASK);
-
-        /*
-         * 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;
-                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 (req_type == _PAGE_CACHE_WB) {
+                u8 mtrr_type;
+
+                mtrr_type = mtrr_type_lookup(start, end);
+                if (mtrr_type == MTRR_TYPE_UNCACHABLE)
+                        return _PAGE_CACHE_UC;
+                if (mtrr_type == MTRR_TYPE_WRCOMB)
+                        return _PAGE_CACHE_WC;
+        }
 
-        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;
-        } else {
-                *ret_prot = prot | _PAGE_CACHE_WB;
+        return req_type;
+}
+
+static int chk_conflict(struct memtype *new, struct memtype *entry,
+                        unsigned long *type)
+{
+        if (new->type != entry->type) {
+                if (type) {
+                        new->type = entry->type;
+                        *type = entry->type;
+                } else
+                        goto conflict;
         }
 
+         /* check overlaps with more than one entry in the list */
+        list_for_each_entry_continue(entry, &memtype_list, nd) {
+                if (new->end <= entry->start)
+                        break;
+                else if (new->type != entry->type)
+                        goto conflict;
+        }
         return 0;
+
+ conflict:
+        printk(KERN_INFO "%s:%d conflicting memory types "
+               "%Lx-%Lx %s<->%s\n", current->comm, current->pid, new->start,
+               new->end, cattr_name(new->type), cattr_name(entry->type));
+        return -EBUSY;
 }
 
 /*
@@ -198,37 +217,36 @@ static int pat_x_mtrr_type(u64 start, u64 end, unsigned long prot,
  * req_type will have a special case value '-1', when requester want to inherit
  * the memory type from mtrr (if WB), existing PAT, defaulting to UC_MINUS.
  *
- * If ret_type is NULL, function will return an error if it cannot reserve the
- * region with req_type. If ret_type is non-null, function will return
- * available type in ret_type in case of no error. In case of any error
+ * If new_type is NULL, function will return an error if it cannot reserve the
+ * region with req_type. If new_type is non-NULL, function will return
+ * available type in new_type in case of no error. In case of any error
  * it will return a negative return value.
  */
 int reserve_memtype(u64 start, u64 end, unsigned long req_type,
-                        unsigned long *ret_type)
+                        unsigned long *new_type)
 {
-        struct memtype *new_entry = NULL;
-        struct memtype *parse;
+        struct memtype *new, *entry;
         unsigned long actual_type;
+        struct list_head *where;
         int err = 0;
 
-        /* Only track when pat_wc_enabled */
-        if (!pat_wc_enabled) {
+        BUG_ON(start >= end); /* end is exclusive */
+
+        if (!pat_enabled) {
                 /* This is identical to page table setting without PAT */
-                if (ret_type) {
-                        if (req_type == -1) {
-                                *ret_type = _PAGE_CACHE_WB;
-                        } else {
-                                *ret_type = req_type;
-                        }
+                if (new_type) {
+                        if (req_type == -1)
+                                *new_type = _PAGE_CACHE_WB;
+                        else
+                                *new_type = req_type & _PAGE_CACHE_MASK;
                 }
                 return 0;
         }
 
         /* Low ISA region is always mapped WB in page table. No need to track */
-        if (start >= ISA_START_ADDRESS && (end - 1) <= ISA_END_ADDRESS) {
-                if (ret_type)
-                        *ret_type = _PAGE_CACHE_WB;
-
+        if (is_ISA_range(start, end - 1)) {
+                if (new_type)
+                        *new_type = _PAGE_CACHE_WB;
                 return 0;
         }
 
@@ -241,206 +259,92 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
                  */
                 u8 mtrr_type = mtrr_type_lookup(start, end);
 
-                if (mtrr_type == MTRR_TYPE_WRBACK) {
-                        req_type = _PAGE_CACHE_WB;
+                if (mtrr_type == MTRR_TYPE_WRBACK)
                         actual_type = _PAGE_CACHE_WB;
-                } else {
-                        req_type = _PAGE_CACHE_UC_MINUS;
+                else
                         actual_type = _PAGE_CACHE_UC_MINUS;
-                }
-        } else {
-                req_type &= _PAGE_CACHE_MASK;
-                err = pat_x_mtrr_type(start, end, req_type, &actual_type);
-        }
-
-        if (err) {
-                if (ret_type)
-                        *ret_type = actual_type;
+        } else
+                actual_type = pat_x_mtrr_type(start, end,
+                                              req_type & _PAGE_CACHE_MASK);
 
-                return -EINVAL;
-        }
-
-        new_entry  = kmalloc(sizeof(struct memtype), GFP_KERNEL);
-        if (!new_entry)
+        new  = kmalloc(sizeof(struct memtype), GFP_KERNEL);
+        if (!new)
                 return -ENOMEM;
 
-        new_entry->start = start;
-        new_entry->end = end;
-        new_entry->type = actual_type;
+        new->start = start;
+        new->end = end;
+        new->type = actual_type;
 
-        if (ret_type)
-                *ret_type = actual_type;
+        if (new_type)
+                *new_type = actual_type;
 
         spin_lock(&memtype_lock);
 
         /* Search for existing mapping that overlaps the current range */
-        list_for_each_entry(parse, &memtype_list, nd) {
-                struct memtype *saved_ptr;
-
-                if (parse->start >= end) {
-                        pr_debug("New Entry\n");
-                        list_add(&new_entry->nd, parse->nd.prev);
-                        new_entry = NULL;
+        where = NULL;
+        list_for_each_entry(entry, &memtype_list, nd) {
+                if (end <= entry->start) {
+                        where = entry->nd.prev;
                         break;
-                }
-
-                if (start <= parse->start && end >= parse->start) {
-                        if (actual_type != parse->type && ret_type) {
-                                actual_type = parse->type;
-                                *ret_type = actual_type;
-                                new_entry->type = actual_type;
+                } else if (start <= entry->start) { /* end > entry->start */
+                        err = chk_conflict(new, entry, new_type);
+                        if (!err) {
+                                dprintk("Overlap at 0x%Lx-0x%Lx\n",
+                                        entry->start, entry->end);
+                                where = entry->nd.prev;
                         }
-
-                        if (actual_type != parse->type) {
-                                printk(
-                KERN_INFO "%s:%d conflicting memory types %Lx-%Lx %s<->%s\n",
-                                        current->comm, current->pid,
-                                        start, end,
-                                        cattr_name(actual_type),
-                                        cattr_name(parse->type));
-                                err = -EBUSY;
-                                break;
-                        }
-
-                        saved_ptr = parse;
-                        /*
-                         * Check to see whether the request overlaps more
-                         * than one entry in the list
-                         */
-                        list_for_each_entry_continue(parse, &memtype_list, nd) {
-                                if (end <= parse->start) {
-                                        break;
-                                }
-
-                                if (actual_type != parse->type) {
-                                        printk(
-                KERN_INFO "%s:%d conflicting memory types %Lx-%Lx %s<->%s\n",
-                                                current->comm, current->pid,
-                                                start, end,
-                                                cattr_name(actual_type),
-                                                cattr_name(parse->type));
-                                        err = -EBUSY;
-                                        break;
-                                }
-                        }
-
-                        if (err) {
-                                break;
-                        }
-
-                        pr_debug("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);
-                        new_entry = NULL;
                         break;
-                }
-
-                if (start < parse->end) {
-                        if (actual_type != parse->type && ret_type) {
-                                actual_type = parse->type;
-                                *ret_type = actual_type;
-                                new_entry->type = actual_type;
-                        }
-
-                        if (actual_type != parse->type) {
-                                printk(
-                KERN_INFO "%s:%d conflicting memory types %Lx-%Lx %s<->%s\n",
-                                        current->comm, current->pid,
-                                        start, end,
-                                        cattr_name(actual_type),
-                                        cattr_name(parse->type));
-                                err = -EBUSY;
-                                break;
-                        }
-
-                        saved_ptr = parse;
-                        /*
-                         * Check to see whether the request overlaps more
-                         * than one entry in the list
-                         */
-                        list_for_each_entry_continue(parse, &memtype_list, nd) {
-                                if (end <= parse->start) {
-                                        break;
-                                }
-
-                                if (actual_type != parse->type) {
-                                        printk(
-                KERN_INFO "%s:%d conflicting memory types %Lx-%Lx %s<->%s\n",
-                                                current->comm, current->pid,
-                                                start, end,
-                                                cattr_name(actual_type),
-                                                cattr_name(parse->type));
-                                        err = -EBUSY;
-                                        break;
-                                }
+                } else if (start < entry->end) { /* start > entry->start */
+                        err = chk_conflict(new, entry, new_type);
+                        if (!err) {
+                                dprintk("Overlap at 0x%Lx-0x%Lx\n",
+                                        entry->start, entry->end);
+                                where = &entry->nd;
                         }
-
-                        if (err) {
-                                break;
-                        }
-
-                        pr_debug(KERN_INFO "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);
-                        new_entry = NULL;
                         break;
                 }
         }
 
         if (err) {
-                printk(KERN_INFO
-        "reserve_memtype failed 0x%Lx-0x%Lx, track %s, req %s\n",
-                        start, end, cattr_name(new_entry->type),
-                        cattr_name(req_type));
-                kfree(new_entry);
+                printk(KERN_INFO "reserve_memtype failed 0x%Lx-0x%Lx, "
+                       "track %s, req %s\n",
+                       start, end, cattr_name(new->type), cattr_name(req_type));
+                kfree(new);
                 spin_unlock(&memtype_lock);
                 return err;
         }
 
-        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");
-        }
-
-        if (ret_type) {
-                pr_debug(
-        "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(
-        "reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s\n",
-                        start, end, cattr_name(actual_type),
-                        cattr_name(req_type));
-        }
+        if (where)
+                list_add(&new->nd, where);
+        else
+                list_add_tail(&new->nd, &memtype_list);
 
         spin_unlock(&memtype_lock);
+
+        dprintk("reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s, ret %s\n",
+                start, end, cattr_name(new->type), cattr_name(req_type),
+                new_type ? cattr_name(*new_type) : "-");
+
         return err;
 }
 
 int free_memtype(u64 start, u64 end)
 {
-        struct memtype *ml;
+        struct memtype *entry;
         int err = -EINVAL;
 
-        /* Only track when pat_wc_enabled */
-        if (!pat_wc_enabled) {
+        if (!pat_enabled)
                 return 0;
-        }
 
         /* Low ISA region is always mapped WB. No need to track */
-        if (start >= ISA_START_ADDRESS && end <= ISA_END_ADDRESS) {
+        if (is_ISA_range(start, end - 1))
                 return 0;
-        }
 
         spin_lock(&memtype_lock);
-        list_for_each_entry(ml, &memtype_list, nd) {
-                if (ml->start == start && ml->end == end) {
-                        list_del(&ml->nd);
-                        kfree(ml);
+        list_for_each_entry(entry, &memtype_list, nd) {
+                if (entry->start == start && entry->end == end) {
+                        list_del(&entry->nd);
+                        kfree(entry);
                         err = 0;
                         break;
                 }
@@ -452,7 +356,7 @@ int free_memtype(u64 start, u64 end)
                         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;
 }
 
@@ -471,8 +375,8 @@ pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
         return vma_prot;
 }
 
-#ifdef CONFIG_NONPROMISC_DEVMEM
-/* This check is done in drivers/char/mem.c in case of NONPROMISC_DEVMEM*/
+#ifdef CONFIG_STRICT_DEVMEM
+/* This check is done in drivers/char/mem.c in case of STRICT_DEVMEM*/
 static inline int range_is_allowed(unsigned long pfn, unsigned long size)
 {
         return 1;
@@ -496,7 +400,7 @@ static inline int range_is_allowed(unsigned long pfn, unsigned long size)
         }
         return 1;
 }
-#endif /* CONFIG_NONPROMISC_DEVMEM */
+#endif /* CONFIG_STRICT_DEVMEM */
 
 int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
                                 unsigned long size, pgprot_t *vma_prot)
@@ -521,12 +425,12 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
          * 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
@@ -547,8 +451,9 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
         if (retval < 0)
                 return 0;
 
-        if (pfn <= max_pfn_mapped &&
-            ioremap_change_attr((unsigned long)__va(offset), size, flags) < 0) {
+        if (((pfn < max_low_pfn_mapped) ||
+             (pfn >= (1UL<<(32 - PAGE_SHIFT)) && pfn < max_pfn_mapped)) &&
+            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",
@@ -587,3 +492,88 @@ void unmap_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot)
         free_memtype(addr, addr + size);
 }
 
+#if defined(CONFIG_DEBUG_FS)
+
+/* get Nth element of the linked list */
+static struct memtype *memtype_get_idx(loff_t pos)
+{
+        struct memtype *list_node, *print_entry;
+        int i = 1;
+
+        print_entry  = kmalloc(sizeof(struct memtype), GFP_KERNEL);
+        if (!print_entry)
+                return NULL;
+
+        spin_lock(&memtype_lock);
+        list_for_each_entry(list_node, &memtype_list, nd) {
+                if (pos == i) {
+                        *print_entry = *list_node;
+                        spin_unlock(&memtype_lock);
+                        return print_entry;
+                }
+                ++i;
+        }
+        spin_unlock(&memtype_lock);
+        kfree(print_entry);
+        return NULL;
+}
+
+static void *memtype_seq_start(struct seq_file *seq, loff_t *pos)
+{
+        if (*pos == 0) {
+                ++*pos;
+                seq_printf(seq, "PAT memtype list:\n");
+        }
+
+        return memtype_get_idx(*pos);
+}
+
+static void *memtype_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+        ++*pos;
+        return memtype_get_idx(*pos);
+}
+
+static void memtype_seq_stop(struct seq_file *seq, void *v)
+{
+}
+
+static int memtype_seq_show(struct seq_file *seq, void *v)
+{
+        struct memtype *print_entry = (struct memtype *)v;
+
+        seq_printf(seq, "%s @ 0x%Lx-0x%Lx\n", cattr_name(print_entry->type),
+                        print_entry->start, print_entry->end);
+        kfree(print_entry);
+        return 0;
+}
+
+static struct seq_operations memtype_seq_ops = {
+        .start = memtype_seq_start,
+        .next  = memtype_seq_next,
+        .stop  = memtype_seq_stop,
+        .show  = memtype_seq_show,
+};
+
+static int memtype_seq_open(struct inode *inode, struct file *file)
+{
+        return seq_open(file, &memtype_seq_ops);
+}
+
+static const struct file_operations memtype_fops = {
+        .open    = memtype_seq_open,
+        .read    = seq_read,
+        .llseek  = seq_lseek,
+        .release = seq_release,
+};
+
+static int __init pat_memtype_list_init(void)
+{
+        debugfs_create_file("pat_memtype_list", S_IRUSR, arch_debugfs_dir,
+                                NULL, &memtype_fops);
+        return 0;
+}
+
+late_initcall(pat_memtype_list_init);
+
+#endif /* CONFIG_DEBUG_FS */