* Loosely based on earlier PAT patchset from Eric Biederman and Andi Kleen.
*/
-#include <linux/mm.h>
+#include <linux/seq_file.h>
+#include <linux/bootmem.h>
+#include <linux/debugfs.h>
#include <linux/kernel.h>
-#include <linux/gfp.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
#include <linux/fs.h>
-#include <linux/bootmem.h>
+#include <linux/rbtree.h>
-#include <asm/msr.h>
-#include <asm/tlbflush.h>
+#include <asm/cacheflush.h>
#include <asm/processor.h>
-#include <asm/page.h>
+#include <asm/tlbflush.h>
+#include <asm/x86_init.h>
#include <asm/pgtable.h>
-#include <asm/pat.h>
-#include <asm/e820.h>
-#include <asm/cacheflush.h>
#include <asm/fcntl.h>
+#include <asm/e820.h>
#include <asm/mtrr.h>
+#include <asm/page.h>
+#include <asm/msr.h>
+#include <asm/pat.h>
#include <asm/io.h>
#ifdef CONFIG_X86_PAT
int __read_mostly pat_enabled = 1;
-void __cpuinit pat_disable(char *reason)
+static inline void pat_disable(const char *reason)
{
pat_enabled = 0;
printk(KERN_INFO "%s\n", reason);
return 0;
}
early_param("nopat", nopat);
+#else
+static inline void pat_disable(const char *reason)
+{
+ (void)reason;
+}
#endif
static int debug_enable;
+
static int __init pat_debug_setup(char *str)
{
debug_enable = 1;
void pat_init(void)
{
u64 pat;
+ bool boot_cpu = !boot_pat_state;
if (!pat_enabled)
return;
- /* Paranoia check. */
- if (!cpu_has_pat && boot_pat_state) {
- /*
- * If this happens we are on a secondary CPU, but
- * switched to PAT on the boot CPU. We have no way to
- * undo PAT.
- */
- printk(KERN_ERR "PAT enabled, "
- "but not supported by secondary CPU\n");
- BUG();
+ if (!cpu_has_pat) {
+ if (!boot_pat_state) {
+ pat_disable("PAT not supported by CPU.");
+ return;
+ } else {
+ /*
+ * If this happens we are on a secondary CPU, but
+ * switched to PAT on the boot CPU. We have no way to
+ * undo PAT.
+ */
+ printk(KERN_ERR "PAT enabled, "
+ "but not supported by secondary CPU\n");
+ BUG();
+ }
}
/* Set PWT to Write-Combining. All other bits stay the same */
rdmsrl(MSR_IA32_CR_PAT, boot_pat_state);
wrmsrl(MSR_IA32_CR_PAT, pat);
- printk(KERN_INFO "x86 PAT enabled: cpu %d, old 0x%Lx, new 0x%Lx\n",
- smp_processor_id(), boot_pat_state, pat);
+
+ if (boot_cpu)
+ printk(KERN_INFO "x86 PAT enabled: cpu %d, old 0x%Lx, new 0x%Lx\n",
+ smp_processor_id(), boot_pat_state, pat);
}
#undef PAT
* areas). All the aliases have the same cache attributes of course.
* Zero attributes are represented as holes.
*
- * Currently the data structure is a list because the number of mappings
- * are expected to be relatively small. If this should be a problem
- * it could be changed to a rbtree or similar.
+ * The data structure is a list that is also organized as an rbtree
+ * sorted on the start address of memtype range.
*
- * memtype_lock protects the whole list.
+ * memtype_lock protects both the linear list and rbtree.
*/
struct memtype {
- u64 start;
- u64 end;
- unsigned long type;
- struct list_head nd;
+ u64 start;
+ u64 end;
+ unsigned long type;
+ struct list_head nd;
+ struct rb_node rb;
};
+static struct rb_root memtype_rbroot = RB_ROOT;
static LIST_HEAD(memtype_list);
-static DEFINE_SPINLOCK(memtype_lock); /* protects memtype list */
+static DEFINE_SPINLOCK(memtype_lock); /* protects memtype list */
+
+static struct memtype *memtype_rb_search(struct rb_root *root, u64 start)
+{
+ struct rb_node *node = root->rb_node;
+ struct memtype *last_lower = NULL;
+
+ while (node) {
+ struct memtype *data = container_of(node, struct memtype, rb);
+
+ if (data->start < start) {
+ last_lower = data;
+ node = node->rb_right;
+ } else if (data->start > start) {
+ node = node->rb_left;
+ } else
+ return data;
+ }
+
+ /* Will return NULL if there is no entry with its start <= start */
+ return last_lower;
+}
+
+static void memtype_rb_insert(struct rb_root *root, struct memtype *data)
+{
+ struct rb_node **new = &(root->rb_node);
+ struct rb_node *parent = NULL;
+
+ while (*new) {
+ struct memtype *this = container_of(*new, struct memtype, rb);
+
+ parent = *new;
+ if (data->start <= this->start)
+ new = &((*new)->rb_left);
+ else if (data->start > this->start)
+ new = &((*new)->rb_right);
+ }
+
+ rb_link_node(&data->rb, parent, new);
+ rb_insert_color(&data->rb, root);
+}
/*
* Does intersection of PAT memory type and MTRR memory type and returns
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_WRBACK)
+ return _PAGE_CACHE_UC_MINUS;
+
+ return _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;
+}
+
+static int pat_pagerange_is_ram(unsigned long start, unsigned long end)
+{
+ int ram_page = 0, not_rampage = 0;
+ unsigned long page_nr;
+
+ for (page_nr = (start >> PAGE_SHIFT); page_nr < (end >> PAGE_SHIFT);
+ ++page_nr) {
+ /*
+ * For legacy reasons, physical address range in the legacy ISA
+ * region is tracked as non-RAM. This will allow users of
+ * /dev/mem to map portions of legacy ISA region, even when
+ * some of those portions are listed(or not even listed) with
+ * different e820 types(RAM/reserved/..)
+ */
+ if (page_nr >= (ISA_END_ADDRESS >> PAGE_SHIFT) &&
+ page_is_ram(page_nr))
+ ram_page = 1;
+ else
+ not_rampage = 1;
+
+ if (ram_page == not_rampage)
+ return -1;
+ }
+
+ return ram_page;
+}
+
+/*
+ * For RAM pages, we use page flags to mark the pages with appropriate type.
+ * Here we do two pass:
+ * - Find the memtype of all the pages in the range, look for any conflicts
+ * - In case of no conflicts, set the new memtype for pages in the range
+ *
+ * Caller must hold memtype_lock for atomicity.
+ */
+static int reserve_ram_pages_type(u64 start, u64 end, unsigned long req_type,
+ unsigned long *new_type)
+{
+ struct page *page;
+ u64 pfn;
+
+ if (req_type == _PAGE_CACHE_UC) {
+ /* We do not support strong UC */
+ WARN_ON_ONCE(1);
+ req_type = _PAGE_CACHE_UC_MINUS;
+ }
+
+ for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) {
+ unsigned long type;
+
+ page = pfn_to_page(pfn);
+ type = get_page_memtype(page);
+ if (type != -1) {
+ printk(KERN_INFO "reserve_ram_pages_type failed "
+ "0x%Lx-0x%Lx, track 0x%lx, req 0x%lx\n",
+ start, end, type, req_type);
+ if (new_type)
+ *new_type = type;
+
+ return -EBUSY;
+ }
+ }
+
+ if (new_type)
+ *new_type = req_type;
+
+ for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) {
+ page = pfn_to_page(pfn);
+ set_page_memtype(page, req_type);
+ }
+ return 0;
+}
+
+static int free_ram_pages_type(u64 start, u64 end)
+{
+ struct page *page;
+ u64 pfn;
+
+ for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) {
+ page = pfn_to_page(pfn);
+ set_page_memtype(page, -1);
+ }
+ return 0;
+}
+
/*
* req_type typically has one of the:
* - _PAGE_CACHE_WB
* - _PAGE_CACHE_UC_MINUS
* - _PAGE_CACHE_UC
*
- * 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 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 *new_type)
+ unsigned long *new_type)
{
struct memtype *new, *entry;
unsigned long actual_type;
+ struct list_head *where;
+ int is_range_ram;
int err = 0;
- /* Only track when pat_enabled */
+ BUG_ON(start >= end); /* end is exclusive */
+
if (!pat_enabled) {
/* This is identical to page table setting without PAT */
if (new_type) {
- if (req_type == -1)
- *new_type = _PAGE_CACHE_WB;
+ if (req_type == _PAGE_CACHE_WC)
+ *new_type = _PAGE_CACHE_UC_MINUS;
else
*new_type = req_type & _PAGE_CACHE_MASK;
}
}
/* Low ISA region is always mapped WB in page table. No need to track */
- if (is_ISA_range(start, end - 1)) {
+ if (x86_platform.is_untracked_pat_range(start, end)) {
if (new_type)
*new_type = _PAGE_CACHE_WB;
return 0;
}
- if (req_type == -1) {
- /*
- * 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);
+ /*
+ * 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.
+ */
+ actual_type = pat_x_mtrr_type(start, end, req_type & _PAGE_CACHE_MASK);
- if (mtrr_type == MTRR_TYPE_WRBACK) {
- req_type = _PAGE_CACHE_WB;
- actual_type = _PAGE_CACHE_WB;
- } else {
- req_type = _PAGE_CACHE_UC_MINUS;
- actual_type = _PAGE_CACHE_UC_MINUS;
- }
- } else {
- req_type &= _PAGE_CACHE_MASK;
- actual_type = pat_x_mtrr_type(start, end, req_type);
+ if (new_type)
+ *new_type = actual_type;
+
+ is_range_ram = pat_pagerange_is_ram(start, end);
+ if (is_range_ram == 1) {
+
+ spin_lock(&memtype_lock);
+ err = reserve_ram_pages_type(start, end, req_type, new_type);
+ spin_unlock(&memtype_lock);
+
+ return err;
+ } else if (is_range_ram < 0) {
+ return -EINVAL;
}
new = kmalloc(sizeof(struct memtype), GFP_KERNEL);
if (!new)
return -ENOMEM;
- new->start = start;
- new->end = end;
- new->type = actual_type;
-
- if (new_type)
- *new_type = actual_type;
+ new->start = start;
+ new->end = end;
+ new->type = actual_type;
spin_lock(&memtype_lock);
/* Search for existing mapping that overlaps the current range */
+ where = NULL;
list_for_each_entry(entry, &memtype_list, nd) {
- struct memtype *saved_ptr;
-
- if (entry->start >= end) {
- dprintk("New Entry\n");
- list_add(&new->nd, entry->nd.prev);
- new = NULL;
+ if (end <= entry->start) {
+ where = entry->nd.prev;
break;
- }
-
- if (start <= entry->start && end >= entry->start) {
- if (actual_type != entry->type && new_type) {
- actual_type = entry->type;
- *new_type = actual_type;
- new->type = actual_type;
- }
-
- if (actual_type != entry->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(entry->type));
- err = -EBUSY;
- break;
- }
-
- saved_ptr = entry;
- /*
- * Check to see whether the request overlaps more
- * than one entry in the list
- */
- list_for_each_entry_continue(entry, &memtype_list, nd) {
- if (end <= entry->start) {
- break;
- }
-
- if (actual_type != entry->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(entry->type));
- err = -EBUSY;
- break;
- }
- }
-
- if (err) {
- break;
+ } 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;
}
-
- 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->nd, saved_ptr->nd.prev);
- new = NULL;
break;
- }
-
- if (start < entry->end) {
- if (actual_type != entry->type && new_type) {
- actual_type = entry->type;
- *new_type = actual_type;
- new->type = actual_type;
- }
-
- if (actual_type != entry->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(entry->type));
- err = -EBUSY;
- break;
- }
-
- saved_ptr = entry;
- /*
- * Check to see whether the request overlaps more
- * than one entry in the list
- */
- list_for_each_entry_continue(entry, &memtype_list, nd) {
- if (end <= entry->start) {
- 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);
+
+ /*
+ * Move to right position in the linked
+ * list to add this new entry
+ */
+ list_for_each_entry_continue(entry,
+ &memtype_list, nd) {
+ if (start <= entry->start) {
+ where = entry->nd.prev;
+ break;
+ }
}
-
- if (actual_type != entry->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(entry->type));
- err = -EBUSY;
- break;
- }
- }
-
- if (err) {
- break;
}
-
- 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->nd, &saved_ptr->nd);
- new = NULL;
break;
}
}
if (err) {
- 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));
+ 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) {
- /* No conflict. Not yet added to the list. Add to the tail */
+ if (where)
+ list_add(&new->nd, where);
+ else
list_add_tail(&new->nd, &memtype_list);
- dprintk("New Entry\n");
- }
- if (new_type) {
- 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(*new_type));
- } else {
- dprintk(
- "reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s\n",
- start, end, cattr_name(actual_type),
- cattr_name(req_type));
- }
+ memtype_rb_insert(&memtype_rbroot, new);
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 *entry;
+ struct memtype *entry, *saved_entry;
int err = -EINVAL;
+ int is_range_ram;
- /* Only track when pat_enabled */
- if (!pat_enabled) {
+ if (!pat_enabled)
return 0;
- }
/* Low ISA region is always mapped WB. No need to track */
- if (is_ISA_range(start, end - 1))
+ if (x86_platform.is_untracked_pat_range(start, end))
return 0;
+ is_range_ram = pat_pagerange_is_ram(start, end);
+ if (is_range_ram == 1) {
+
+ spin_lock(&memtype_lock);
+ err = free_ram_pages_type(start, end);
+ spin_unlock(&memtype_lock);
+
+ return err;
+ } else if (is_range_ram < 0) {
+ return -EINVAL;
+ }
+
spin_lock(&memtype_lock);
- list_for_each_entry(entry, &memtype_list, nd) {
+
+ entry = memtype_rb_search(&memtype_rbroot, start);
+ if (unlikely(entry == NULL))
+ goto unlock_ret;
+
+ /*
+ * Saved entry points to an entry with start same or less than what
+ * we searched for. Now go through the list in both directions to look
+ * for the entry that matches with both start and end, with list stored
+ * in sorted start address
+ */
+ saved_entry = entry;
+ list_for_each_entry_from(entry, &memtype_list, nd) {
if (entry->start == start && entry->end == end) {
+ rb_erase(&entry->rb, &memtype_rbroot);
list_del(&entry->nd);
kfree(entry);
err = 0;
break;
+ } else if (entry->start > start) {
+ break;
+ }
+ }
+
+ if (!err)
+ goto unlock_ret;
+
+ entry = saved_entry;
+ list_for_each_entry_reverse(entry, &memtype_list, nd) {
+ if (entry->start == start && entry->end == end) {
+ rb_erase(&entry->rb, &memtype_rbroot);
+ list_del(&entry->nd);
+ kfree(entry);
+ err = 0;
+ break;
+ } else if (entry->start < start) {
+ break;
}
}
+unlock_ret:
spin_unlock(&memtype_lock);
if (err) {
}
dprintk("free_memtype request 0x%Lx-0x%Lx\n", start, end);
+
return err;
}
-/*
- * /dev/mem mmap interface. The memtype used for mapping varies:
- * - Use UC for mappings with O_SYNC flag
- * - Without O_SYNC flag, if there is any conflict in reserve_memtype,
- * inherit the memtype from existing mapping.
- * - Else use UC_MINUS memtype (for backward compatibility with existing
- * X drivers.
+/**
+ * lookup_memtype - Looksup the memory type for a physical address
+ * @paddr: physical address of which memory type needs to be looked up
+ *
+ * Only to be called when PAT is enabled
+ *
+ * Returns _PAGE_CACHE_WB, _PAGE_CACHE_WC, _PAGE_CACHE_UC_MINUS or
+ * _PAGE_CACHE_UC
+ */
+static unsigned long lookup_memtype(u64 paddr)
+{
+ int rettype = _PAGE_CACHE_WB;
+ struct memtype *entry;
+
+ if (x86_platform.is_untracked_pat_range(paddr, paddr + PAGE_SIZE))
+ return rettype;
+
+ if (pat_pagerange_is_ram(paddr, paddr + PAGE_SIZE)) {
+ struct page *page;
+ spin_lock(&memtype_lock);
+ page = pfn_to_page(paddr >> PAGE_SHIFT);
+ rettype = get_page_memtype(page);
+ spin_unlock(&memtype_lock);
+ /*
+ * -1 from get_page_memtype() implies RAM page is in its
+ * default state and not reserved, and hence of type WB
+ */
+ if (rettype == -1)
+ rettype = _PAGE_CACHE_WB;
+
+ return rettype;
+ }
+
+ spin_lock(&memtype_lock);
+
+ entry = memtype_rb_search(&memtype_rbroot, paddr);
+ if (entry != NULL)
+ rettype = entry->type;
+ else
+ rettype = _PAGE_CACHE_UC_MINUS;
+
+ spin_unlock(&memtype_lock);
+ return rettype;
+}
+
+/**
+ * io_reserve_memtype - Request a memory type mapping for a region of memory
+ * @start: start (physical address) of the region
+ * @end: end (physical address) of the region
+ * @type: A pointer to memtype, with requested type. On success, requested
+ * or any other compatible type that was available for the region is returned
+ *
+ * On success, returns 0
+ * On failure, returns non-zero
+ */
+int io_reserve_memtype(resource_size_t start, resource_size_t end,
+ unsigned long *type)
+{
+ resource_size_t size = end - start;
+ unsigned long req_type = *type;
+ unsigned long new_type;
+ int ret;
+
+ WARN_ON_ONCE(iomem_map_sanity_check(start, size));
+
+ ret = reserve_memtype(start, end, req_type, &new_type);
+ if (ret)
+ goto out_err;
+
+ if (!is_new_memtype_allowed(start, size, req_type, new_type))
+ goto out_free;
+
+ if (kernel_map_sync_memtype(start, size, new_type) < 0)
+ goto out_free;
+
+ *type = new_type;
+ return 0;
+
+out_free:
+ free_memtype(start, end);
+ ret = -EBUSY;
+out_err:
+ return ret;
+}
+
+/**
+ * io_free_memtype - Release a memory type mapping for a region of memory
+ * @start: start (physical address) of the region
+ * @end: end (physical address) of the region
*/
+void io_free_memtype(resource_size_t start, resource_size_t end)
+{
+ free_memtype(start, end);
+}
+
pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t vma_prot)
{
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;
}
#else
+/* This check is needed to avoid cache aliasing when PAT is enabled */
static inline int range_is_allowed(unsigned long pfn, unsigned long size)
{
u64 from = ((u64)pfn) << PAGE_SHIFT;
u64 to = from + size;
u64 cursor = from;
+ if (!pat_enabled)
+ return 1;
+
while (cursor < to) {
if (!devmem_is_allowed(pfn)) {
printk(KERN_INFO
}
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)
{
- u64 offset = ((u64) pfn) << PAGE_SHIFT;
- unsigned long flags = _PAGE_CACHE_UC_MINUS;
- int retval;
+ unsigned long flags = _PAGE_CACHE_WB;
if (!range_is_allowed(pfn, size))
return 0;
- if (file->f_flags & O_SYNC) {
- flags = _PAGE_CACHE_UC;
- }
+ if (file->f_flags & O_DSYNC)
+ flags = _PAGE_CACHE_UC_MINUS;
#ifdef CONFIG_X86_32
/*
}
#endif
- /*
- * With O_SYNC, we can only take UC mapping. Fail if we cannot.
- * Without O_SYNC, we want to get
- * - WB for WB-able memory and no other conflicting mappings
- * - UC_MINUS for non-WB-able memory with no other conflicting mappings
- * - Inherit from confliting mappings otherwise
- */
- if (flags != _PAGE_CACHE_UC_MINUS) {
- retval = reserve_memtype(offset, offset + size, flags, NULL);
- } else {
- retval = reserve_memtype(offset, offset + size, -1, &flags);
- }
+ *vma_prot = __pgprot((pgprot_val(*vma_prot) & ~_PAGE_CACHE_MASK) |
+ flags);
+ return 1;
+}
+
+/*
+ * Change the memory type for the physial address range in kernel identity
+ * mapping space if that range is a part of identity map.
+ */
+int kernel_map_sync_memtype(u64 base, unsigned long size, unsigned long flags)
+{
+ unsigned long id_sz;
- if (retval < 0)
+ if (base >= __pa(high_memory))
return 0;
- if (pfn <= max_pfn_mapped &&
- ioremap_change_attr((unsigned long)__va(offset), size, flags) < 0) {
- free_memtype(offset, offset + size);
+ id_sz = (__pa(high_memory) < base + size) ?
+ __pa(high_memory) - base :
+ size;
+
+ if (ioremap_change_attr((unsigned long)__va(base), id_sz, flags) < 0) {
printk(KERN_INFO
- "%s:%d /dev/mem ioremap_change_attr failed %s for %Lx-%Lx\n",
+ "%s:%d ioremap_change_attr failed %s "
+ "for %Lx-%Lx\n",
current->comm, current->pid,
cattr_name(flags),
- offset, (unsigned long long)(offset + size));
+ base, (unsigned long long)(base + size));
+ return -EINVAL;
+ }
+ return 0;
+}
+
+/*
+ * Internal interface to reserve a range of physical memory with prot.
+ * Reserved non RAM regions only and after successful reserve_memtype,
+ * this func also keeps identity mapping (if any) in sync with this new prot.
+ */
+static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot,
+ int strict_prot)
+{
+ int is_ram = 0;
+ int ret;
+ unsigned long want_flags = (pgprot_val(*vma_prot) & _PAGE_CACHE_MASK);
+ unsigned long flags = want_flags;
+
+ is_ram = pat_pagerange_is_ram(paddr, paddr + size);
+
+ /*
+ * reserve_pfn_range() for RAM pages. We do not refcount to keep
+ * track of number of mappings of RAM pages. We can assert that
+ * the type requested matches the type of first page in the range.
+ */
+ if (is_ram) {
+ if (!pat_enabled)
+ return 0;
+
+ flags = lookup_memtype(paddr);
+ if (want_flags != flags) {
+ printk(KERN_WARNING
+ "%s:%d map pfn RAM range req %s for %Lx-%Lx, got %s\n",
+ current->comm, current->pid,
+ cattr_name(want_flags),
+ (unsigned long long)paddr,
+ (unsigned long long)(paddr + size),
+ cattr_name(flags));
+ *vma_prot = __pgprot((pgprot_val(*vma_prot) &
+ (~_PAGE_CACHE_MASK)) |
+ flags);
+ }
return 0;
}
- *vma_prot = __pgprot((pgprot_val(*vma_prot) & ~_PAGE_CACHE_MASK) |
- flags);
- return 1;
+ ret = reserve_memtype(paddr, paddr + size, want_flags, &flags);
+ if (ret)
+ return ret;
+
+ if (flags != want_flags) {
+ if (strict_prot ||
+ !is_new_memtype_allowed(paddr, size, want_flags, flags)) {
+ free_memtype(paddr, paddr + size);
+ printk(KERN_ERR "%s:%d map pfn expected mapping type %s"
+ " for %Lx-%Lx, got %s\n",
+ current->comm, current->pid,
+ cattr_name(want_flags),
+ (unsigned long long)paddr,
+ (unsigned long long)(paddr + size),
+ cattr_name(flags));
+ return -EINVAL;
+ }
+ /*
+ * We allow returning different type than the one requested in
+ * non strict case.
+ */
+ *vma_prot = __pgprot((pgprot_val(*vma_prot) &
+ (~_PAGE_CACHE_MASK)) |
+ flags);
+ }
+
+ if (kernel_map_sync_memtype(paddr, size, flags) < 0) {
+ free_memtype(paddr, paddr + size);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+/*
+ * Internal interface to free a range of physical memory.
+ * Frees non RAM regions only.
+ */
+static void free_pfn_range(u64 paddr, unsigned long size)
+{
+ int is_ram;
+
+ is_ram = pat_pagerange_is_ram(paddr, paddr + size);
+ if (is_ram == 0)
+ free_memtype(paddr, paddr + size);
+}
+
+/*
+ * track_pfn_vma_copy is called when vma that is covering the pfnmap gets
+ * copied through copy_page_range().
+ *
+ * If the vma has a linear pfn mapping for the entire range, we get the prot
+ * from pte and reserve the entire vma range with single reserve_pfn_range call.
+ */
+int track_pfn_vma_copy(struct vm_area_struct *vma)
+{
+ resource_size_t paddr;
+ unsigned long prot;
+ unsigned long vma_size = vma->vm_end - vma->vm_start;
+ pgprot_t pgprot;
+
+ if (is_linear_pfn_mapping(vma)) {
+ /*
+ * reserve the whole chunk covered by vma. We need the
+ * starting address and protection from pte.
+ */
+ if (follow_phys(vma, vma->vm_start, 0, &prot, &paddr)) {
+ WARN_ON_ONCE(1);
+ return -EINVAL;
+ }
+ pgprot = __pgprot(prot);
+ return reserve_pfn_range(paddr, vma_size, &pgprot, 1);
+ }
+
+ return 0;
}
-void map_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot)
+/*
+ * track_pfn_vma_new is called when a _new_ pfn mapping is being established
+ * for physical range indicated by pfn and size.
+ *
+ * prot is passed in as a parameter for the new mapping. If the vma has a
+ * linear pfn mapping for the entire range reserve the entire vma range with
+ * single reserve_pfn_range call.
+ */
+int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot,
+ unsigned long pfn, unsigned long size)
{
- u64 addr = (u64)pfn << PAGE_SHIFT;
unsigned long flags;
- unsigned long want_flags = (pgprot_val(vma_prot) & _PAGE_CACHE_MASK);
+ resource_size_t paddr;
+ unsigned long vma_size = vma->vm_end - vma->vm_start;
- reserve_memtype(addr, addr + size, want_flags, &flags);
- if (flags != want_flags) {
- printk(KERN_INFO
- "%s:%d /dev/mem expected mapping type %s for %Lx-%Lx, got %s\n",
- current->comm, current->pid,
- cattr_name(want_flags),
- addr, (unsigned long long)(addr + size),
- cattr_name(flags));
+ if (is_linear_pfn_mapping(vma)) {
+ /* reserve the whole chunk starting from vm_pgoff */
+ paddr = (resource_size_t)vma->vm_pgoff << PAGE_SHIFT;
+ return reserve_pfn_range(paddr, vma_size, prot, 0);
}
+
+ if (!pat_enabled)
+ return 0;
+
+ /* for vm_insert_pfn and friends, we set prot based on lookup */
+ flags = lookup_memtype(pfn << PAGE_SHIFT);
+ *prot = __pgprot((pgprot_val(vma->vm_page_prot) & (~_PAGE_CACHE_MASK)) |
+ flags);
+
+ return 0;
}
-void unmap_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot)
+/*
+ * untrack_pfn_vma is called while unmapping a pfnmap for a region.
+ * untrack can be called for a specific region indicated by pfn and size or
+ * can be for the entire vma (in which case size can be zero).
+ */
+void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn,
+ unsigned long size)
{
- u64 addr = (u64)pfn << PAGE_SHIFT;
+ resource_size_t paddr;
+ unsigned long vma_size = vma->vm_end - vma->vm_start;
+
+ if (is_linear_pfn_mapping(vma)) {
+ /* free the whole chunk starting from vm_pgoff */
+ paddr = (resource_size_t)vma->vm_pgoff << PAGE_SHIFT;
+ free_pfn_range(paddr, vma_size);
+ return;
+ }
+}
- free_memtype(addr, addr + size);
+pgprot_t pgprot_writecombine(pgprot_t prot)
+{
+ if (pat_enabled)
+ return __pgprot(pgprot_val(prot) | _PAGE_CACHE_WC);
+ else
+ return pgprot_noncached(prot);
}
+EXPORT_SYMBOL_GPL(pgprot_writecombine);
+
+#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_X86_PAT)
+
+/* 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 const 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)
+{
+ if (pat_enabled) {
+ 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 && CONFIG_X86_PAT */
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff