Merge tag 'please-pull-pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux

Pull pstore update from Tony Luck:
 "Fixes for pstore for 3.11 merge window"

* tag 'please-pull-pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
  efivars: If pstore_register fails, free unneeded pstore buffer
  acpi: Eliminate console msg if pstore.backend excludes ERST
  pstore: Return unique error if backend registration excluded by kernel param
  pstore: Fail to unlink if a driver has not defined pstore_erase
  pstore/ram: remove the power of buffer size limitation
  pstore/ram: avoid atomic accesses for ioremapped regions
  efi, pstore: Cocci spatch "memdup.spatch"

4 files changed, 60 insertions, 9 deletions

diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index e4bcb2cf055a..bfd95bf38005 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -178,6 +178,8 @@ static int pstore_unlink(struct inode *dir, struct dentry *dentry)
         if (p->psi->erase)
                 p->psi->erase(p->type, p->id, p->count,
                               dentry->d_inode->i_ctime, p->psi);
+        else
+                return -EPERM;
 
         return simple_unlink(dir, dentry);
 }
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 86d1038b5a12..b7ffe2bcd9c4 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -239,17 +239,15 @@ int pstore_register(struct pstore_info *psi)
 {
         struct module *owner = psi->owner;
 
+        if (backend && strcmp(backend, psi->name))
+                return -EPERM;
+
         spin_lock(&pstore_lock);
         if (psinfo) {
                 spin_unlock(&pstore_lock);
                 return -EBUSY;
         }
 
-        if (backend && strcmp(backend, psi->name)) {
-                spin_unlock(&pstore_lock);
-                return -EINVAL;
-        }
-
         if (!psi->write)
                 psi->write = pstore_write_compat;
         psinfo = psi;
@@ -274,6 +272,9 @@ int pstore_register(struct pstore_info *psi)
                 add_timer(&pstore_timer);
         }
 
+        pr_info("pstore: Registered %s as persistent store backend\n",
+                psi->name);
+
         return 0;
 }
 EXPORT_SYMBOL_GPL(pstore_register);
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 1376e5a8f0d6..43abee2c6cb9 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -399,8 +399,6 @@ static int ramoops_probe(struct platform_device *pdev)
                 goto fail_out;
         }
 
-        if (!is_power_of_2(pdata->mem_size))
-                pdata->mem_size = rounddown_pow_of_two(pdata->mem_size);
         if (!is_power_of_2(pdata->record_size))
                 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
         if (!is_power_of_2(pdata->console_size))
diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index 59337326e288..de272d426763 100644
--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -46,7 +46,7 @@ static inline size_t buffer_start(struct persistent_ram_zone *prz)
 }
 
 /* increase and wrap the start pointer, returning the old value */
-static inline size_t buffer_start_add(struct persistent_ram_zone *prz, size_t a)
+static size_t buffer_start_add_atomic(struct persistent_ram_zone *prz, size_t a)
 {
         int old;
         int new;
@@ -62,7 +62,7 @@ static inline size_t buffer_start_add(struct persistent_ram_zone *prz, size_t a)
 }
 
 /* increase the size counter until it hits the max size */
-static inline void buffer_size_add(struct persistent_ram_zone *prz, size_t a)
+static void buffer_size_add_atomic(struct persistent_ram_zone *prz, size_t a)
 {
         size_t old;
         size_t new;
@@ -78,6 +78,53 @@ static inline void buffer_size_add(struct persistent_ram_zone *prz, size_t a)
         } while (atomic_cmpxchg(&prz->buffer->size, old, new) != old);
 }
 
+static DEFINE_RAW_SPINLOCK(buffer_lock);
+
+/* increase and wrap the start pointer, returning the old value */
+static size_t buffer_start_add_locked(struct persistent_ram_zone *prz, size_t a)
+{
+        int old;
+        int new;
+        unsigned long flags;
+
+        raw_spin_lock_irqsave(&buffer_lock, flags);
+
+        old = atomic_read(&prz->buffer->start);
+        new = old + a;
+        while (unlikely(new > prz->buffer_size))
+                new -= prz->buffer_size;
+        atomic_set(&prz->buffer->start, new);
+
+        raw_spin_unlock_irqrestore(&buffer_lock, flags);
+
+        return old;
+}
+
+/* increase the size counter until it hits the max size */
+static void buffer_size_add_locked(struct persistent_ram_zone *prz, size_t a)
+{
+        size_t old;
+        size_t new;
+        unsigned long flags;
+
+        raw_spin_lock_irqsave(&buffer_lock, flags);
+
+        old = atomic_read(&prz->buffer->size);
+        if (old == prz->buffer_size)
+                goto exit;
+
+        new = old + a;
+        if (new > prz->buffer_size)
+                new = prz->buffer_size;
+        atomic_set(&prz->buffer->size, new);
+
+exit:
+        raw_spin_unlock_irqrestore(&buffer_lock, flags);
+}
+
+static size_t (*buffer_start_add)(struct persistent_ram_zone *, size_t) = buffer_start_add_atomic;
+static void (*buffer_size_add)(struct persistent_ram_zone *, size_t) = buffer_size_add_atomic;
+
 static void notrace persistent_ram_encode_rs8(struct persistent_ram_zone *prz,
         uint8_t *data, size_t len, uint8_t *ecc)
 {
@@ -372,6 +419,9 @@ static void *persistent_ram_iomap(phys_addr_t start, size_t size)
                 return NULL;
         }
 
+        buffer_start_add = buffer_start_add_locked;
+        buffer_size_add = buffer_size_add_locked;
+
         return ioremap(start, size);
 }