omap2+: add drm device
[pandora-kernel.git] / mm / percpu.c
index bf80e55..5c29750 100644 (file)
@@ -116,9 +116,9 @@ static int pcpu_atom_size __read_mostly;
 static int pcpu_nr_slots __read_mostly;
 static size_t pcpu_chunk_struct_size __read_mostly;
 
-/* cpus with the lowest and highest unit numbers */
-static unsigned int pcpu_first_unit_cpu __read_mostly;
-static unsigned int pcpu_last_unit_cpu __read_mostly;
+/* cpus with the lowest and highest unit addresses */
+static unsigned int pcpu_low_unit_cpu __read_mostly;
+static unsigned int pcpu_high_unit_cpu __read_mostly;
 
 /* the address of the first chunk which starts with the kernel static area */
 void *pcpu_base_addr __read_mostly;
@@ -273,11 +273,11 @@ static void __maybe_unused pcpu_next_pop(struct pcpu_chunk *chunk,
             (rs) = (re) + 1, pcpu_next_pop((chunk), &(rs), &(re), (end)))
 
 /**
- * pcpu_mem_alloc - allocate memory
+ * pcpu_mem_zalloc - allocate memory
  * @size: bytes to allocate
  *
  * Allocate @size bytes.  If @size is smaller than PAGE_SIZE,
- * kzalloc() is used; otherwise, vmalloc() is used.  The returned
+ * kzalloc() is used; otherwise, vzalloc() is used.  The returned
  * memory is always zeroed.
  *
  * CONTEXT:
@@ -286,7 +286,7 @@ static void __maybe_unused pcpu_next_pop(struct pcpu_chunk *chunk,
  * RETURNS:
  * Pointer to the allocated area on success, NULL on failure.
  */
-static void *pcpu_mem_alloc(size_t size)
+static void *pcpu_mem_zalloc(size_t size)
 {
        if (WARN_ON_ONCE(!slab_is_available()))
                return NULL;
@@ -302,7 +302,7 @@ static void *pcpu_mem_alloc(size_t size)
  * @ptr: memory to free
  * @size: size of the area
  *
- * Free @ptr.  @ptr should have been allocated using pcpu_mem_alloc().
+ * Free @ptr.  @ptr should have been allocated using pcpu_mem_zalloc().
  */
 static void pcpu_mem_free(void *ptr, size_t size)
 {
@@ -384,7 +384,7 @@ static int pcpu_extend_area_map(struct pcpu_chunk *chunk, int new_alloc)
        size_t old_size = 0, new_size = new_alloc * sizeof(new[0]);
        unsigned long flags;
 
-       new = pcpu_mem_alloc(new_size);
+       new = pcpu_mem_zalloc(new_size);
        if (!new)
                return -ENOMEM;
 
@@ -604,11 +604,12 @@ static struct pcpu_chunk *pcpu_alloc_chunk(void)
 {
        struct pcpu_chunk *chunk;
 
-       chunk = pcpu_mem_alloc(pcpu_chunk_struct_size);
+       chunk = pcpu_mem_zalloc(pcpu_chunk_struct_size);
        if (!chunk)
                return NULL;
 
-       chunk->map = pcpu_mem_alloc(PCPU_DFL_MAP_ALLOC * sizeof(chunk->map[0]));
+       chunk->map = pcpu_mem_zalloc(PCPU_DFL_MAP_ALLOC *
+                                               sizeof(chunk->map[0]));
        if (!chunk->map) {
                kfree(chunk);
                return NULL;
@@ -977,6 +978,17 @@ bool is_kernel_percpu_address(unsigned long addr)
  * address.  The caller is responsible for ensuring @addr stays valid
  * until this function finishes.
  *
+ * percpu allocator has special setup for the first chunk, which currently
+ * supports either embedding in linear address space or vmalloc mapping,
+ * and, from the second one, the backing allocator (currently either vm or
+ * km) provides translation.
+ *
+ * The addr can be tranlated simply without checking if it falls into the
+ * first chunk. But the current code reflects better how percpu allocator
+ * actually works, and the verification can discover both bugs in percpu
+ * allocator itself and per_cpu_ptr_to_phys() callers. So we keep current
+ * code.
+ *
  * RETURNS:
  * The physical address for @addr.
  */
@@ -984,19 +996,19 @@ phys_addr_t per_cpu_ptr_to_phys(void *addr)
 {
        void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr);
        bool in_first_chunk = false;
-       unsigned long first_start, first_end;
+       unsigned long first_low, first_high;
        unsigned int cpu;
 
        /*
-        * The following test on first_start/end isn't strictly
+        * The following test on unit_low/high isn't strictly
         * necessary but will speed up lookups of addresses which
         * aren't in the first chunk.
         */
-       first_start = pcpu_chunk_addr(pcpu_first_chunk, pcpu_first_unit_cpu, 0);
-       first_end = pcpu_chunk_addr(pcpu_first_chunk, pcpu_last_unit_cpu,
-                                   pcpu_unit_pages);
-       if ((unsigned long)addr >= first_start &&
-           (unsigned long)addr < first_end) {
+       first_low = pcpu_chunk_addr(pcpu_first_chunk, pcpu_low_unit_cpu, 0);
+       first_high = pcpu_chunk_addr(pcpu_first_chunk, pcpu_high_unit_cpu,
+                                    pcpu_unit_pages);
+       if ((unsigned long)addr >= first_low &&
+           (unsigned long)addr < first_high) {
                for_each_possible_cpu(cpu) {
                        void *start = per_cpu_ptr(base, cpu);
 
@@ -1011,9 +1023,11 @@ phys_addr_t per_cpu_ptr_to_phys(void *addr)
                if (!is_vmalloc_addr(addr))
                        return __pa(addr);
                else
-                       return page_to_phys(vmalloc_to_page(addr));
+                       return page_to_phys(vmalloc_to_page(addr)) +
+                              offset_in_page(addr);
        } else
-               return page_to_phys(pcpu_addr_to_page(addr));
+               return page_to_phys(pcpu_addr_to_page(addr)) +
+                      offset_in_page(addr);
 }
 
 /**
@@ -1233,7 +1247,9 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
 
        for (cpu = 0; cpu < nr_cpu_ids; cpu++)
                unit_map[cpu] = UINT_MAX;
-       pcpu_first_unit_cpu = NR_CPUS;
+
+       pcpu_low_unit_cpu = NR_CPUS;
+       pcpu_high_unit_cpu = NR_CPUS;
 
        for (group = 0, unit = 0; group < ai->nr_groups; group++, unit += i) {
                const struct pcpu_group_info *gi = &ai->groups[group];
@@ -1253,9 +1269,13 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
                        unit_map[cpu] = unit + i;
                        unit_off[cpu] = gi->base_offset + i * ai->unit_size;
 
-                       if (pcpu_first_unit_cpu == NR_CPUS)
-                               pcpu_first_unit_cpu = cpu;
-                       pcpu_last_unit_cpu = cpu;
+                       /* determine low/high unit_cpu */
+                       if (pcpu_low_unit_cpu == NR_CPUS ||
+                           unit_off[cpu] < unit_off[pcpu_low_unit_cpu])
+                               pcpu_low_unit_cpu = cpu;
+                       if (pcpu_high_unit_cpu == NR_CPUS ||
+                           unit_off[cpu] > unit_off[pcpu_high_unit_cpu])
+                               pcpu_high_unit_cpu = cpu;
                }
        }
        pcpu_nr_units = unit;
@@ -1622,6 +1642,16 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
                areas[group] = ptr;
 
                base = min(ptr, base);
+       }
+
+       /*
+        * Copy data and free unused parts.  This should happen after all
+        * allocations are complete; otherwise, we may end up with
+        * overlapping groups.
+        */
+       for (group = 0; group < ai->nr_groups; group++) {
+               struct pcpu_group_info *gi = &ai->groups[group];
+               void *ptr = areas[group];
 
                for (i = 0; i < gi->nr_units; i++, ptr += ai->unit_size) {
                        if (gi->cpu_map[i] == NR_CPUS) {
@@ -1889,7 +1919,7 @@ void __init percpu_init_late(void)
 
                BUILD_BUG_ON(size > PAGE_SIZE);
 
-               map = pcpu_mem_alloc(size);
+               map = pcpu_mem_zalloc(size);
                BUG_ON(!map);
 
                spin_lock_irqsave(&pcpu_lock, flags);