ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS

Commit c19fa94a8fed ("Add HAVE_64BIT_ALIGNED_ACCESS") added the config for
architectures that required 64bit aligned access for all 64bit words. As
the ftrace ring buffer stores data on 4 byte alignment, this config option
was used to force it to store data on 8 byte alignment to make sure the data
being stored and written directly into the ring buffer was 8 byte aligned as
it would cause issues trying to write an 8 byte word on a 4 not 8 byte
aligned memory location.

But with the removal of the metag architecture, which was the only
architecture to use this, there is no architecture supported by Linux that
requires 8 byte aligne access for all 8 byte words (4 byte alignment is good
enough). Removing this config can simplify the code a bit.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

1 files changed, 4 insertions, 13 deletions

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 05b0b3139ebc..66358d66c933 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -128,16 +128,7 @@ int ring_buffer_print_entry_header(struct trace_seq *s)
 #define RB_ALIGNMENT            4U
 #define RB_MAX_SMALL_DATA       (RB_ALIGNMENT * RINGBUF_TYPE_DATA_TYPE_LEN_MAX)
 #define RB_EVNT_MIN_SIZE        8U      /* two 32bit words */
-
-#ifndef CONFIG_HAVE_64BIT_ALIGNED_ACCESS
-# define RB_FORCE_8BYTE_ALIGNMENT       0
-# define RB_ARCH_ALIGNMENT              RB_ALIGNMENT
-#else
-# define RB_FORCE_8BYTE_ALIGNMENT       1
-# define RB_ARCH_ALIGNMENT              8U
-#endif
-
-#define RB_ALIGN_DATA           __aligned(RB_ARCH_ALIGNMENT)
+#define RB_ALIGN_DATA           __aligned(RB_ALIGNMENT)
 
 /* define RINGBUF_TYPE_DATA for 'case RINGBUF_TYPE_DATA:' */
 #define RINGBUF_TYPE_DATA 0 ... RINGBUF_TYPE_DATA_TYPE_LEN_MAX
@@ -2373,7 +2364,7 @@ rb_update_event(struct ring_buffer_per_cpu *cpu_buffer,
 
         event->time_delta = delta;
         length -= RB_EVNT_HDR_SIZE;
-        if (length > RB_MAX_SMALL_DATA || RB_FORCE_8BYTE_ALIGNMENT) {
+        if (length > RB_MAX_SMALL_DATA) {
                 event->type_len = 0;
                 event->array[0] = length;
         } else
@@ -2388,11 +2379,11 @@ static unsigned rb_calculate_event_length(unsigned length)
         if (!length)
                 length++;
 
-        if (length > RB_MAX_SMALL_DATA || RB_FORCE_8BYTE_ALIGNMENT)
+        if (length > RB_MAX_SMALL_DATA)
                 length += sizeof(event.array[0]);
 
         length += RB_EVNT_HDR_SIZE;
-        length = ALIGN(length, RB_ARCH_ALIGNMENT);
+        length = ALIGN(length, RB_ALIGNMENT);
 
         /*
          * In case the time delta is larger than the 27 bits for it