VPP-189 Fix Coverity warnings

Remove a bunch of historical SMP code that we're not using; clean up
coverity warnings as a side-effect.

Change-Id: Ic80d2f87c7fd4e654078cac23ad5ec287a1d7ffe
Signed-off-by: Dave Barach <dave@barachs.net>

5 files changed, 8 insertions, 289 deletions

diff --git a/vppinfra/Makefile.am b/vppinfra/Makefile.am
index a9de5ad0..f9855e34 100644
--- a/vppinfra/Makefile.am
+++ b/vppinfra/Makefile.am
@@ -200,7 +200,6 @@ nobase_include_HEADERS = \
   vppinfra/serialize.h \
   vppinfra/slist.h \
   vppinfra/smp.h \
-  vppinfra/smp_fifo.h \
   vppinfra/socket.h \
   vppinfra/sparse_vec.h \
   vppinfra/string.h \
@@ -247,8 +246,6 @@ CLIB_CORE = \
   vppinfra/random_isaac.c \
   vppinfra/serialize.c \
   vppinfra/slist.c \
-  vppinfra/smp.c \
-  vppinfra/smp_fifo.c \
   vppinfra/std-formats.c \
   vppinfra/string.c \
   vppinfra/time.c \
diff --git a/vppinfra/vppinfra/mem_mheap.c b/vppinfra/vppinfra/mem_mheap.c
index 5718c8ce..00437b01 100644
--- a/vppinfra/vppinfra/mem_mheap.c
+++ b/vppinfra/vppinfra/mem_mheap.c
@@ -43,13 +43,6 @@
 #include <vppinfra/memcheck.h>
 #include <vppinfra/valgrind.h>
 
-clib_smp_main_t clib_smp_main = {
-  .n_cpus = 0,
-  .log2_n_per_cpu_stack_bytes = 20,
-  .log2_n_per_cpu_vm_bytes = 28,
-  .n_tls_4k_pages = 1,
-};
-
 void * clib_per_cpu_mheaps[CLIB_MAX_MHEAPS];
 
 void clib_mem_exit (void)
diff --git a/vppinfra/vppinfra/os.h b/vppinfra/vppinfra/os.h
index b63b35cc..124864f5 100644
--- a/vppinfra/vppinfra/os.h
+++ b/vppinfra/vppinfra/os.h
@@ -57,6 +57,7 @@ void os_out_of_memory (void);
 f64 os_cpu_clock_frequency (void);
 
 uword os_get_cpu_number (void);
+uword os_get_ncpus (void);
 
 #include <vppinfra/smp.h>
 
diff --git a/vppinfra/vppinfra/smp.h b/vppinfra/vppinfra/smp.h
index 9f92a9fc..7f0b93cc 100644
--- a/vppinfra/vppinfra/smp.h
+++ b/vppinfra/vppinfra/smp.h
@@ -41,70 +41,6 @@
 #include <vppinfra/cache.h>
 #include <vppinfra/os.h>		/* for os_panic */
 
-/* Per-CPU state. */
-typedef struct {
-  /* Per-cpu local heap. */
-  void * heap;
-
-  u32 thread_id;
-} clib_smp_per_cpu_main_t;
-
-typedef struct {
-  /* Number of CPUs used to model current computer. */
-  u32 n_cpus;
-
-  /* Number of cpus that are done and have exited. */
-  u32 n_cpus_exited;
-
-  /* Log2 stack and vm (heap) size. */
-  u8 log2_n_per_cpu_stack_bytes, log2_n_per_cpu_vm_bytes;
-
-  /* Thread local store (TLS) is stored at stack top.
-     Number of 4k pages to allocate for TLS. */
-  u16 n_tls_4k_pages;
-
-  /* Per cpus stacks/heaps start at these addresses. */
-  void * vm_base;
-
-  /* Thread-safe global heap.  Objects here can be allocated/freed by any cpu. */
-  void * global_heap;
-
-  clib_smp_per_cpu_main_t * per_cpu_mains;
-} clib_smp_main_t;
-
-extern clib_smp_main_t clib_smp_main;
-
-always_inline void *
-clib_smp_vm_base_for_cpu (clib_smp_main_t * m, uword cpu)
-{
-  return m->vm_base + (cpu << m->log2_n_per_cpu_vm_bytes);
-}
-
-always_inline void *
-clib_smp_stack_top_for_cpu (clib_smp_main_t * m, uword cpu)
-{
-  /* Stack is at top of per cpu VM area. */
-  return clib_smp_vm_base_for_cpu (m, cpu + 1) - ((uword) 1 << m->log2_n_per_cpu_stack_bytes);
-}
-
-always_inline uword
-os_get_cpu_number_inline (void)
-{
-  clib_smp_main_t * m = &clib_smp_main;
-  void * sp;
-  uword n;
-
-  /* Get any old stack address. */
-  sp = &sp;
-
-  n = ((uword)sp - (uword)m->vm_base) >> m->log2_n_per_cpu_vm_bytes;
-
-  if (CLIB_DEBUG && m->n_cpus > 0 && n >= m->n_cpus)
-    os_panic ();
-
-  return n < m->n_cpus ? n : 0;
-}
-
 #define clib_smp_compare_and_swap(addr,new,old) __sync_val_compare_and_swap(addr,old,new)
 #define clib_smp_swap(addr,new) __sync_lock_test_and_set(addr,new)
 #define clib_smp_atomic_add(addr,increment) __sync_fetch_and_add(addr,increment)
@@ -129,217 +65,5 @@ os_sched_yield (void)
 { clib_smp_pause (); }
 #endif
 
-typedef enum {
-  CLIB_SMP_LOCK_TYPE_READER,
-  CLIB_SMP_LOCK_TYPE_WRITER,
-  CLIB_SMP_LOCK_TYPE_SPIN,
-} clib_smp_lock_type_t;
-
-typedef enum {
-  CLIB_SMP_LOCK_WAIT_EMPTY,
-  CLIB_SMP_LOCK_WAIT_DONE,
-  CLIB_SMP_LOCK_WAIT_READER,
-  CLIB_SMP_LOCK_WAIT_WRITER,
-} clib_smp_lock_wait_type_t;
-
-#if uword_bits == 64
-typedef u16 clib_smp_quarter_word_t;
-typedef u32 clib_smp_half_word_t;
-#else
-typedef u8 clib_smp_quarter_word_t;
-typedef u16 clib_smp_half_word_t;
-#endif
-
-typedef union {
-  struct {
-    /* FIFO of CPUs (threads) waiting for lock. */
-    struct {
-      clib_smp_quarter_word_t head_index, n_elts;
-    } waiting_fifo;
-
-    /* Requesting CPU for atomic compare_and_swap instructions.
-       This makes CPUs requesting same header change unique. */
-    clib_smp_quarter_word_t request_cpu;
-
-    /* Count of readers who have been given read lock.
-       Not applicable for spin locks. */
-    clib_smp_quarter_word_t n_readers_with_lock : BITS (clib_smp_quarter_word_t) - 1;
-
-    /* Set when writer has been given write lock.  Only one of
-       these can happen at a time. */
-    clib_smp_quarter_word_t writer_has_lock : 1;
-  };
-
-  uword as_uword;
-} clib_smp_lock_header_t;
-
-always_inline uword
-clib_smp_lock_header_is_equal (clib_smp_lock_header_t h0, clib_smp_lock_header_t h1)
-{ return h0.as_uword == h1.as_uword; }
-
-typedef struct {
-  volatile clib_smp_lock_wait_type_t wait_type;
-  u8 pad[CLIB_CACHE_LINE_BYTES - 1 * sizeof (clib_smp_lock_wait_type_t)];
-} clib_smp_lock_waiting_fifo_elt_t;
-
-/* Cache aligned. */
-typedef struct {
-  clib_smp_lock_header_t header;
-
-  /* Size of waiting FIFO; equal to max number of threads less one. */
-  u32 n_waiting_fifo_elts;
-
-  u8 pad[CLIB_CACHE_LINE_BYTES - sizeof (clib_smp_lock_header_t) - sizeof (u32)];
-
-  clib_smp_lock_waiting_fifo_elt_t waiting_fifo[0];
-} clib_smp_lock_t;
-
-always_inline clib_smp_lock_header_t
-clib_smp_lock_set_header (clib_smp_lock_t * l, clib_smp_lock_header_t new_hdr, clib_smp_lock_header_t old)
-{
-  clib_smp_lock_header_t cmp;
-  cmp.as_uword = clib_smp_compare_and_swap (&l->header.as_uword, new_hdr.as_uword, old.as_uword);
-  return cmp;
-}
-
-void clib_smp_lock_init (clib_smp_lock_t ** l);
-void clib_smp_lock_free (clib_smp_lock_t ** l);
-void clib_smp_lock_slow_path (clib_smp_lock_t * l, uword my_cpu, clib_smp_lock_header_t h, clib_smp_lock_type_t type);
-void clib_smp_unlock_slow_path (clib_smp_lock_t * l, uword my_cpu, clib_smp_lock_header_t h, clib_smp_lock_type_t type);
-
-always_inline void
-clib_smp_lock_inline (clib_smp_lock_t * l, clib_smp_lock_type_t type)
-{
-  clib_smp_lock_header_t h0, h1, h2;
-  uword is_reader = type == CLIB_SMP_LOCK_TYPE_READER;
-  uword my_cpu;
-
-  /* Null lock means n_cpus <= 1: nothing to lock. */
-  if (! l)
-    return;
-
-  my_cpu = os_get_cpu_number_inline ();
-  h0 = l->header;
-  while (! h0.writer_has_lock)
-    {
-      /* Want to write but there are still readers with lock? */
-      if (type == CLIB_SMP_LOCK_TYPE_WRITER && h0.n_readers_with_lock != 0)
-	break;
-
-      if (type == CLIB_SMP_LOCK_TYPE_SPIN)
-	ASSERT_AND_PANIC (h0.waiting_fifo.n_elts == 0);
-
-      /* Read/write can't proceed when waiting fifo is non-empty. */
-      else if (h0.waiting_fifo.n_elts != 0)
-	break;
-
-      h1 = h0;
-      h1.request_cpu = my_cpu;
-      h1.writer_has_lock = ! is_reader;
-      h1.n_readers_with_lock += is_reader;
-
-      /* Try to set head and tail to zero and thereby get the lock. */
-      h2 = clib_smp_lock_set_header (l, h1, h0);
-
-      /* Compare and swap succeeded?  If so, we got the lock. */
-      if (clib_smp_lock_header_is_equal (h2, h0))
-	return;
-
-      /* Header for slow path. */
-      h0 = h2;
-    }
-
-  clib_smp_lock_slow_path (l, my_cpu, h0, type);
-}
-
-always_inline void
-clib_smp_unlock_inline (clib_smp_lock_t * l, clib_smp_lock_type_t type)
-{
-  clib_smp_lock_header_t h0, h1;
-  uword is_reader = type == CLIB_SMP_LOCK_TYPE_READER;
-  uword my_cpu;
-  
-  /* Null means no locking is necessary. */
-  if (! l)
-    return;
-
-  my_cpu = os_get_cpu_number_inline ();
-  h0 = l->header;
-
-  /* Should be locked. */
-  if (is_reader)
-    {
-      ASSERT_AND_PANIC (h0.n_readers_with_lock != 0);
-      ASSERT_AND_PANIC (h0.writer_has_lock == 0);
-    }
-  else
-    {
-      ASSERT_AND_PANIC (h0.n_readers_with_lock == 0);
-      ASSERT_AND_PANIC (h0.writer_has_lock);
-    }
-
-  /* Locked but empty waiting fifo? */
-  while (h0.waiting_fifo.n_elts == 0)
-    {
-      /* Try to mark it unlocked. */
-      h1 = h0;
-      if (is_reader)
-	h1.n_readers_with_lock -= 1;
-      else
-	h1.writer_has_lock = 0;
-      h1.request_cpu = my_cpu;
-      h1 = clib_smp_lock_set_header (l, h1, h0);
-      if (clib_smp_lock_header_is_equal (h1, h0))
-	return;
-      h0 = h1;
-    }
-
-  /* Other cpus are waiting. */
-  clib_smp_unlock_slow_path (l, my_cpu, h0, type);
-}
-
-always_inline void
-clib_smp_lock (clib_smp_lock_t * l)
-{ clib_smp_lock_inline (l, CLIB_SMP_LOCK_TYPE_SPIN); }
-
-always_inline void
-clib_smp_lock_for_writer (clib_smp_lock_t * l)
-{ clib_smp_lock_inline (l, CLIB_SMP_LOCK_TYPE_WRITER); }
-
-always_inline void
-clib_smp_lock_for_reader (clib_smp_lock_t * l)
-{ clib_smp_lock_inline (l, CLIB_SMP_LOCK_TYPE_READER); }
-
-always_inline void
-clib_smp_unlock (clib_smp_lock_t * l)
-{ clib_smp_unlock_inline (l, CLIB_SMP_LOCK_TYPE_SPIN); }
-
-always_inline void
-clib_smp_unlock_for_writer (clib_smp_lock_t * l)
-{ clib_smp_unlock_inline (l, CLIB_SMP_LOCK_TYPE_WRITER); }
-
-always_inline void
-clib_smp_unlock_for_reader (clib_smp_lock_t * l)
-{ clib_smp_unlock_inline (l, CLIB_SMP_LOCK_TYPE_READER); }
-
-#define clib_exec_on_global_heap(body)					\
-do {									\
-  void * __clib_exec_on_global_heap_saved_heap;				\
-									\
-  /* Switch to global (thread-safe) heap. */				\
-  __clib_exec_on_global_heap_saved_heap = clib_mem_set_heap (clib_smp_main.global_heap); \
-									\
-  /* Execute body. */							\
-  body;									\
-									\
-  /* Switch back to previous heap. */					\
-  clib_mem_set_heap (__clib_exec_on_global_heap_saved_heap);		\
-} while (0)
-
-uword os_smp_bootstrap (uword n_cpus,
-			void * bootstrap_function,
-			uword bootstrap_function_arg);
-
-void clib_smp_init (void);
 
 #endif /* included_clib_smp_h */
diff --git a/vppinfra/vppinfra/unix-misc.c b/vppinfra/vppinfra/unix-misc.c
index 7b6683a6..4a654066 100644
--- a/vppinfra/vppinfra/unix-misc.c
+++ b/vppinfra/vppinfra/unix-misc.c
@@ -174,14 +174,14 @@ void os_puts (u8 * string, uword string_length, uword is_error)
 
 void os_puts (u8 * string, uword string_length, uword is_error)
 {
-  clib_smp_main_t * m = &clib_smp_main;
   int cpu = os_get_cpu_number ();
+  int ncpus = os_get_ncpus();
   char buf[64];
   int fd = is_error ? 2 : 1;
   struct iovec iovs[2];
   int n_iovs = 0;
 
-  if (m->n_cpus > 1)
+  if (ncpus > 1)
     {
       snprintf (buf, sizeof(buf), "%d: ", cpu);
 
@@ -204,4 +204,8 @@ void os_out_of_memory (void)
 
 uword os_get_cpu_number (void) __attribute__ ((weak));
 uword os_get_cpu_number (void)
-{ return os_get_cpu_number_inline(); }
+{ return 0; }
+
+uword os_get_ncpus (void) __attribute__ ((weak));
+uword os_get_ncpus (void)
+{ return 1; }