kernel: mmu: rename z_eviction* to k_mem_paging_eviction*

These functions and data structures are those that need
to be implemented by eviction algorithm and application
outside kernel. Promote them from z_* so these can be
included in documentation.

Signed-off-by: Daniel Leung <daniel.leung@intel.com>

arch/Kconfig

@@ -742,7 +742,7 @@ config DEMAND_PAGING_TIMING_HISTOGRAM_NUM_BINS
 	  Defines the number of bins (buckets) in the histogram used for
 	  gathering execution timing information for demand paging.
 
-	  This requires z_eviction_histogram_bounds[] and
+	  This requires k_mem_paging_eviction_histogram_bounds[] and
 	  z_backing_store_histogram_bounds[] to define the upper bounds
 	  for each bin. See kernel/statistics.c for information.
 

include/sys/mem_manage.h

@@ -503,6 +503,40 @@ __syscall void k_mem_paging_histogram_backing_store_page_out_get(
 
 /** @} */
 
+/**
+ * Eviction algorithm APIs
+ *
+ * @defgroup mem-demand-paging-eviction Eviction Algorithm APIs
+ * @{
+ */
+
+/**
+ * Select a page frame for eviction
+ *
+ * The kernel will invoke this to choose a page frame to evict if there
+ * are no free page frames.
+ *
+ * This function will never be called before the initial
+ * k_mem_paging_eviction_init().
+ *
+ * This function is invoked with interrupts locked.
+ *
+ * @param [out] Whether the page to evict is dirty
+ * @return The page frame to evict
+ */
+struct z_page_frame *k_mem_paging_eviction_select(bool *dirty);
+
+/**
+ * Initialization function
+ *
+ * Called at POST_KERNEL to perform any necessary initialization tasks for the
+ * eviction algorithm. k_mem_paging_eviction_select() is guaranteed to never be
+ * called until this has returned, and this will only be called once.
+ */
+void k_mem_paging_eviction_init(void);
+
+/** @} */
+
 #ifdef __cplusplus
 }
 #endif

kernel/include/mmu.h

@@ -230,34 +230,6 @@ extern size_t z_free_page_count;
 #endif
 
 #ifdef CONFIG_DEMAND_PAGING
-/*
- * Eviction algorihm APIs
- */
-
-/**
- * Select a page frame for eviction
- *
- * The kernel will invoke this to choose a page frame to evict if there
- * are no free page frames.
- *
- * This function will never be called before the initial z_eviction_init().
- *
- * This function is invoked with interrupts locked.
- *
- * @param [out] Whether the page to evict is dirty
- * @return The page frame to evict
- */
-struct z_page_frame *z_eviction_select(bool *dirty);
-
-/**
- * Initialization function
- *
- * Called at POST_KERNEL to perform any necessary initialization tasks for the
- * eviction algorithm. z_eviction_select() is guaranteed to never be called
- * until this has returned, and this will only be called once.
- */
-void z_eviction_init(void);
-
 /*
  * Backing store APIs
  */

kernel/mmu.c

@@ -430,7 +430,7 @@ static int map_anon_page(void *addr, uint32_t flags)
 		bool dirty;
 		int ret;
 
-		pf = z_eviction_select(&dirty);
+		pf = k_mem_paging_eviction_select(&dirty);
 		__ASSERT(pf != NULL, "failed to get a page frame");
 		LOG_DBG("evicting %p at 0x%lx", pf->addr,
 			z_page_frame_to_phys(pf));
@@ -791,7 +791,7 @@ void z_mem_manage_init(void)
 	z_paging_histogram_init();
 #endif
 	z_backing_store_init();
-	z_eviction_init();
+	k_mem_paging_eviction_init();
 #endif
 #if __ASSERT_ON
 	page_frames_initialized = true;
@@ -1162,7 +1162,7 @@ static inline struct z_page_frame *do_eviction_select(bool *dirty)
 #endif /* CONFIG_DEMAND_PAGING_STATS_USING_TIMING_FUNCTIONS */
 #endif /* CONFIG_DEMAND_PAGING_TIMING_HISTOGRAM */
 
-	pf = z_eviction_select(dirty);
+	pf = k_mem_paging_eviction_select(dirty);
 
 #ifdef CONFIG_DEMAND_PAGING_TIMING_HISTOGRAM
 #ifdef CONFIG_DEMAND_PAGING_STATS_USING_TIMING_FUNCTIONS
@@ -1195,7 +1195,7 @@ static bool do_page_fault(void *addr, bool pin)
 
 	/*
 	 * TODO: Add performance accounting:
-	 * - z_eviction_select() metrics
+	 * - k_mem_paging_eviction_select() metrics
 	 *   * periodic timer execution time histogram (if implemented)
 	 */
 

kernel/paging/statistics.c

@@ -28,7 +28,8 @@ struct k_mem_paging_histogram_t z_paging_histogram_backing_store_page_out;
  */
 
 extern unsigned long
-z_eviction_histogram_bounds[CONFIG_DEMAND_PAGING_TIMING_HISTOGRAM_NUM_BINS];
+k_mem_paging_eviction_histogram_bounds[
+	CONFIG_DEMAND_PAGING_TIMING_HISTOGRAM_NUM_BINS];
 
 extern unsigned long
 z_backing_store_histogram_bounds[CONFIG_DEMAND_PAGING_TIMING_HISTOGRAM_NUM_BINS];
@@ -40,7 +41,7 @@ z_backing_store_histogram_bounds[CONFIG_DEMAND_PAGING_TIMING_HISTOGRAM_NUM_BINS]
  * This provides the upper bounds of the bins in eviction timing histogram.
  */
 __weak unsigned long
-z_eviction_histogram_bounds[CONFIG_DEMAND_PAGING_TIMING_HISTOGRAM_NUM_BINS] = {
+k_mem_paging_eviction_histogram_bounds[CONFIG_DEMAND_PAGING_TIMING_HISTOGRAM_NUM_BINS] = {
 	NS_TO_CYC(1),
 	NS_TO_CYC(5),
 	NS_TO_CYC(10),
@@ -142,7 +143,8 @@ void z_paging_histogram_init(void)
 	 */
 
 	memset(&z_paging_histogram_eviction, 0, sizeof(z_paging_histogram_eviction));
-	memcpy(z_paging_histogram_eviction.bounds, z_eviction_histogram_bounds,
+	memcpy(z_paging_histogram_eviction.bounds,
+	       k_mem_paging_eviction_histogram_bounds,
 	       sizeof(z_paging_histogram_eviction.bounds));
 
 	memset(&z_paging_histogram_backing_store_page_in, 0,

subsys/demand_paging/eviction/nru.c

@@ -40,7 +40,7 @@ static void nru_periodic_update(struct k_timer *timer)
 	irq_unlock(key);
 }
 
-struct z_page_frame *z_eviction_select(bool *dirty_ptr)
+struct z_page_frame *k_mem_paging_eviction_select(bool *dirty_ptr)
 {
 	unsigned int last_prec = 4U;
 	struct z_page_frame *last_pf = NULL, *pf;
@@ -89,7 +89,7 @@ struct z_page_frame *z_eviction_select(bool *dirty_ptr)
 
 static K_TIMER_DEFINE(nru_timer, nru_periodic_update, NULL);
 
-void z_eviction_init(void)
+void k_mem_paging_eviction_init(void)
 {
 	k_timer_start(&nru_timer, K_NO_WAIT,
 		      K_MSEC(CONFIG_EVICTION_NRU_PERIOD));

tests/kernel/mem_protect/demand_paging/src/main.c

@@ -20,7 +20,8 @@
 
 #ifdef CONFIG_BOARD_QEMU_X86
 unsigned long
-z_eviction_histogram_bounds[CONFIG_DEMAND_PAGING_TIMING_HISTOGRAM_NUM_BINS] = {
+k_mem_paging_eviction_histogram_bounds[
+	CONFIG_DEMAND_PAGING_TIMING_HISTOGRAM_NUM_BINS] = {
 	10000,
 	20000,
 	30000,