Eliminate psci_suspend_context array

psci_suspend_context is an array of cache-line aligned structures
containing the single power_state integer per cpu. This array is
the only structure indexed by the aff_map_node.data integer.

This patch saves 2KB of BL3-1 memory by placing the CPU
power_state value directly in the aff_map_node structure. As a
result, this value is now never cached and the cache clean when
writing the value is no longer required.

Fixes ARM-software/tf-issues#195

Change-Id: Ib4c70c8f79eed295ea541e7827977a588a19ef9b

diff --git a/services/std_svc/psci/psci_afflvl_suspend.c b/services/std_svc/psci/psci_afflvl_suspend.c
index f43dcedf1e6f857cdc0f413516f9682bc02d4cf4..ea9038963ee30de9c275bd97cc2f2c6682cb8438 100644 (file)
--- a/services/std_svc/psci/psci_afflvl_suspend.c
+++ b/services/std_svc/psci/psci_afflvl_suspend.c
@@ -57,16 +57,11 @@ void psci_set_suspend_power_state(aff_map_node_t *node, unsigned int power_state
        assert(node->mpidr == (read_mpidr() & MPIDR_AFFINITY_MASK));
        assert(node->level == MPIDR_AFFLVL0);
 
-       /* Save PSCI power state parameter for the core in suspend context */
-       psci_suspend_context[node->data].power_state = power_state;
-
        /*
-        * Flush the suspend data to PoC since it will be accessed while
-        * returning back from suspend with the caches turned off
+        * Save PSCI power state parameter for the core in suspend context.
+        * The node is in always-coherent RAM so it does not need to be flushed
         */
-       flush_dcache_range(
-               (unsigned long)&psci_suspend_context[node->data],
-               sizeof(suspend_context_t));
+       node->power_state = power_state;
 }
 
 /*******************************************************************************
@@ -97,7 +92,7 @@ int psci_get_aff_map_node_suspend_afflvl(aff_map_node_t *node)
 
        assert(node->level == MPIDR_AFFLVL0);
 
-       power_state = psci_suspend_context[node->data].power_state;
+       power_state = node->power_state;
        return ((power_state == PSCI_INVALID_DATA) ?
                                power_state : psci_get_pstate_afflvl(power_state));
 }
@@ -117,7 +112,7 @@ int psci_get_suspend_stateid(unsigned long mpidr)
        assert(node);
        assert(node->level == MPIDR_AFFLVL0);
 
-       power_state = psci_suspend_context[node->data].power_state;
+       power_state = node->power_state;
        return ((power_state == PSCI_INVALID_DATA) ?
                                        power_state : psci_get_pstate_id(power_state));
 }

diff --git a/services/std_svc/psci/psci_common.c b/services/std_svc/psci/psci_common.c
index d69c5f5183d15f5539c8610b72709ed1f7dcc2c6..87be843b2ea2c7c31e99e56ae4944889897a0846 100644 (file)
--- a/services/std_svc/psci/psci_common.c
+++ b/services/std_svc/psci/psci_common.c
@@ -45,13 +45,6 @@
  */
 const spd_pm_ops_t *psci_spd_pm;
 
-/*******************************************************************************
- * Arrays that contains information needs to resume a cpu's execution when woken
- * out of suspend or off states. Each cpu is allocated a single entry in each
- * array during startup.
- ******************************************************************************/
-suspend_context_t psci_suspend_context[PSCI_NUM_AFFS];
-
 /*******************************************************************************
  * Grand array that holds the platform's topology information for state
  * management of affinity instances. Each node (aff_map_node) in the array

diff --git a/services/std_svc/psci/psci_private.h b/services/std_svc/psci/psci_private.h
index 970ad21e411a3a6d32e6bbbed8f806b3d0de696a..08a4a34a59d5ff597ae0b22e2e258d8e91efee48 100644 (file)
--- a/services/std_svc/psci/psci_private.h
+++ b/services/std_svc/psci/psci_private.h
@@ -44,7 +44,7 @@ typedef struct aff_map_node {
        unsigned short ref_count;
        unsigned char state;
        unsigned char level;
-       unsigned int data;
+       unsigned int power_state;
        bakery_lock_t lock;
 } aff_map_node_t;
 
@@ -53,14 +53,6 @@ typedef struct aff_limits_node {
        int max;
 } aff_limits_node_t;
 
-/*******************************************************************************
- * This data structure holds secure world context that needs to be preserved
- * across cpu_suspend calls which enter the power down state.
- ******************************************************************************/
-typedef struct suspend_context {
-       unsigned int power_state;
-} __aligned(CACHE_WRITEBACK_GRANULE) suspend_context_t;
-
 typedef aff_map_node_t (*mpidr_aff_map_nodes_t[MPIDR_MAX_AFFLVL]);
 typedef unsigned int (*afflvl_power_on_finisher_t)(unsigned long,
                                                 aff_map_node_t *);
@@ -68,7 +60,6 @@ typedef unsigned int (*afflvl_power_on_finisher_t)(unsigned long,
 /*******************************************************************************
  * Data prototypes
  ******************************************************************************/
-extern suspend_context_t psci_suspend_context[PSCI_NUM_AFFS];
 extern const plat_pm_ops_t *psci_plat_pm_ops;
 extern aff_map_node_t psci_aff_map[PSCI_NUM_AFFS];
 

diff --git a/services/std_svc/psci/psci_setup.c b/services/std_svc/psci/psci_setup.c
index af82150674b4601a1610f9ab09ca16872ebf0c1b..68f19a0090f4f2eb94742e419247816a57f621cf 100644 (file)
--- a/services/std_svc/psci/psci_setup.c
+++ b/services/std_svc/psci/psci_setup.c
@@ -57,12 +57,6 @@ static cpu_context_t psci_ns_context[PLATFORM_CORE_COUNT];
  ******************************************************************************/
 static aff_limits_node_t psci_aff_limits[MPIDR_MAX_AFFLVL + 1];
 
-/*******************************************************************************
- * 'psci_ns_einfo_idx' keeps track of the next free index in the
- * 'psci_suspend_context' arrays.
- ******************************************************************************/
-static unsigned int psci_ns_einfo_idx;
-
 /*******************************************************************************
  * Routines for retrieving the node corresponding to an affinity level instance
  * in the mpidr. The first one uses binary search to find the node corresponding
@@ -195,13 +189,8 @@ static void psci_init_aff_map_node(unsigned long mpidr,
                if (state & PSCI_AFF_PRESENT)
                        psci_set_state(&psci_aff_map[idx], PSCI_STATE_OFF);
 
-               /* Ensure that we have not overflowed the psci_ns_einfo array */
-               assert(psci_ns_einfo_idx < PSCI_NUM_AFFS);
-
-               psci_aff_map[idx].data = psci_ns_einfo_idx;
                /* Invalidate the suspend context for the node */
-               psci_suspend_context[psci_ns_einfo_idx].power_state = PSCI_INVALID_DATA;
-               psci_ns_einfo_idx++;
+               psci_aff_map[idx].power_state = PSCI_INVALID_DATA;
 
                /*
                 * Associate a non-secure context with this affinity
@@ -301,7 +290,6 @@ int32_t psci_setup(void)
        int afflvl, affmap_idx, max_afflvl;
        aff_map_node_t *node;
 
-       psci_ns_einfo_idx = 0;
        psci_plat_pm_ops = NULL;
 
        /* Find out the maximum affinity level that the platform implements */