[Skiboot] [RFC PATCH] core/opal: Add OPAL call statistics

[Cédric Le Goater]

Here is a proposal to collect OPAL call statistics, counts and duration,
and track areas we could possibly improve.

With a small Linux driver to dump the stats in debugfs, here is what
we get on a P9 after boot:

OPAL_CONSOLE_WRITE : #22318 0/0/47
OPAL_RTC_READ : #9 0/4/15
OPAL_READ_NVRAM : #3468 0/0/6
OPAL_HANDLE_INTERRUPT : #4724 0/57/10026
OPAL_POLL_EVENTS : #508 2/141/10033
OPAL_PCI_CONFIG_READ_BYTE : #3623 0/0/4
OPAL_PCI_CONFIG_READ_HALF_WORD : #5579 0/0/8
OPAL_PCI_CONFIG_READ_WORD : #6156 0/0/7
OPAL_PCI_CONFIG_WRITE_BYTE : #2 0/0/0
OPAL_PCI_CONFIG_WRITE_HALF_WORD : #1282 0/0/1
OPAL_PCI_CONFIG_WRITE_WORD : #1335 0/0/1
OPAL_PCI_EEH_FREEZE_STATUS : #11123 0/0/2
OPAL_CONSOLE_WRITE_BUFFER_SPACE : #139088 0/0/11
OPAL_PCI_EEH_FREEZE_CLEAR : #148 1/2/8
OPAL_PCI_PHB_MMIO_ENABLE : #22 0/0/0
OPAL_PCI_SET_PHB_MEM_WINDOW : #22 0/0/1
OPAL_PCI_MAP_PE_MMIO_WINDOW : #56 0/0/0
OPAL_PCI_SET_PE : #44 279/284/293
OPAL_PCI_SET_PELTV : #66 0/0/0
OPAL_PCI_SET_XIVE_PE : #1123 0/0/1
OPAL_GET_MSI_64 : #1120 0/0/0
OPAL_START_CPU : #238 8/21/35
OPAL_QUERY_CPU_STATUS : #357 0/11/69
OPAL_PCI_MAP_PE_DMA_WINDOW : #16 0/0/1
OPAL_PCI_MAP_PE_DMA_WINDOW_REAL : #16 0/0/1
OPAL_PCI_RESET : #35 0/471/851
OPAL62 : #6 0/10/46
OPAL_XSCOM_READ : #26 0/0/2
OPAL_XSCOM_WRITE : #8 0/0/1
OPAL_REINIT_CPUS : #4 348/8247/11061
OPAL_CHECK_TOKEN : #134112 0/0/0
OPAL_GET_MSG : #30 0/0/1
OPAL87 : #1 0/0/0
OPAL_PCI_SET_PHB_CAPI_MODE : #2 0/60/121
OPAL_SLW_SET_REG : #1080 3/3/13
OPAL_IPMI_SEND : #53 0/5/11
OPAL_IPMI_RECV : #53 0/0/2
OPAL_I2C_REQUEST : #20 6/10/19
OPAL_FLASH_READ : #10 19/10452/58305
OPAL_PRD_MSG : #1 0/3/3
OPAL_CONSOLE_FLUSH : #134079 0/0/12
OPAL_PCI_GET_PRESENCE_STATE : #7 1/1/3
OPAL_PCI_GET_POWER_STATE : #9 0/0/0
OPAL_PCI_TCE_KILL : #20 1/8/133
OPAL_NMMU_SET_PTCR : #3 253/255/257
OPAL_XIVE_RESET : #3 0/114709/115403
OPAL_XIVE_GET_IRQ_INFO : #1427 0/0/6
OPAL_XIVE_SET_IRQ_CONFIG : #1113 0/125/2810
OPAL_XIVE_GET_QUEUE_INFO : #240 0/0/2
OPAL_XIVE_SET_QUEUE_INFO : #360 0/60/1216
OPAL_XIVE_ALLOCATE_VP_BLOCK : #2 0/59/60
OPAL_XIVE_GET_VP_INFO : #240 0/0/0
OPAL_XIVE_SET_VP_INFO : #360 0/298/3080
OPAL_XIVE_ALLOCATE_IRQ : #240 0/0/3
OPAL140 : #119 0/253/1109
OPAL_IMC_COUNTERS_INIT : #60 9/10/20
OPAL_IMC_COUNTERS_STOP : #36 0/0/2
OPAL_PCI_GET_PBCQ_TUNNEL_BAR : #1 2/2/2
OPAL_PCI_SET_PBCQ_TUNNEL_BAR : #1 1/1/1
OPAL_NX_COPROC_INIT : #2 3/4/5

Signed-off-by: Cédric Le Goater <clg at kaod.org>
---
 core/opal.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/core/opal.c b/core/opal.c
index dc9944dcac5d..5712a42ebe94 100644
--- a/core/opal.c
+++ b/core/opal.c
@@ -44,6 +44,27 @@ static uint64_t opal_dynamic_events;
 extern uint32_t attn_trigger;
 extern uint32_t hir_trigger;
 
+/* Call stats */
+struct opal_call_stat {
+	uint64_t count;
+	uint64_t sum;
+	uint64_t min;
+	uint64_t max;
+};
+
+static struct opal_call_stat opal_call_stats[OPAL_LAST+1];
+
+static void opal_call_stat_update(uint64_t token, uint64_t call_time)
+{
+	struct opal_call_stat *s = &opal_call_stats[token];
+
+	s->count++;
+	s->sum += call_time;
+	if (call_time > s->max)
+		s->max = call_time;
+	if (call_time < s->min)
+		s->min = call_time;
+}
 
 void opal_table_init(void)
 {
@@ -55,6 +76,10 @@ void opal_table_init(void)
 	while(s < e) {
 		opal_branch_table[s->token] = function_entry_address(s->func);
 		opal_num_args[s->token] = s->nargs;
+		opal_call_stats[s->token].count = 0;
+		opal_call_stats[s->token].min = 0xFFFFFFFFF;
+		opal_call_stats[s->token].max = 0;
+		opal_call_stats[s->token].sum = 0;
 		s++;
 	}
 }
@@ -190,6 +215,8 @@ int64_t opal_exit_check(int64_t retval, struct stack_frame *eframe)
 		      call_time, token);
 	}
 
+	opal_call_stat_update(token, tb_to_usecs(now - cpu->entered_opal_call_at));
+
 	cpu->current_token = 0;
 
 	return retval;
@@ -420,6 +447,9 @@ void add_opal_node(void)
 	add_opal_firmware_node();
 	add_associativity_ref_point();
 	memcons_add_properties();
+
+	dt_add_property_u64(opal_node, "ibm,opal-call-stats",
+			    (uint64_t) &opal_call_stats);
 }
 
 static struct lock evt_lock = LOCK_UNLOCKED;
-- 
2.21.1