From 9d77db3c730780c8ef5ccd4b66403ff5675cfe4e Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 13 May 2024 10:30:14 +0000
Subject: [PATCH] modify sin led gpio
---
kernel/drivers/cpuidle/cpuidle-pseries.c | 257 ++++++++++++++++++++++++++++++++++++++++++--------
1 files changed, 214 insertions(+), 43 deletions(-)
diff --git a/kernel/drivers/cpuidle/cpuidle-pseries.c b/kernel/drivers/cpuidle/cpuidle-pseries.c
index 74c2479..f4cf3ad 100644
--- a/kernel/drivers/cpuidle/cpuidle-pseries.c
+++ b/kernel/drivers/cpuidle/cpuidle-pseries.c
@@ -19,9 +19,11 @@
#include <asm/machdep.h>
#include <asm/firmware.h>
#include <asm/runlatch.h>
+#include <asm/idle.h>
#include <asm/plpar_wrappers.h>
+#include <asm/rtas.h>
-struct cpuidle_driver pseries_idle_driver = {
+static struct cpuidle_driver pseries_idle_driver = {
.name = "pseries_idle",
.owner = THIS_MODULE,
};
@@ -31,39 +33,15 @@
static u64 snooze_timeout __read_mostly;
static bool snooze_timeout_en __read_mostly;
-static inline void idle_loop_prolog(unsigned long *in_purr)
-{
- ppc64_runlatch_off();
- *in_purr = mfspr(SPRN_PURR);
- /*
- * Indicate to the HV that we are idle. Now would be
- * a good time to find other work to dispatch.
- */
- get_lppaca()->idle = 1;
-}
-
-static inline void idle_loop_epilog(unsigned long in_purr)
-{
- u64 wait_cycles;
-
- wait_cycles = be64_to_cpu(get_lppaca()->wait_state_cycles);
- wait_cycles += mfspr(SPRN_PURR) - in_purr;
- get_lppaca()->wait_state_cycles = cpu_to_be64(wait_cycles);
- get_lppaca()->idle = 0;
-
- ppc64_runlatch_on();
-}
-
static int snooze_loop(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
- unsigned long in_purr;
u64 snooze_exit_time;
set_thread_flag(TIF_POLLING_NRFLAG);
- idle_loop_prolog(&in_purr);
+ pseries_idle_prolog();
local_irq_enable();
snooze_exit_time = get_tb() + snooze_timeout;
@@ -87,7 +65,7 @@
local_irq_disable();
- idle_loop_epilog(in_purr);
+ pseries_idle_epilog();
return index;
}
@@ -109,22 +87,152 @@
}
}
+/*
+ * XCEDE: Extended CEDE states discovered through the
+ * "ibm,get-systems-parameter" RTAS call with the token
+ * CEDE_LATENCY_TOKEN
+ */
+
+/*
+ * Section 7.3.16 System Parameters Option of PAPR version 2.8.1 has a
+ * table with all the parameters to ibm,get-system-parameters.
+ * CEDE_LATENCY_TOKEN corresponds to the token value for Cede Latency
+ * Settings Information.
+ */
+#define CEDE_LATENCY_TOKEN 45
+
+/*
+ * If the platform supports the cede latency settings information system
+ * parameter it must provide the following information in the NULL terminated
+ * parameter string:
+ *
+ * a. The first byte is the length “N” of each cede latency setting record minus
+ * one (zero indicates a length of 1 byte).
+ *
+ * b. For each supported cede latency setting a cede latency setting record
+ * consisting of the first “N” bytes as per the following table.
+ *
+ * -----------------------------
+ * | Field | Field |
+ * | Name | Length |
+ * -----------------------------
+ * | Cede Latency | 1 Byte |
+ * | Specifier Value | |
+ * -----------------------------
+ * | Maximum wakeup | |
+ * | latency in | 8 Bytes |
+ * | tb-ticks | |
+ * -----------------------------
+ * | Responsive to | |
+ * | external | 1 Byte |
+ * | interrupts | |
+ * -----------------------------
+ *
+ * This version has cede latency record size = 10.
+ *
+ * The structure xcede_latency_payload represents a) and b) with
+ * xcede_latency_record representing the table in b).
+ *
+ * xcede_latency_parameter is what gets returned by
+ * ibm,get-systems-parameter RTAS call when made with
+ * CEDE_LATENCY_TOKEN.
+ *
+ * These structures are only used to represent the data obtained by the RTAS
+ * call. The data is in big-endian.
+ */
+struct xcede_latency_record {
+ u8 hint;
+ __be64 latency_ticks;
+ u8 wake_on_irqs;
+} __packed;
+
+// Make space for 16 records, which "should be enough".
+struct xcede_latency_payload {
+ u8 record_size;
+ struct xcede_latency_record records[16];
+} __packed;
+
+struct xcede_latency_parameter {
+ __be16 payload_size;
+ struct xcede_latency_payload payload;
+ u8 null_char;
+} __packed;
+
+static unsigned int nr_xcede_records;
+static struct xcede_latency_parameter xcede_latency_parameter __initdata;
+
+static int __init parse_cede_parameters(void)
+{
+ struct xcede_latency_payload *payload;
+ u32 total_xcede_records_size;
+ u8 xcede_record_size;
+ u16 payload_size;
+ int ret, i;
+
+ ret = rtas_call(rtas_token("ibm,get-system-parameter"), 3, 1,
+ NULL, CEDE_LATENCY_TOKEN, __pa(&xcede_latency_parameter),
+ sizeof(xcede_latency_parameter));
+ if (ret) {
+ pr_err("xcede: Error parsing CEDE_LATENCY_TOKEN\n");
+ return ret;
+ }
+
+ payload_size = be16_to_cpu(xcede_latency_parameter.payload_size);
+ payload = &xcede_latency_parameter.payload;
+
+ xcede_record_size = payload->record_size + 1;
+
+ if (xcede_record_size != sizeof(struct xcede_latency_record)) {
+ pr_err("xcede: Expected record-size %lu. Observed size %u.\n",
+ sizeof(struct xcede_latency_record), xcede_record_size);
+ return -EINVAL;
+ }
+
+ pr_info("xcede: xcede_record_size = %d\n", xcede_record_size);
+
+ /*
+ * Since the payload_size includes the last NULL byte and the
+ * xcede_record_size, the remaining bytes correspond to array of all
+ * cede_latency settings.
+ */
+ total_xcede_records_size = payload_size - 2;
+ nr_xcede_records = total_xcede_records_size / xcede_record_size;
+
+ for (i = 0; i < nr_xcede_records; i++) {
+ struct xcede_latency_record *record = &payload->records[i];
+ u64 latency_ticks = be64_to_cpu(record->latency_ticks);
+ u8 wake_on_irqs = record->wake_on_irqs;
+ u8 hint = record->hint;
+
+ pr_info("xcede: Record %d : hint = %u, latency = 0x%llx tb ticks, Wake-on-irq = %u\n",
+ i, hint, latency_ticks, wake_on_irqs);
+ }
+
+ return 0;
+}
+
+#define NR_DEDICATED_STATES 2 /* snooze, CEDE */
+static u8 cede_latency_hint[NR_DEDICATED_STATES];
+
static int dedicated_cede_loop(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
- unsigned long in_purr;
+ u8 old_latency_hint;
- idle_loop_prolog(&in_purr);
+ pseries_idle_prolog();
get_lppaca()->donate_dedicated_cpu = 1;
+ old_latency_hint = get_lppaca()->cede_latency_hint;
+ get_lppaca()->cede_latency_hint = cede_latency_hint[index];
HMT_medium();
check_and_cede_processor();
local_irq_disable();
get_lppaca()->donate_dedicated_cpu = 0;
+ get_lppaca()->cede_latency_hint = old_latency_hint;
- idle_loop_epilog(in_purr);
+ pseries_idle_epilog();
return index;
}
@@ -133,9 +241,8 @@
struct cpuidle_driver *drv,
int index)
{
- unsigned long in_purr;
- idle_loop_prolog(&in_purr);
+ pseries_idle_prolog();
/*
* Yield the processor to the hypervisor. We return if
@@ -147,7 +254,7 @@
check_and_cede_processor();
local_irq_disable();
- idle_loop_epilog(in_purr);
+ pseries_idle_epilog();
return index;
}
@@ -155,7 +262,7 @@
/*
* States for dedicated partition case.
*/
-static struct cpuidle_state dedicated_states[] = {
+static struct cpuidle_state dedicated_states[NR_DEDICATED_STATES] = {
{ /* Snooze */
.name = "snooze",
.desc = "snooze",
@@ -236,29 +343,93 @@
return 0;
}
+static void __init fixup_cede0_latency(void)
+{
+ struct xcede_latency_payload *payload;
+ u64 min_latency_us;
+ int i;
+
+ min_latency_us = dedicated_states[1].exit_latency; // CEDE latency
+
+ if (parse_cede_parameters())
+ return;
+
+ pr_info("cpuidle: Skipping the %d Extended CEDE idle states\n",
+ nr_xcede_records);
+
+ payload = &xcede_latency_parameter.payload;
+ for (i = 0; i < nr_xcede_records; i++) {
+ struct xcede_latency_record *record = &payload->records[i];
+ u64 latency_tb = be64_to_cpu(record->latency_ticks);
+ u64 latency_us = DIV_ROUND_UP_ULL(tb_to_ns(latency_tb), NSEC_PER_USEC);
+
+ if (latency_us == 0)
+ pr_warn("cpuidle: xcede record %d has an unrealistic latency of 0us.\n", i);
+
+ if (latency_us < min_latency_us)
+ min_latency_us = latency_us;
+ }
+
+ /*
+ * By default, we assume that CEDE(0) has exit latency 10us,
+ * since there is no way for us to query from the platform.
+ *
+ * However, if the wakeup latency of an Extended CEDE state is
+ * smaller than 10us, then we can be sure that CEDE(0)
+ * requires no more than that.
+ *
+ * Perform the fix-up.
+ */
+ if (min_latency_us < dedicated_states[1].exit_latency) {
+ /*
+ * We set a minimum of 1us wakeup latency for cede0 to
+ * distinguish it from snooze
+ */
+ u64 cede0_latency = 1;
+
+ if (min_latency_us > cede0_latency)
+ cede0_latency = min_latency_us - 1;
+
+ dedicated_states[1].exit_latency = cede0_latency;
+ dedicated_states[1].target_residency = 10 * (cede0_latency);
+ pr_info("cpuidle: Fixed up CEDE exit latency to %llu us\n",
+ cede0_latency);
+ }
+
+}
+
/*
* pseries_idle_probe()
* Choose state table for shared versus dedicated partition
*/
-static int pseries_idle_probe(void)
+static int __init pseries_idle_probe(void)
{
if (cpuidle_disable != IDLE_NO_OVERRIDE)
return -ENODEV;
if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
- /*
- * Use local_paca instead of get_lppaca() since
- * preemption is not disabled, and it is not required in
- * fact, since lppaca_ptr does not need to be the value
- * associated to the current CPU, it can be from any CPU.
- */
- if (lppaca_shared_proc(local_paca->lppaca_ptr)) {
+ if (lppaca_shared_proc()) {
cpuidle_state_table = shared_states;
max_idle_state = ARRAY_SIZE(shared_states);
} else {
+ /*
+ * Use firmware provided latency values
+ * starting with POWER10 platforms. In the
+ * case that we are running on a POWER10
+ * platform but in an earlier compat mode, we
+ * can still use the firmware provided values.
+ *
+ * However, on platforms prior to POWER10, we
+ * cannot rely on the accuracy of the firmware
+ * provided latency values. On such platforms,
+ * go with the conservative default estimate
+ * of 10us.
+ */
+ if (cpu_has_feature(CPU_FTR_ARCH_31) || pvr_version_is(PVR_POWER10))
+ fixup_cede0_latency();
cpuidle_state_table = dedicated_states;
- max_idle_state = ARRAY_SIZE(dedicated_states);
+ max_idle_state = NR_DEDICATED_STATES;
}
} else
return -ENODEV;
--
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