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[PATCH for-5.0 7/8] acpi: cpuhp: add CPHP_GET_CPU_ID_CMD command
From: |
Igor Mammedov |
Subject: |
[PATCH for-5.0 7/8] acpi: cpuhp: add CPHP_GET_CPU_ID_CMD command |
Date: |
Wed, 4 Dec 2019 18:05:46 +0100 |
Extend CPU hotplug interface to return architecture specific
identifier for current CPU in 2 registers:
- lower 32 bits existing ACPI_CPU_CMD_DATA_OFFSET_RW
- upper 32 bits in new ACPI_CPU_CMD_DATA2_OFFSET_R at
offset 0.
Target user is UEFI firmware, which needs a way to enumerate
all CPUs (including possible CPUs) to allocate and initialize
CPU structures on boot.
(for x86: it needs APIC ID and later command will be used to
retrieve ARM's MPIDR which serves the similar to APIC ID purpose)
The new ACPI_CPU_CMD_DATA2_OFFSET_R register will also be used
to detect presence of modern CPU hotplug, which will be described
in follow up patch.
Signed-off-by: Igor Mammedov <address@hidden>
---
v1:
- s/ACPI_CPU_CMD_DATA2_OFFSET_RW/ACPI_CPU_CMD_DATA2_OFFSET_R/.
---
docs/specs/acpi_cpu_hotplug.txt | 10 ++++++++--
hw/acpi/cpu.c | 15 +++++++++++++++
hw/acpi/trace-events | 1 +
3 files changed, 24 insertions(+), 2 deletions(-)
diff --git a/docs/specs/acpi_cpu_hotplug.txt b/docs/specs/acpi_cpu_hotplug.txt
index 58c16c6..bb33144 100644
--- a/docs/specs/acpi_cpu_hotplug.txt
+++ b/docs/specs/acpi_cpu_hotplug.txt
@@ -44,7 +44,11 @@ keeps the current value.
read access:
offset:
- [0x0-0x3] reserved
+ [0x0-0x3] Command data 2: (DWORD access)
+ if last stored 'Command field' value:
+ 3: upper 32 bits of architecture specific identifying CPU
value
+ (n x86 case: 0x0)
+ other values: reserved
[0x4] CPU device status fields: (1 byte access)
bits:
0: Device is enabled and may be used by guest
@@ -96,7 +100,9 @@ write access:
2: stores value into OST status register, triggers
ACPI_DEVICE_OST QMP event from QEMU to external applications
with current values of OST event and status registers.
- other values: reserved
+ 3: lower 32 bit of architecture specific identifier
+ (in x86 case: APIC ID)
+ other values: reserved
Typical usecases:
- Get a cpu with pending event
diff --git a/hw/acpi/cpu.c b/hw/acpi/cpu.c
index 87f30a3..87813ce 100644
--- a/hw/acpi/cpu.c
+++ b/hw/acpi/cpu.c
@@ -12,11 +12,13 @@
#define ACPI_CPU_FLAGS_OFFSET_RW 4
#define ACPI_CPU_CMD_OFFSET_WR 5
#define ACPI_CPU_CMD_DATA_OFFSET_RW 8
+#define ACPI_CPU_CMD_DATA2_OFFSET_R 0
enum {
CPHP_GET_NEXT_CPU_WITH_EVENT_CMD = 0,
CPHP_OST_EVENT_CMD = 1,
CPHP_OST_STATUS_CMD = 2,
+ CPHP_GET_CPU_ID_CMD = 3,
CPHP_CMD_MAX
};
@@ -74,11 +76,24 @@ static uint64_t cpu_hotplug_rd(void *opaque, hwaddr addr,
unsigned size)
case CPHP_GET_NEXT_CPU_WITH_EVENT_CMD:
val = cpu_st->selector;
break;
+ case CPHP_GET_CPU_ID_CMD:
+ val = cdev->arch_id & 0xFFFFFFFF;
+ break;
default:
break;
}
trace_cpuhp_acpi_read_cmd_data(cpu_st->selector, val);
break;
+ case ACPI_CPU_CMD_DATA2_OFFSET_R:
+ switch (cpu_st->command) {
+ case CPHP_GET_CPU_ID_CMD:
+ val = cdev->arch_id >> 32;
+ break;
+ default:
+ break;
+ }
+ trace_cpuhp_acpi_read_cmd_data2(cpu_st->selector, val);
+ break;
default:
break;
}
diff --git a/hw/acpi/trace-events b/hw/acpi/trace-events
index 96b8273..afbc77d 100644
--- a/hw/acpi/trace-events
+++ b/hw/acpi/trace-events
@@ -23,6 +23,7 @@ cpuhp_acpi_read_flags(uint32_t idx, uint8_t flags)
"idx[0x%"PRIx32"] flags: 0x%"
cpuhp_acpi_write_idx(uint32_t idx) "set active cpu idx: 0x%"PRIx32
cpuhp_acpi_write_cmd(uint32_t idx, uint8_t cmd) "idx[0x%"PRIx32"] cmd:
0x%"PRIx8
cpuhp_acpi_read_cmd_data(uint32_t idx, uint32_t data) "idx[0x%"PRIx32"] data:
0x%"PRIx32
+cpuhp_acpi_read_cmd_data2(uint32_t idx, uint32_t data) "idx[0x%"PRIx32"] data:
0x%"PRIx32
cpuhp_acpi_cpu_has_events(uint32_t idx, bool ins, bool rm) "idx[0x%"PRIx32"]
inserting: %d, removing: %d"
cpuhp_acpi_clear_inserting_evt(uint32_t idx) "idx[0x%"PRIx32"]"
cpuhp_acpi_clear_remove_evt(uint32_t idx) "idx[0x%"PRIx32"]"
--
2.7.4
[PATCH for-5.0 8/8] acpi: cpuhp: spec: document procedure for enabling modern CPU hotplug, Igor Mammedov, 2019/12/04