On 2020-11-04 18:36, David Brazdil wrote:
The version of PSCI that the kernel should use to communicate with
firmware is typically obtained from probing PSCI_VERSION. However, that
doesn't work for PSCI v0.1 where the host gets the information from
DT/ACPI, or if PSCI is not supported / was disabled.
KVM's PSCI proxy for the host needs to be configured with the same
version used by the host driver. Expose the PSCI version used by the
host.
Signed-off-by: David Brazdil <dbraz...@google.com>
---
drivers/firmware/psci/psci.c | 6 ++++++
include/linux/psci.h | 8 ++++++++
2 files changed, 14 insertions(+)
diff --git a/drivers/firmware/psci/psci.c
b/drivers/firmware/psci/psci.c
index 00af99b6f97c..ff523bdbfe3f 100644
--- a/drivers/firmware/psci/psci.c
+++ b/drivers/firmware/psci/psci.c
@@ -49,6 +49,8 @@ static int resident_cpu = -1;
struct psci_operations psci_ops;
static enum arm_smccc_conduit psci_conduit = SMCCC_CONDUIT_NONE;
+int psci_driver_version = PSCI_VERSION(0, 0);
+
bool psci_tos_resident_on(int cpu)
{
return cpu == resident_cpu;
@@ -461,6 +463,8 @@ static int __init psci_probe(void)
return -EINVAL;
}
+ psci_driver_version = ver;
+
psci_0_2_set_functions();
psci_init_migrate();
@@ -514,6 +518,8 @@ static int __init psci_0_1_init(struct device_node
*np)
pr_info("Using PSCI v0.1 Function IDs from DT\n");
+ psci_driver_version = PSCI_VERSION(0, 1);
+
if (!of_property_read_u32(np, "cpu_suspend", &id)) {
psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
psci_ops.cpu_suspend = psci_cpu_suspend;
diff --git a/include/linux/psci.h b/include/linux/psci.h
index 2a1bfb890e58..cb35b90d1746 100644
--- a/include/linux/psci.h
+++ b/include/linux/psci.h
@@ -21,6 +21,14 @@ bool psci_power_state_is_valid(u32 state);
int psci_set_osi_mode(bool enable);
bool psci_has_osi_support(void);
+/**
+ * The version of the PSCI specification followed by the driver.
+ * This is equivalent to calling PSCI_VERSION except:
+ * (a) it also works for PSCI v0.1, which does not support
PSCI_VERSION, and
+ * (b) it is set to v0.0 if the PSCI driver was not initialized.
+ */
+extern int psci_driver_version;
+
struct psci_operations {
u32 (*get_version)(void);
int (*cpu_suspend)(u32 state, unsigned long entry_point);
How about providing a get_version callback for pre-0.2 implementations
instead? This would avoid exposing more symbols (psci_ops is already
global).
Thanks,
M.
diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
index 00af99b6f97c..b84454e12d92 100644
--- a/drivers/firmware/psci/psci.c
+++ b/drivers/firmware/psci/psci.c
@@ -500,6 +500,11 @@ static int __init psci_0_2_init(struct device_node
*np)
return psci_probe();
}
+static u32 psci_0_1_get_version(void)
+{
+ return PSCI_VERSION(0, 1);
+}
+
/*
* PSCI < v0.2 get PSCI Function IDs via DT.
*/
@@ -514,6 +519,8 @@ static int __init psci_0_1_init(struct device_node
*np)
pr_info("Using PSCI v0.1 Function IDs from DT\n");
+ psci_ops.get_version = psci_0_1_get_version;
+
if (!of_property_read_u32(np, "cpu_suspend", &id)) {
psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
psci_ops.cpu_suspend = psci_cpu_suspend;
--
Jazz is not dead. It just smells funny...
