Re: [PATCH v2 2/3] firmware: psci: Add support for dt-supplied SYSTEM_RESET2 type
From: Mark Rutland <mark.rutland@arm.com>
Date: 2020-02-26 12:10:12
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On Mon, Feb 24, 2020 at 12:57:37PM -0800, Elliot Berman wrote:
Some implementors of PSCI may relax the requirements of the PSCI architectural warm reset. In order to comply with PSCI specification, a different reset_type value must be used. The alternate PSCI SYSTEM_RESET2 may be used in all warm/soft reboot scenarios, replacing the architectural warm reset.
As with the binding patch, this sounds like a workaround for a firmware bug. Can you please elaborate on what exactly your firmware does in this case? Thanks, Mark.
quoted hunk ↗ jump to hunk
Signed-off-by: Elliot Berman <redacted> --- drivers/firmware/psci/psci.c | 22 ++++++++++++++++++---- include/uapi/linux/psci.h | 2 ++ 2 files changed, 20 insertions(+), 4 deletions(-)diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c index 2937d44..8f4609c 100644 --- a/drivers/firmware/psci/psci.c +++ b/drivers/firmware/psci/psci.c@@ -90,6 +90,8 @@ static u32 psci_function_id[PSCI_FN_MAX]; static u32 psci_cpu_suspend_feature; static bool psci_system_reset2_supported; +static u32 psci_sys_reset2_reset_param = + PSCI_1_1_SYSTEM_RESET2_SYSTEM_WARM_RESET; static inline bool psci_has_ext_power_state(void) {@@ -272,11 +274,10 @@ static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd) if ((reboot_mode == REBOOT_WARM || reboot_mode == REBOOT_SOFT) && psci_system_reset2_supported) { /* - * reset_type[31] = 0 (architectural) - * reset_type[30:0] = 0 (SYSTEM_WARM_RESET) * cookie = 0 (ignored by the implementation) */ - invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), 0, 0, 0); + invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), + psci_sys_reset2_reset_param, 0, 0); } else { invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0); }@@ -493,6 +494,7 @@ typedef int (*psci_initcall_t)(const struct device_node *); static int __init psci_0_2_init(struct device_node *np) { int err; + u32 param; err = get_set_conduit_method(np); if (err)@@ -505,7 +507,19 @@ static int __init psci_0_2_init(struct device_node *np) * can be carried out according to the specific version reported * by firmware */ - return psci_probe(); + err = psci_probe(); + if (err) + return err; + + if (psci_system_reset2_supported && + !of_property_read_u32(np, "arm,psci-sys-reset2-param", ¶m)) { + if ((s32)param > 0) + pr_warn("%08x is an invalid architectural reset type.\n", + param); + psci_sys_reset2_reset_param = param; + } + + return 0; } /*diff --git a/include/uapi/linux/psci.h b/include/uapi/linux/psci.h index 2fcad1d..d786ec8 100644 --- a/include/uapi/linux/psci.h +++ b/include/uapi/linux/psci.h@@ -55,6 +55,8 @@ #define PSCI_1_0_FN64_SYSTEM_SUSPEND PSCI_0_2_FN64(14) #define PSCI_1_1_FN64_SYSTEM_RESET2 PSCI_0_2_FN64(18) +#define PSCI_1_1_SYSTEM_RESET2_SYSTEM_WARM_RESET 0 + /* PSCI v0.2 power state encoding for CPU_SUSPEND function */ #define PSCI_0_2_POWER_STATE_ID_MASK 0xffff #define PSCI_0_2_POWER_STATE_ID_SHIFT 0-- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
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