From: Elliot Berman <quic_eberman@quicinc.com> To: Bjorn Andersson <andersson@kernel.org>, Konrad Dybcio <konrad.dybcio@linaro.org>, Sebastian Reichel <sre@kernel.org>, Rob Herring <robh@kernel.org>, Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>, Conor Dooley <conor+dt@kernel.org>, Vinod Koul <vkoul@kernel.org>, Andy Yan <andy.yan@rock-chips.com>, Lorenzo Pieralisi <lpieralisi@kernel.org>, "Mark Rutland" <mark.rutland@arm.com>, Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Cc: Satya Durga Srinivasu Prabhala <quic_satyap@quicinc.com>, Melody Olvera <quic_molvera@quicinc.com>, Shivendra Pratap <quic_spratap@quicinc.com>, <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, Florian Fainelli <florian.fainelli@broadcom.com>, <linux-pm@vger.kernel.org>, <linux-arm-msm@vger.kernel.org>, Elliot Berman <quic_eberman@quicinc.com> Subject: [PATCH v2 3/4] firmware: psci: Read and use vendor reset types Date: Sun, 14 Apr 2024 12:30:26 -0700 [thread overview] Message-ID: <20240414-arm-psci-system_reset2-vendor-reboots-v2-3-da9a055a648f@quicinc.com> (raw) In-Reply-To: <20240414-arm-psci-system_reset2-vendor-reboots-v2-0-da9a055a648f@quicinc.com> SoC vendors have different types of resets and are controlled through various registers. For instance, Qualcomm chipsets can reboot to a "download mode" that allows a RAM dump to be collected. Another example is they also support writing a cookie that can be read by bootloader during next boot. PSCI offers a mechanism, SYSTEM_RESET2, for these vendor reset types to be implemented without requiring drivers for every register/cookie. Add support in PSCI to statically map reboot mode commands from userspace to a vendor reset and cookie value using the device tree. Reboot mode framework is close but doesn't quite fit with the design and requirements for PSCI SYSTEM_RESET2. Some of these issues can be solved but doesn't seem reasonable in sum: 1. reboot mode registers against the reboot_notifier_list, which is too early to call SYSTEM_RESET2. PSCI would need to remember the reset type from the reboot-mode framework callback and use it psci_sys_reset. 2. reboot mode assumes only one cookie/parameter is described in the device tree. SYSTEM_RESET2 uses 2: one for the type and one for cookie. 3. psci cpuidle driver already registers a driver against the arm,psci-1.0 compatible. Refactoring would be needed to have both a cpuidle and reboot-mode driver. Signed-off-by: Elliot Berman <quic_eberman@quicinc.com> --- drivers/firmware/psci/psci.c | 90 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c index d9629ff87861..e0a764743a20 100644 --- a/drivers/firmware/psci/psci.c +++ b/drivers/firmware/psci/psci.c @@ -29,6 +29,8 @@ #include <asm/smp_plat.h> #include <asm/suspend.h> +#define REBOOT_PREFIX "mode-" + /* * While a 64-bit OS can make calls with SMC32 calling conventions, for some * calls it is necessary to use SMC64 to pass or return 64-bit values. @@ -79,6 +81,14 @@ struct psci_0_1_function_ids get_psci_0_1_function_ids(void) static u32 psci_cpu_suspend_feature; static bool psci_system_reset2_supported; +struct psci_reset_param { + const char *mode; + u32 reset_type; + u32 cookie; +}; +static struct psci_reset_param *psci_reset_params; +static size_t num_psci_reset_params; + static inline bool psci_has_ext_power_state(void) { return psci_cpu_suspend_feature & @@ -305,9 +315,29 @@ static int get_set_conduit_method(const struct device_node *np) return 0; } +static void psci_vendor_sys_reset2(unsigned long action, void *data) +{ + const char *cmd = data; + unsigned long ret; + size_t i; + + for (i = 0; i < num_psci_reset_params; i++) { + if (!strcmp(psci_reset_params[i].mode, cmd)) { + ret = invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), + psci_reset_params[i].reset_type, + psci_reset_params[i].cookie, 0); + pr_err("failed to perform reset \"%s\": %ld\n", + cmd, (long)ret); + } + } +} + static int psci_sys_reset(struct notifier_block *nb, unsigned long action, void *data) { + if (data && num_psci_reset_params) + psci_vendor_sys_reset2(action, data); + if ((reboot_mode == REBOOT_WARM || reboot_mode == REBOOT_SOFT) && psci_system_reset2_supported) { /* @@ -748,6 +778,66 @@ static const struct of_device_id psci_of_match[] __initconst = { {}, }; +static int __init psci_init_system_reset2_modes(void) +{ + const size_t len = strlen(REBOOT_PREFIX); + struct psci_reset_param *param; + struct device_node *np; + struct property *prop; + size_t count = 0; + u32 magic[2]; + int num; + + if (!psci_system_reset2_supported) + return 0; + + np = of_find_matching_node(NULL, psci_of_match); + if (!np) + return 0; + + for_each_property_of_node(np, prop) { + if (strncmp(prop->name, REBOOT_PREFIX, len)) + continue; + num = of_property_count_elems_of_size(np, prop->name, sizeof(magic[0])); + if (num != 1 && num != 2) + continue; + + count++; + } + + param = psci_reset_params = kcalloc(count, sizeof(*psci_reset_params), GFP_KERNEL); + if (!psci_reset_params) { + of_node_put(np); + return -ENOMEM; + } + + for_each_property_of_node(np, prop) { + if (strncmp(prop->name, REBOOT_PREFIX, len)) + continue; + + param->mode = kstrdup_const(prop->name + len, GFP_KERNEL); + if (!param->mode) + continue; + + num = of_property_read_variable_u32_array(np, prop->name, magic, 1, 2); + if (num < 0) { + pr_warn("Failed to parse vendor reboot mode %s\n", param->mode); + kfree_const(param->mode); + continue; + } + + /* Force reset type to be in vendor space */ + param->reset_type = PSCI_1_1_RESET_TYPE_VENDOR_START | magic[0]; + param->cookie = num == 2 ? magic[1] : 0; + param++; + num_psci_reset_params++; + } + + of_node_put(np); + return 0; +} +arch_initcall(psci_init_system_reset2_modes); + int __init psci_dt_init(void) { struct device_node *np; -- 2.34.1
WARNING: multiple messages have this Message-ID (diff)
From: Elliot Berman <quic_eberman@quicinc.com> To: Bjorn Andersson <andersson@kernel.org>, Konrad Dybcio <konrad.dybcio@linaro.org>, Sebastian Reichel <sre@kernel.org>, Rob Herring <robh@kernel.org>, Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>, Conor Dooley <conor+dt@kernel.org>, Vinod Koul <vkoul@kernel.org>, Andy Yan <andy.yan@rock-chips.com>, Lorenzo Pieralisi <lpieralisi@kernel.org>, "Mark Rutland" <mark.rutland@arm.com>, Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Cc: Satya Durga Srinivasu Prabhala <quic_satyap@quicinc.com>, Melody Olvera <quic_molvera@quicinc.com>, Shivendra Pratap <quic_spratap@quicinc.com>, <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, Florian Fainelli <florian.fainelli@broadcom.com>, <linux-pm@vger.kernel.org>, <linux-arm-msm@vger.kernel.org>, Elliot Berman <quic_eberman@quicinc.com> Subject: [PATCH v2 3/4] firmware: psci: Read and use vendor reset types Date: Sun, 14 Apr 2024 12:30:26 -0700 [thread overview] Message-ID: <20240414-arm-psci-system_reset2-vendor-reboots-v2-3-da9a055a648f@quicinc.com> (raw) In-Reply-To: <20240414-arm-psci-system_reset2-vendor-reboots-v2-0-da9a055a648f@quicinc.com> SoC vendors have different types of resets and are controlled through various registers. For instance, Qualcomm chipsets can reboot to a "download mode" that allows a RAM dump to be collected. Another example is they also support writing a cookie that can be read by bootloader during next boot. PSCI offers a mechanism, SYSTEM_RESET2, for these vendor reset types to be implemented without requiring drivers for every register/cookie. Add support in PSCI to statically map reboot mode commands from userspace to a vendor reset and cookie value using the device tree. Reboot mode framework is close but doesn't quite fit with the design and requirements for PSCI SYSTEM_RESET2. Some of these issues can be solved but doesn't seem reasonable in sum: 1. reboot mode registers against the reboot_notifier_list, which is too early to call SYSTEM_RESET2. PSCI would need to remember the reset type from the reboot-mode framework callback and use it psci_sys_reset. 2. reboot mode assumes only one cookie/parameter is described in the device tree. SYSTEM_RESET2 uses 2: one for the type and one for cookie. 3. psci cpuidle driver already registers a driver against the arm,psci-1.0 compatible. Refactoring would be needed to have both a cpuidle and reboot-mode driver. Signed-off-by: Elliot Berman <quic_eberman@quicinc.com> --- drivers/firmware/psci/psci.c | 90 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c index d9629ff87861..e0a764743a20 100644 --- a/drivers/firmware/psci/psci.c +++ b/drivers/firmware/psci/psci.c @@ -29,6 +29,8 @@ #include <asm/smp_plat.h> #include <asm/suspend.h> +#define REBOOT_PREFIX "mode-" + /* * While a 64-bit OS can make calls with SMC32 calling conventions, for some * calls it is necessary to use SMC64 to pass or return 64-bit values. @@ -79,6 +81,14 @@ struct psci_0_1_function_ids get_psci_0_1_function_ids(void) static u32 psci_cpu_suspend_feature; static bool psci_system_reset2_supported; +struct psci_reset_param { + const char *mode; + u32 reset_type; + u32 cookie; +}; +static struct psci_reset_param *psci_reset_params; +static size_t num_psci_reset_params; + static inline bool psci_has_ext_power_state(void) { return psci_cpu_suspend_feature & @@ -305,9 +315,29 @@ static int get_set_conduit_method(const struct device_node *np) return 0; } +static void psci_vendor_sys_reset2(unsigned long action, void *data) +{ + const char *cmd = data; + unsigned long ret; + size_t i; + + for (i = 0; i < num_psci_reset_params; i++) { + if (!strcmp(psci_reset_params[i].mode, cmd)) { + ret = invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), + psci_reset_params[i].reset_type, + psci_reset_params[i].cookie, 0); + pr_err("failed to perform reset \"%s\": %ld\n", + cmd, (long)ret); + } + } +} + static int psci_sys_reset(struct notifier_block *nb, unsigned long action, void *data) { + if (data && num_psci_reset_params) + psci_vendor_sys_reset2(action, data); + if ((reboot_mode == REBOOT_WARM || reboot_mode == REBOOT_SOFT) && psci_system_reset2_supported) { /* @@ -748,6 +778,66 @@ static const struct of_device_id psci_of_match[] __initconst = { {}, }; +static int __init psci_init_system_reset2_modes(void) +{ + const size_t len = strlen(REBOOT_PREFIX); + struct psci_reset_param *param; + struct device_node *np; + struct property *prop; + size_t count = 0; + u32 magic[2]; + int num; + + if (!psci_system_reset2_supported) + return 0; + + np = of_find_matching_node(NULL, psci_of_match); + if (!np) + return 0; + + for_each_property_of_node(np, prop) { + if (strncmp(prop->name, REBOOT_PREFIX, len)) + continue; + num = of_property_count_elems_of_size(np, prop->name, sizeof(magic[0])); + if (num != 1 && num != 2) + continue; + + count++; + } + + param = psci_reset_params = kcalloc(count, sizeof(*psci_reset_params), GFP_KERNEL); + if (!psci_reset_params) { + of_node_put(np); + return -ENOMEM; + } + + for_each_property_of_node(np, prop) { + if (strncmp(prop->name, REBOOT_PREFIX, len)) + continue; + + param->mode = kstrdup_const(prop->name + len, GFP_KERNEL); + if (!param->mode) + continue; + + num = of_property_read_variable_u32_array(np, prop->name, magic, 1, 2); + if (num < 0) { + pr_warn("Failed to parse vendor reboot mode %s\n", param->mode); + kfree_const(param->mode); + continue; + } + + /* Force reset type to be in vendor space */ + param->reset_type = PSCI_1_1_RESET_TYPE_VENDOR_START | magic[0]; + param->cookie = num == 2 ? magic[1] : 0; + param++; + num_psci_reset_params++; + } + + of_node_put(np); + return 0; +} +arch_initcall(psci_init_system_reset2_modes); + int __init psci_dt_init(void) { struct device_node *np; -- 2.34.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2024-04-14 19:32 UTC|newest] Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-04-14 19:30 [PATCH v2 0/4] Implement vendor resets for PSCI SYSTEM_RESET2 Elliot Berman 2024-04-14 19:30 ` Elliot Berman 2024-04-14 19:30 ` [PATCH v2 1/4] dt-bindings: power: reset: Convert mode-.* properties to array Elliot Berman 2024-04-14 19:30 ` Elliot Berman 2024-04-20 0:50 ` Krzysztof Kozlowski 2024-04-20 0:50 ` Krzysztof Kozlowski 2024-04-14 19:30 ` [PATCH v2 2/4] dt-bindings: arm: Document reboot mode magic Elliot Berman 2024-04-14 19:30 ` Elliot Berman 2024-04-15 19:34 ` Konrad Dybcio 2024-04-15 19:34 ` Konrad Dybcio 2024-04-16 9:30 ` Sudeep Holla 2024-04-16 9:30 ` Sudeep Holla 2024-04-16 12:32 ` Dmitry Baryshkov 2024-04-16 12:32 ` Dmitry Baryshkov 2024-04-14 19:30 ` Elliot Berman [this message] 2024-04-14 19:30 ` [PATCH v2 3/4] firmware: psci: Read and use vendor reset types Elliot Berman 2024-04-15 19:39 ` Konrad Dybcio 2024-04-15 19:39 ` Konrad Dybcio 2024-04-14 19:30 ` [PATCH v2 4/4] arm64: dts: qcom: Add PSCI SYSTEM_RESET2 types for qcm6490-idp Elliot Berman 2024-04-14 19:30 ` Elliot Berman 2024-04-14 23:13 ` Dmitry Baryshkov 2024-04-14 23:13 ` Dmitry Baryshkov 2024-04-15 0:32 ` Elliot Berman 2024-04-15 0:32 ` Elliot Berman 2024-04-15 19:42 ` Konrad Dybcio 2024-04-15 19:42 ` Konrad Dybcio 2024-04-16 1:11 ` Elliot Berman 2024-04-16 1:11 ` Elliot Berman 2024-04-16 9:35 ` [PATCH v2 0/4] Implement vendor resets for PSCI SYSTEM_RESET2 Sudeep Holla 2024-04-16 9:35 ` Sudeep Holla 2024-04-17 17:50 ` Florian Fainelli 2024-04-17 17:50 ` Florian Fainelli 2024-04-19 12:38 ` Sudeep Holla 2024-04-19 12:38 ` Sudeep Holla 2024-05-02 2:21 ` Elliot Berman 2024-05-02 2:21 ` Elliot Berman 2024-04-17 21:54 ` Elliot Berman 2024-04-17 21:54 ` Elliot Berman 2024-04-17 22:01 ` Florian Fainelli 2024-04-17 22:01 ` Florian Fainelli 2024-04-18 17:52 ` Elliot Berman 2024-04-18 17:52 ` Elliot Berman 2024-04-19 8:53 ` Sudeep Holla 2024-04-19 8:53 ` Sudeep Holla 2024-04-19 23:31 ` Elliot Berman 2024-04-19 23:31 ` Elliot Berman
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