- 14 Jun, 2017 1 commit
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Varun Wadekar authored
This patch enables the 'sign-compare' flag, to enable warning/errors for comparisons between signed/unsigned variables. The warning has been enabled for all the Tegra platforms, to start with. Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
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- 03 May, 2017 1 commit
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dp-arm authored
To make software license auditing simpler, use SPDX[0] license identifiers instead of duplicating the license text in every file. NOTE: Files that have been imported by FreeBSD have not been modified. [0]: https://spdx.org/ Change-Id: I80a00e1f641b8cc075ca5a95b10607ed9ed8761a Signed-off-by: dp-arm <dimitris.papastamos@arm.com>
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- 13 Feb, 2017 1 commit
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dp-arm authored
This patch introduces the following three platform interfaces: * void plat_psci_stat_accounting_start(const psci_power_state_t *state_info) This is an optional hook that platforms can implement in order to perform accounting before entering a low power state. This typically involves capturing a timestamp. * void plat_psci_stat_accounting_stop(const psci_power_state_t *state_info) This is an optional hook that platforms can implement in order to perform accounting after exiting from a low power state. This typically involves capturing a timestamp. * u_register_t plat_psci_stat_get_residency(unsigned int lvl, const psci_power_state_t *state_info, unsigned int last_cpu_index) This is an optional hook that platforms can implement in order to calculate the PSCI stat residency. If any of these interfaces are overridden by the platform, it is recommended that all of them are. By default `ENABLE_PSCI_STAT` is disabled. If `ENABLE_PSCI_STAT` is set but `ENABLE_PMF` is not set then an alternative PSCI stat collection backend must be provided. If both are set, then default weak definitions of these functions are provided, using PMF to calculate the residency. NOTE: Previously, platforms did not have to explicitly set `ENABLE_PMF` since this was automatically done by the top-level Makefile. Change-Id: I17b47804dea68c77bc284df15ee1ccd66bc4b79b Signed-off-by: dp-arm <dimitris.papastamos@arm.com>
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- 12 Oct, 2016 1 commit
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dp-arm authored
In order to quantify the overall time spent in the PSCI software implementation, an initial collection of PMF instrumentation points has been added. Instrumentation has been added to the following code paths: - Entry to PSCI SMC handler. The timestamp is captured as early as possible during the runtime exception and stored in memory before entering the PSCI SMC handler. - Exit from PSCI SMC handler. The timestamp is captured after normal return from the PSCI SMC handler or if a low power state was requested it is captured in the bl31 warm boot path before return to normal world. - Entry to low power state. The timestamp is captured before entry to a low power state which implies either standby or power down. As these power states are mutually exclusive, only one timestamp is defined to describe both. It is possible to differentiate between the two power states using the PSCI STAT interface. - Exit from low power state. The timestamp is captured after a standby or power up operation has completed. To calculate the number of cycles spent running code in Trusted Firmware one can perform the following calculation: (exit_psci - enter_psci) - (exit_low_pwr - enter_low_pwr). The resulting number of cycles can be converted to time given the frequency of the counter. Change-Id: Ie3b8f3d16409b6703747093b3a2d5c7429ad0166 Signed-off-by: dp-arm <dimitris.papastamos@arm.com>
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- 15 Sep, 2016 1 commit
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Jeenu Viswambharan authored
This patch adds support for NODE_HW_STATE PSCI API by introducing a new PSCI platform hook (get_node_hw_state). The implementation validates supplied arguments, and then invokes this platform-defined hook and returns its result to the caller. PSCI capabilities are updated accordingly. Also updates porting and firmware design guides. Change-Id: I808e55bdf0c157002a7c104b875779fe50a68a30
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- 25 Jul, 2016 1 commit
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Sandrine Bailleux authored
This patch adds a runtime check that psci_find_target_suspend_lvl() returns a valid value back to psci_cpu_suspend() and psci_get_stat(). If it is invalid, BL31 will now panic. Note that on the PSCI CPU suspend path there is already a debug assertion checking the validity of the target composite power state, which effectively also checks the validity of the target suspend level. Therefore, the error condition would already be caught in debug builds, but in a release build this assertion would be compiled out. On the PSCI stat path, there is currently no debug assertion checking the validity of the power state before using it as an index into the power domain state array. Although BL31 platforms ports are responsible for validating the power state parameter, the security impact (i.e. an out-of-bounds array access) of a potential platform port bug in this code would be quite high, given that this parameter comes from an untrusted source. The cost of checking this in runtime generic code is low. Change-Id: Icea85b8020e39928ac03ec0cd49805b5857b3906
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- 19 Jul, 2016 1 commit
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Soby Mathew authored
This patch introduces the PSCI Library interface. The major changes introduced are as follows: * Earlier BL31 was responsible for Architectural initialization during cold boot via bl31_arch_setup() whereas PSCI was responsible for the same during warm boot. This functionality is now consolidated by the PSCI library and it does Architectural initialization via psci_arch_setup() during both cold and warm boots. * Earlier the warm boot entry point was always `psci_entrypoint()`. This was not flexible enough as a library interface. Now PSCI expects the runtime firmware to provide the entry point via `psci_setup()`. A new function `bl31_warm_entrypoint` is introduced in BL31 and the previous `psci_entrypoint()` is deprecated. * The `smc_helpers.h` is reorganized to separate the SMC Calling Convention defines from the Trusted Firmware SMC helpers. The former is now in a new header file `smcc.h` and the SMC helpers are moved to Architecture specific header. * The CPU context is used by PSCI for context initialization and restoration after power down (PSCI Context). It is also used by BL31 for SMC handling and context management during Normal-Secure world switch (SMC Context). The `psci_smc_handler()` interface is redefined to not use SMC helper macros thus enabling to decouple the PSCI context from EL3 runtime firmware SMC context. This enables PSCI to be integrated with other runtime firmware using a different SMC context. NOTE: With this patch the architectural setup done in `bl31_arch_setup()` is done as part of `psci_setup()` and hence `bl31_platform_setup()` will be invoked prior to architectural setup. It is highly unlikely that the platform setup will depend on architectural setup and cause any failure. Please be be aware of this change in sequence. Change-Id: I7f497a08d33be234bbb822c28146250cb20dab73
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- 18 Jul, 2016 3 commits
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Soby Mathew authored
This patch moves the PSCI services and BL31 frameworks like context management and per-cpu data into new library components `PSCI` and `el3_runtime` respectively. This enables PSCI to be built independently from BL31. A new `psci_lib.mk` makefile is introduced which adds the relevant PSCI library sources and gets included by `bl31.mk`. Other changes which are done as part of this patch are: * The runtime services framework is now moved to the `common/` folder to enable reuse. * The `asm_macros.S` and `assert_macros.S` helpers are moved to architecture specific folder. * The `plat_psci_common.c` is moved from the `plat/common/aarch64/` folder to `plat/common` folder. The original file location now has a stub which just includes the file from new location to maintain platform compatibility. Most of the changes wouldn't affect platform builds as they just involve changes to the generic bl1.mk and bl31.mk makefiles. NOTE: THE `plat_psci_common.c` FILE HAS MOVED LOCATION AND THE STUB FILE AT THE ORIGINAL LOCATION IS NOW DEPRECATED. PLATFORMS SHOULD MODIFY THEIR MAKEFILES TO INCLUDE THE FILE FROM THE NEW LOCATION. Change-Id: I6bd87d5b59424995c6a65ef8076d4fda91ad5e86
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Soby Mathew authored
This patch fixes some coding guideline warnings reported by the checkpatch script. Only files related to upcoming feature development have been fixed. Change-Id: I26fbce75c02ed62f00493ed6c106fe7c863ddbc5
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Soby Mathew authored
This patch reworks type usage in generic code, drivers and ARM platform files to make it more portable. The major changes done with respect to type usage are as listed below: * Use uintptr_t for storing address instead of uint64_t or unsigned long. * Review usage of unsigned long as it can no longer be assumed to be 64 bit. * Use u_register_t for register values whose width varies depending on whether AArch64 or AArch32. * Use generic C types where-ever possible. In addition to the above changes, this patch also modifies format specifiers in print invocations so that they are AArch64/AArch32 agnostic. Only files related to upcoming feature development have been reworked. Change-Id: I9f8c78347c5a52ba7027ff389791f1dad63ee5f8
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- 16 Jun, 2016 1 commit
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Yatharth Kochar authored
This patch adds following optional PSCI STAT functions: - PSCI_STAT_RESIDENCY: This call returns the amount of time spent in power_state in microseconds, by the node represented by the `target_cpu` and the highest level of `power_state`. - PSCI_STAT_COUNT: This call returns the number of times a `power_state` has been used by the node represented by the `target_cpu` and the highest power level of `power_state`. These APIs provides residency statistics for power states that has been used by the platform. They are implemented according to v1.0 of the PSCI specification. By default this optional feature is disabled in the PSCI implementation. To enable it, set the boolean flag `ENABLE_PSCI_STAT` to 1. This also sets `ENABLE_PMF` to 1. Change-Id: Ie62e9d37d6d416ccb1813acd7f616d1ddd3e8aff
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- 25 Apr, 2016 1 commit
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Sandrine Bailleux authored
The "end power level" value passed as the 3rd argument to the psci_cpu_on_start() function is not used so this patch removes it. Change-Id: Icaa68b8c4ecd94507287970455fbff354faaa41e
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- 13 Aug, 2015 3 commits
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Soby Mathew authored
This patch reworks the PSCI generic implementation to conform to ARM Trusted Firmware coding guidelines as described here: https://github.com/ARM-software/arm-trusted-firmware/wiki This patch also reviews the use of signed data types within PSCI Generic code and replaces them with their unsigned counterparts wherever they are not appropriate. The PSCI_INVALID_DATA macro which was defined to -1 is now replaced with PSCI_INVALID_PWR_LVL macro which is defined to PLAT_MAX_PWR_LVL + 1. Change-Id: Iaea422d0e46fc314e0b173c2b4c16e0d56b2515a
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Soby Mathew authored
As per PSCI1.0 specification, the error code to be returned when an invalid non secure entrypoint address is specified by the PSCI client for CPU_SUSPEND, CPU_ON or SYSTEM_SUSPEND must be PSCI_E_INVALID_ADDRESS. The current PSCI implementation returned PSCI_E_INVAL_PARAMS. This patch rectifies this error and also implements a common helper function to validate the entrypoint information to be used across these PSCI API implementations. Change-Id: I52d697d236c8bf0cd3297da4008c8e8c2399b170
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Soby Mathew authored
This commit does the switch to the new PSCI framework implementation replacing the existing files in PSCI folder with the ones in PSCI1.0 folder. The corresponding makefiles are modified as required for the new implementation. The platform.h header file is also is switched to the new one as required by the new frameworks. The build flag ENABLE_PLAT_COMPAT defaults to 1 to enable compatibility layer which let the existing platform ports to continue to build and run with minimal changes. The default weak implementation of platform_get_core_pos() is now removed from platform_helpers.S and is provided by the compatibility layer. Note: The Secure Payloads and their dispatchers still use the old platform and framework APIs and hence it is expected that the ENABLE_PLAT_COMPAT build flag will remain enabled in subsequent patch. The compatibility for SPDs using the older APIs on platforms migrated to the new APIs will be added in the following patch. Change-Id: I18c51b3a085b564aa05fdd98d11c9f3335712719
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- 22 Jun, 2015 1 commit
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Soby Mathew authored
This patch adds support for SYSTEM_SUSPEND API as mentioned in the PSCI 1.0 specification. This API, on being invoked on the last running core on a supported platform, will put the system into a low power mode with memory retention. The psci_afflvl_suspend() internal API has been reused as most of the actions to suspend a system are the same as invoking the PSCI CPU_SUSPEND API with the target affinity level as 'system'. This API needs the 'power state' parameter for the target low power state. This parameter is not passed by the caller of the SYSTEM_SUSPEND API. Hence, the platform needs to implement the get_sys_suspend_power_state() platform function to provide this information. Also, the platform also needs to add support for suspending the system to the existing 'plat_pm_ops' functions: affinst_suspend() and affinst_suspend_finish(). Change-Id: Ib6bf10809cb4e9b92f463755608889aedd83cef5
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- 12 Feb, 2015 1 commit
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Soby Mathew authored
This patch removes the plat_get_max_afflvl() platform API and instead replaces it with a platform macro PLATFORM_MAX_AFFLVL. This is done because the maximum affinity level for a platform is a static value and it is more efficient for it to be defined as a platform macro. NOTE: PLATFORM PORTS NEED TO BE UPDATED ON MERGE OF THIS COMMIT Fixes ARM-Software/tf-issues#265 Change-Id: I31d89b30c2ccda30d28271154d869060d50df7bf
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- 26 Jan, 2015 3 commits
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Soby Mathew authored
This patch implements conditional checks in psci_smc_handler() to verify that the psci function invoked by the caller is supported by the platform or SPD implementation. The level of support is saved in the 'psci_caps' variable. This check allows the PSCI implementation to return an error early. As a result of the above verification, the checks performed within the psci handlers for the pm hooks are now removed and replaced with assertions. Change-Id: I9b5b646a01d8566dc28c4d77dd3aa54e9bf3981a
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Soby Mathew authored
This patch implements the PSCI_FEATURES function which is a mandatory API in the PSCI 1.0 specification. A capability variable is constructed during initialization by examining the plat_pm_ops and spd_pm_ops exported by the platform and the Secure Payload Dispatcher. This is used by the PSCI FEATURES function to determine which PSCI APIs are supported by the platform. Change-Id: I147ffc1bd5d90b469bd3cc4bbe0a20e95c247df7
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Soby Mathew authored
This patch reworks the PSCI MIGRATE, MIGRATE_INFO_TYPE and MIGRATE_INFO_UP_CPU support for Trusted Firmware. The implementation does the appropriate validation of parameters and invokes the appropriate hook exported by the SPD. The TSP is a MP Trusted OS. Hence the ability to actually migrate a Trusted OS has not been implemented. The corresponding function is not populated in the spd_pm_hooks structure for the TSPD. The `spd_pm_ops_t` has undergone changes with this patch. SPD PORTS MAY NEED TO BE UPDATED. Fixes ARM-software/tf-issues#249 Change-Id: Iabd87521bf7c530a5e4506b6d3bfd4f1bf87604f
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- 23 Jan, 2015 4 commits
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Soby Mathew authored
This patch adds support to return SUCCESS if a pending interrupt is detected during a CPU_SUSPEND call to a power down state. The check is performed as late as possible without losing the ability to return to the caller. This reduces the overhead incurred by a CPU in undergoing a complete power cycle when a wakeup interrupt is already pending. Fixes ARM-Software/tf-issues#102 Change-Id: I1aff04a74b704a2f529734428030d1d10750fd4b
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Soby Mathew authored
This patch allows the platform to validate the power_state and entrypoint information from the normal world early on in PSCI calls so that we can return the error safely. New optional pm_ops hooks `validate_power_state` and `validate_ns_entrypoint` are introduced to do this. As a result of these changes, all the other pm_ops handlers except the PSCI_ON handler are expected to be successful. Also, the PSCI implementation will now assert if a PSCI API is invoked without the corresponding pm_ops handler being registered by the platform. NOTE : PLATFORM PORTS WILL BREAK ON MERGE OF THIS COMMIT. The pm hooks have 2 additional optional callbacks and the return type of the other hooks have changed. Fixes ARM-Software/tf-issues#229 Change-Id: I036bc0cff2349187c7b8b687b9ee0620aa7e24dc
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Soby Mathew authored
This patch adds support to save the "power state" parameter before the affinity level specific handlers are called in a CPU_SUSPEND call. This avoids the need to pass the power_state as a parameter to the handlers and Secure Payload Dispatcher (SPD) suspend spd_pm_ops. The power_state arguments in the spd_pm_ops operations are now reserved and must not be used. The SPD can query the relevant power_state fields by using the psci_get_suspend_afflvl() & psci_get_suspend_stateid() APIs. NOTE: THIS PATCH WILL BREAK THE SPD_PM_OPS INTERFACE. HENCE THE SECURE PAYLOAD DISPATCHERS WILL NEED TO BE REWORKED TO USE THE NEW INTERFACE. Change-Id: I1293d7dc8cf29cfa6a086a009eee41bcbf2f238e
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Soby Mathew authored
This patch replaces the internal psci_save_ns_entry() API with a psci_get_ns_ep_info() API. The new function splits the work done by the previous one such that it populates and returns an 'entry_point_info_t' structure with the information to enter the normal world upon completion of the CPU_SUSPEND or CPU_ON call. This information is used to populate the non-secure context structure separately. This allows the new internal API `psci_get_ns_ep_info` to return error and enable the code to return safely. Change-Id: Ifd87430a4a3168eac0ebac712f59c93cbad1b231
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- 12 Dec, 2014 1 commit
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Soby Mathew authored
This patch fixes the assertion failure when CPU_SUSPEND is invoked with an affinity level higher than supported by the platform by adding suitable checks for affinity level within `psci_cpu_suspend`. Also added suitable bound checks within `psci_aff_map_get_idx` to prevent indexing beyond array limits. Fixes ARM-software/tf-issues#260 Change-Id: I04b75c49729e6c6d1983add590f60146c8fc3630
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- 19 Aug, 2014 1 commit
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Juan Castillo authored
This patch adds support for SYSTEM_OFF and SYSTEM_RESET PSCI operations. A platform should export handlers to complete the requested operation. The FVP port exports fvp_system_off() and fvp_system_reset() as an example. If the SPD provides a power management hook for system off and system reset, then the SPD is notified about the corresponding operation so it can do some bookkeeping. The TSPD exports tspd_system_off() and tspd_system_reset() for that purpose. Versatile Express shutdown and reset methods have been removed from the FDT as new PSCI sys_poweroff and sys_reset services have been added. For those kernels that do not support yet these PSCI services (i.e. GICv3 kernel), the original dtsi files have been renamed to *-no_psci.dtsi. Fixes ARM-software/tf-issues#218 Change-Id: Ic8a3bf801db979099ab7029162af041c4e8330c8
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- 19 Jul, 2014 1 commit
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Achin Gupta authored
This patch uses stacks allocated in normal memory to enable the MMU early in the warm boot path thus removing the dependency on stacks allocated in coherent memory. Necessary cache and stack maintenance is performed when a cpu is being powered down and up. This avoids any coherency issues that can arise from reading speculatively fetched stale stack memory from another CPUs cache. These changes affect the warm boot path in both BL3-1 and BL3-2. The EL3 system registers responsible for preserving the MMU state are not saved and restored any longer. Static values are used to program these system registers when a cpu is powered on or resumed from suspend. Change-Id: I8357e2eb5eb6c5f448492c5094b82b8927603784
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- 25 Jun, 2014 1 commit
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Andrew Thoelke authored
Many of the interfaces internal to PSCI pass the current CPU MPIDR_EL1 value from function to function. This is not required, and with inline access to the system registers is less efficient than requiring the code to read that register whenever required. This patch remove the mpidr parameter from the affected interfaces and reduces code in FVP BL3-1 size by 160 bytes. Change-Id: I16120a7c6944de37232016d7e109976540775602
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- 10 Jun, 2014 1 commit
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Andrew Thoelke authored
The SMC handler for PSCI was not correctly handling calls from secure states, or from AArch32. This patch completes the handler implementation to correctly detect secure callers and to clear the top bits in parameters from AArch32 callers. The patch also reorganises the switch statement to separate SMC64 and SMC32 function IDs which allows the compiler to generate much smaller code for the function. Change-Id: I36b1ac81fb14253d257255d0477771d54fab0d11
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- 12 May, 2014 1 commit
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Achin Gupta authored
This patch fixes the broken support for entry into standby states introduced under commit-id 'd118f9f8' (tf-issues#94). Upon exit from the platform defined standby state instead of returning to the caller of the SMC, execution would get stuck in the wfi instruction meant for entering a power down state. This patch ensures that exit from a standby state and entry into a power down state do not interfere with each other. Fixes ARM-software/tf-issues#154 Change-Id: I56e5df353368e44d6eefc94ffedefe21929f5cfe
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- 06 May, 2014 3 commits
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Dan Handley authored
Reduce the number of header files included from other header files as much as possible without splitting the files. Use forward declarations where possible. This allows removal of some unnecessary "#ifndef __ASSEMBLY__" statements. Also, review the .c and .S files for which header files really need including and reorder the #include statements alphabetically. Fixes ARM-software/tf-issues#31 Change-Id: Iec92fb976334c77453e010b60bcf56f3be72bd3e
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Dan Handley authored
Add tag names to all unnamed structs in header files. This allows forward declaration of structs, which is necessary to reduce header file nesting (to be implemented in a subsequent commit). Also change the typedef names across the codebase to use the _t suffix to be more conformant with the Linux coding style. The coding style actually prefers us not to use typedefs at all but this is considered a step too far for Trusted Firmware. Also change the IO framework structs defintions to use typedef'd structs to be consistent with the rest of the codebase. Change-Id: I722b2c86fc0d92e4da3b15e5cab20373dd26786f
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Dan Handley authored
Make codebase consistent in its use of #include "" syntax for user includes and #include <> syntax for system includes. Fixes ARM-software/tf-issues#65 Change-Id: If2f7c4885173b1fd05ac2cde5f1c8a07000c7a33
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- 29 Apr, 2014 1 commit
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Vikram Kanigiri authored
This patch saves the 'power_state' parameter prior to suspending a cpu and invalidates it upon its resumption. The 'affinity level' and 'state id' fields of this parameter can be read using a set of public and private apis. Validation of power state parameter is introduced which checks for SBZ bits are zero. This change also takes care of flushing the parameter from the cache to main memory. This ensures that it is available after cpu reset when the caches and mmu are turned off. The earlier support for saving only the 'affinity level' field of the 'power_state' parameter has also been reworked. Fixes ARM-Software/tf-issues#26 Fixes ARM-Software/tf-issues#130 Change-Id: Ic007ccb5e39bf01e0b67390565d3b4be33f5960a
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- 26 Mar, 2014 1 commit
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Vikram Kanigiri authored
This patch adds support in the generic PSCI implementation to call a platform specific function to enter a standby state using an example implementation in ARM FVP port Fixes ARM-software/tf-issues#94 Change-Id: Ic1263fcf25f28e09162ad29dca954125f9aa8cc9
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- 20 Mar, 2014 1 commit
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Jeenu Viswambharan authored
This patch implements ARM Standard Service as a runtime service and adds support for call count, UID and revision information SMCs. The existing PSCI implementation is subsumed by the Standard Service calls and all PSCI calls are therefore dispatched by the Standard Service to the PSCI handler. At present, PSCI is the only specification under Standard Service. Thus call count returns the number of PSCI calls implemented. As this is the initial implementation, a revision number of 0.1 is returned for call revision. Fixes ARM-software/tf-issues#62 Change-Id: I6d4273f72ad6502636efa0f872e288b191a64bc1
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- 20 Feb, 2014 2 commits
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Achin Gupta authored
This patch implements a set of handlers in the SPD which are called by the PSCI runtime service upon receiving a power management operation. These handlers in turn pass control to the Secure Payload image if required before returning control to PSCI. This ensures that the Secure Payload has complete visibility of all power transitions in the system and can prepare accordingly. Change-Id: I2d1dba5629b7cf2d53999d39fe807dfcf3f62fe2
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Achin Gupta authored
This patch creates a 'services' directory and moves the PSCI under it. Other runtime services e.g. the Secure Payload Dispatcher service will be placed under the same directory in the future. Also fixes issue ARM-software/tf-issues#12 Change-Id: I187f83dcb660b728f82155d91882e961d2255068
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- 17 Feb, 2014 1 commit
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Jeenu Viswambharan authored
This patch uses the reworked exception handling support to handle runtime service requests through SMCs following the SMC calling convention. This is a giant commit since all the changes are inter-related. It does the following: 1. Replace the old exception handling mechanism with the new one 2. Enforce that SP_EL0 is used C runtime stacks. 3. Ensures that the cold and warm boot paths use the 'cpu_context' structure to program an ERET into the next lower EL. 4. Ensures that SP_EL3 always points to the next 'cpu_context' structure prior to an ERET into the next lower EL 5. Introduces a PSCI SMC handler which completes the use of PSCI as a runtime service Change-Id: I661797f834c0803d2c674d20f504df1b04c2b852 Co-authored-by: Achin Gupta <achin.gupta@arm.com>
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- 20 Jan, 2014 1 commit
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Achin Gupta authored
The psci implementation does not track target affinity level requests specified during cpu_suspend calls correctly as per the following example. 1. cpu0.cluster0 calls cpu_suspend with the target affinity level as 0 2. Only the cpu0.cluster0 is powered down while cluster0 remains powered up 3. cpu1.cluster0 calls cpu_off to power itself down to highest possible affinity level 4. cluster0 will be powered off even though cpu0.cluster0 does not allow cluster shutdown This patch introduces reference counts at affinity levels > 0 to track the number of cpus which want an affinity instance at level X to remain powered up. This instance can be turned off only if its reference count is 0. Cpus still undergo the normal state transitions (ON, OFF, ON_PENDING, SUSPEND) but the higher levels can only be either ON or OFF depending upon their reference count. The above issue is thus fixed as follows: 1. cluster0's reference count is incremented by two when cpu0 and cpu1 are initially powered on. 2. cpu0.cluster0 calls cpu_suspend with the target affinity level as 0. This does not affect the cluster0 reference count. 3. Only the cpu0.cluster0 is powered down while cluster0 remains powered up as it has a non-zero reference count. 4. cpu1.cluster0 call cpu_off to power itself down to highest possible affinity level. This decrements the cluster0 reference count. 5. cluster0 is still not powered off since its reference count will at least be 1 due to the restriction placed by cpu0. Change-Id: I433dfe82b946f5f6985b1602c2de87800504f7a9
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