1. 15 Aug, 2014 1 commit
    • Achin Gupta's avatar
      Unmask SError interrupt and clear SCR_EL3.EA bit · 0c8d4fef
      Achin Gupta authored
      This patch disables routing of external aborts from lower exception levels to
      EL3 and ensures that a SError interrupt generated as a result of execution in
      EL3 is taken locally instead of a lower exception level.
      
      The SError interrupt is enabled in the TSP code only when the operation has not
      been directly initiated by the normal world. This is to prevent the possibility
      of an asynchronous external abort which originated in normal world from being
      taken when execution is in S-EL1.
      
      Fixes ARM-software/tf-issues#153
      
      Change-Id: I157b996c75996d12fd86d27e98bc73dd8bce6cd5
      0c8d4fef
  2. 01 Aug, 2014 2 commits
    • Vikram Kanigiri's avatar
      Support asynchronous method for BL3-2 initialization · faaa2e76
      Vikram Kanigiri authored
      This patch adds support for BL3-2 initialization by asynchronous
      method where BL3-1 transfers control to BL3-2 using world switch.
      After BL3-2 initialization, it transfers control to BL3-3 via SPD
      service handler. The SPD service handler initializes the CPU context
      to BL3-3 entrypoint depending on the return function indentifier from
      TSP initialization.
      
      Fixes ARM-software/TF-issues#184
      
      Change-Id: I7b135c2ceeb356d3bb5b6a287932e96ac67c7a34
      faaa2e76
    • Vikram Kanigiri's avatar
      Rework the TSPD setup code · 50e27dad
      Vikram Kanigiri authored
      There is no mechanism which allows the TSPD to specify what SPSR to
      use when entering BL3-2 instead of BL3-3. This patch divides the
      responsibility between tspd_setup() and tspd_init() for initializing
      the TSPD and TSP to support the alternate BL3-2 initialization flow
      where BL3-1 handsover control to BL3-2 instead of BL3-3.
      SPSR generated by TSPD for TSP is preserved due the new division of
      labour which fixes #174.
      
      This patch also moves the cpu_context initialization code from
      tspd_setup() to tspd_init() immediately before entering the TSP.
      Instead tspd_setup() updates the BL3-2 entrypoint info structure
      with the state required for initializing the TSP later.
      
      Fixes  ARM-software/TF-issues#174
      
      Change-Id: Ida0a8a48d466c71d5b07b8c7f2af169b73f96940
      50e27dad
  3. 31 Jul, 2014 1 commit
    • Soby Mathew's avatar
      Optimize EL3 register state stored in cpu_context structure · fdfabec1
      Soby Mathew authored
      This patch further optimizes the EL3 register state stored in
      cpu_context. The 2 registers which are removed from cpu_context are:
      
        * cntfrq_el0 is the system timer register which is writable
          only in EL3 and it can be programmed during cold/warm boot. Hence
          it need not be saved to cpu_context.
      
        * cptr_el3 controls access to Trace, Floating-point, and Advanced
          SIMD functionality and it is programmed every time during cold
          and warm boot. The current BL3-1 implementation does not need to
          modify the access controls during normal execution and hence
          they are expected to remain static.
      
      Fixes ARM-software/tf-issues#197
      
      Change-Id: I599ceee3b73a7dcfd37069fd41b60e3d397a7b18
      fdfabec1
  4. 28 Jul, 2014 3 commits
    • Juan Castillo's avatar
      Rework incorrect use of assert() and panic() in codebase · d3280beb
      Juan Castillo authored
      Assert a valid security state using the macro sec_state_is_valid().
      Replace assert() with panic() in those cases that might arise
      because of runtime errors and not programming errors.
      Replace panic() with assert() in those cases that might arise
      because of programming errors.
      
      Fixes ARM-software/tf-issues#96
      
      Change-Id: I51e9ef0439fd5ff5e0edfef49050b69804bf14d5
      d3280beb
    • Achin Gupta's avatar
      Simplify management of SCTLR_EL3 and SCTLR_EL1 · ec3c1003
      Achin Gupta authored
      This patch reworks the manner in which the M,A, C, SA, I, WXN & EE bits of
      SCTLR_EL3 & SCTLR_EL1 are managed. The EE bit is cleared immediately after reset
      in EL3. The I, A and SA bits are set next in EL3 and immediately upon entry in
      S-EL1. These bits are no longer managed in the blX_arch_setup() functions. They
      do not have to be saved and restored either. The M, WXN and optionally the C
      bit are set in the enable_mmu_elX() function. This is done during both the warm
      and cold boot paths.
      
      Fixes ARM-software/tf-issues#226
      
      Change-Id: Ie894d1a07b8697c116960d858cd138c50bc7a069
      ec3c1003
    • Achin Gupta's avatar
      Remove the concept of coherent stacks · 539a7b38
      Achin Gupta authored
      This patch removes the allocation of memory for coherent stacks, associated
      accessor function and some dead code which called the accessor function. It also
      updates the porting guide to remove the concept and the motivation behind using
      stacks allocated in coherent memory.
      
      Fixes ARM-software/tf-issues#198
      
      Change-Id: I00ff9a04f693a03df3627ba39727e3497263fc38
      539a7b38
  5. 19 Jul, 2014 2 commits
    • Achin Gupta's avatar
      Remove coherent stack usage from the warm boot path · b51da821
      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
      b51da821
    • Achin Gupta's avatar
      Make enablement of the MMU more flexible · afff8cbd
      Achin Gupta authored
      This patch adds a 'flags' parameter to each exception level specific function
      responsible for enabling the MMU. At present only a single flag which indicates
      whether the data cache should also be enabled is implemented. Subsequent patches
      will use this flag when enabling the MMU in the warm boot paths.
      
      Change-Id: I0eafae1e678c9ecc604e680851093f1680e9cefa
      afff8cbd
  6. 25 Jun, 2014 1 commit
    • Andrew Thoelke's avatar
      Remove current CPU mpidr from PSCI common code · 56378aa6
      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
      56378aa6
  7. 24 Jun, 2014 1 commit
  8. 23 Jun, 2014 4 commits
    • Andrew Thoelke's avatar
      Remove calling CPU mpidr from bakery lock API · 634ec6c2
      Andrew Thoelke authored
      The bakery lock code currently expects the calling code to pass
      the MPIDR_EL1 of the current CPU.
      
      This is not always done correctly. Also the change to provide
      inline access to system registers makes it more efficient for the
      bakery lock code to obtain the MPIDR_EL1 directly.
      
      This change removes the mpidr parameter from the bakery lock
      interface, and results in a code reduction of 160 bytes for the
      ARM FVP port.
      
      Fixes ARM-software/tf-issues#213
      
      Change-Id: I7ec7bd117bcc9794a0d948990fcf3336a367d543
      634ec6c2
    • Andrew Thoelke's avatar
      Correctly dimension the PSCI aff_map_node array · 6c0b45d1
      Andrew Thoelke authored
      The array of affinity nodes is currently allocated for 32 entries
      with the PSCI_NUM_AFFS value defined in psci.h. This is not enough
      for large systems, and will substantially over allocate the array
      for small systems.
      
      This patch introduces an optional platform definition
      PLATFORM_NUM_AFFS to platform_def.h. If defined this value is
      used for PSCI_NUM_AFFS, otherwise a value of two times the number
      of CPU cores is used.
      
      The FVP port defines PLATFORM_NUM_AFFS to be 10 which saves
      nearly 1.5KB of memory.
      
      Fixes ARM-software/tf-issues#192
      
      Change-Id: I68e30ac950de88cfbd02982ba882a18fb69c1445
      6c0b45d1
    • Andrew Thoelke's avatar
      Eliminate psci_suspend_context array · 13ac44a5
      Andrew Thoelke authored
      psci_suspend_context is an array of cache-line aligned structures
      containing the single power_state integer per cpu. This array is
      the only structure indexed by the aff_map_node.data integer.
      
      This patch saves 2KB of BL3-1 memory by placing the CPU
      power_state value directly in the aff_map_node structure. As a
      result, this value is now never cached and the cache clean when
      writing the value is no longer required.
      
      Fixes ARM-software/tf-issues#195
      
      Change-Id: Ib4c70c8f79eed295ea541e7827977a588a19ef9b
      13ac44a5
    • Andrew Thoelke's avatar
      Initialise CPU contexts from entry_point_info · 167a9357
      Andrew Thoelke authored
      Consolidate all BL3-1 CPU context initialization for cold boot, PSCI
      and SPDs into two functions:
      *  The first uses entry_point_info to initialize the relevant
         cpu_context for first entry into a lower exception level on a CPU
      *  The second populates the EL1 and EL2 system registers as needed
         from the cpu_context to ensure correct entry into the lower EL
      
      This patch alters the way that BL3-1 determines which exception level
      is used when first entering EL1 or EL2 during cold boot - this is now
      fully determined by the SPSR value in the entry_point_info for BL3-3,
      as set up by the platform code in BL2 (or otherwise provided to BL3-1).
      
      In the situation that EL1 (or svc mode) is selected for a processor
      that supports EL2, the context management code will now configure all
      essential EL2 register state to ensure correct execution of EL1. This
      allows the platform code to run non-secure EL1 payloads directly
      without requiring a small EL2 stub or OS loader.
      
      Change-Id: If9fbb2417e82d2226e47568203d5a369f39d3b0f
      167a9357
  9. 17 Jun, 2014 1 commit
    • Andrew Thoelke's avatar
      Remove early_exceptions from BL3-1 · ee94cc6f
      Andrew Thoelke authored
      The crash reporting support and early initialisation of the
      cpu_data allow the runtime_exception vectors to be used from
      the start in BL3-1, removing the need for the additional
      early_exception vectors and 2KB of code from BL3-1.
      
      Change-Id: I5f8997dabbaafd8935a7455910b7db174a25d871
      ee94cc6f
  10. 16 Jun, 2014 1 commit
    • Andrew Thoelke's avatar
      Per-cpu data cache restructuring · 5e910074
      Andrew Thoelke authored
      This patch prepares the per-cpu pointer cache for wider use by:
      * renaming the structure to cpu_data and placing in new header
      * providing accessors for this CPU, or other CPUs
      * splitting the initialization of the TPIDR pointer from the
        initialization of the cpu_data content
      * moving the crash stack initialization to a crash stack function
      * setting the TPIDR pointer very early during boot
      
      Change-Id: Icef9004ff88f8eb241d48c14be3158087d7e49a3
      5e910074
  11. 11 Jun, 2014 1 commit
    • Andrew Thoelke's avatar
      Provide cm_get/set_context() for current CPU · 08ab89d3
      Andrew Thoelke authored
      All callers of cm_get_context() pass the calling CPU MPIDR to the
      function. Providing a specialised version for the current
      CPU results in a reduction in code size and better readability.
      
      The current function has been renamed to cm_get_context_by_mpidr()
      and the existing name is now used for the current-CPU version.
      
      The same treatment has been done to cm_set_context(), although
      only both forms are used at present in the PSCI and TSPD code.
      
      Change-Id: I91cb0c2f7bfcb950a045dbd9ff7595751c0c0ffb
      08ab89d3
  12. 10 Jun, 2014 1 commit
    • Andrew Thoelke's avatar
      PSCI SMC handler improvements · 5003ecab
      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
      5003ecab
  13. 29 May, 2014 1 commit
  14. 27 May, 2014 2 commits
    • Dan Handley's avatar
      Further renames of platform porting functions · 9865ac15
      Dan Handley authored
      Rename the ic_* platform porting functions to plat_ic_* to be
      consistent with the other functions in platform.h. Also rename
      bl31_get_next_image_info() to bl31_plat_get_next_image_ep_info()
      and remove the duplicate declaration in bl31.h.
      
      Change-Id: I4851842069d3cff14c0a468daacc0a891a7ede84
      9865ac15
    • Soby Mathew's avatar
      Fixup Standard SMC Resume Handling · 10b65ecf
      Soby Mathew authored
      This patch fixes a missed return and code alignment issues
      in TSP_FID_RESUME handling.
      
      Change-Id: Icf8aeb76dfd6898745653ce039e3bac45e0a9b3a
      10b65ecf
  15. 23 May, 2014 6 commits
    • Dan Handley's avatar
      Add enable mmu platform porting interfaces · dff8e47a
      Dan Handley authored
      Previously, the enable_mmu_elX() functions were implicitly part of
      the platform porting layer since they were included by generic
      code. These functions have been placed behind 2 new platform
      functions, bl31_plat_enable_mmu() and bl32_plat_enable_mmu().
      These are weakly defined so that they can be optionally overridden
      by platform ports.
      
      Also, the enable_mmu_elX() functions have been moved to
      lib/aarch64/xlat_tables.c for optional re-use by platform ports.
      These functions are tightly coupled with the translation table
      initialization code.
      
      Fixes ARM-software/tf-issues#152
      
      Change-Id: I0a2251ce76acfa3c27541f832a9efaa49135cc1c
      dff8e47a
    • Dan Handley's avatar
      Split platform.h into separate headers · 5f0cdb05
      Dan Handley authored
      Previously, platform.h contained many declarations and definitions
      used for different purposes. This file has been split so that:
      
      * Platform definitions used by common code that must be defined
        by the platform are now in platform_def.h. The exact include
        path is exported through $PLAT_INCLUDES in the platform makefile.
      
      * Platform definitions specific to the FVP platform are now in
        /plat/fvp/fvp_def.h.
      
      * Platform API declarations specific to the FVP platform are now
        in /plat/fvp/fvp_private.h.
      
      * The remaining platform API declarations that must be ported by
        each platform are still in platform.h but this file has been
        moved to /include/plat/common since this can be shared by all
        platforms.
      
      Change-Id: Ieb3bb22fbab3ee8027413c6b39a783534aee474a
      5f0cdb05
    • Dan Handley's avatar
      Remove unused data declarations · 7a9a5f2d
      Dan Handley authored
      Some data variables were declared but not used. These have been
      removed.
      
      Change-Id: I038632af3c32d88984cd25b886c43ff763269bf9
      7a9a5f2d
    • Dan Handley's avatar
      Remove extern keyword from function declarations · c6bc0710
      Dan Handley authored
      Function declarations implicitly have external linkage so do not
      need the extern keyword.
      
      Change-Id: Ia0549786796d8bf5956487e8996450a0b3d79f32
      c6bc0710
    • Andrew Thoelke's avatar
      Use a vector table for TSP entrypoints · 399fb08f
      Andrew Thoelke authored
      The TSP has a number of entrypoints used by the TSP on different
      occasions. These were provided to the TSPD as a table of function
      pointers, and required the TSPD to read the entry in the table,
      which is in TSP memory, in order to program the exception return
      address.
      
      Ideally, the TSPD has no access to the TSP memory.
      
      This patch changes the table of function pointers into a vector
      table of single instruction entrypoints. This allows the TSPD to
      calculate the entrypoint address instead of read it.
      
      Fixes ARM-software/tf-issues#160
      
      Change-Id: Iec6e055d537ade78a45799fbc6f43765a4725ad3
      399fb08f
    • Soby Mathew's avatar
      Non-Secure Interrupt support during Standard SMC processing in TSP · 239b04fa
      Soby Mathew authored
      Implements support for Non Secure Interrupts preempting the
      Standard SMC call in EL1. Whenever an IRQ is trapped in the
      Secure world we securely handover to the Normal world
      to process the interrupt. The normal world then issues
      "resume" smc call to resume the previous interrupted SMC call.
      Fixes ARM-software/tf-issues#105
      
      Change-Id: I72b760617dee27438754cdfc9fe9bcf4cc024858
      239b04fa
  16. 22 May, 2014 8 commits
    • Achin Gupta's avatar
      Add S-EL1 interrupt handling support in the TSPD · b44a4435
      Achin Gupta authored
      This patch adds support in the TSPD for registering a handler for
      S-EL1 interrupts. This handler ferries the interrupts generated in the
      non-secure state to the TSP at 'tsp_fiq_entry'. Support has been added
      to the smc handler to resume execution in the non-secure state once
      interrupt handling has been completed by the TSP.
      
      There is also support for resuming execution in the normal world if
      the TSP receives a EL3 interrupt. This code is currently unused.
      
      Change-Id: I816732595a2635e299572965179f11aa0bf93b69
      b44a4435
    • Achin Gupta's avatar
      Use secure timer to generate S-EL1 interrupts · fa9c08b7
      Achin Gupta authored
      This patch adds support in the TSP to program the secure physical
      generic timer to generate a EL-1 interrupt every half second. It also
      adds support for maintaining the timer state across power management
      operations. The TSPD ensures that S-EL1 can access the timer by
      programming the SCR_EL3.ST bit.
      
      This patch does not actually enable the timer. This will be done in a
      subsequent patch once the complete framework for handling S-EL1
      interrupts is in place.
      
      Change-Id: I1b3985cfb50262f60824be3a51c6314ce90571bc
      fa9c08b7
    • Achin Gupta's avatar
      Introduce interrupt handling framework in BL3-1 · dce74b89
      Achin Gupta authored
      This patch adds a common handler for FIQ and IRQ exceptions in the
      BL3-1 runtime exception vector table. This function determines the
      interrupt type and calls its handler. A crash is reported if an
      inconsistency in the interrupt management framework is detected. In
      the event of a spurious interrupt, execution resumes from the
      instruction where the interrupt was generated.
      
      This patch also removes 'cm_macros.S' as its contents have been moved
      to 'runtime_exceptions.S'
      
      Change-Id: I3c85ecf8eaf43a3fac429b119ed0bd706d2e2093
      dce74b89
    • Achin Gupta's avatar
      Add context library API to change a bit in SCR_EL3 · c429b5e9
      Achin Gupta authored
      This patch adds an API to write to any bit in the SCR_EL3 member of
      the 'cpu_context' structure of the current CPU for a specified
      security state. This API will be used in subsequent patches which
      introduce interrupt management in EL3 to specify the interrupt routing
      model when execution is not in EL3.
      
      It also renames the cm_set_el3_elr() function to cm_set_elr_el3()
      which is more in line with the system register name being targeted by
      the API.
      
      Change-Id: I310fa7d8f827ad3f350325eca2fb28cb350a85ed
      c429b5e9
    • Achin Gupta's avatar
      Rework 'state' field usage in per-cpu TSP context · 3ee8a164
      Achin Gupta authored
      This patch lays the foundation for using the per-cpu 'state' field in
      the 'tsp_context' structure for other flags apart from the power state
      of the TSP.
      
      It allocates 2 bits for the power state, introduces the necessary
      macros to manipulate the power state in the 'state' field and
      accordingly reworks all use of the TSP_STATE_* states.
      
      It also allocates a flag bit to determine if the TSP is handling a
      standard SMC. If this flag is set then the TSP was interrupted due to
      non-secure or EL3 interupt depending upon the chosen routing
      model. Macros to get, set and clear this flag have been added as
      well. This flag will be used by subsequent patches.
      
      Change-Id: Ic6ee80bd5895812c83b35189cf2c3be70a9024a6
      3ee8a164
    • Vikram Kanigiri's avatar
      Rework memory information passing to BL3-x images · 6871c5d3
      Vikram Kanigiri authored
      The issues addressed in this patch are:
      
      1. Remove meminfo_t from the common interfaces in BL3-x,
      expecting that platform code will find a suitable mechanism
      to determine the memory extents in these images and provide
      it to the BL3-x images.
      
      2. Remove meminfo_t and bl31_plat_params_t from all FVP BL3-x
      code as the images use link-time information to determine
      memory extents.
      
      meminfo_t is still used by common interface in BL1/BL2 for
      loading images
      
      Change-Id: I4e825ebf6f515b59d84dc2bdddf6edbf15e2d60f
      6871c5d3
    • Vikram Kanigiri's avatar
      Populate BL31 input parameters as per new spec · 4112bfa0
      Vikram Kanigiri authored
      This patch is based on spec published at
      https://github.com/ARM-software/tf-issues/issues/133
      
      It rearranges the bl31_args struct into
      bl31_params and bl31_plat_params which provide the
      information needed for Trusted firmware and platform
      specific data via x0 and x1
      
      On the FVP platform BL3-1 params and BL3-1 plat params
      and its constituents are stored at the start of TZDRAM.
      
      The information about memory availability and size for
      BL3-1, BL3-2 and BL3-3 is moved into platform specific data.
      
      Change-Id: I8b32057a3d0dd3968ea26c2541a0714177820da9
      4112bfa0
    • Vikram Kanigiri's avatar
      Introduce macros to manipulate the SPSR · 23ff9baa
      Vikram Kanigiri authored
      This patch introduces macros (SPSR_64 and SPSR_32) to
      create a SPSR for both aarch32 and aarch64 execution
      states. These macros allow the user to set fields
      in the SPSR depending upon its format.
      The make_spsr() function which did not allow
      manipulation of all the fields in the aarch32 SPSR
      has been replaced by these new macros.
      
      Change-Id: I9425dda0923e8d5f03d03ddb8fa0e28392c4c61e
      23ff9baa
  17. 16 May, 2014 1 commit
    • Soby Mathew's avatar
      Rework BL3-1 unhandled exception handling and reporting · a43d431b
      Soby Mathew authored
      This patch implements the register reporting when unhandled exceptions are
      taken in BL3-1. Unhandled exceptions will result in a dump of registers
      to the console, before halting execution by that CPU. The Crash Stack,
      previously called the Exception Stack, is used for this activity.
      This stack is used to preserve the CPU context and runtime stack
      contents for debugging and analysis.
      
      This also introduces the per_cpu_ptr_cache, referenced by tpidr_el3,
      to provide easy access to some of BL3-1 per-cpu data structures.
      Initially, this is used to provide a pointer to the Crash stack.
      
      panic() now prints the the error file and line number in Debug mode
      and prints the PC value in release mode.
      
      The Exception Stack is renamed to Crash Stack with this patch.
      The original intention of exception stack is no longer valid
      since we intend to support several valid exceptions like IRQ
      and FIQ in the trusted firmware context. This stack is now
      utilized for dumping and reporting the system state when a
      crash happens and hence the rename.
      
      Fixes ARM-software/tf-issues#79 Improve reporting of unhandled exception
      
      Change-Id: I260791dc05536b78547412d147193cdccae7811a
      a43d431b
  18. 12 May, 2014 1 commit
    • Achin Gupta's avatar
      Fix broken standby state implementation in PSCI · 317ba090
      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
      317ba090
  19. 09 May, 2014 1 commit
    • Sandrine Bailleux's avatar
      fvp: Provide per-EL MMU setup functions · b793e431
      Sandrine Bailleux authored
      Instead of having a single version of the MMU setup functions for all
      bootloader images that can execute either in EL3 or in EL1, provide
      separate functions for EL1 and EL3. Each bootloader image can then
      call the appropriate version of these functions. The aim is to reduce
      the amount of code compiled in each BL image by embedding only what's
      needed (e.g. BL1 to embed only EL3 variants).
      
      Change-Id: Ib86831d5450cf778ae78c9c1f7553fe91274c2fa
      b793e431
  20. 08 May, 2014 1 commit
    • Soby Mathew's avatar
      Preserve x19-x29 across world switch for exception handling · c3260f9b
      Soby Mathew authored
      Previously exception handlers in BL3-1, X19-X29 were not saved
      and restored on every SMC/trap into EL3. Instead these registers
      were 'saved as needed' as a side effect of the A64 ABI used by the C
      compiler.
      
      That approach failed when world switching but was not visible
      with the TSP/TSPD code because the TSP is 64-bit, did not
      clobber these registers when running and did not support pre-emption
      by normal world interrupts. These scenarios showed
      that the values in these registers can be passed through a world
      switch, which broke the normal and trusted world assumptions
      about these registers being preserved.
      
      The Ideal solution saves and restores these registers when a
      world switch occurs - but that type of implementation is more complex.
      So this patch always saves and restores these registers on entry and
      exit of EL3.
      
      Fixes ARM-software/tf-issues#141
      
      Change-Id: I9a727167bbc594454e81cf78a97ca899dfb11c27
      c3260f9b