1. 13 Jul, 2018 1 commit
    • Antonio Nino Diaz's avatar
      xlat v2: Remove architectural headers · 468e2382
      Antonio Nino Diaz authored
      
      
      They only contained one function that is easily integrated in the private
      library header and the existing architectural C files.
      
      This also helps making the library more portable, as the Makefile of the
      library now doesn't use the variable INCLUDES, which is specific to this
      codebase and doesn't respect the namespace of the library.
      
      Change-Id: I22228e6a97e9b4f346f5cd8947609263e8df71d8
      Signed-off-by: default avatarAntonio Nino Diaz <antonio.ninodiaz@arm.com>
      468e2382
  2. 11 Jul, 2018 3 commits
  3. 10 Jul, 2018 1 commit
    • Roberto Vargas's avatar
      Fix MISRA rule 8.3 · c96f297f
      Roberto Vargas authored
      
      
      Rule 8.3: All declarations of an object or function shall
                    use the same names and type qualifiers.
      
      Fixed for:
      	make DEBUG=1 PLAT=juno ARCH=aarch32 AARCH32_SP=sp_min RESET_TO_SP_MIN=1 JUNO_AARCH32_EL3_RUNTIME=1 bl32
      
      Change-Id: Ia34f5155e1cdb67161191f69e8d1248cbaa39e1a
      Signed-off-by: default avatarRoberto Vargas <roberto.vargas@arm.com>
      c96f297f
  4. 03 Jul, 2018 3 commits
    • Antonio Nino Diaz's avatar
      xlat v2: Make get/set attrs functions less verbose · 6a086061
      Antonio Nino Diaz authored
      
      
      It is useful to have LOG_LEVEL_VERBOSE because it prints the memory map
      of each image, but that also means that the change_mem_attributes and
      get_mem_attributes functions have verbose prints, and generate a too
      long text output that hides other useful information.
      
      As they were mostly there for debug purposes, this patch removes them.
      
      Change-Id: I2986537377d1f78be2b79cc8a6cf230c380bdb55
      Signed-off-by: default avatarAntonio Nino Diaz <antonio.ninodiaz@arm.com>
      6a086061
    • Antonio Nino Diaz's avatar
      xlat v2: Clean debug xlat tables descriptor print · f9d58d17
      Antonio Nino Diaz authored
      
      
      The previous debug output for EL1&0 translation regimes was too verbose,
      which makes it hard to read and hides the intent behind the parameters
      assigned to each region. This patch simplifies this output and makes the
      outputs for EL3 and EL1&0 mostly the same. The difference is that in
      EL1&0 it is specified whether the region is exclusively accessible from
      EL1 (PRIV) or both EL0 and EL1 (USER).
      
      For example:
      
          MEM-RW(PRIV)-NOACCESS(USER)-XN(PRIV)-XN(USER)-S
          MEM-RO(PRIV)-NOACCESS(USER)-EXEC(PRIV)-EXEC(USER)-S
      
      After the change, it becomes this:
      
          MEM-RW-XN-PRIV-S
          MEM-RO-EXEC-PRIV-S
      
      Change-Id: I15f4b99058429d42107fbf89e15f4838a9b559a5
      Signed-off-by: default avatarAntonio Nino Diaz <antonio.ninodiaz@arm.com>
      f9d58d17
    • Antonio Nino Diaz's avatar
      xlat v2: Split code into separate files · fd2299e6
      Antonio Nino Diaz authored
      
      
      Instead of having one big file with all the code, it's better to have
      a few smaller files that are more manageable:
      
      - xlat_tables_core.c: Code related to the core functionality of the
        library (map and unmap regions, initialize xlat context).
      - xlat_tables_context.c: Instantiation of the active image context
        as well as APIs to manipulate it.
      - xlat_tables_utils.c: Helper code that isn't part of the core
        functionality (change attributes, debug print messages).
      
      Change-Id: I3ea956fc1afd7473c0bb5e7c6aab3b2e5d88c711
      Signed-off-by: default avatarAntonio Nino Diaz <antonio.ninodiaz@arm.com>
      fd2299e6
  5. 27 Jun, 2018 3 commits
    • Jeenu Viswambharan's avatar
      DynamIQ: Enable MMU without using stack · 64ee263e
      Jeenu Viswambharan authored
      
      
      Having an active stack while enabling MMU has shown coherency problems.
      This patch builds on top of translation library changes that introduces
      MMU-enabling without using stacks.
      
      Previously, with HW_ASSISTED_COHERENCY, data caches were disabled while
      enabling MMU only because of active stack. Now that we can enable MMU
      without using stack, we can enable both MMU and data caches at the same
      time.
      
      NOTE: Since this feature depends on using translation table library v2,
      disallow using translation table library v1 with HW_ASSISTED_COHERENCY.
      
      Fixes ARM-software/tf-issues#566
      
      Change-Id: Ie55aba0c23ee9c5109eb3454cb8fa45d74f8bbb2
      Signed-off-by: default avatarJeenu Viswambharan <jeenu.viswambharan@arm.com>
      64ee263e
    • Jeenu Viswambharan's avatar
      xlat v1: Provide direct MMU-enabling stubs · 92bec97f
      Jeenu Viswambharan authored
      
      
      An earlier patch split MMU-enabling function for translation library v2.
      Although we don't intend to introduce the exact same functionality for
      xlat v1, this patch introduces stubs for directly enabling MMU to
      maintain API-compatibility.
      
      Change-Id: Id7d56e124c80af71de999fcda10f1734b50bca97
      Signed-off-by: default avatarJeenu Viswambharan <jeenu.viswambharan@arm.com>
      92bec97f
    • Jeenu Viswambharan's avatar
      xlat v2: Split MMU setup and enable · 0cc7aa89
      Jeenu Viswambharan authored
      
      
      At present, the function provided by the translation library to enable
      MMU constructs appropriate values for translation library, and programs
      them to the right registers. The construction of initial values,
      however, is only required once as both the primary and secondaries
      program the same values.
      
      Additionally, the MMU-enabling function is written in C, which means
      there's an active stack at the time of enabling MMU. On some systems,
      like Arm DynamIQ, having active stack while enabling MMU during warm
      boot might lead to coherency problems.
      
      This patch addresses both the above problems by:
      
        - Splitting the MMU-enabling function into two: one that sets up
          values to be programmed into the registers, and another one that
          takes the pre-computed values and writes to the appropriate
          registers. With this, the primary effectively calls both functions
          to have the MMU enabled, but secondaries only need to call the
          latter.
      
        - Rewriting the function that enables MMU in assembly so that it
          doesn't use stack.
      
      This patch fixes a bunch of MISRA issues on the way.
      
      Change-Id: I0faca97263a970ffe765f0e731a1417e43fbfc45
      Signed-off-by: default avatarJeenu Viswambharan <jeenu.viswambharan@arm.com>
      0cc7aa89
  6. 22 Jun, 2018 1 commit
    • Antonio Nino Diaz's avatar
      xlat: Remove mmap_attr_t enum type · 3a1b7b10
      Antonio Nino Diaz authored
      
      
      The values defined in this type are used in logical operations, which
      goes against MISRA Rule 10.1: "Operands shall not be of an inappropriate
      essential type".
      
      Now, `unsigned int` is used instead. This also allows us to move the
      dynamic mapping bit from 30 to 31. It was an undefined behaviour in the
      past because an enum is signed by default, and bit 31 corresponds to the
      sign bit. It is undefined behaviour to modify the sign bit. Now, bit 31
      is free to use as it was originally meant to be.
      
      mmap_attr_t is now defined as an `unsigned int` for backwards
      compatibility.
      
      Change-Id: I6b31218c14b9c7fdabebe432de7fae6e90a97f34
      Signed-off-by: default avatarAntonio Nino Diaz <antonio.ninodiaz@arm.com>
      3a1b7b10
  7. 21 Jun, 2018 2 commits
  8. 19 Jun, 2018 1 commit
  9. 14 Jun, 2018 1 commit
    • Yann Gautier's avatar
      xlat_v2: add a check on mm_cursor->size to avoid infinite loop · 75df6269
      Yann Gautier authored
      
      
      The issue can occur if end_va is equal to the max architecture address,
      and when mm_cursor point to the last entry of mmap_region_t table: {0}.
      The first line of the while will then be true, e.g. on AARCH32, we have:
      mm_cursor->base_va (=0) + mm_cursor->size (=0) - 1 == end_va (=0xFFFFFFFF)
      And the mm_cursor->size = 0 will be lesser than mm->size
      
      A check on mm_cursor->size != 0 should be done as in the previous while,
      to avoid such kind of infinite loop.
      
      fixes arm-software/tf-issues#594
      Signed-off-by: default avatarYann Gautier <yann.gautier@st.com>
      75df6269
  10. 13 Jun, 2018 1 commit
    • Antonio Nino Diaz's avatar
      xlat v2: Introduce xlat granule size helpers · a0b9bb79
      Antonio Nino Diaz authored
      
      
      The function xlat_arch_is_granule_size_supported() can be used to check
      if a specific granule size is supported. In Armv8, AArch32 only supports
      4 KiB pages. AArch64 supports 4 KiB, 16 KiB or 64 KiB depending on the
      implementation, which is detected at runtime.
      
      The function xlat_arch_get_max_supported_granule_size() returns the max
      granule size supported by the implementation.
      
      Even though right now they are only used by SPM, they may be useful in
      other places in the future. This patch moves the code currently in SPM
      to the xlat tables lib so that it can be reused.
      
      Change-Id: If54624a5ecf20b9b9b7f38861b56383a03bbc8a4
      Signed-off-by: default avatarAntonio Nino Diaz <antonio.ninodiaz@arm.com>
      a0b9bb79
  11. 12 Jun, 2018 4 commits
    • Daniel Boulby's avatar
      Fix MISRA Rule 5.7 Part 3 · 776ff52a
      Daniel Boulby authored
      
      
      Rule 5.7: A tag name shall be a unique identifier
      
      Follow convention of shorter names for smaller scope to fix
      violations of MISRA rule 5.7
      
      Fixed For:
          make ARM_TSP_RAM_LOCATION=tdram LOG_LEVEL=50 PLAT=fvp SPD=opteed
      
      Change-Id: I5fbb5d6ebddf169550eddb07ed880f5c8076bb76
      Signed-off-by: default avatarDaniel Boulby <daniel.boulby@arm.com>
      776ff52a
    • Daniel Boulby's avatar
      Fix MISRA Rule 5.7 Part 1 · 40692923
      Daniel Boulby authored
      
      
      Rule 5.7: A tag name shall be a unique identifier
      
      There were 2 amu_ctx struct type definitions:
          - In lib/extensions/amu/aarch64/amu.c
          - In lib/cpus/aarch64/cpuamu.c
      
      Renamed the latter to cpuamu_ctx to avoid this name clash
      
      To avoid violation of Rule 8.3 also change name of function
      amu_ctxs to unique name (cpuamu_ctxs) since it now returns a
      different type (cpuamu_ctx) than the other amu_ctxs function
      
      Fixed for:
          make LOG_LEVEL=50 PLAT=fvp
      
      Change-Id: Ieeb7e390ec2900fd8b775bef312eda93804a43ed
      Signed-off-by: default avatarDaniel Boulby <daniel.boulby@arm.com>
      40692923
    • Daniel Boulby's avatar
      Fix MISRA Rule 5.3 Part 4 · 7cb81945
      Daniel Boulby authored
      
      
      Use a _ prefix for macro arguments to prevent that argument from
      hiding variables of the same name in the outer scope
      
      Rule 5.3: An identifier declared in an inner scope shall not
                hide an identifier declared in an outer scope
      
      Fixed For:
          make PLAT=fvp USE_COHERENT_MEM=0
      
      Change-Id: If50c583d3b63799ee6852626b15be00c0f6b10a0
      Signed-off-by: default avatarDaniel Boulby <daniel.boulby@arm.com>
      7cb81945
    • Daniel Boulby's avatar
      Fix MISRA Rule 5.3 Part 2 · 896a5902
      Daniel Boulby authored
      
      
      Use a _ prefix for Macro arguments to prevent that argument from
      hiding variables of the same name in the outer scope
      
      Rule 5.3: An identifier declared in an inner scope shall not
                hide an identifier declared in an outer scope
      
      Fixed For:
          make LOG_LEVEL=50 PLAT=fvp
      
      Change-Id: I67b6b05cbad4aeca65ce52981b4679b340604708
      Signed-off-by: default avatarDaniel Boulby <daniel.boulby@arm.com>
      896a5902
  12. 11 Jun, 2018 1 commit
    • John Tsichritzis's avatar
      MISRA rule 21.15 fix · bdcd33a8
      John Tsichritzis authored
      
      
          Rule 21.15: The pointer arguments to the Standard Library functions
          memcpy, memmove and memcmp shall be pointers to qualified or unqualified
          versions of compatible types.
      
          Basically that means that both pointer arguments must be of the same
          type. However, even if the pointers passed as arguments to the above
          functions are of the same type, Coverity still thinks it's a violation
          if we do pointer arithmetics directly at the function call. Thus the
          pointer arithmetic operations were moved outside of the function
          argument.
      
          First detected on the following configuration
                  make PLAT=fvp LOG_LEVEL=50
      
          Change-Id: I8b912ec1bfa6f2d60857cb1bd453981fd7001b94
      Signed-off-by: default avatarJohn Tsichritzis <john.tsichritzis@arm.com>
      bdcd33a8
  13. 08 Jun, 2018 4 commits
  14. 07 Jun, 2018 1 commit
    • Dimitris Papastamos's avatar
      Fast path SMCCC_ARCH_WORKAROUND_1 calls from AArch32 · 2b915366
      Dimitris Papastamos authored
      
      
      When SMCCC_ARCH_WORKAROUND_1 is invoked from a lower EL running in
      AArch32 state, ensure that the SMC call will take a shortcut in EL3.
      This minimizes the time it takes to apply the mitigation in EL3.
      
      When lower ELs run in AArch32, it is preferred that they execute the
      `BPIALL` instruction to invalidate the BTB.  However, on some cores
      the `BPIALL` instruction may be a no-op and thus would benefit from
      making the SMCCC_ARCH_WORKAROUND_1 call go through the fast path.
      
      Change-Id: Ia38abd92efe2c4b4a8efa7b70f260e43c5bda8a5
      Signed-off-by: default avatarDimitris Papastamos <dimitris.papastamos@arm.com>
      2b915366
  15. 23 May, 2018 5 commits
    • Antonio Nino Diaz's avatar
      context_mgmt: Make cm_init_context_common public · 1634cae8
      Antonio Nino Diaz authored
      
      
      This function can be currently accessed through the wrappers
      cm_init_context_by_index() and cm_init_my_context(). However, they only
      work on contexts that are associated to a CPU.
      
      By making this function public, it is possible to set up a context that
      isn't associated to any CPU. For consistency, it has been renamed to
      cm_setup_context().
      
      Change-Id: Ib2146105abc8137bab08745a8adb30ca2c4cedf4
      Signed-off-by: default avatarAntonio Nino Diaz <antonio.ninodiaz@arm.com>
      1634cae8
    • Dimitris Papastamos's avatar
      Add support for dynamic mitigation for CVE-2018-3639 · fe007b2e
      Dimitris Papastamos authored
      
      
      Some CPUS may benefit from using a dynamic mitigation approach for
      CVE-2018-3639.  A new SMC interface is defined to allow software
      executing in lower ELs to enable or disable the mitigation for their
      execution context.
      
      It should be noted that regardless of the state of the mitigation for
      lower ELs, code executing in EL3 is always mitigated against
      CVE-2018-3639.
      
      NOTE: This change is a compatibility break for any platform using
      the declare_cpu_ops_workaround_cve_2017_5715 macro.  Migrate to
      the declare_cpu_ops_wa macro instead.
      
      Change-Id: I3509a9337ad217bbd96de9f380c4ff8bf7917013
      Signed-off-by: default avatarDimitris Papastamos <dimitris.papastamos@arm.com>
      fe007b2e
    • Dimitris Papastamos's avatar
      aarch32: Implement static workaround for CVE-2018-3639 · e0865708
      Dimitris Papastamos authored
      
      
      Implement static mitigation for CVE-2018-3639 on
      Cortex A57 and A72.
      
      Change-Id: I83409a16238729b84142b19e258c23737cc1ddc3
      Signed-off-by: default avatarDimitris Papastamos <dimitris.papastamos@arm.com>
      e0865708
    • Dimitris Papastamos's avatar
      Implement static workaround for CVE-2018-3639 · b8a25bbb
      Dimitris Papastamos authored
      For affected CPUs, this approach enables the mitigation during EL3
      initialization, following every PE reset. No mechanism is provided to
      disable the mitigation at runtime.
      
      This approach permanently mitigates the entire software stack and no
      additional mitigation code is required in other software components.
      
      TF-A implements this approach for the following affected CPUs:
      
      *   Cortex-A57 and Cortex-A72, by setting bit 55 (Disable load pass store) of
          `CPUACTLR_EL1` (`S3_1_C15_C2_0`).
      
      *   Cortex-A73, by setting bit 3 of `S3_0_C15_C0_0` (not documented in the
          Technical Reference Manual (TRM)).
      
      *   Cortex-A75, by setting bit 35 (reserved in TRM) of `CPUACTLR_EL1`
          (`S3_0_C15_C1_0`).
      
      Additionally, a new SMC interface is implemented to allow software
      executing in lower ELs to discover whether the system is mitigated
      against CVE-2018-3639.
      
      Refer to "Firmware interfaces for mitigating cache speculation
      vulnerabilities System Software on Arm Systems"[0] for more
      information.
      
      [0] https://developer.arm.com/cache-speculation-vulnerability-firmware-specification
      
      
      
      Change-Id: I084aa7c3bc7c26bf2df2248301270f77bed22ceb
      Signed-off-by: default avatarDimitris Papastamos <dimitris.papastamos@arm.com>
      b8a25bbb
    • Dimitris Papastamos's avatar
      Rename symbols and files relating to CVE-2017-5715 · 2c3a1078
      Dimitris Papastamos authored
      
      
      This patch renames symbols and files relating to CVE-2017-5715 to make
      it easier to introduce new symbols and files for new CVE mitigations.
      
      Change-Id: I24c23822862ca73648c772885f1690bed043dbc7
      Signed-off-by: default avatarDimitris Papastamos <dimitris.papastamos@arm.com>
      2c3a1078
  16. 15 May, 2018 1 commit
    • Varun Wadekar's avatar
      Workaround for CVE-2017-5715 on NVIDIA Denver CPUs · b0301467
      Varun Wadekar authored
      
      
      Flush the indirect branch predictor and RSB on entry to EL3 by issuing
      a newly added instruction for Denver CPUs. Support for this operation
      can be determined by comparing bits 19:16 of ID_AFR0_EL1 with 0b0001.
      
      To achieve this without performing any branch instruction, a per-cpu
      vbar is installed which executes the workaround and then branches off
      to the corresponding vector entry in the main vector table. A side
      effect of this change is that the main vbar is configured before any
      reset handling. This is to allow the per-cpu reset function to override
      the vbar setting.
      
      Change-Id: Ief493cd85935bab3cfee0397e856db5101bc8011
      Signed-off-by: default avatarVarun Wadekar <vwadekar@nvidia.com>
      b0301467
  17. 09 May, 2018 2 commits
    • Varun Wadekar's avatar
      lib: el3_runtime: initialise actlr_el1 to hardware defaults · 2ab9617e
      Varun Wadekar authored
      
      
      The context management library initialises the CPU context for the
      secure/non-secure worlds to zero. This leads to zeros being stored
      to the actual registers when we restore the CPU context, during a
      world switch. Denver CPUs dont expect zero to be written to the
      implementation defined, actlr_el1 register, at any point of time.
      Writing a zero to some fields of this register, results in an
      UNDEFINED exception.
      
      This patch bases the context actlr_el1 value on the actual hardware
      register, to maintain parity with the expected settings
      
      Change-Id: I1c806d7ff12daa7fd1e5c72825494b81454948f2
      Signed-off-by: default avatarVarun Wadekar <vwadekar@nvidia.com>
      2ab9617e
    • Roberto Vargas's avatar
      Don't use variables as tf_printf format strings · a83a74d2
      Roberto Vargas authored
      
      
      Using variables as format strings can generate security problems when
      the user can control those strings. Some compilers generate warnings
      in that cases, even when the variables are constants and are not
      controlled by the user.
      
      Change-Id: I65dee1d1b66feab38cbf298290a86fa56e6cca40
      Signed-off-by: default avatarRoberto Vargas <roberto.vargas@arm.com>
      a83a74d2
  18. 04 May, 2018 5 commits
    • Jeenu Viswambharan's avatar
      RAS: Add fault injection support · 1a7c1cfe
      Jeenu Viswambharan authored
      
      
      The ARMv8.4 RAS extensions introduce architectural support for software
      to inject faults into the system in order to test fault-handling
      software. This patch introduces the build option FAULT_HANDLING_SUPPORT
      to allow for lower ELs to use registers in the Standard Error Record to
      inject fault. The build option RAS_EXTENSIONS must also be enabled along
      with fault injection.
      
      This feature is intended for testing purposes only, and is advisable to
      keep disabled for production images.
      
      Change-Id: I6f7a4454b15aec098f9505a10eb188c2f928f7ea
      Signed-off-by: default avatarJeenu Viswambharan <jeenu.viswambharan@arm.com>
      1a7c1cfe
    • Jeenu Viswambharan's avatar
      RAS: Allow individual interrupt registration · ca6d9185
      Jeenu Viswambharan authored
      
      
      EHF currently allows for registering interrupt handlers for a defined
      priority ranges. This is primarily targeted at various EL3 dispatchers
      to own ranges of secure interrupt priorities in order to delegate
      execution to lower ELs.
      
      The RAS support added by earlier patches necessitates registering
      handlers based on interrupt number so that error handling agents shall
      receive and handle specific Error Recovery or Fault Handling interrupts
      at EL3.
      
      This patch introduces a macro, RAS_INTERRUPTS() to declare an array of
      interrupt numbers and handlers. Error handling agents can use this macro
      to register handlers for individual RAS interrupts. The array is
      expected to be sorted in the increasing order of interrupt numbers.
      
      As part of RAS initialisation, the list of all RAS interrupts are sorted
      based on their ID so that, given an interrupt, its handler can be looked
      up with a simple binary search.
      
      For an error handling agent that wants to handle a RAS interrupt,
      platform must:
      
        - Define PLAT_RAS_PRI to be the priority of all RAS exceptions.
      
        - Enumerate interrupts to have the GIC driver program individual EL3
          interrupts to the required priority range. This is required by EHF
          even before this patch.
      
      Documentation to follow.
      
      Change-Id: I9471e4887ff541f8a7a63309e9cd8f771f76aeda
      Signed-off-by: default avatarJeenu Viswambharan <jeenu.viswambharan@arm.com>
      ca6d9185
    • Jeenu Viswambharan's avatar
      RAS: Add support for node registration · 362599ec
      Jeenu Viswambharan authored
      
      
      Previous patches added frameworks for handling RAS errors. This patch
      introduces features that the platform can use to enumerate and iterate
      RAS nodes:
      
        - The REGISTER_RAS_NODES() can be used to expose an array of
          ras_node_info_t structures. Each ras_node_info_t describes a RAS
          node, along with handlers for probing the node for error, and if
          did record an error, another handler to handle it.
      
        - The macro for_each_ras_node() can be used to iterate over the
          registered RAS nodes, probe for, and handle any errors.
      
      The common platform EA handler has been amended using error handling
      primitives introduced by both this and previous patches.
      
      Change-Id: I2e13f65a88357bc48cd97d608db6c541fad73853
      Signed-off-by: default avatarJeenu Viswambharan <jeenu.viswambharan@arm.com>
      362599ec
    • Jeenu Viswambharan's avatar
      RAS: Add helpers to access Standard Error Records · 30d81c36
      Jeenu Viswambharan authored
      
      
      The ARMv8 RAS Extensions introduced Standard Error Records which are a
      set of standard registers through which:
      
        - Platform can configure RAS node policy; e.g., notification
          mechanism;
      
        - RAS nodes can record and expose error information for error handling
          agents.
      
      Standard Error Records can either be accessed via. memory-mapped
      or System registers. This patch adds helper functions to access
      registers and fields within an error record.
      
      Change-Id: I6594ba799f4a1789d7b1e45b3e17fd40e7e0ba5c
      Signed-off-by: default avatarJeenu Viswambharan <jeenu.viswambharan@arm.com>
      30d81c36
    • Jeenu Viswambharan's avatar
      AArch64: Introduce RAS handling · 14c6016a
      Jeenu Viswambharan authored
      
      
      RAS extensions are mandatory for ARMv8.2 CPUs, but are also optional
      extensions to base ARMv8.0 architecture.
      
      This patch adds build system support to enable RAS features in ARM
      Trusted Firmware. A boolean build option RAS_EXTENSION is introduced for
      this.
      
      With RAS_EXTENSION, an Exception Synchronization Barrier (ESB) is
      inserted at all EL3 vector entry and exit. ESBs will synchronize pending
      external aborts before entering EL3, and therefore will contain and
      attribute errors to lower EL execution. Any errors thus synchronized are
      detected via. DISR_EL1 register.
      
      When RAS_EXTENSION is set to 1, HANDLE_EL3_EA_FIRST must also be set to 1.
      
      Change-Id: I38a19d84014d4d8af688bd81d61ba582c039383a
      Signed-off-by: default avatarJeenu Viswambharan <jeenu.viswambharan@arm.com>
      14c6016a