Define and use no_ret macro where no return is expected ...

There are many instances in ARM Trusted Firmware where control is
transferred to functions from which return isn't expected. Such jumps
are made using 'bl' instruction to provide the callee with the location
from which it was jumped to. Additionally, debuggers infer the caller by
examining where 'lr' register points to. If a 'bl' of the nature
described above falls at the end of an assembly function, 'lr' will be
left pointing to a location outside of the function range. This misleads
the debugger back trace.

This patch defines a 'no_ret' macro to be used when jumping to functions
from which return isn't expected. The macro ensures to use 'bl'
instruction for the jump, and also, for debug builds, places a 'nop'
instruction immediately thereafter (unless instructed otherwise) so as
to leave 'lr' pointing within the function range.

Change-Id: Ib34c69fc09197cfd57bc06e147cc8252910e01b0
Co-authored-by: Douglas Raillard <douglas.raillard@arm.com>
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>

Merge pull request #761 from soby-mathew/sm/bakery_lock_fixes ...

Fix normal memory bakery lock implementation

Merge pull request #765 from Xilinx/rk3399-cfi ...

rk3399: Add CFI debug information to SRAM functions

rk3399: Add CFI debug information to SRAM functions ...

Commit b91d935
("Add CFI debug frame information for ASM functions") modifies the
assembly macros 'func' and 'endfunc' to include CFI debug frame
information.

The rockchip platform uses a custom version of the 'func' macro with the
common 'endfunc' macro. The custom macro wasn't updated in
b91d935 resulting in the following
build error:
  plat/rockchip/rk3399/drivers/pmu/plat_pmu_macros.S: Assembler messages:
  plat/rockchip/rk3399/drivers/pmu/plat_pmu_macros.S:155: Error: .cfi_endproc without corresponding .cfi_startproc
  Makefile:532: recipe for target 'build/rk3399/release/bl31/plat_helpers.o' failed
  make: *** [build/rk3399/release/bl31/plat_helpers.o] Error 1

Fixing this by updating the sram_func macro in the rk3399 port.

Fixes: b91d935 ("Add CFI debug frame information for ASM functions")
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>

Merge pull request #763 from douglas-raillard-arm/dr/add_debug_frame_info ...

Add CFI debug frame information for ASM functions

Merge pull request #764 from sandrine-bailleux-arm/sb/fix-trusty-build ...

Minor fixes in the Trusty SPD code

Fix a coding style issue in trusty.c ...

This patch fixes the following coding style error reported
by the checkpatch.pl script:

  Bad function definition - void el3_exit() should probably
  be void el3_exit(void)

There is another one but it's a false positive so there's no
point in fixing it:

  space prohibited after that '&' (ctx:WxW)
  +#define SMC_NR(entity, fn, fastcall, smc64) ((((fastcall) & 0x1) << 31) | \
                                                            ^
Change-Id: I34de0337c7216dabd16395879f13845a60ee6df0

Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>

Fix compilation warning in Trusty SPD ...

In release builds, the Trusty SPD fails to build because of an unused
variable. Note that this warning message doesn't show in debug builds
because INFO() messages are not compiled out like in release mode.

This patch fixes this issue by removing this variable and using its
value in place directly in the INFO() macro call.

Change-Id: I1f552421181a09412315eef4eaca586012022018
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>

Merge pull request #762 from douglas-raillard-arm/dr/doc_build_info ...

Clarify dependency for PSCI_EXTENDED_STATE_ID

Merge pull request #760 from Xilinx/zynqmp-2016-11 ...

ZynqMP Updates

Merge pull request #755 from vwadekar/trusty-spd ...

spd: dispatcher for interacting with the Trusty TEE

Clarify dependency for PSCI_EXTENDED_STATE_ID ...

Add dependency information in the user guide for ARM_RECOM_STATE_ID_ENC
that needs to be set when using PSCI_EXTENDED_STATE_ID on ARM
platforms. Also clarify the build error message.

Change-Id: Id125a0299b179f5f222bca4e2503204bf89a3c59
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>

Fix normal memory bakery lock implementation ...

This patch fixes an issue in the normal memory bakery lock
implementation. During assertion of lock status, there is a possibility
that the assertion could fail. This is because the previous update done
to the lock status by the owning CPU when not participating in cache
coherency could result in stale data in the cache due to cache maintenance
operations not propagating to all the caches. This patch fixes this issue
by doing an extra read cache maintenance operation prior to the assertion.

Fixes ARM-software/tf-issues#402

Change-Id: I0f38a7c52476a4f58e17ebe0141d256d198be88d
Signed-off-by: Soby Mathew <soby.mathew@arm.com>

Add CFI debug frame information for ASM functions ...

This allows the debugger to print the callstack when there is an
assembly function in the callstack.

It will work as long as the CFA pointer (frame pointer) location is not
modified (i.e. x29 is not touched in AArch64 state). It is the case in
almost all assembly functions, so this patch improves the average
debugging experience. Call stacks from the debugger should still be
interpreted with care. In more complex functions, one could use .cfi*
directives to inform the debugger about the new location of the CFA
pointer.

Change-Id: I9dabfbc033b45e8528e67f4823c17de7bf02fa24
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>

Merge pull request #759 from douglas-raillard-arm/dr/cosmetic_vectors_tables ...

Cosmetic change to exception table

Merge pull request #758 from douglas-raillard-arm/dr/doc_interrupt_handler ...

Docs: Clarify IRQ/FIQ handler API in Interrupt Design Guide

Docs: Clarify IRQ/FIQ handler API in Interrupt Design Guide ...

The API description currently states that interrupt handlers
(interrupt_type_handler_t pointers) SHOULD return a pointer
to the target cpu_context.

This patch rewords the description of the interrupts handlers to state
that it MUST return a pointer to the target security context. It also
warns about potential portability issue. Specifically, this pointer is
not used on AArch64 and calls to context library APIs must be used to
ask BL31 to return to a specific context. However, this could change in
the future and interrupt handlers must always return the pointer.

Change-Id: I3f82a046de4d7a5b51a8cbebe7eb2a00dbbdb4f0
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>

zynqmp: pm: Add SiP call to obtain PM callback data ...

The callback IRQ is delivered to the NS OS. Provide an interface to
allow the NS OS to obtain the callback data from the secure HW.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>

zynqmp: pm: Enable IPI IRQ when API version is probed ...

The IPI hardware is secure and managed by ATF, nevertheless we deliver
the IRQ to the rich OS. The IRQ is needed to receive PM callbacks.
Enable the IPI interrupt when the rich OS probes the API version.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>

zynqmp: Remove dead code ...

Remove dead code pieces and stale comments.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>

zynqmp: Fix UART1 base address ...

Cc: Michal Simek <michal.simek@xilinx.com>
Reported-by: Jonas Karlsson <jonas.karlsson@atero.se>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>

zynqmp: PM: Migrate to new shutdown interface ...

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>

zynqmp: pm: Plumb get_chipid through FW interface ...

Use the PMUFW get_chipid call to obtain IDCODE and version register.

Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>

zynqmp: pm: Allow obtaining additional return values from FW ...

Allow reading more than just a single value from the message buffer.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>

zynqmp: Do not alter system counter ...

On ZynqMP the FSBL will configure the system counter. Hence, remove the
initialization of the system counter with hardcoded values from the ATF
and use the setup provided by the bootloader.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>

zynqmp: Read silicon ID register only once ...

The silicon ID does not change at runtime. Skip the IO access if the
ID has been read before.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>

Merge pull request #757 from douglas-raillard-arm/dr/doc_plat_psci_ops ...

Document plat_psci_ops.(system_off|system_reset)

Merge pull request #756 from douglas-raillard-arm/dr/doc_fix_link_fw_design ...

firmware-design.md: Fix broken link

Merge pull request #754 from davidcunado-arm/dc/reset_debug_reg ...

Reset debug registers MDCR-EL3/SDCR and MDCR_EL2/HDCR

Cosmetic change to exception table ...

* Move comments on unhandled exceptions at the right place.
* Reformat the existing comments to highlight the start of
  each block of 4 entries in the exception table to ease
  navigation (lines of dash reserved for head comments).
* Reflow comments to 80 columns.

Change-Id: I5ab88a93d0628af8e151852cb5b597eb34437677
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>