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This patch introduces two workarounds for ARMv7 systems.  The
workarounds need to be applied prior to any `branch` instruction in
secure world.  This is achieved using a custom vector table where each
entry is an `add sp, sp, #1` instruction.

On entry to monitor mode, once the sequence of `ADD` instructions is
executed, the branch target buffer (BTB) is invalidated.  The bottom
bits of `SP` are then used to decode the exception entry type.

A side effect of this change is that the exception vectors are
installed before the CPU specific reset function.  This is now
consistent with how it is done on AArch64.

Note, on AArch32 systems, the exception vectors are typically tightly
integrated with the secure payload (e.g. the Trusted OS).  This
workaround will need porting to each secure payload that requires it.

The patch to modify the AArch32 per-cpu vbar to the corresponding
workaround vector table according to the CPU type will be done in a
later patch.

Change-Id: I5786872497d359e496ebe0757e8017fa98f753fa
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>

Currently TF does not initialise the PMCR_EL0 register in
the secure context or save/restore the register.

In particular, the DP field may not be set to one to prohibit
cycle counting in the secure state, even though event counting
generally is prohibited via the default setting of MDCR_EL3.SMPE
to 0.

This patch initialises PMCR_EL0.DP to one in the secure state
to prohibit cycle counting and also initialises other fields
that have an architectually UNKNOWN reset value.

Additionally, PMCR_EL0 is added to the list of registers that are
saved and restored during a world switch.

Similar changes are made for PMCR for the AArch32 execution state.

NOTE: secure world code at lower ELs that assume other values in PMCR_EL0
will be impacted.

Change-Id: Iae40e8c0a196d74053accf97063ebc257b4d2f3a
Signed-off-by: David Cunado <david.cunado@arm.com>

security_state is either 0 or 1. Prevent sign conversion potential
error (setting -Werror=sign-conversion results in a build error).
Signed-off-by: Yann Gautier <yann.gautier@st.com>
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>

The current SMC context data structure `smc_ctx_t` and related helpers are
optimized for case when SMC call does not result in world switch. This was
the case for SP_MIN and BL1 cold boot flow. But the firmware update usecase
requires world switch as a result of SMC and the current SMC context helpers
were not helping very much in this regard. Therefore this patch does the
following changes to improve this:

1. Add monitor stack pointer, `spmon` to `smc_ctx_t`

The C Runtime stack pointer in monitor mode, `sp_mon` is added to the
SMC context, and the `smc_ctx_t` pointer is cached in `sp_mon` prior
to exit from Monitor mode. This makes is easier to retrieve the
context when the next SMC call happens. As a result of this change,
the SMC context helpers no longer depend on the stack to save and
restore the register.

This aligns it with the context save and restore mechanism in AArch64.

2. Add SCR in `smc_ctx_t`

Adding the SCR register to `smc_ctx_t` makes it easier to manage this
register state when switching between non secure and secure world as a
result of an SMC call.

Change-Id: I5e12a7056107c1701b457b8f7363fdbf892230bf
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>

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>

The AArch32 Procedure call Standard mandates that the stack must be aligned
to 8 byte boundary at external interfaces. This patch does the required
changes.

This problem was detected when a crash was encountered in
`psci_print_power_domain_map()` while printing 64 bit values. Aligning
the stack to 8 byte boundary resolved the problem.

Fixes ARM-Software/tf-issues#437

Change-Id: I517bd8203601bb88e9311bd36d477fb7b3efb292
Signed-off-by: Soby Mathew <soby.mathew@arm.com>

This patch defines a SMCC context to save and restore
registers during a SMC call. It also adds appropriate helpers
to save and restore from this context for use by AArch32
secure payload and BL stages.

Change-Id: I64c8d6fe1d6cac22e1f1f39ea1b54ee1b1b72248