The ARM32 has PLx Privilege Levels instead of Exception Levels present
on ARM64. Introduce current_pl() function which reports the current PL
on ARM32.

Introduce current_el() for ARM32 as well and current_pl() for ARM64
which each call the other matching function. This is mainly mean to
allow code like this to compile and retain compile time code coverage:

if (IS_ENABLED(CONFIG_ARM64) && current_el() != 3) { ... }
if (!IS_ENABLED(CONFIG_ARM64) && current_pl() != 0) { ... }

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>

The mcr and msr instructions are available in Thumb mode only if
Thumb2 is supported. Therefore, if __thumb2__ is not set, make
sure we switch to ARM mode by inserting a .arm directive in the
inline assembly.

Fixes LTO link errors with kirkwood platforms, triggered by a later
commit:

 tools/buildman/buildman -o /tmp/build -eP sheevaplug
 [...]
 {standard input}:24085: Error: selected processor does not support `mrc p15,0,r3,c1,c0,0' in Thumb mode

Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>

The ARM ARM (Rev L.a) on section 8.17.1 describes the cases where
break-before-make is required when changing live page tables.
Since we can use a function to tweak block and page permissions,
where BBM is not required split the existing mmu_change_region_attr()
into two functions and create one that doesn't require BBM. Subsequent
patches will use the new function to map the U-Boot binary with proper
page permissions.
While at it add function descriptions in their header files.

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

Add empty weak assembler function armv8_switch_to_el2_prep() which is
jumped to just before U-Boot determines which EL it is running in and
decides which path to take to boot the Linux kernel.

This weak function is meant to be used by architecture specific code
to implement jump to a firmware blob, which then returns right past
this weak function and continues execution of U-Boot code which then
boots the Linux kernel. One example of such use case is when U-Boot
jump tp TFA BL31, which switches from EL3 to EL2 and then returns to
U-Boot code newly running in EL2 and starts the Linux kernel.

The weak function is called with caches already disabled and DM shut
down. Any preparatory work or even loading of more data must be done
in board_prep_linux(), this hook is meant only for the final jump to
the firmware and return to U-Boot before booting Linux.

Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>

SCTLR_EL2 is a 64-bit register [1]. Return its value as long (64 bit)
instead of int (32 bit) in get_sctlr() to make sure it's not trimmed.

[1] https://developer.arm.com/documentation/ddi0595/2021-06/AArch64-Registers/SCTLR-EL2--System-Control-Register--EL2-?lang=en

Fixes: 0ae7653128c8 ("arm64: core support")
Suggested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

Currently, a number of generic cache related functions have their common
prototype declared in include/cpu_func.h. Move the current set of
noncached functions there as well to match.

Signed-off-by: Tom Rini <trini@konsulko.com>

Implement read_mpidr() on armv7 to make use of it in generic
code that compiles on both armv7 and armv8.

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

In some cases we might want to map some memory region after enabling
caches. Introduce a new helper for this.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>

Polling cntpct_el0 in a tight loop for delays is inefficient.
This is particularly apparent on Arm FVPs, which do not simulate
real time, meaning that a 1s sleep can take a couple of orders
of magnitude longer to execute in wall time.

If running at EL2 or above (where CNTHCTL_EL2 is available), enable
the cntpct_el0 event stream temporarily and use wfe to implement
the delay more efficiently. The event period is chosen as a
trade-off between efficiency and the fact that Arm FVPs do not
typically simulate real time.

This is only implemented for Armv8 boards, where an architectural
timer exists, and only enabled by default for the ARCH_VEXPRESS64
board family.

Signed-off-by: Peter Hoyes <Peter.Hoyes@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>

The sev() and wfe() asm macros are currently defined only for
mach-exynos. As these are common Arm instructions, move them to the
common asm/system.h header file, for both Armv7 and Armv8, so they
can be used by other machines.

wfe may theoretically trigger a context switch if an interrupt occurs
so add a memory barrier to this call.

Signed-off-by: Peter Hoyes <Peter.Hoyes@arm.com>
Reviewed-by: Andre Przywara<andre.przywara@arm.com>