fix(bl1): use per-world context correctly

Currently, the configuration with BL1 and BL2 at SEL1 will transition
via el3_exit which will restore per-world context. However, that context
is never writ

fix(bl1): use per-world context correctly

Currently, the configuration with BL1 and BL2 at SEL1 will transition
via el3_exit which will restore per-world context. However, that context
is never written to and so zeroes end up in registers, which is not
necessarily correct.

This patch gets BL1 to call cm_manage_extensions_per_world() whenever
BL2 runs in a lower EL. This allows the per-world registers to have the
reset values we intend. An accompanying call to
cm_manage_extensions_el3() is also added for completeness.

Doing this shows a small deficiency in cptr_el3 - bits TFP and TCPAC
change a lot. This patch makes them consistent by always setting TCPAC
and TFP to 0 which unconditionally enable access to CPTR_EL2 and FPCR by
default as they are always accessible. Other places that manipulate the
TFP bit are removed.

A nice side effect of all of this is that we're now in a position to
enable and use any architectural extension in BL2.

Change-Id: I070d62bbf8e9d9b472caf7e2c931c303523be308
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>

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fix(cpufeat): configure CPTR_EL2.ZEN and CPTR_EL2.TZ to match Linux

Linux Documentation/arch/arm64/booting.rst states that:
"
For CPUs with the Scalable Vector Extension (FEAT_SVE) present:
...
-

fix(cpufeat): configure CPTR_EL2.ZEN and CPTR_EL2.TZ to match Linux

Linux Documentation/arch/arm64/booting.rst states that:
"
For CPUs with the Scalable Vector Extension (FEAT_SVE) present:
...
- If the kernel is entered at EL1 and EL2 is present:
- CPTR_EL2.TZ (bit 8) must be initialised to 0b0.
- CPTR_EL2.ZEN (bits 17:16) must be initialised to 0b11.
"
Without these settings, Linux kernel hangs on boot when trying
to use SVE. Adjust the register settings to match Linux kernel
expectations.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Change-Id: I9a72810dd902b08f9c61f157cc31e603aad2f73a

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perf(cm): drop ZCR_EL3 saving and some ISBs and replace them with root context

SVE and SME aren't enabled symmetrically for all worlds, but EL3 needs
to context switch them nonetheless. Previously,

perf(cm): drop ZCR_EL3 saving and some ISBs and replace them with root context

SVE and SME aren't enabled symmetrically for all worlds, but EL3 needs
to context switch them nonetheless. Previously, this had to happen by
writing the enable bits just before reading/writing the relevant
context. But since the introduction of root context, this need not be
the case. We can have these enables always be present for EL3 and save
on some work (and ISBs!) on every context switch.

We can also hoist ZCR_EL3 to a never changing register, as we set its
value to be identical for every world, which happens to be the one we
want for EL3 too.

Change-Id: I3d950e72049a298008205ba32f230d5a5c02f8b0
Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>

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refactor(cm): move EL3 registers to global context

Currently, EL3 context registers are duplicated per-world per-cpu.
Some registers have the same value across all CPUs, so this patch
moves these re

refactor(cm): move EL3 registers to global context

Currently, EL3 context registers are duplicated per-world per-cpu.
Some registers have the same value across all CPUs, so this patch
moves these registers out into a per-world context to reduce
memory usage.

Change-Id: I91294e3d5f4af21a58c23599af2bdbd2a747c54a
Signed-off-by: Elizabeth Ho <elizabeth.ho@arm.com>
Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>

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