The differences from ARMv7-M NVIC are:
* ARMv6-M only supports up to 32 external interrupts
(configurable feature already). The ICTR is reserved.
* Active Bit Register is reserved.
* ARMv6-M supports 4 priority levels against 256 in ARMv7-M.
Signed-off-by: Julia Suvorova <jusual@mail.ru>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
For the v8M security extension, there should be two systick
devices, which use separate banked systick exceptions. The
register interface is banked in the same way as for other
banked registers, including the existence of an NS alias
region for secure code to access the nonsecure timer.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 1512154296-5652-3-git-send-email-peter.maydell@linaro.org
For v8M, the NVIC has a new set of registers per interrupt,
NVIC_ITNS<n>. These determine whether the interrupt targets Secure
or Non-secure state. Implement the register read/write code for
these, and make them cause NVIC_IABR, NVIC_ICER, NVIC_ISER,
NVIC_ICPR, NVIC_IPR and NVIC_ISPR to RAZ/WI for non-secure
accesses to fields corresponding to interrupts which are
configured to target secure state.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1505240046-11454-8-git-send-email-peter.maydell@linaro.org
The Application Interrupt and Reset Control Register has some changes
for v8M:
* new bits SYSRESETREQS, BFHFNMINS and PRIS: these all have
real state if the security extension is implemented and otherwise
are constant
* the PRIGROUP field is banked between security states
* non-secure code can be blocked from using the SYSRESET bit
to reset the system if SYSRESETREQS is set
Implement the new state and the changes to register read and write.
For the moment we ignore the effects of the secure PRIGROUP.
We will implement the effects of PRIS and BFHFNMIS later.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1505240046-11454-6-git-send-email-peter.maydell@linaro.org
Instead of looking up the pending priority
in nvic_pending_prio(), cache it in a new state struct
field. The calculation of the pending priority given
the interrupt number is more complicated in v8M with
the security extension, so the caching will be worthwhile.
This changes nvic_pending_prio() from returning a full
(group + subpriority) priority value to returning a group
priority. This doesn't require changes to its callsites
because we use it only in comparisons of the form
execution_prio > nvic_pending_prio()
and execution priority is always a group priority, so
a test (exec prio > full prio) is true if and only if
(execprio > group_prio).
(Architecturally the expected comparison is with the
group priority for this sort of "would we preempt" test;
we were only doing a test with a full priority as an
optimisation to avoid the mask, which is possible
precisely because the two comparisons always give the
same answer.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1505240046-11454-5-git-send-email-peter.maydell@linaro.org
With banked exceptions, just the exception number in
s->vectpending is no longer sufficient to uniquely identify
the pending exception. Add a vectpending_is_s_banked bool
which is true if the exception is using the sec_vectors[]
array.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1505240046-11454-4-git-send-email-peter.maydell@linaro.org
For the v8M security extension, some exceptions must be banked
between security states. Add the new vecinfo array which holds
the state for the banked exceptions and migrate it if the
CPU the NVIC is attached to implements the security extension.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
For v8M the range 0xe002e000..0xe002efff is an alias region which
for secure accesses behaves like a NonSecure access to the main
SCS region. (For nonsecure accesses including when the security
extension is not implemented, it is RAZ/WI.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1503414539-28762-11-git-send-email-peter.maydell@linaro.org
The armv7m_nvic.h header file was accidentally placed in
include/hw/arm; move it to include/hw/intc to match where
its corresponding .c file lives.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1501692241-23310-15-git-send-email-peter.maydell@linaro.org
