Commit Graph

90 Commits

Author SHA1 Message Date
Peter Maydell
27f26bfed9 nvic: Make systick banked
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
2017-12-13 17:59:26 +00:00
Peter Maydell
62f018482c nvic: Make nvic_sysreg_ns_ops work with any MemoryRegion
Generalize nvic_sysreg_ns_ops so that we can pass it an
arbitrary MemoryRegion which it will use as the underlying
register implementation to apply the NS-alias behaviour
to. We'll want this so we can do the same with systick.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 1512154296-5652-2-git-send-email-peter.maydell@linaro.org
2017-12-13 17:59:26 +00:00
Peter Maydell
2b75ef01ca nvic: Fix ARMv7M MPU_RBAR reads
Fix an incorrect mask expression in the handling of v7M MPU_RBAR
reads that meant that we would always report the ADDR field as zero.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 1509732813-22957-1-git-send-email-peter.maydell@linaro.org
2017-11-20 13:39:48 +00:00
Peter Maydell
cf5f7937b0 nvic: Fix miscalculation of offsets into ITNS array
This calculation of the first exception vector in
the ITNS<n> register being accessed:
        int startvec = 32 * (offset - 0x380) + NVIC_FIRST_IRQ;

is incorrect, because offset is in bytes, so we only want
to multiply by 8.

Spotted by Coverity (CID 1381484, CID 1381488), though it is
not correct that it actually overflows the buffer, because
we have a 'startvec + i < s->num_irq' guard.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1507650856-11718-1-git-send-email-peter.maydell@linaro.org
2017-10-12 16:33:16 +01:00
Peter Maydell
a94bb9cd58 nvic: Add missing 'break'
Coverity points out that we forgot the 'break' for
the SAU_CTRL write case (CID1381683). This has
no actual visible consequences because it happens
that the following case is effectively a no-op.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 1507742676-9908-1-git-send-email-peter.maydell@linaro.org
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2017-10-12 13:24:39 +01:00
Peter Maydell
04829ce334 nvic: Add missing code for writing SHCSR.HARDFAULTPENDED bit
When we added support for the new SHCSR bits in v8M in commit
437d59c17e the code to support writing to the new HARDFAULTPENDED
bit was accidentally only added for non-secure writes; the
secure banked version of the bit should also be writable.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1506092407-26985-21-git-send-email-peter.maydell@linaro.org
2017-10-06 16:46:49 +01:00
Peter Maydell
9901c576f6 nvic: Implement Security Attribution Unit registers
Implement the register interface for the SAU: SAU_CTRL,
SAU_TYPE, SAU_RNR, SAU_RBAR and SAU_RLAR. None of the
actual behaviour is implemented here; registers just
read back as written.

When the CPU definition for Cortex-M33 is eventually
added, its initfn will set cpu->sau_sregion, in the same
way that we currently set cpu->pmsav7_dregion for the
M3 and M4.

Number of SAU regions is typically a configurable
CPU parameter, but this patch doesn't provide a
QEMU CPU property for it. We can easily add one when
we have a board that requires it.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1506092407-26985-14-git-send-email-peter.maydell@linaro.org
2017-10-06 16:46:49 +01:00
Peter Maydell
bed079da04 target/arm: Add new-in-v8M SFSR and SFAR
Add the new M profile Secure Fault Status Register
and Secure Fault Address Register.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1506092407-26985-10-git-send-email-peter.maydell@linaro.org
2017-10-06 16:46:48 +01:00
Peter Maydell
de2db7ec89 target/arm: Prepare for CONTROL.SPSEL being nonzero in Handler mode
In the v7M architecture, there is an invariant that if the CPU is
in Handler mode then the CONTROL.SPSEL bit cannot be nonzero.
This in turn means that the current stack pointer is always
indicated by CONTROL.SPSEL, even though Handler mode always uses
the Main stack pointer.

In v8M, this invariant is removed, and CONTROL.SPSEL may now
be nonzero in Handler mode (though Handler mode still always
uses the Main stack pointer). In preparation for this change,
change how we handle this bit: rename switch_v7m_sp() to
the now more accurate write_v7m_control_spsel(), and make it
check both the handler mode state and the SPSEL bit.

Note that this implicitly changes the point at which we switch
active SP on exception exit from before we pop the exception
frame to after it.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1506092407-26985-4-git-send-email-peter.maydell@linaro.org
2017-10-06 16:46:47 +01:00
Peter Maydell
8ff26a3344 nvic: Clear the vector arrays and prigroup on reset
Reset for devices does not include an automatic clear of the
device state (unlike CPU state, where most of the state
structure is cleared to zero). Add some missing initialization
of NVIC state that meant that the device was left in the wrong
state if the guest did a warm reset.

(In particular, since we were resetting the computed state like
s->exception_prio but not all the state it was computed
from like s->vectors[x].active, the NVIC wound up in an
inconsistent state that could later trigger assertion failures.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 1506092407-26985-2-git-send-email-peter.maydell@linaro.org
2017-10-06 16:46:47 +01:00
Peter Maydell
5cb18069d7 nvic: Support banked exceptions in acknowledge and complete
Update armv7m_nvic_acknowledge_irq() and armv7m_nvic_complete_irq()
to handle banked exceptions:
 * acknowledge needs to use the correct vector, which may be
   in sec_vectors[]
 * acknowledge needs to return to its caller whether the
   exception should be taken to secure or non-secure state
 * complete needs its caller to tell it whether the exception
   being completed is a secure one or not

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1505240046-11454-20-git-send-email-peter.maydell@linaro.org
2017-09-21 16:31:09 +01:00
Peter Maydell
437d59c17e nvic: Make SHCSR banked for v8M
Handle banking of SHCSR: some register bits are banked between
Secure and Non-Secure, and some are only accessible to Secure.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1505240046-11454-19-git-send-email-peter.maydell@linaro.org
2017-09-21 16:31:09 +01:00
Peter Maydell
3f1e0eb7c3 nvic: Make ICSR banked for v8M
The ICSR NVIC register is banked for v8M. This doesn't
require any new state, but it does mean that some bits
are controlled by BFHNFNMINS and some bits must work
with the correct banked exception. There is also a new
in v8M PENDNMICLR bit.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1505240046-11454-18-git-send-email-peter.maydell@linaro.org
2017-09-21 16:31:09 +01:00
Peter Maydell
5d4791991d target/arm: Handle banking in negative-execution-priority check in cpu_mmu_index()
Now that we have a banked FAULTMASK register and banked exceptions,
we can implement the correct check in cpu_mmu_index() for whether
the MPU_CTRL.HFNMIENA bit's effect should apply. This bit causes
handlers which have requested a negative execution priority to run
with the MPU disabled. In v8M the test has to check this for the
current security state and so takes account of banking.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1505240046-11454-17-git-send-email-peter.maydell@linaro.org
2017-09-21 16:31:09 +01:00
Peter Maydell
49c80c380d nvic: Handle v8M changes in nvic_exec_prio()
Update nvic_exec_prio() to support the v8M changes:
 * BASEPRI, FAULTMASK and PRIMASK are all banked
 * AIRCR.PRIS can affect NS priorities
 * AIRCR.BFHFNMINS affects FAULTMASK behaviour

These changes mean that it's no longer possible to
definitely say that if FAULTMASK is set it overrides
PRIMASK, and if PRIMASK is set it overrides BASEPRI
(since if PRIMASK_NS is set and AIRCR.PRIS is set then
whether that 0x80 priority should take effect or the
priority in BASEPRI_S depends on the value of BASEPRI_S,
for instance). So we switch to the same approach used
by the pseudocode of working through BASEPRI, PRIMASK
and FAULTMASK and overriding the previous values if
needed.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1505240046-11454-16-git-send-email-peter.maydell@linaro.org
2017-09-21 16:31:09 +01:00
Peter Maydell
7208b426c7 nvic: Disable the non-secure HardFault if AIRCR.BFHFNMINS is clear
If AIRCR.BFHFNMINS is clear, then although NonSecure HardFault
can still be pended via SHCSR.HARDFAULTPENDED it mustn't actually
preempt execution. The simple way to achieve this is to clear the
enable bit for it, since the enable bit isn't guest visible.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1505240046-11454-15-git-send-email-peter.maydell@linaro.org
2017-09-21 16:31:09 +01:00
Peter Maydell
331f4bae6c nvic: Implement v8M changes to fixed priority exceptions
In v7M, the fixed-priority exceptions are:
 Reset: -3
 NMI: -2
 HardFault: -1

In v8M, this changes because Secure HardFault may need
to be prioritised above NMI:
 Reset: -4
 Secure HardFault if AIRCR.BFHFNMINS == 1: -3
 NMI: -2
 Secure HardFault if AIRCR.BFHFNMINS == 0: -1
 NonSecure HardFault: -1

Make these changes, including support for changing the
priority of Secure HardFault as AIRCR.BFHFNMINS changes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1505240046-11454-14-git-send-email-peter.maydell@linaro.org
2017-09-21 16:31:09 +01:00
Peter Maydell
94a34abe32 nvic: In escalation to HardFault, support HF not being priority -1
When escalating to HardFault, we must go into Lockup if we
can't take the synchronous HardFault because the current
execution priority is already at or below the priority of
HardFault. In v7M HF is always priority -1 so a simple < 0
comparison sufficed; in v8M the priority of HardFault can
vary depending on whether it is a Secure or NonSecure
HardFault, so we must check against the priority of the
HardFault exception vector we're about to use.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1505240046-11454-13-git-send-email-peter.maydell@linaro.org
2017-09-21 16:31:09 +01:00
Peter Maydell
80ac239035 nvic: Compare group priority for escalation to HF
In armv7m_nvic_set_pending() we have to compare the
priority of an exception against the execution priority
to decide whether it needs to be escalated to HardFault.
In the specification this is a comparison against the
exception's group priority; for v7M we implemented it
as a comparison against the raw exception priority
because the two comparisons will always give the
same answer. For v8M the existence of AIRCR.PRIS and
the possibility of different PRIGROUP values for secure
and nonsecure exceptions means we need to explicitly
calculate the vector's group priority for this check.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1505240046-11454-12-git-send-email-peter.maydell@linaro.org
2017-09-21 16:31:09 +01:00
Peter Maydell
e6a0d3500d nvic: Make SHPR registers banked
Make the set_prio() function take a bool indicating
whether to pend the secure or non-secure version of a banked
interrupt, and use this to implement the correct banking
semantics for the SHPR registers.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1505240046-11454-11-git-send-email-peter.maydell@linaro.org
2017-09-21 16:31:09 +01:00
Peter Maydell
2fb50a3340 nvic: Make set_pending and clear_pending take a secure parameter
Make the armv7m_nvic_set_pending() and armv7m_nvic_clear_pending()
functions take a bool indicating whether to pend the secure
or non-secure version of a banked interrupt, and update the
callsites accordingly.

In most callsites we can simply pass the correct security
state in; in a couple of cases we use TODO comments to indicate
that we will return the code in a subsequent commit.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1505240046-11454-10-git-send-email-peter.maydell@linaro.org
2017-09-21 16:31:09 +01:00
Peter Maydell
ff96c64aec nvic: Handle banked exceptions in nvic_recompute_state()
Update the nvic_recompute_state() code to handle the security
extension and its associated banked registers.

Code that uses the resulting cached state (ie the irq
acknowledge and complete code) will be updated in a later
commit.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1505240046-11454-9-git-send-email-peter.maydell@linaro.org
2017-09-21 16:31:09 +01:00
Peter Maydell
e1be0a576b nvic: Implement NVIC_ITNS<n> registers
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
2017-09-21 16:29:27 +01:00
Peter Maydell
028b0da424 nvic: Make ICSR.RETTOBASE handle banked exceptions
Update the code in nvic_rettobase() so that it checks the
sec_vectors[] array as well as the vectors[] array if needed.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1505240046-11454-7-git-send-email-peter.maydell@linaro.org
2017-09-21 16:29:27 +01:00
Peter Maydell
3b2e934463 nvic: Implement AIRCR changes for v8M
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
2017-09-21 16:29:27 +01:00
Peter Maydell
5255fcf8e4 nvic: Add cached vectpending_prio state
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
2017-09-21 16:29:27 +01:00
Peter Maydell
e93bc2ac11 nvic: Add cached vectpending_is_s_banked state
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
2017-09-21 16:29:23 +01:00
Peter Maydell
17906a162a nvic: Add banked exception states
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>
2017-09-21 16:28:59 +01:00
Peter Maydell
22a9c26af6 nvic: Don't apply group priority mask to negative priorities
In several places we were unconditionally applying the
nvic_gprio_mask() to a priority value. This is incorrect
if the priority is one of the fixed negative priority
values (for NMI and HardFault), so don't do it.

This bug would have caused both NMI and HardFault to be
considered as the same priority and so NMI wouldn't
correctly preempt HardFault.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1505137930-13255-5-git-send-email-peter.maydell@linaro.org
2017-09-14 18:43:17 +01:00
Peter Maydell
334e8dad7a target/arm: Make CFSR register banked for v8M
Make the CFSR register banked if v8M security extensions are enabled.

Not all the bits in this register are banked: the BFSR
bits [15:8] are shared between S and NS, and we store them
in the NS copy of the register.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1503414539-28762-19-git-send-email-peter.maydell@linaro.org
2017-09-07 13:54:54 +01:00
Peter Maydell
c51a5cfc9f target/arm: Make MMFAR banked for v8M
Make the MMFAR register banked if v8M security extensions are
enabled.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1503414539-28762-18-git-send-email-peter.maydell@linaro.org
2017-09-07 13:54:54 +01:00
Peter Maydell
9d40cd8a68 target/arm: Make CCR register banked for v8M
Make the CCR register banked if v8M security extensions are enabled.

This is slightly more complicated than the other "add banking"
patches because there is one bit in the register which is not
banked. We keep the live data in the NS copy of the register,
and adjust it on register reads and writes. (Since we don't
currently implement the behaviour that the bit controls, there
is nowhere else that needs to care.)

This patch includes the enforcement of the bits which are newly
RES1 in ARMv8M.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1503414539-28762-17-git-send-email-peter.maydell@linaro.org
2017-09-07 13:54:54 +01:00
Peter Maydell
ecf5e8eae8 target/arm: Make MPU_CTRL register banked for v8M
Make the MPU_CTRL register banked if v8M security extensions are
enabled.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1503414539-28762-16-git-send-email-peter.maydell@linaro.org
2017-09-07 13:54:53 +01:00
Peter Maydell
1bc04a8880 target/arm: Make MPU_RNR register banked for v8M
Make the MPU_RNR register banked if v8M security extensions are
enabled.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1503414539-28762-15-git-send-email-peter.maydell@linaro.org
2017-09-07 13:54:53 +01:00
Peter Maydell
62c58ee0b2 target/arm: Make MPU_RBAR, MPU_RLAR banked for v8M
Make the MPU registers MPU_MAIR0 and MPU_MAIR1 banked if v8M security
extensions are enabled.

We can freely add more items to vmstate_m_security without
breaking migration compatibility, because no CPU currently
has the ARM_FEATURE_M_SECURITY bit enabled and so this
subsection is not yet used by anything.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1503414539-28762-14-git-send-email-peter.maydell@linaro.org
2017-09-07 13:54:53 +01:00
Peter Maydell
4125e6feb7 target/arm: Make MPU_MAIR0, MPU_MAIR1 registers banked for v8M
Make the MPU registers MPU_MAIR0 and MPU_MAIR1 banked if v8M security
extensions are enabled.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1503414539-28762-13-git-send-email-peter.maydell@linaro.org
2017-09-07 13:54:53 +01:00
Peter Maydell
45db7ba681 target/arm: Make VTOR register banked for v8M
Make the VTOR register banked if v8M security extensions are enabled.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1503414539-28762-12-git-send-email-peter.maydell@linaro.org
2017-09-07 13:54:53 +01:00
Peter Maydell
f104919d15 nvic: Add NS alias SCS region
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
2017-09-07 13:54:53 +01:00
Peter Maydell
42a6686b2f target/arm: Make FAULTMASK register banked for v8M
Make the FAULTMASK register banked if v8M security extensions are enabled.

Note that we do not yet implement the functionality of the new
AIRCR.PRIS bit (which allows the effect of the NS copy of FAULTMASK to
be restricted).

This patch includes the code to determine for v8M which copy
of FAULTMASK should be updated on exception exit; further
changes will be required to the exception exit code in general
to support v8M, so this is just a small piece of that.

The v8M ARM ARM introduces a notation where individual paragraphs
are labelled with R (for rule) or I (for information) followed
by a random group of subscript letters. In comments where we want
to refer to a particular part of the manual we use this convention,
which should be more stable across document revisions than using
section or page numbers.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1503414539-28762-9-git-send-email-peter.maydell@linaro.org
2017-09-07 13:54:52 +01:00
Peter Maydell
6d80483419 target/arm: Make PRIMASK register banked for v8M
Make the PRIMASK register banked if v8M security extensions are enabled.

Note that we do not yet implement the functionality of the new
AIRCR.PRIS bit (which allows the effect of the NS copy of PRIMASK to
be restricted).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1503414539-28762-8-git-send-email-peter.maydell@linaro.org
2017-09-07 13:54:52 +01:00
Peter Maydell
acf949411f target/arm: Make BASEPRI register banked for v8M
Make the BASEPRI register banked if v8M security extensions are enabled.

Note that we do not yet implement the functionality of the new
AIRCR.PRIS bit (which allows the effect of the NS copy of BASEPRI to
be restricted).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1503414539-28762-7-git-send-email-peter.maydell@linaro.org
2017-09-07 13:54:52 +01:00
Peter Maydell
0e1a46bbd2 target/arm: Implement ARMv8M's PMSAv8 registers
As part of ARMv8M, we need to add support for the PMSAv8 MPU
architecture.

PMSAv8 differs from PMSAv7 both in register/data layout (for instance
using base and limit registers rather than base and size) and also in
behaviour (for example it does not have subregions); rather than
trying to wedge it into the existing PMSAv7 code and data structures,
we define separate ones.

This commit adds the data structures which hold the state for a
PMSAv8 MPU and the register interface to it.  The implementation of
the MPU behaviour will be added in a subsequent commit.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1503414539-28762-2-git-send-email-peter.maydell@linaro.org
2017-09-07 13:54:51 +01:00
Peter Maydell
eb578a2394 nvic: Implement "user accesses BusFault" SCS region behaviour
The ARMv7M architecture specifies that most of the addresses in the
PPB region (which includes the NVIC, systick and system registers)
are not accessible to unprivileged accesses, which should
BusFault with a few exceptions:
 * the STIR is configurably user-accessible
 * the ITM (which we don't implement at all) is always
   user-accessible

Implement this by switching the register access functions
to the _with_attrs scheme that lets us distinguish user
mode accesses.

This allows us to pull the handling of the CCR.USERSETMPEND
flag up to the level where we can make it generate a BusFault
as it should for non-permitted accesses.

Note that until the core ARM CPU code implements turning
MEMTX_ERROR into a BusFault the registers will continue to
act as RAZ/WI to user accesses.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1501692241-23310-16-git-send-email-peter.maydell@linaro.org
2017-09-04 15:21:53 +01:00
Peter Maydell
d2db1de6ff armv7m_nvic.h: Move from include/hw/arm to include/hw/intc
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
2017-09-04 15:21:53 +01:00
Peter Maydell
e6ae5981ea target/arm: Don't store M profile PRIMASK and FAULTMASK in daif
We currently store the M profile CPU register state PRIMASK and
FAULTMASK in the daif field of the CPU state in its I and F
bits. This is a legacy from the original implementation, which
tried to share the cpu_exec_interrupt code between A profile
and M profile. We've since separated out the two cases because
they are significantly different, so now there is no common
code between M and A profile which looks at env->daif: all the
uses are either in A-only or M-only code paths. Sharing the state
fields now is just confusing, and will make things awkward
when we implement v8M, where the PRIMASK and FAULTMASK
registers are banked between security states.

Switch M profile over to using v7m.faultmask and v7m.primask
fields for these registers.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1501692241-23310-10-git-send-email-peter.maydell@linaro.org
2017-09-04 15:21:52 +01:00
Peter Maydell
79c857a35f hw/intc/armv7m_nvic.c: Remove out of date comment
Remove an out of date comment which says there's only one
item in the NVIC container region -- we put systick into its
own device object a while back and so now there are two
things in the container.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1501692241-23310-6-git-send-email-peter.maydell@linaro.org
2017-09-04 15:21:52 +01:00
Peter Maydell
8531eb4f61 target/arm: Rename cp15.c6_rgnr to pmsav7.rnr
Almost all of the PMSAv7 state is in the pmsav7 substruct of
the ARM CPU state structure. The exception is the region
number register, which is in cp15.c6_rgnr. This exception
is a bit odd for M profile, which otherwise generally does
not store state in the cp15 substruct.

Rename cp15.c6_rgnr to pmsav7.rnr accordingly.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 1501153150-19984-4-git-send-email-peter.maydell@linaro.org
2017-07-31 13:09:52 +01:00
Michael Davidsaver
29c483a506 arm: add MPU support to M profile CPUs
The M series MPU is almost the same as the already implemented R
profile MPU (v7 PMSA).  So all we need to implement here is the MPU
register interface in the system register space.

This implementation has the same restriction as the R profile MPU
that it doesn't permit regions to be sized down smaller than 1K.

We also do not yet implement support for MPU_CTRL.HFNMIENA; this
bit should if zero disable use of the MPU when running HardFault,
NMI or with FAULTMASK set to 1 (ie at an execution priority of
less than zero) -- if the MPU is enabled we don't treat these
cases any differently.

Signed-off-by: Michael Davidsaver <mdavidsaver@gmail.com>
Message-id: 1493122030-32191-13-git-send-email-peter.maydell@linaro.org
[PMM: Keep all the bits in mpu_ctrl field, rather than
 using SCTLR bits for them; drop broken HFNMIENA support;
 various cleanup]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-06-02 11:51:48 +01:00
Peter Maydell
ff68dacbc7 armv7m: Split systick out from NVIC
The SysTick timer isn't really part of the NVIC proper;
we just modelled it that way back when we couldn't
easily have devices that only occupied a small chunk
of a memory region. Split it out into its own device.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1487604965-23220-10-git-send-email-peter.maydell@linaro.org
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
2017-02-28 16:18:49 +00:00
Peter Maydell
98957a94ef armv7m: Make NVIC expose a memory region rather than mapping itself
Make the NVIC device expose a memory region for its users
to map, rather than mapping itself into the system memory
space on realize, and get the one user (the ARMv7M object)
to do this.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 1487604965-23220-7-git-send-email-peter.maydell@linaro.org
2017-02-28 16:18:49 +00:00