The M-profile architecture specifies that the DebugMonitor exception
should be initially disabled, not enabled. It should be controlled
by the DEMCR register's MON_EN bit, but we don't implement that
register yet (like most of the debug architecture for M-profile).
Note that BKPT instructions will still work, because they
will be escalated to HardFault.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190430131439.25251-4-peter.maydell@linaro.org
The non-secure versions of the BFAR and BFSR registers are
supposed to be RAZ/WI if AICR.BFHFNMINS == 0; we were
incorrectly allowing NS code to access the real values.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190430131439.25251-3-peter.maydell@linaro.org
Rule R_CQRV says that if two pending interrupts have the same
group priority then ties are broken by looking at the subpriority.
We had a comment describing this but had forgotten to actually
implement the subpriority comparison. Correct the omission.
(The further tie break rules of "lowest exception number" and
"secure before non-secure" are handled implicitly by the order
in which we iterate through the exceptions in the loops.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190430131439.25251-2-peter.maydell@linaro.org
In the v7M architecture, if an exception is generated in the process
of doing the lazy stacking of FP registers, the handling of
possible escalation to HardFault is treated differently to the normal
approach: it works based on the saved information about exception
readiness that was stored in the FPCCR when the stack frame was
created. Provide a new function armv7m_nvic_set_pending_lazyfp()
which pends exceptions during lazy stacking, and implements
this logic.
This corresponds to the pseudocode TakePreserveFPException().
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190416125744.27770-22-peter.maydell@linaro.org
Implement the code which updates the FPCCR register on an
exception entry where we are going to use lazy FP stacking.
We have to defer to the NVIC to determine whether the
various exceptions are currently ready or not.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20190416125744.27770-12-peter.maydell@linaro.org
The M-profile floating point support has three associated config
registers: FPCAR, FPCCR and FPDSCR. It also makes the registers
CPACR and NSACR have behaviour other than reads-as-zero.
Add support for all of these as simple reads-as-written registers.
We will hook up actual functionality later.
The main complexity here is handling the FPCCR register, which
has a mix of banked and unbanked bits.
Note that we don't share storage with the A-profile
cpu->cp15.nsacr and cpu->cp15.cpacr_el1, though the behaviour
is quite similar, for two reasons:
* the M profile CPACR is banked between security states
* it preserves the invariant that M profile uses no state
inside the cp15 substruct
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190416125744.27770-4-peter.maydell@linaro.org
For M-profile the MVFR* ID registers are memory mapped, in the
range we implement via the NVIC. Allow them to be read.
(If the CPU has no FPU, these registers are defined to be RAZ.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190416125744.27770-3-peter.maydell@linaro.org
The code for handling the NVIC SHPR1 register intends to permit
byte and halfword accesses (as the architecture requires). However
the 'case' line for it only lists the base address of the
register, so attempts to access bytes other than the first one
end up in the "bad write" default logic. This bug was added
accidentally when we split out the SHPR1 logic from SHPR2 and
SHPR3 to support v6M.
Fixes: 7c9140afd5 ("nvic: Handle ARMv6-M SCS reserved registers")
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
The Zephyr RTOS happens to access SHPR1 byte at a time,
which is how I spotted this.
Currently the ARMv7M NVIC object's realize method assumes that the
CPU the NVIC is attached to is CPU 0, because it thinks there can
only ever be one CPU in the system. To allow a dual-Cortex-M33
setup we need to remove this assumption; instead the armv7m
wrapper object tells the NVIC its CPU, in the same way that it
already tells the CPU what the NVIC is.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190121185118.18550-2-peter.maydell@linaro.org
Create struct ARMISARegisters, to be accessed during translation.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20181016223115.24100-2-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
On real v7M hardware, the NMI line is an externally visible signal
that an SoC or board can toggle to assert an NMI. Expose it in
our QEMU NVIC and armv7m container objects so that a board model
can wire it up if it needs to.
In particular, the MPS2 watchdog is wired to NMI.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
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>
Forbid stack alignment change. (CCR)
Reserve FAULTMASK, BASEPRI registers.
Report any fault as a HardFault. Disable MemManage, BusFault and
UsageFault, so they always escalated to HardFault. (SHCSR)
Signed-off-by: Julia Suvorova <jusual@mail.ru>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20180718095628.26442-1-jusual@mail.ru
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Handle SCS reserved registers listed in ARMv6-M ARM D3.6.1.
All reserved registers are RAZ/WI. ARM_FEATURE_M_MAIN is used for the
checks, because these registers are reserved in ARMv8-M Baseline too.
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>
The vmstate save/load code insists that subsections of a VMState must
have names which include their parent VMState's name as a leading
substring. Unfortunately it neither documents this nor checks it on
device init or state save, but instead fails state load with a
confusing error message ("Missing section footer for armv7m_nvic").
Fix the name of the m-security subsection of the NVIC, so that
state save/load works correctly for the security-enabled NVIC.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180727113854.20283-2-peter.maydell@linaro.org
When we escalate a v8M exception to HardFault, if AIRCR.BFHFNMINNS is
set then we need to decide whether it should become a secure HardFault
or a nonsecure HardFault. We should always escalate to the same
target security state as the original exception. The current code
tries to test this using the 'secure' bool, which is not right because
that flag indicates whether the target security state only for
banked exceptions; the effect was that we were incorrectly escalating
always-secure exceptions like SecureFault to a nonsecure HardFault.
Fix this by defining, logging and using a new 'targets_secure' bool
which tracks the condition we actually want.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180723123457.2038-1-peter.maydell@linaro.org
QEMU currently crashes when introspecting the "iotkit" device and
runnint "info qtree" afterwards, e.g. when running QEMU like this:
echo "{'execute':'qmp_capabilities'} {'execute':'device-list-properties'," \
"'arguments':{'typename':'iotkit'}}" "{'execute': 'human-monitor-command', " \
"'arguments': {'command-line': 'info qtree'}}" | \
aarch64-softmmu/qemu-system-aarch64 -M none,accel=qtest -qmp stdio
Use the new functions object_initialize_child() and sysbus_init_child_obj()
to make sure that all objects get cleaned up correctly when the instances
are destroyed.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 1531745974-17187-5-git-send-email-thuth@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The Cortex-M CPU and its NVIC are two intimately intertwined parts of
the same hardware; it is not possible to use one without the other.
Unfortunately a lot of our board models don't do any sanity checking
on the CPU type the user asks for, so a command line like
qemu-system-arm -M versatilepb -cpu cortex-m3
will create an M3 without an NVIC, and coredump immediately.
In the other direction, trying a non-M-profile CPU in an M-profile
board won't blow up, but doesn't do anything useful either:
qemu-system-arm -M lm3s6965evb -cpu arm926
Add some checking in the NVIC and CPU realize functions that the
user isn't trying to use an NVIC without an M-profile CPU or
an M-profile CPU without an NVIC, so we can produce a helpful
error message rather than a core dump.
Fixes: https://bugs.launchpad.net/qemu/+bug/1766896
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20180601160355.15393-1-peter.maydell@linaro.org
In many of the NVIC registers relating to interrupts, we
have to convert from a byte offset within a register set
into the number of the first interrupt which is affected.
We were getting this wrong for:
* reads of NVIC_ISPR<n>, NVIC_ISER<n>, NVIC_ICPR<n>, NVIC_ICER<n>,
NVIC_IABR<n> -- in all these cases we were missing the "* 8"
needed to convert from the byte offset to the interrupt number
(since all these registers use one bit per interrupt)
* writes of NVIC_IPR<n> had the opposite problem of a spurious
"* 8" (since these registers use one byte per interrupt)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20180209165810.6668-9-peter.maydell@linaro.org
We were previously making the system control register (SCR)
just RAZ/WI. Although we don't implement the functionality
this register controls, we should at least provide the state,
including the banked state for v8M.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180209165810.6668-7-peter.maydell@linaro.org
M profile cores have a similar setup for cache ID registers
to A profile:
* Cache Level ID Register (CLIDR) is a fixed value
* Cache Type Register (CTR) is a fixed value
* Cache Size ID Registers (CCSIDR) are a bank of registers;
which one you see is selected by the Cache Size Selection
Register (CSSELR)
The only difference is that they're in the NVIC memory mapped
register space rather than being coprocessor registers.
Implement the M profile view of them.
Since neither Cortex-M3 nor Cortex-M4 implement caches,
we don't need to update their init functions and can leave
the ctr/clidr/ccsidr[] fields in their ARMCPU structs at zero.
Newer cores (like the Cortex-M33) will want to be able to
set these ID registers to non-zero values, though.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180209165810.6668-6-peter.maydell@linaro.org
The Coprocessor Power Control Register (CPPWR) is new in v8M.
It allows software to control whether coprocessors are allowed
to power down and lose their state. QEMU doesn't have any
notion of power control, so we choose the IMPDEF option of
making the whole register RAZ/WI (indicating that no coprocessors
can ever power down and lose state).
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180209165810.6668-5-peter.maydell@linaro.org
For M profile cores, cache maintenance operations are done by
writing to special registers in the system register space.
For QEMU, cache operations are always NOPs, since we don't
implement the cache. Implementing these explicitly avoids
a spurious LOG_GUEST_ERROR when the guest uses them.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180209165810.6668-4-peter.maydell@linaro.org
The PENDNMISET/CLR bits in the ICSR should be RAZ/WI from
NonSecure state if the AIRCR.BFHFNMINS bit is zero. We had
misimplemented this as making the bits RAZ/WI from both
Secure and NonSecure states. Fix this bug by checking
attrs.secure so that Secure code can pend and unpend NMIs.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180209165810.6668-3-peter.maydell@linaro.org
Instead of hardcoding the values of M profile ID registers in the
NVIC, use the fields in the CPU struct. This will allow us to
give different M profile CPU types different ID register values.
This commit includes the addition of the missing ID_ISAR5,
which exists as RES0 in both v7M and v8M.
(The values of the ID registers might be wrong for the M4 --
this commit leaves the behaviour there unchanged.)
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: 20180209165810.6668-2-peter.maydell@linaro.org
Currently armv7m_nvic_acknowledge_irq() does three things:
* make the current highest priority pending interrupt active
* return a bool indicating whether that interrupt is targeting
Secure or NonSecure state
* implicitly tell the caller which is the highest priority
pending interrupt by setting env->v7m.exception
We need to split these jobs, because v7m_exception_taken()
needs to know whether the pending interrupt targets Secure so
it can choose to stack callee-saves registers or not, but it
must not make the interrupt active until after it has done
that stacking, in case the stacking causes a derived exception.
Similarly, it needs to know the number of the pending interrupt
so it can read the correct vector table entry before the
interrupt is made active, because vector table reads might
also cause a derived exception.
Create a new armv7m_nvic_get_pending_irq_info() function which simply
returns information about the highest priority pending interrupt, and
use it to rearrange the v7m_exception_taken() code so we don't
acknowledge the exception until we've done all the things which could
possibly cause a derived exception.
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: 1517324542-6607-3-git-send-email-peter.maydell@linaro.org
In order to support derived exceptions (exceptions generated in
the course of trying to take an exception), we need to be able
to handle prioritizing whether to take the original exception
or the derived exception.
We do this by introducing a new function
armv7m_nvic_set_pending_derived() which the exception-taking code in
helper.c will call when a derived exception occurs. Derived
exceptions are dealt with mostly like normal pending exceptions, so
we share the implementation with the armv7m_nvic_set_pending()
function.
Note that the way we structure this is significantly different
from the v8M Arm ARM pseudocode: that does all the prioritization
logic in the DerivedLateArrival() function, whereas we choose to
let the existing "identify highest priority exception" logic
do the prioritization for us. The effect is the same, though.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1517324542-6607-2-git-send-email-peter.maydell@linaro.org
The Configurable Fault Status Register for ARMv7M and v8M is
supposed to be byte and halfword accessible, but we were only
implementing word accesses. Add support for the other access
sizes, which are used by the Zephyr RTOS.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reported-by: Andy Gross <andy.gross@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 1512742372-31517-1-git-send-email-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
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
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
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
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>
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
