hw/intc/armv7m_nvic: Implement SCR

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 p

hw/intc/armv7m_nvic: Implement SCR

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

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hw/intc/armv7m_nvic: Implement cache ID registers

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

hw/intc/armv7m_nvic: Implement cache ID registers

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

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hw/intc/armv7m_nvic: Implement v8M CPPWR register

The Coprocessor Power Control Register (CPPWR) is new in v8M.
It allows software to control whether coprocessors are allowed
to power down and lose

hw/intc/armv7m_nvic: Implement v8M CPPWR register

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

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hw/intc/armv7m_nvic: Implement M profile cache maintenance ops

For M profile cores, cache maintenance operations are done by
writing to special registers in the system register space.
For QEMU, cach

hw/intc/armv7m_nvic: Implement M profile cache maintenance ops

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

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hw/intc/armv7m_nvic: Fix ICSR PENDNMISET/CLR handling

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 maki

hw/intc/armv7m_nvic: Fix ICSR PENDNMISET/CLR handling

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

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hw/intc/armv7m_nvic: Don't hardcode M profile ID registers in NVIC

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
giv

hw/intc/armv7m_nvic: Don't hardcode M profile ID registers in NVIC

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

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target/arm: Split "get pending exception info" from "acknowledge it"

Currently armv7m_nvic_acknowledge_irq() does three things:
* make the current highest priority pending interrupt active
* retur

target/arm: Split "get pending exception info" from "acknowledge it"

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

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target/arm: Add armv7m_nvic_set_pending_derived()

In order to support derived exceptions (exceptions generated in
the course of trying to take an exception), we need to be able
to handle prioritizin

target/arm: Add armv7m_nvic_set_pending_derived()

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

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hw/intc/armv7m: Support byte and halfword accesses to CFSR

The Configurable Fault Status Register for ARMv7M and v8M is
supposed to be byte and halfword accessible, but we were only
implementing wor

hw/intc/armv7m: Support byte and halfword accesses to CFSR

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

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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 o

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

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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

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

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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 <p

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

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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_I

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

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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

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>

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nvic: Add missing code for writing SHCSR.HARDFAULTPENDED bit

When we added support for the new SHCSR bits in v8M in commit
437d59c17e9 the code to support writing to the new HARDFAULTPENDED
bit was

nvic: Add missing code for writing SHCSR.HARDFAULTPENDED bit

When we added support for the new SHCSR bits in v8M in commit
437d59c17e9 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

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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

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

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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: R

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

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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.
Th

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

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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)

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

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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 v

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

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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.may

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

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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

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

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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_i

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

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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.BFHF

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

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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
pr

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

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