Commit Graph

75 Commits

Author SHA1 Message Date
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
Peter Maydell 6bf436cf9d armv7m: Move NVICState struct definition into header
Move the NVICState struct definition into a header, so we can
embed it into other QOM objects like SoCs.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 1487604965-23220-3-git-send-email-peter.maydell@linaro.org
2017-02-28 16:18:49 +00:00
Peter Maydell 5db53e353d armv7m: Allow SHCSR writes to change pending and active bits
Implement the NVIC SHCSR write behaviour which allows pending and
active status of some exceptions to be changed.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
2017-02-28 12:08:19 +00:00
Peter Maydell aa488fe3bb armv7m: Check exception return consistency
Implement the exception return consistency checks
described in the v7M pseudocode ExceptionReturn().

Inspired by a patch from Michael Davidsaver's series, but
this is a reimplementation from scratch based on the
ARM ARM pseudocode.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
2017-02-28 12:08:19 +00:00
Michael Davidsaver 14790f730a armv7m: VECTCLRACTIVE and VECTRESET are UNPREDICTABLE
The VECTCLRACTIVE and VECTRESET bits in the AIRCR are both
documented as UNPREDICTABLE if you write a 1 to them when
the processor is not halted in Debug state (ie stopped
and under the control of an external JTAG debugger).
Since we don't implement Debug state or emulated JTAG
these bits are always UNPREDICTABLE for us. Instead of
logging them as unimplemented we can simply log writes
as guest errors and ignore them.

Signed-off-by: Michael Davidsaver <mdavidsaver@gmail.com>
[PMM: change extracted from another patch; commit message
 constructed from scratch]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
2017-02-28 12:08:18 +00:00
Peter Maydell a5d8235545 armv7m: Remove unused armv7m_nvic_acknowledge_irq() return value
Having armv7m_nvic_acknowledge_irq() return the new value of
env->v7m.exception and its one caller assign the return value
back to env->v7m.exception is pointless. Just make the return
type void instead.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
2017-02-28 12:08:18 +00:00
Michael Davidsaver a73c98e159 armv7m: Escalate exceptions to HardFault if necessary
The v7M exception architecture requires that if a synchronous
exception cannot be taken immediately (because it is disabled
or at too low a priority) then it should be escalated to
HardFault (and the HardFault exception is then taken).
Implement this escalation logic.

Signed-off-by: Michael Davidsaver <mdavidsaver@gmail.com>
[PMM: extracted from another patch]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
2017-02-28 12:08:17 +00:00
Peter Maydell 7ecdaa4a96 armv7m: Fix condition check for taking exceptions
The M profile condition for when we can take a pending exception or
interrupt is not the same as that for A/R profile.  The code
originally copied from the A/R profile version of the
cpu_exec_interrupt function only worked by chance for the
very simple case of exceptions being masked by PRIMASK.
Replace it with a call to a function in the NVIC code that
correctly compares the priority of the pending exception
against the current execution priority of the CPU.

[Michael Davidsaver's patchset had a patch to do something
similar but the implementation ended up being a rewrite.]

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
2017-02-28 12:08:17 +00:00
Michael Davidsaver da6d674e50 armv7m: Rewrite NVIC to not use any GIC code
Despite some superficial similarities of register layout, the
M-profile NVIC is really very different from the A-profile GIC.
Our current attempt to reuse the GIC code means that we have
significant bugs in our NVIC.

Implement the NVIC as an entirely separate device, to give
us somewhere we can get the behaviour correct.

This initial commit does not attempt to implement exception
priority escalation, since the GIC-based code didn't either.
It does fix a few bugs in passing:
 * ICSR.RETTOBASE polarity was wrong and didn't account for
   internal exceptions
 * ICSR.VECTPENDING was 16 too high if the pending exception
   was for an external interrupt
 * UsageFault, BusFault and MemFault were not disabled on reset
   as they are supposed to be

Signed-off-by: Michael Davidsaver <mdavidsaver@gmail.com>
[PMM: reworked, various bugs and stylistic cleanups]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
2017-02-28 12:08:17 +00:00
Peter Maydell 1004102a77 armv7m: Implement reading and writing of PRIGROUP
Add a state field for the v7M PRIGROUP register and implent
reading and writing it. The current NVIC doesn't honour
the values written, but the new version will.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
2017-02-28 12:08:16 +00:00
Peter Maydell f797c07507 armv7m: Rename nvic_state to NVICState
Rename the nvic_state struct to NVICState, to match
our naming conventions.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
2017-02-28 12:08:16 +00:00
Michael Davidsaver bdd04fc76a armv7m: Honour CCR.USERSETMPEND
The CCR.USERSETMPEND bit has to be set to permit unprivileged code to
write to the Software Triggered Interrupt register; honour this bit
rather than letting any code write to the register.

Signed-off-by: Michael Davidsaver <mdavidsaver@gmail.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 1485285380-10565-9-git-send-email-peter.maydell@linaro.org
[PMM: Tweak commit message, comment, phrasing of condition]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-01-27 15:29:08 +00:00
Michael Davidsaver e6b332097d armv7m: implement CCR, CFSR, HFSR, DFSR, BFAR, and MMFAR
Implement the v7M system registers CCR, CFSR, HFSR, DFSR, BFAR and
MMFAR.  For the moment these simply read as written (with some basic
handling of RAZ/WI bits and W1C semantics).

Signed-off-by: Michael Davidsaver <mdavidsaver@gmail.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 1485285380-10565-5-git-send-email-peter.maydell@linaro.org
[PMM: drop warning about setting unimplemented CCR bits;
 tweak commit message; add DFSR]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-01-27 15:29:08 +00:00
Michael Davidsaver d713ea6c46 armv7m_nvic: keep a pointer to the CPU
Many NVIC operations access the CPU state, so store a pointer in
struct nvic_state rather than fetching it via qemu_get_cpu() every
time we need it.

As with the arm_gicv3_common code, we currently just call
qemu_get_cpu() in the NVIC's realize method, but in future we might
want to use a QOM property to pass the CPU to the NVIC.

This imposes an ordering requirement that the CPU is
realized before the NVIC, but that is always true since
both are dealt with in armv7m_init().

Signed-off-by: Michael Davidsaver <mdavidsaver@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 1485285380-10565-3-git-send-email-peter.maydell@linaro.org
[PMM: Use qemu_get_cpu(0) rather than first_cpu; expand
 commit message]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-01-27 15:29:08 +00:00
Andrey Smirnov a19861666b armv7m_nvic: Use qemu_get_cpu(0) instead of current_cpu
Starting QEMU with -S results in current_cpu containing its initial
value of NULL. It is however possible to connect to such QEMU instance
and query various CPU registers, one example being CPUID, and doing that
results in QEMU segfaulting.

Using qemu_get_cpu(0) seem reasonable enough given that ARMv7M
architecture is a single core architecture.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-07-04 13:15:22 +01:00
Paolo Bonzini 03dd024ff5 hw: explicitly include qemu/log.h
Move the inclusion out of hw/hw.h, most files do not need it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-19 16:42:29 +02:00