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.
Backports commit e6ae5981ea4b0f6feb223009a5108582e7644f8f from qemu
When the PMSAv7 implementation was originally added it was for R profile
CPUs only, and reset was handled using the cpreg .resetfn hooks.
Unfortunately for M profile cores this doesn't work, because they do
not register any cpregs. Move the reset handling into arm_cpu_reset(),
where it will work for both R profile and M profile cores.
Backports commit 69ceea64bf565559a2b865ffb2a097d2caab805b from qemu
The Cortex-M3 and M4 CPUs always have 8 PMSA MPU regions (this isn't
a configurable option for the hardware). Make the default value of
the pmsav7-dregion property be set per-cpu, so we don't need to have
every user of these CPUs set it manually. (The existing default of
16 is correct for the other PMSAv7 core, the Cortex-R5.)
This fixes a bug where we were creating the M3 and M4 with
too many regions; most guest software would not notice or
care, though, since it would just not use the registers
associated with the unexpected extra regions.
Backports commit 8d92e26b452f8961ec90df3f93cf5f3b7a9d158f from qemu
The cp15, CRn=15, opc1=0, CRm=5, opc2=0 instruction invalidates all the
data cache on the cortex-r5. Implementing it as a NOP.
Backports commit 95e9a242e2a393c7d4e5cc04340e39c3a9420f03 from qemu
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.
Backports commit 7ecdaa4a9635f1ded0dfa9218c25273b6d4dcd44 from qemu
All M profile CPUs are PMSA, so set the feature bit.
(We haven't actually implemented the M profile MPU register
interface yet, but setting this feature bit gives us closer
to correct behaviour for the MPU-disabled case.)
Backports commit 790a11503cfb5e1dcd031ea2212bbebae4ca3cec from qemu
Fix the handling of QOM properties for PMSA CPUs with no MPU:
Allow no-MPU to be specified by either:
* has-mpu = false
* pmsav7_dregion = 0
and make setting one imply the other. Don't clear the PMSA
feature bit in this situation.
Backports commit f50cd31413d8bc9d1eef8edd1f878324543bf65d from qemu
ARM CPUs come in two flavours:
* proper MMU ("VMSA")
* only an MPU ("PMSA")
For PMSA, the MPU may be implemented, or not (in which case there
is default "always acts the same" behaviour, but it isn't guest
programmable).
QEMU is a bit confused about how we indicate this: we have an
ARM_FEATURE_MPU, but it's not clear whether this indicates
"PMSA, not VMSA" or "PMSA and MPU present" , and sometimes we
use it for one purpose and sometimes the other.
Currently trying to implement a PMSA-without-MPU core won't
work correctly because we turn off the ARM_FEATURE_MPU bit
and then a lot of things which should still exist get
turned off too.
As the first step in cleaning this up, rename the feature
bit to ARM_FEATURE_PMSA, which indicates a PMSA CPU (with
or without MPU).
Backports commit 452a095526a0537f16c271516a2200877a272ea8 from qemu
The PMUv3 driver of linux kernel (in arch/arm64/kernel/perf_event.c)
relies on the PMUVER field of id_aa64dfr0_el1 to decide if PMU support
is present or not. This patch clears the PMUVER field under TCG mode
when vPMU=off. Without it, PMUv3 will init insider guest VMs even
with vPMU=off. This patch also removes a redundant line inside the
if-statement.
Backports commit 2b3ffa929249b15a75d8bde3e8e57a744f52aff0 from qemu
Now that we've rewritten M-profile exception return so that the magic
PC values are not visible to other parts of QEMU, we can delete the
special casing of them elsewhere.
Backports commit f4e8e4edda875cab9df91dc4ae9767f7cb1f50aa from qemu
For M profile (unlike A profile) the reset value of R14 is specified
as 0xffffffff. (The rationale is that this is an illegal exception
return value, so if guest code tries to return to it it will result
in a helpful exception.)
Registers r0 to r12 and the flags are architecturally UNKNOWN on
reset, so we leave those at zero.
Backports commit 056f43df9168413f304500b69c33158d66efb7cf from qemu
For M profile CPUs, FAULTMASK should be 0 on reset, like PRIMASK.
QEMU stores FAULTMASK in the PSTATE F bit, so (as with PRIMASK in the
I bit) we have to clear these to undo the A profile default of 1.
Update the comment accordingly and move it so that it's closer to the
code it's referring to.
Backports commit dc7abe4d65ad39390b2db120f5ad18f8f6576f8b from qemu
Add the structure fields, VMState fields, reset code and macros for
the v7M system control registers CCR, CFSR, HFSR, DFSR, MMFAR and
BFAR.
Backports commit 2c4da50d9477fb830d778bb5d6a11215aa359b44 from qemu
For v7m we need to catch attempts to execute from special
addresses at 0xfffffff0 and above. Previously we did this
with the aid of a hacky special purpose lump of memory
in the address space and a check in translate.c for whether
we were translating code at those addresses.
We can implement this more cleanly using a CPU
unassigned access handler which throws the exception
if the unassigned access is for one of the special addresses.
Backports commit 542b3478a00cb7ef51c259255b3ab1e2a7daada2 from qemu
In BE32 mode, sub-word size watchpoints can fail to trigger because the
address of the access is adjusted in the opcode helpers before being
compared with the watchpoint registers. This patch reverses the address
adjustment before performing the comparison with the help of a new CPUClass
hook.
This version of the patch augments and tidies up comments a little.
Backports commit 40612000599e52e792d23c998377a0fa429c4036 from qemu
Add a new "cfgend" property which selects whether the CPU resets into
big-endian mode or not. This setting affects whether we reset with
SCTLR_B (ARMv6 and earlier) or SCTLR_EE (ARMv7 and later) set.
Backports commit 3a062d5730266b2386eeda68b1a1c6e96451db31 from qemu
We only use the IS_M() macro in two places, and it's a bit of a
namespace grab to put in cpu.h. Drop it in favour of just explicitly
calling arm_feature() in the places where it was used.
Backports commit 531c60a97ab51618b4b9ccef1c5fe00607079706 from qemu
Enable the ARM_FEATURE_EL2 bit on Cortex-A52 and
Cortex-A57, since this is all now sufficiently implemented
to work with the GICv3. We provide the usual CPU property
to disable it for backwards compatibility with the older
virt boards.
In this commit, we disable the EL2 feature on the
virt and ZynpMP boards, so there is no overall effect.
Another commit will expose a board-level property to
allow the user to enable EL2.
Backports commit c25bd18a04c8bd0f19556d719864b7b08528222d from qemu
We've currently got 18 architectures in QEMU, and thus 18 target-xxx
folders in the root folder of the QEMU source tree. More architectures
(e.g. RISC-V, AVR) are likely to be included soon, too, so the main
folder of the QEMU sources slowly gets quite overcrowded with the
target-xxx folders.
To disburden the main folder a little bit, let's move the target-xxx
folders into a dedicated target/ folder, so that target-xxx/ simply
becomes target/xxx/ instead.
Backports commit fcf5ef2ab52c621a4617ebbef36bf43b4003f4c0 from qemu
