The AST2600 has the same sets of 3.6v gpios as the AST2400 plus an
addtional two sets of 1.8V gpios.
Signed-off-by: Rashmica Gupta <rashmica.g@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Acked-by: Joel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-15-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The AST2600 SoC SMC controller is a SPI only controller now and has a
few extensions which we will need to take into account when SW
requires it. This is enough to support u-boot and Linux.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Acked-by: Joel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-14-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
AST2600 will use a different encoding for the addresses defined in the
Segment Register.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Acked-by: Joel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-13-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The AST2600 has four watchdogs, and they each have a 0x40 of registers.
When running as part of an ast2600 system we must check a different
offset for the system reset control register in the SCU.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20190925143248.10000-12-clg@kaod.org
[clg: - reworked model integration into new object class ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
It cleanups the current models for the Aspeed AST2400 and AST2500 SoCs
and prepares ground for future SoCs.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-11-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The AST2600 SDMC controller is slightly different from its predecessor
(DRAM training). Max memory is now 2G on the AST2600.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20190925143248.10000-10-clg@kaod.org
[clg: - improved commit log
- reworked model integration into new object class ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Use class handlers and class constants to differentiate the
characteristics of the memory controller and remove the 'silicon_rev'
property.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-9-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The AST2600 timer replaces control register 2 with a interrupt status
register. It is set by hardware when an IRQ occurs and cleared by
software.
Modify the vmstate version to take into account the new fields.
Based on previous work from Joel Stanley.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-8-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The AST2600 timer has a third control register that is used to
implement a set-to-clear feature for the main control register.
On the AST2600, it is not configurable via 0x38 (control register 3)
as it is on the AST2500.
Based on previous work from Joel Stanley.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-7-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The AST2500 timer has a third control register that is used to
implement a set-to-clear feature for the main control register.
This models the behaviour expected by the AST2500 while maintaining
the same behaviour for the AST2400.
The vmstate version is not increased yet because the structure is
modified again in the following patches.
Based on previous work from Joel Stanley.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-6-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The most important changes will be on the register range 0x34 - 0x3C
memops. Introduce class read/write operations to handle the
differences between SoCs.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Message-id: 20190925143248.10000-5-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The SCU controller on the AST2600 SoC has extra registers. Increase
the number of regs of the model and introduce a new field in the class
to customize the MemoryRegion operations depending on the SoC model.
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20190925143248.10000-4-clg@kaod.org
[clg: - improved commit log
- changed vmstate version
- reworked model integration into new object class
- included AST2600_HPLL_PARAM value ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The Aspeed SOCs have two SD/MMC controllers. Add a device that
encapsulates both of these controllers and models the Aspeed-specific
registers and behavior.
Tested by reading from mmcblk0 in Linux:
qemu-system-arm -machine romulus-bmc -nographic \
-drive file=flash-romulus,format=raw,if=mtd \
-device sd-card,drive=sd0 -drive file=_tmp/kernel,format=raw,if=sd,id=sd0
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20190925143248.10000-3-clg@kaod.org
[clg: - changed the controller MMIO window size to 0x1000
- moved the MMIO mapping of the SDHCI slots at the SoC level
- merged code to add SD drives on the SD buses at the machine level ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
When WDT_RESTART is written, the data is not the contents
of the WDT_CTRL register. Hence ensure we are looking at
WDT_CTRL to check if bit WDT_CTRL_1MHZ_CLK is set or not.
Signed-off-by: Amithash Prasad <amithash@fb.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 20190925143248.10000-2-clg@kaod.org
[clg: improved Suject prefix ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
SH_EXT_STDOUT_STDERR is a v2.0 semihosting extension: the guest
can open ":tt" with a file mode requesting append access in
order to open stderr, in addition to the existing "open for
read for stdin or write for stdout". Implement this and
report it via the :semihosting-features data.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20190916141544.17540-16-peter.maydell@linaro.org
SH_EXT_EXIT_EXTENDED is a v2.0 semihosting extension: it
indicates that the implementation supports the SYS_EXIT_EXTENDED
function. This function allows both A64 and A32/T32 guests to
exit with a specified exit status, unlike the older SYS_EXIT
function which only allowed this for A64 guests. Implement
this extension.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20190916141544.17540-15-peter.maydell@linaro.org
Version 2.0 of the semihosting specification added support for
allowing a guest to detect whether the implementation supported
particular features. This works by the guest opening a magic
file ":semihosting-features", which contains a fixed set of
data with some magic numbers followed by a sequence of bytes
with feature flags. The file is expected to behave sensibly
for the various semihosting calls which operate on files
(SYS_FLEN, SYS_SEEK, etc).
Implement this as another kind of guest FD using our function
table dispatch mechanism. Initially we report no extended
features, so we have just one feature flag byte which is zero.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20190916141544.17540-14-peter.maydell@linaro.org
Factor out the implementation of SYS_FLEN via the new
function tables.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190916141544.17540-13-peter.maydell@linaro.org
Factor out the implementation of SYS_SEEK via the new function
tables.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190916141544.17540-12-peter.maydell@linaro.org
Factor out the implementation of SYS_ISTTY via the new function
tables.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190916141544.17540-11-peter.maydell@linaro.org
Factor out the implementation of SYS_READ via the
new function tables.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190916141544.17540-10-peter.maydell@linaro.org
Factor out the implementation of SYS_WRITE via the
new function tables.
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: 20190916141544.17540-9-peter.maydell@linaro.org
Currently for the semihosting calls which take a file descriptor
(SYS_CLOSE, SYS_WRITE, SYS_READ, SYS_ISTTY, SYS_SEEK, SYS_FLEN)
we have effectively two implementations, one for real host files
and one for when we indirect via the gdbstub. We want to add a
third one to deal with the magic :semihosting-features file.
Instead of having a three-way if statement in each of these
cases, factor out the implementation of the calls to separate
functions which we dispatch to via function pointers selected
via the GuestFDType for the guest fd.
In this commit, we set up the framework for the dispatch,
and convert the SYS_CLOSE call to use it.
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: 20190916141544.17540-8-peter.maydell@linaro.org
When we are routing semihosting operations through the gdbstub, the
work of sorting out the return value and setting errno if necessary
is done by callback functions which are invoked by the gdbstub code.
Clean up some ifdeffery in those functions by having them call
set_swi_errno() to set the semihosting errno.
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: 20190916141544.17540-7-peter.maydell@linaro.org
The semihosting code needs accuss to the linux-user only
TaskState pointer so it can set the semihosting errno per-thread
for linux-user mode. At the moment we do this by having some
ifdefs so that we define a 'ts' local in do_arm_semihosting()
which is either a real TaskState * or just a CPUARMState *,
depending on which mode we're compiling for.
This is awkward if we want to refactor do_arm_semihosting()
into other functions which might need to be passed the TaskState.
Restrict usage of the TaskState local by:
* making set_swi_errno() always take the CPUARMState pointer
and (for the linux-user version) get TaskState from that
* creating a new get_swi_errno() which reads the errno
* having the two semihosting calls which need the TaskState
for other purposes (SYS_GET_CMDLINE and SYS_HEAPINFO)
define a variable with scope restricted to just that code
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-6-peter.maydell@linaro.org
Currently the Arm semihosting code returns the guest file descriptors
(handles) which are simply the fd values from the host OS or the
remote gdbstub. Part of the semihosting 2.0 specification requires
that we implement special handling of opening a ":semihosting-features"
filename. Guest fds which result from opening the special file
won't correspond to host fds, so to ensure that we don't end up
with duplicate fds we need to have QEMU code control the allocation
of the fd values we give the guest.
Add in an abstraction layer which lets us allocate new guest FD
values, and translate from a guest FD value back to the host one.
This also fixes an odd hole where a semihosting guest could
use the semihosting API to read, write or close file descriptors
that it had never allocated but which were being used by QEMU itself.
(This isn't a security hole, because enabling semihosting permits
the guest to do arbitrary file access to the whole host filesystem,
and so should only be done if the guest is completely trusted.)
Currently the only kind of guest fd is one which maps to a
host fd, but in a following commit we will add one which maps
to the :semihosting-features magic data.
If the guest is migrated with an open semihosting file descriptor
then subsequent attempts to use the fd will all fail; this is
not a change from the previous situation (where the host fd
being used on the source end would not be re-opened on the
destination end).
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-5-peter.maydell@linaro.org
In arm_gdb_syscall() we have a comment suggesting a race
because the syscall completion callback might not happen
before the gdb_do_syscallv() call returns. The comment is
correct that the callback may not happen but incorrect about
the effects. Correct it and note the important caveat that
callers must never do any work of any kind after return from
arm_gdb_syscall() that depends on its return value.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-4-peter.maydell@linaro.org
If we fail a semihosting call we should always set the
semihosting errno to something; we were failing to do
this for some of the "check inputs for sanity" cases.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190916141544.17540-3-peter.maydell@linaro.org
The set_swi_errno() function is called to capture the errno
from a host system call, so that we can return -1 from the
semihosting function and later allow the guest to get a more
specific error code with the SYS_ERRNO function. It comes in
two versions, one for user-only and one for softmmu. We forgot
to capture the errno in the softmmu version; fix the error.
(Semihosting calls directed to gdb are unaffected because
they go through a different code path that captures the
error return from the gdbstub call in arm_semi_cb() or
arm_semi_flen_cb().)
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: 20190916141544.17540-2-peter.maydell@linaro.org
Switch the cmsdk-apb-watchdog code away from bottom-half based
ptimers to the new transaction-based ptimer API. This just requires
adding begin/commit calls around the various places that modify the
ptimer state, and using the new ptimer_init() function to create the
timer.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-22-peter.maydell@linaro.org
Switch the cmsdk-apb-watchdog code away from bottom-half based
ptimers to the new transaction-based ptimer API. This just requires
adding begin/commit calls around the various places that modify the
ptimer state, and using the new ptimer_init() function to create the
timer.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-21-peter.maydell@linaro.org
Switch the mss-timer code away from bottom-half based ptimers to
the new transaction-based ptimer API. This just requires adding
begin/commit calls around the various places that modify the ptimer
state, and using the new ptimer_init() function to create the timer.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-20-peter.maydell@linaro.org
Switch the imx_epit.c code away from bottom-half based ptimers to
the new transaction-based ptimer API. This just requires adding
begin/commit calls around the various places that modify the ptimer
state, and using the new ptimer_init() function to create the timer.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-19-peter.maydell@linaro.org
Switch the imx_epit.c code away from bottom-half based ptimers to
the new transaction-based ptimer API. This just requires adding
begin/commit calls around the various places that modify the ptimer
state, and using the new ptimer_init() function to create the timer.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-18-peter.maydell@linaro.org
Switch the exynos41210_rtc main ptimer over to the transaction-based
API, completing the transition for this device.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-17-peter.maydell@linaro.org
Switch the exynos41210_rtc 1Hz ptimer over to the transaction-based
API. (We will switch the other ptimer used by this device in a
separate commit.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-16-peter.maydell@linaro.org
Switch the exynos4210_pwm code away from bottom-half based ptimers to
the new transaction-based ptimer API. This just requires adding
begin/commit calls around the various places that modify the ptimer
state, and using the new ptimer_init() function to create the timer.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-15-peter.maydell@linaro.org
Switch the ltick ptimer over to the ptimer transaction API.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-14-peter.maydell@linaro.org
Switch the exynos MCT LFRC timers over to the ptimer transaction API.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-13-peter.maydell@linaro.org
We want to switch the exynos MCT code away from bottom-half based ptimers to
the new transaction-based ptimer API. The MCT is complicated
and uses multiple different ptimers, so it's clearer to switch
it a piece at a time. Here we change over only the GFRC.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-12-peter.maydell@linaro.org
Switch the digic-timer.c code away from bottom-half based ptimers to
the new transaction-based ptimer API. This just requires adding
begin/commit calls around the various places that modify the ptimer
state, and using the new ptimer_init() function to create the timer.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-11-peter.maydell@linaro.org
Switch the cmsdk-apb-timer code away from bottom-half based ptimers
to the new transaction-based ptimer API. This just requires adding
begin/commit calls around the various places that modify the ptimer
state, and using the new ptimer_init() function to create the timer.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-10-peter.maydell@linaro.org
Switch the cmsdk-apb-dualtimer code away from bottom-half based
ptimers to the new transaction-based ptimer API. This just requires
adding begin/commit calls around the various places that modify the
ptimer state, and using the new ptimer_init() function to create the
timer.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-9-peter.maydell@linaro.org
Switch the arm_mptimer.c code away from bottom-half based ptimers to
the new transaction-based ptimer API. This just requires adding
begin/commit calls around the various places that modify the ptimer
state, and using the new ptimer_init() function to create the timer.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-8-peter.maydell@linaro.org
Switch the allwinner-a10-pit code away from bottom-half based ptimers to
the new transaction-based ptimer API. This just requires adding
begin/commit calls around the various places that modify the ptimer
state, and using the new ptimer_init() function to create the timer.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-7-peter.maydell@linaro.org
Switch the musicpal code away from bottom-half based ptimers to
the new transaction-based ptimer API. This just requires adding
begin/commit calls around the various places that modify the ptimer
state, and using the new ptimer_init() function to create the timer.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-6-peter.maydell@linaro.org
Switch the arm_timer.c code away from bottom-half based ptimers
to the new transaction-based ptimer API. This just requires
adding begin/commit calls around the various arms of
arm_timer_write() that modify the ptimer state, and using the
new ptimer_init() function to create the timer.
Fixes: https://bugs.launchpad.net/qemu/+bug/1777777
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-5-peter.maydell@linaro.org
Convert the ptimer test cases to the transaction-based ptimer API,
by changing to ptimer_init(), dropping the now-unused QEMUBH
variables, and surrounding each set of changes to the ptimer
state in ptimer_transaction_begin/commit calls.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-4-peter.maydell@linaro.org
Provide the new transaction-based API. If a ptimer is created
using ptimer_init() rather than ptimer_init_with_bh(), then
instead of providing a QEMUBH, it provides a pointer to the
callback function directly, and has opted into the transaction
API. All calls to functions which modify ptimer state:
- ptimer_set_period()
- ptimer_set_freq()
- ptimer_set_limit()
- ptimer_set_count()
- ptimer_run()
- ptimer_stop()
must be between matched calls to ptimer_transaction_begin()
and ptimer_transaction_commit(). When ptimer_transaction_commit()
is called it will evaluate the state of the timer after all the
changes in the transaction, and call the callback if necessary.
In the old API the individual update functions generally would
call ptimer_trigger() immediately, which would schedule the QEMUBH.
In the new API the update functions will instead defer the
"set s->next_event and call ptimer_reload()" work to
ptimer_transaction_commit().
Because ptimer_trigger() can now immediately call into the
device code which may then call other ptimer functions that
update ptimer_state fields, we must be more careful in
ptimer_reload() not to cache fields from ptimer_state across
the ptimer_trigger() call. (This was harmless with the QEMUBH
mechanism as the BH would not be invoked until much later.)
We use assertions to check that:
* the functions modifying ptimer state are not called outside
a transaction block
* ptimer_transaction_begin() and _commit() calls are paired
* the transaction API is not used with a QEMUBH ptimer
There is some slight repetition of code:
* most of the set functions have similar looking "if s->bh
call ptimer_reload, otherwise set s->need_reload" code
* ptimer_init() and ptimer_init_with_bh() have similar code
We deliberately don't try to avoid this repetition, because
it will all be deleted when the QEMUBH version of the API
is removed.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-3-peter.maydell@linaro.org
Currently the ptimer design uses a QEMU bottom-half as its
mechanism for calling back into the device model using the
ptimer when the timer has expired. Unfortunately this design
is fatally flawed, because it means that there is a lag
between the ptimer updating its own state and the device
callback function updating device state, and guest accesses
to device registers between the two can return inconsistent
device state.
We want to replace the bottom-half design with one where
the guest device's callback is called either immediately
(when the ptimer triggers by timeout) or when the device
model code closes a transaction-begin/end section (when the
ptimer triggers because the device model changed the
ptimer's count value or other state). As the first step,
rename ptimer_init() to ptimer_init_with_bh(), to free up
the ptimer_init() name for the new API. We can then convert
all the ptimer users away from ptimer_init_with_bh() before
removing it entirely.
(Commit created with
git grep -l ptimer_init | xargs sed -i -e 's/ptimer_init/ptimer_init_with_bh/'
and three overlong lines folded by hand.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-2-peter.maydell@linaro.org
