MFC: r266470, r273546, r276017, r277932, r279153, r279778, r279780, r278797,
r278861, r280283, r280284, r280294, r280452, r280558, r280571, r281863,
r282049, r282357, r282440, r282441, r282358, r282359, r283550, r283918,
r290171, r290667, r290381, r290533, r290666, r292483, r295659, r297545,
r298305, r298383, r298428, r306489, r306557, r307067, r307068, r307087,
r307088, r307089, r307091, r307092, r307093, r307098, r307115, r307154,
r307240, r307241, r315967, r316476

Unbreak BCM2835/RPI-B support by bringing it in line with stable/11 and
head:

- Optimise reading of pending interrupt registers.

- Fix a bug where some DTS layouts could cause the premature ending of the
search (i.e. without returning any result) and you would end up with a
random MAC address.

- Reduce the diff between head and arm_intrng with the bcm2835 interrupt
controller.

- Allow the retrieving of the reserved pins state.

- Add support to the bcm2835 mailbox driver to work before interrupts are
enabled. This will be needed to enable the power on devices early on in the
boot process.

- Add support for enabling the USB on the Raspberry Pi boards when it hasn't
been done by U-Boot. This allows the USB to work when we load the kernel
directly.

- Call config_intrhook_disestablish on failure of the bcm2835 fb and fbd intr
hooks. With this we can get through the boot even if these functions fail.

- Add the structures needed to get/set the power state. These can be used
when, for example, we boot without U-Boot and wish to enable USB, or to
suspend an unneeded device.

- Add a mask to match only the relative base address of BSC controllers.

- Move the code to set the device power to the bcm2835 mailbox driver so it
can be reused by other drivers.

- Add the SOC_BCM2835 and SOC_BCM2836 options for the arm kernel and add the
former to std.bcm2835.

- Add a helper function to read clock frequencies from videocore and use this
to get the default frequency of the sdhci device.

- Add partial support for the Raspberry Pi 2.

- Remove a debug #error from the bcm2835 sdhci driver.

- Fetch the SDHCI frequency from videocore (our prefered source) and only if
it fails, fetch the clock-frequency from DTB. If both methods fail, use the
hardcoded default.

- Pass the supplied buffer length instead of a fixed size.

- Add the routines to query and setup the framebuffer state using the
BCM2835_MBOX_CHAN_PROP channel. The old channel (BCM2835_MBOX_CHAN_FB)
seems deprecated on recent firmware versions and is causing a freeze on
RPi 2.

- Fix DMA on RPi 2. BCM2836 has a different base address for peripherals.

- Enable DMA for sdhci on RPi 2 (BCM2836).

- Add a missing wakeup when releasing ownership of the SPI hardware.

- Fix framebuffer compatibility with new RPi firmware.

- Refactor bcm2835_cpufreq to use bcm2835_mbox_property API.

- Fix the sc(4) framebuffer driver on RPi 2.

- Fix the vt(4) framebuffer driver on RPi 2.

- Remove unused mutex and softc variables.

- Refactor mailbox property API to make it usable for /dev/vcio driver.

- Replace semaphore-base locking with sleep/wait synchronization.

- Fix infinite loop if response from VideoCore never received.

- Set have_message in interrupt to handle "response before READ" case.

- Serialize access to property channel when using bcm2835_mbox_property.

- Force framebuffer virtual viewport to be the same as physical.

- Use proper type of tag in bcm2835_mbox_fb_init.

- bcm2835_cpufreq: Only attach driver if we correcly match on the machine
compatible string.

- Add dev.fb.X.resync sysctl to resync ARM framebuffer with VideoCore.

- Do not use DMA channels used by GPU.

- Define local-intc for BCM2836 platform (RPI2) and make BCM2835 intc
a child of it.

- Fix build for Pi kernels with syscons enabled.

- Use VM_MEMATTR_WRITE_COMBINING memattr for mmap(2) on framebuffer.

- Make intc driver compatible with upstream DTS.

- Make Rapsberry Pi watchdog driver compatible with upstream DTS.

- Make sure intc is attached before interrupt consumers.

- Make framebuffer driver compatible with upstream DT.

- Add one more heuristic to determine MAC address of the SMSC device.

- Add compatibility strings from upstream DT.

- Fix spelling mistake, BCM2835_PASWORD -> BCM2835_PASSWORD.

Approved by: re (kib)

MFC r280278, r280402:

Allow to override default kernel virtual address assignment on ARM.

Do not save/restore the TLS pointer on context switch for armv6.

MFC r274937:

Add ARMV6 as an arm option. This will cause obscure magic in config(8)
to automatically set the armv6 option when MACHINE_ARCH is armv6. That
allows replacing ever-growing lists of cpu names as options to compile
a given file with the using either "optional armv6" or "optional !armv6".

MFC r273703:

Remove the ARM_DEVICE_MULTIPASS option and make its effect be the default.

MFC r269594, r269596, r269597, r269598, r269605, r269606:

Set ofwbus and simplebus to attach during BUS_PASS_BUS.

Define names that drivers can use to adjust their position relative to
other drivers within a BUS_PASS

Adjust ofwbus and simplebus to attach at BUS_PASS_ORDER_MIDDLE, so that
a platform can attach some other bus first if necessary.

Set the pl310 L2 cache driver to attach during the middle of BUS_PASS_CPU.

Attach arm generic interrupt and timer drivers in the middle of
BUS_PASS_INTERRUPT and BUS_PASS_TIMER, respectively.

Add an arm option, ARM_DEVICE_MULTIPASS, used to opt-in to multi-pass
device attachment on arm platforms. If this is defined, nexus attaches
early in BUS_PASS_BUS, and other busses and devices attach later, in the
pass number they are set up for. Without it defined, nexus attaches in
BUS_PASS_DEFAULT and thus so does everything else, which is status quo.

MFC 264054, 264056

Switch imx6 to using the mpcore per-cpu event timers, but continue to use
the GPT timer, which is fixed-frequency, as a timecounter.

Change NO_EVENTTIMERS from an arm-specific to an MI option, so that it can
be used in MI code.

MFC 262952, 262958, 262966, 262979, 262980, 262986, 262987, 262995, 262997,
263030, 263033, 263034, 263056, 263057,

Remove all the redundant external declarations of exception vectors and
runtime setting of the pointers that's scattered around various places.

Remove all traces of support for ARM chips prior to the arm9 series.

Make the default exception handler vectors point to where I thought they
were already pointing: the default handlers (not a panic that says there
is no default handler).

Eliminate irq_dispatch.S. Move the data items it contained into
arm/intr.c and the functionality it provided into arm/exception.S.

Move the exception vector table (so-called "page0" data) into exception.S
and eliminate vectors.S.

Change the way the asm GET_CURTHREAD_PTR() macro is defined so that code
using it doesn't have to have an "AST_LOCALS" macro somewhere in the file.

Arrange for arm fork_trampoline() to return to userland via the standard
swi_exit code in exception.S instead of having its own inline expansion
of the DO_AST and PULLFRAME macros.

Now that the PUSHFRAME and PULLFRAME macros are used only in the swi
entry/exit code, they don't need to be macros. Except that didn't work
and the whole change was reverted.

Remove some unnecessary indirection and jump right to the handler functions.

Use panic rather than printf to "handle" an arm26 address exception
(should never happen on arm32).

Remove the unreferenced DATA() macro.

Remove #include <machine/asmacros.h> from files that don't need it.

MFC r257549, r261642

Don't create a distinct free page pool for segregating allocations that are
accessed through the direct map unless the kernel configuration actually
includes a direct map. Only a few configurations do, and for the rest the
unnecessary free page pool is a small pessimization.

Remove the ARM_USE_SMALL_ALLOC option and code related to it.

MFC r261252, r261279, r261304, r261305, r261322, r261336, r261337, r261338,
r261353

Fix the name of the dts file for the HL201...

When mapping an address, the bsh needs the same offset we do for other things.

Add explicit depends on bus_if.h and device_if.h to avoid a
chicken and egg problem in some compilation environments.

Switch to using PAs rather than VAs for the addresses we map for
devices. This is a nop, except for what's reported by atmelbus for the
resources.

Comment cleanups. Move things around for diff reduction against FDT work.

MFC r261038, r261039, r261040, r261041

Implement generic support for early printf.

MFC r260092, r260093, r260121, r260180,

Allow AT91_MCI_ALLOW_OVERCLOCK to be an option in kernel config files.

Set the SoC name for the atmelbus name.

Add support for Samsung K9F2G08U0A (256MiB SLC) NAND

Comment updates.

MFC r258359, r258742, r258845, r259936, r259640

Apply access flags for managed and unmanaged pages properly on ARMv6/v7

Set the PGA_WRITEABLE flag when the protections indicate write access, not
just when the current access is a write.

Enable missing Access Flag for secondary cores on ARMv6/v7

Add identification and necessary type checks for Krait CPU cores.

MFC r280278, r280402:

Allow to override default kernel virtual address assignment on ARM.

Do not save/restore the TLS pointer on context switch for armv6.

MFC r274937:

Add ARMV6 as an arm option. This will cause obscure magic in config(8)
to automatically set the armv6 option when MACHINE_ARCH is armv6. That
allows replacing ever-growing lists of cpu names as options to compile
a given file with the using either "optional armv6" or "optional !armv6".

MFC r273703:

Remove the ARM_DEVICE_MULTIPASS option and make its effect be the default.

MFC r269594, r269596, r269597, r269598, r269605, r269606:

Set ofwbus and simplebus to attach during BUS_PASS_BUS.

Define names that drivers can use to adjust their position relative to
other drivers within a BUS_PASS

Adjust ofwbus and simplebus to attach at BUS_PASS_ORDER_MIDDLE, so that
a platform can attach some other bus first if necessary.

Set the pl310 L2 cache driver to attach during the middle of BUS_PASS_CPU.

Attach arm generic interrupt and timer drivers in the middle of
BUS_PASS_INTERRUPT and BUS_PASS_TIMER, respectively.

Add an arm option, ARM_DEVICE_MULTIPASS, used to opt-in to multi-pass
device attachment on arm platforms. If this is defined, nexus attaches
early in BUS_PASS_BUS, and other busses and devices attach later, in the
pass number they are set up for. Without it defined, nexus attaches in
BUS_PASS_DEFAULT and thus so does everything else, which is status quo.

MFC 264054, 264056

Switch imx6 to using the mpcore per-cpu event timers, but continue to use
the GPT timer, which is fixed-frequency, as a timecounter.

Change NO_EVENTTIMERS from an arm-specific to an MI option, so that it can
be used in MI code.

MFC 262952, 262958, 262966, 262979, 262980, 262986, 262987, 262995, 262997,
263030, 263033, 263034, 263056, 263057,

Remove all the redundant external declarations of exception vectors and
runtime setting of the pointers that's scattered around various places.

Remove all traces of support for ARM chips prior to the arm9 series.

Make the default exception handler vectors point to where I thought they
were already pointing: the default handlers (not a panic that says there
is no default handler).

Eliminate irq_dispatch.S. Move the data items it contained into
arm/intr.c and the functionality it provided into arm/exception.S.

Move the exception vector table (so-called "page0" data) into exception.S
and eliminate vectors.S.

Change the way the asm GET_CURTHREAD_PTR() macro is defined so that code
using it doesn't have to have an "AST_LOCALS" macro somewhere in the file.

Arrange for arm fork_trampoline() to return to userland via the standard
swi_exit code in exception.S instead of having its own inline expansion
of the DO_AST and PULLFRAME macros.

Now that the PUSHFRAME and PULLFRAME macros are used only in the swi
entry/exit code, they don't need to be macros. Except that didn't work
and the whole change was reverted.

Remove some unnecessary indirection and jump right to the handler functions.

Use panic rather than printf to "handle" an arm26 address exception
(should never happen on arm32).

Remove the unreferenced DATA() macro.

Remove #include <machine/asmacros.h> from files that don't need it.

MFC r257549, r261642

Don't create a distinct free page pool for segregating allocations that are
accessed through the direct map unless the kernel configuration actually
includes a direct map. Only a few configurations do, and for the rest the
unnecessary free page pool is a small pessimization.

Remove the ARM_USE_SMALL_ALLOC option and code related to it.

MFC r261252, r261279, r261304, r261305, r261322, r261336, r261337, r261338,
r261353

Fix the name of the dts file for the HL201...

When mapping an address, the bsh needs the same offset we do for other things.

Add explicit depends on bus_if.h and device_if.h to avoid a
chicken and egg problem in some compilation environments.

Switch to using PAs rather than VAs for the addresses we map for
devices. This is a nop, except for what's reported by atmelbus for the
resources.

Comment cleanups. Move things around for diff reduction against FDT work.

MFC r261038, r261039, r261040, r261041

Implement generic support for early printf.

MFC r260092, r260093, r260121, r260180,

Allow AT91_MCI_ALLOW_OVERCLOCK to be an option in kernel config files.

Set the SoC name for the atmelbus name.

Add support for Samsung K9F2G08U0A (256MiB SLC) NAND

Comment updates.

MFC r258359, r258742, r258845, r259936, r259640

Apply access flags for managed and unmanaged pages properly on ARMv6/v7

Set the PGA_WRITEABLE flag when the protections indicate write access, not
just when the current access is a write.

Enable missing Access Flag for secondary cores on ARMv6/v7

Add identification and necessary type checks for Krait CPU cores.