At present the GEM support in sifive_u machine is seriously broken.
The GEM block register base was set to a weird number (0x100900FC),
which for no way could work with the cadence_gem model in QEMU.
Not like other GEM variants, the FU540-specific GEM has a management
block to control 10/100/1000Mbps link speed changes, that is mapped
to 0x100a0000. We can simply map it into MMIO space without special
handling using create_unimplemented_device().
Update the GEM node compatible string to use the official name used
by the upstream Linux kernel, and add the management block reg base
& size to the <reg> property encoding.
Tested with upstream U-Boot and Linux kernel MACB drivers.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This adds an OTP memory with a given serial number to the sifive_u
machine. With such support, the upstream U-Boot for sifive_fu540
boots out of the box on the sifive_u machine.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This implements a simple model for SiFive FU540 OTP (One-Time
Programmable) Memory interface, primarily for reading out the
stored serial number from the first 1 KiB of the 16 KiB OTP
memory reserved by SiFive for internal use.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
OpenSBI for fu540 does DT fix up (see fu540_modify_dt()) by updating
chosen "stdout-path" to point to "/soc/serial@...", and U-Boot will
use this information to locate the serial node and probe its driver.
However currently we generate the UART node name as "/soc/uart@...",
causing U-Boot fail to find the serial node in DT.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This updates the UART base address and IRQs to match the hardware.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Jonathan Behrens <fintelia@gmail.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Chih-Min Chao <chihmin.chao@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Now that we have added a PRCI node, update existing UART and ethernet
nodes to reference PRCI as their clock sources, to keep in sync with
the Linux kernel device tree.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Add PRCI mmio base address and size mappings to sifive_u machine,
and generate the corresponding device tree node.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
To keep in sync with Linux kernel device tree, generate hfclk and
rtcclk nodes in the device tree, to be referenced by PRCI node.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This adds a simple PRCI model for FU540 (sifive_u). It has different
register layout from the existing PRCI model for FE310 (sifive_e).
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
With heterogeneous harts config, the PLIC hart topology configuration
string are "M,MS,.." because of the monitor hart #0.
Suggested-by: Fabien Chouteau <chouteau@adacore.com>
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
The FU540-C000 includes a 64-bit E51 RISC-V core and four 64-bit U54
RISC-V cores. Currently the sifive_u machine only populates 4 U54
cores. Update the max cpu number to 5 to reflect the real hardware,
by creating 2 CPU clusters as containers for RISC-V hart arrays to
populate heterogeneous harts.
The cpu nodes in the generated DTS have been updated as well.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
It is not useful if we only have one management CPU.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
[Palmer: Set default CPUs to 2]
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
At present each hart's hartid in a RISC-V hart array is assigned
the same value of its index in the hart array. But for a system
that has multiple hart arrays, this is not the case any more.
Add a new "hartid-base" property so that hartid number can be
assigned based on the property value.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Currently riscv_harts_realize() creates all harts based on the
same cpu type given in the hart array property. With current
implementation it can only create homogeneous harts. Exact the
hart realize to a separate routine in preparation for supporting
multiple hart arrays.
Note the file header says the RISC-V hart array holds the state
of a heterogeneous array of RISC-V harts, which is not true.
Update the comment to mention homogeneous array of RISC-V harts.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Use create_unimplemented_device() instead.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Currently the PRCI register block size is set to 0x8000, but in fact
0x1000 is enough, which is also what the manual says.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Chih-Min Chao <chihmin.chao@sifive.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
For hfxosccfg register programming, SIFIVE_E_PRCI_HFXOSCCFG_RDY and
SIFIVE_E_PRCI_HFXOSCCFG_EN should be used.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Chih-Min Chao <chihmin.chao@sifive.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Current SiFive PRCI model only works with sifive_e machine, as it
only emulates registers or PRCI block in the FE310 SoC.
Rename the file name to make it clear that it is for sifive_e.
This also prefix "sifive_e"/"SIFIVE_E" for all macros, variables
and functions.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Chih-Min Chao <chihmin.chao@sifive.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
sifive_u machine does not use PRCI as of today. Remove the prci
header inclusion.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
The inclusion of "target/riscv/cpu.h" is unnecessary in various
sifive model drivers.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Replace the call to hw_error() with qemu_log_mask(LOG_GUEST_ERROR,...)
in various sifive models.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
There is no need to return fdt at the end of create_fdt() because
it's already saved in s->fdt.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Chih-Min Chao <chihmin.chao@sifive.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This removes "reg-names" and "riscv,max-priority" properties of the
PLIC node from device tree.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Jonathan Behrens <fintelia@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Some of the properties only have 1 cell so we should use
qemu_fdt_setprop_cell() instead of qemu_fdt_setprop_cells().
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
"linux,phandle" property is optional. Remove all instances in the
sifive_u, virt and spike machine device trees.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Commit a27bd6c779 ("Include hw/qdev-properties.h less") wrongly
added "hw/hw.h" to sifive_prci.c and sifive_test.c.
Another inclusion of "hw/hw.h" was later added via
commit 650d103d3e ("Include hw/hw.h exactly where needed"), that
resulted in duplicated inclusion of "hw/hw.h".
Fixes: a27bd6c779 ("Include hw/qdev-properties.h less")
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This adds a reset opcode for sifive_test device to trigger a system
reset for testing purpose.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
At present when "-bios image" is supplied, we just use the straight
path without searching for the configured data directories. Like
"-bios default", we add the same logic so that "-L" actually works.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This adds a helper routine for finding firmware. It is currently
used only for "-bios default" case.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
The correct property name is clock-names, not clocks-names.
Without this patch, the Ethernet driver fails to instantiate with
the following error.
macb 100900fc.ethernet: failed to get macb_clk (-2)
macb: probe of 100900fc.ethernet failed with error -2
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
The riscv uart needs valid clocks. This requires a refereence
to the clock node. Since the SOC clock is not emulated by qemu,
add a reference to a fixed clock instead. The clock-frequency
entry in the uart node does not seem to be necessary, so drop it.
In addition to a reference to the clock, the driver also needs
an aliases entry for the serial node. Add it as well.
Without this patch, the serial driver fails to instantiate with
the following error message.
sifive-serial 10013000.uart: unable to find controller clock
sifive-serial: probe of 10013000.uart failed with error -2
when trying to boot Linux.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Add support for loading initrd with "-initrd <filename>"
to the sifive_u machine. This lets us boot into Linux without
disk drive.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
In my "build everything" tree, changing sysemu/sysemu.h triggers a
recompile of some 5400 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).
hw/qdev-core.h includes sysemu/sysemu.h since recent commit e965ffa70a
"qdev: add qdev_add_vm_change_state_handler()". This is a bad idea:
hw/qdev-core.h is widely included.
Move the declaration of qdev_add_vm_change_state_handler() to
sysemu/sysemu.h, and drop the problematic include from hw/qdev-core.h.
Touching sysemu/sysemu.h now recompiles some 1800 objects.
qemu/uuid.h also drops from 5400 to 1800. A few more headers show
smaller improvement: qemu/notify.h drops from 5600 to 5200,
qemu/timer.h from 5600 to 4500, and qapi/qapi-types-run-state.h from
5500 to 5000.
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20190812052359.30071-28-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
hw/boards.h pulls in almost 60 headers. The less we include it into
headers, the better. As a first step, drop superfluous inclusions,
and downgrade some more to what's actually needed. Gets rid of just
one inclusion into a header.
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-23-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
In my "build everything" tree, changing hw/qdev-properties.h triggers
a recompile of some 2700 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).
Many places including hw/qdev-properties.h (directly or via hw/qdev.h)
actually need only hw/qdev-core.h. Include hw/qdev-core.h there
instead.
hw/qdev.h is actually pointless: all it does is include hw/qdev-core.h
and hw/qdev-properties.h, which in turn includes hw/qdev-core.h.
Replace the remaining uses of hw/qdev.h by hw/qdev-properties.h.
While there, delete a few superfluous inclusions of hw/qdev-core.h.
Touching hw/qdev-properties.h now recompiles some 1200 objects.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Daniel P. Berrangé" <berrange@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20190812052359.30071-22-armbru@redhat.com>
In my "build everything" tree, changing hw/hw.h triggers a recompile
of some 2600 out of 6600 objects (not counting tests and objects that
don't depend on qemu/osdep.h).
The previous commits have left only the declaration of hw_error() in
hw/hw.h. This permits dropping most of its inclusions. Touching it
now recompiles less than 200 objects.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-19-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
In my "build everything" tree, changing migration/vmstate.h triggers a
recompile of some 2700 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).
hw/hw.h supposedly includes it for convenience. Several other headers
include it just to get VMStateDescription. The previous commit made
that unnecessary.
Include migration/vmstate.h only where it's still needed. Touching it
now recompiles only some 1600 objects.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-16-armbru@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
In my "build everything" tree, changing hw/irq.h triggers a recompile
of some 5400 out of 6600 objects (not counting tests and objects that
don't depend on qemu/osdep.h).
hw/hw.h supposedly includes it for convenience. Several other headers
include it just to get qemu_irq and.or qemu_irq_handler.
Move the qemu_irq and qemu_irq_handler typedefs from hw/irq.h to
qemu/typedefs.h, and then include hw/irq.h only where it's still
needed. Touching it now recompiles only some 500 objects.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190812052359.30071-13-armbru@redhat.com>
In my "build everything" tree, changing sysemu/reset.h triggers a
recompile of some 2600 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).
The main culprit is hw/hw.h, which supposedly includes it for
convenience.
Include sysemu/reset.h only where it's needed. Touching it now
recompiles less than 200 objects.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190812052359.30071-9-armbru@redhat.com>
Fix a typo in the warning message displayed to users, don't print the
message when running inside qtest and don't mention a specific QEMU
version for the deprecation.
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
If the user hasn't specified a firmware to load (with -bios) or
specified no bios (with -bios none) then load OpenSBI by default. This
allows users to boot a RISC-V kernel with just -kernel.
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
The global smp variables in riscv are replaced with smp machine properties.
A local variable of the same name would be introduced in the declaration
phase if it's used widely in the context OR replace it on the spot if it's
only used once. No semantic changes.
Signed-off-by: Like Xu <like.xu@linux.intel.com>
Message-Id: <20190518205428.90532-6-like.xu@linux.intel.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
[ehabkost: fix spike_board_init()]
[ehabkost: fix riscv_sifive_e_soc_init()]
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Extend the RISC-V kernel loader to support Image and uImage files.
A Linux kernel can now be booted with:
qemu-system-riscv64 -machine virt -bios fw_jump.bin -kernel Image
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Add support for loading a firmware file for the virt machine and the
SiFive U. This can be run with the following command:
qemu-system-riscv64 -machine virt -bios fw_jump.bin -kernel vmlinux
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Split the common RISC-V boot functions into a seperate file. This allows
us to share the common code.
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
At present the PLIC is instantiated to support only one hart, while
the machine allows at most 4 harts to be created. When more than 1
hart is configured, PLIC needs to instantiated to support multicore,
otherwise an SMP OS does not work.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
At present the cpu, plic and ethclk nodes' phandles are hard-coded
to 1/2/3 in DT. If we configure more than 1 cpu for the machine,
all cpu nodes' phandles conflict with each other as they are all 1.
Fix it by removing the hardcode.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Currently, there is no cpu topology defined in RISC-V.
Define a device tree node that clearly describes the
entire topology. This saves the trouble of scanning individual
cache to figure out the topology.
Here is the linux kernel patch series that enables topology
for RISC-V.
http://lists.infradead.org/pipermail/linux-riscv/2019-June/005072.html
CPU topology after applying this patch in QEMU & above series in kernel
/ # cat /sys/devices/system/cpu/cpu2/topology/thread_siblings_list
2
/ # cat /sys/devices/system/cpu/cpu2/topology/physical_package_id
0
/ # cat /sys/devices/system/cpu/cpu2/topology/core_siblings_list
0-7
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Coverity pointed out a memory leak in riscv_sifive_e_soc_realize(),
where a pair of recently added MemoryRegion instances would not be freed
if there were errors elsewhere in the function. The fix here is to
simply not use dynamic allocation for these instances: there's always
one of each in SiFiveESoCState, so instead we just include them within
the struct.
Fixes: 30efbf330a ("SiFive RISC-V GPIO Device")
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>