Using a mask instead of the number of PMU devices supports the accurate
emulation of platforms that have a discontinuous set of PMU counters.
The "pmu-num" property now generates a warning when used by the user on
the command line.
Rather than storing the value for "pmu-num" convert it directly to the
mask if it is specified (overwriting the default "pmu-mask" value)
likewise the value is calculated from the mask if the property value is
obtained.
In the unusual situation that both "pmu-mask" and "pmu-num" are provided
then then the order on the command line determines which takes
precedence (later overwriting earlier.)
Signed-off-by: Rob Bradford <rbradford@rivosinc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20231031154000.18134-5-rbradford@rivosinc.com>
[Changes by AF
- Fixup ext_zihpm logic after rebase
]
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This change adds support for inserting virtual interrupts from HS-mode
into VS-mode using hvien and hvip csrs. This also allows for IRQ filtering
from HS-mode.
Also, the spec doesn't mandate the interrupt to be actually supported
in hardware. Which allows HS-mode to assert virtual interrupts to VS-mode
that have no connection to any real interrupt events.
This is defined as part of the AIA specification [0], "6.3.2 Virtual
interrupts for VS level".
[0]: https://github.com/riscv/riscv-aia/releases/download/1.0/riscv-interrupts-1.0.pdf
Signed-off-by: Rajnesh Kanwal <rkanwal@rivosinc.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-ID: <20231016111736.28721-7-rkanwal@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This change adds support for inserting virtual interrupts from M-mode
into S-mode using mvien and mvip csrs. IRQ filtering is a use case of
this change, i-e M-mode can stop delegating an interrupt to S-mode and
instead enable it in MIE and receive those interrupts in M-mode and then
selectively inject the interrupt using mvien and mvip.
Also, the spec doesn't mandate the interrupt to be actually supported
in hardware. Which allows M-mode to assert virtual interrupts to S-mode
that have no connection to any real interrupt events.
This is defined as part of the AIA specification [0], "5.3 Interrupt
filtering and virtual interrupts for supervisor level".
[0]: https://github.com/riscv/riscv-aia/releases/download/1.0/riscv-interrupts-1.0.pdf
Signed-off-by: Rajnesh Kanwal <rkanwal@rivosinc.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-ID: <20231016111736.28721-6-rkanwal@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
These fields shouldn't be accessed when KVM is not available.
Restrict the KVM timer migration state. Rename the KVM timer
post_load() handler accordingly, because cpu_post_load() is
too generic.
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-Id: <20230626232007.8933-3-philmd@linaro.org>
Fix identation problems, and try to use the same indentation strategy
in the same file.
Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-Id: <20230405085813.40643-3-liweiwei@iscas.ac.cn>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Currently we only use the env->virt to encode the virtual mode enabled
status. Let's make it a bool type.
Signed-off-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Message-ID: <20230325145348.1208-1-zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230327080858.39703-6-liweiwei@iscas.ac.cn>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Add encode, trans* functions and helper functions support for Zcmt
instrutions.
Add support for jvt csr.
Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230307081403.61950-8-liweiwei@iscas.ac.cn>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The attribute is no longer used since we can retrieve all the enabled
features in the hart by using cpu->cfg instead.
Remove env->feature, riscv_feature() and riscv_set_feature(). We also
need to bump vmstate_riscv_cpu version_id and minimal_version_id since
'features' is no longer being migrated.
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Reviewed-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Message-ID: <20230222185205.355361-11-dbarboza@ventanamicro.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
RISCV_FEATURE_PMP is being set via riscv_set_feature() by mirroring the
cpu->cfg.pmp flag. Use the flag instead.
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Reviewed-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Message-ID: <20230222185205.355361-8-dbarboza@ventanamicro.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
RISCV_FEATURE_DEBUG will always follow the value defined by
cpu->cfg.debug flag. Read the flag instead.
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Reviewed-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Message-ID: <20230222185205.355361-5-dbarboza@ventanamicro.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
At present for some unknown reason the HTIF registers (fromhost &
tohost) are defined in the RISC-V CPUArchState. It should really
be put in the HTIFState struct as it is only meaningful to HTIF.
Signed-off-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20221229091828.1945072-6-bmeng@tinylab.org>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Avoid calling riscv_itrigger_enabled() when calculate the tbflags.
As the itrigger enable status can only be changed when write
tdata1, migration load or itrigger fire, update env->itrigger_enabled
at these places.
Signed-off-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20221013062946.7530-5-zhiwei_liu@linux.alibaba.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Smstateen extension specifies a mechanism to close
the potential covert channels that could cause security issues.
This patch adds the CSRs defined in the specification and
the corresponding predicates and read/write functions.
Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20221016124726.102129-2-mchitale@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Replace type2_trigger_t with the real tdata1, tdata2, and tdata3 CSRs,
which allows us to support more types of triggers in the future.
Signed-off-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Message-Id: <20220909134215.1843865-4-bmeng.cn@gmail.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Current RISC-V debug assumes that only type 2 trigger is supported.
To allow more types of triggers to be supported in the future
(e.g. type 6 trigger, which is similar to type 2 trigger with additional
functionality), we should determine the trigger type from tdata1.type.
RV_MAX_TRIGGERS is also introduced in replacement of TRIGGER_TYPE2_NUM.
Signed-off-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
[bmeng: fixed MXL_RV128 case, and moved macros to the following patch]
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Message-Id: <20220909134215.1843865-2-bmeng.cn@gmail.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Instead of using our properties to set a config value which then might
be used to set the resetvec (depending on your timing), let's instead
just set the resetvec directly in the env struct.
This allows us to set the reset vec from the command line with:
-global driver=riscv.hart_array,property=resetvec,value=0x20000400
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220914101108.82571-2-alistair.francis@wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The Sscofpmf ('Ss' for Privileged arch and Supervisor-level extensions,
and 'cofpmf' for Count OverFlow and Privilege Mode Filtering)
extension allows the perf to handle overflow interrupts and filtering
support. This patch provides a framework for programmable
counters to leverage the extension. As the extension doesn't have any
provision for the overflow bit for fixed counters, the fixed events
can also be monitoring using programmable counters. The underlying
counters for cycle and instruction counters are always running. Thus,
a separate timer device is programmed to handle the overflow.
Tested-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Message-Id: <20220824221701.41932-2-atishp@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
vstimecmp CSR allows the guest OS or to program the next guest timer
interrupt directly. Thus, hypervisor no longer need to inject the
timer interrupt to the guest if vstimecmp is used. This was ratified
as a part of the Sstc extension.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Message-Id: <20220824221357.41070-4-atishp@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
stimecmp allows the supervisor mode to update stimecmp CSR directly
to program the next timer interrupt. This CSR is part of the Sstc
extension which was ratified recently.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Message-Id: <20220824221357.41070-3-atishp@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Historically, The mtime/mtimecmp has been part of the CPU because
they are per hart entities. However, they actually belong to aclint
which is a MMIO device.
Move them to the ACLINT device. This also emulates the real hardware
more closely.
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Message-Id: <20220824221357.41070-2-atishp@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
mcycle/minstret are actually WARL registers and can be written with any
given value. With SBI PMU extension, it will be used to store a initial
value provided from supervisor OS. The Qemu also need prohibit the counter
increment if mcountinhibit is set.
Support mcycle/minstret through generic counter infrastructure.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Message-Id: <20220620231603.2547260-8-atishp@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
With SBI PMU extension, user can use any of the available hpmcounters to
track any perf events based on the value written to mhpmevent csr.
Add read/write functionality for these csrs.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Message-Id: <20220620231603.2547260-7-atishp@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
As per the privilege specification v1.11, mcountinhibit allows to start/stop
a pmu counter selectively.
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Message-Id: <20220620231603.2547260-6-atishp@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Add a subsection to machine.c to migrate debug CSR state.
Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20220421003324.1134983-5-bmeng.cn@gmail.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The RISC-V privileged specification v1.12 defines few execution
environment configuration CSRs that can be used enable/disable
extensions per privilege levels.
Add the basic support for these CSRs.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Message-Id: <20220303185440.512391-6-atishp@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The AIA hvictl and hviprioX CSRs allow hypervisor to control
interrupts visible at VS-level. This patch implements AIA hvictl
and hviprioX CSRs.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Message-id: 20220204174700.534953-12-anup@brainfault.org
[ Changes by AF:
- Fix possible unintilised variable error in rmw_sie()
]
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The AIA specification adds new CSRs for RV32 so that RISC-V hart can
support 64 local interrupts on both RV32 and RV64.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Message-id: 20220204174700.534953-11-anup@brainfault.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The AIA spec defines programmable 8-bit priority for each local interrupt
at M-level, S-level and VS-level so we extend local interrupt processing
to consider AIA interrupt priorities. The AIA CSRs which help software
configure local interrupt priorities will be added by subsequent patches.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20220204174700.534953-10-anup@brainfault.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The hgeie and hgeip CSRs are required for emulating an external
interrupt controller capable of injecting virtual external interrupt
to Guest/VM running at VS-level.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Message-id: 20220204174700.534953-4-anup@brainfault.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
We need not specially process vtype when XLEN changes.
Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20220120122050.41546-16-zhiwei_liu@c-sky.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220120122050.41546-12-zhiwei_liu@c-sky.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Current xlen has been used in helper functions and many other places.
The computation of current xlen is not so trivial, so that we should
recompute it as little as possible.
Fortunately, xlen only changes in very seldom cases, such as exception,
misa write, mstatus write, cpu reset, migration load. So that we can only
recompute xlen in this places and cache it into CPURISCVState.
Signed-off-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20220120122050.41546-6-zhiwei_liu@c-sky.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Add virtual time context description to vmstate_kvmtimer. After cpu being
loaded, virtual time context is updated to KVM.
Signed-off-by: Yifei Jiang <jiangyifei@huawei.com>
Signed-off-by: Mingwang Li <limingwang@huawei.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20220112081329.1835-13-jiangyifei@huawei.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Adding the high part of a very minimal set of csr.
Signed-off-by: Frédéric Pétrot <frederic.petrot@univ-grenoble-alpes.fr>
Co-authored-by: Fabien Portas <fabien.portas@grenoble-inp.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20220106210108.138226-16-frederic.petrot@univ-grenoble-alpes.fr
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The upper 64-bit of the 128-bit registers have now a place inside
the cpu state structure, and are created as globals for future use.
Signed-off-by: Frédéric Pétrot <frederic.petrot@univ-grenoble-alpes.fr>
Co-authored-by: Fabien Portas <fabien.portas@grenoble-inp.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20220106210108.138226-7-frederic.petrot@univ-grenoble-alpes.fr
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Move the codes around so that the order of .subsections matches
the one they are referenced in vmstate_riscv_cpu.
Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20211030030606.32297-1-bmeng.cn@gmail.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
The hw representation of misa.mxl is at the high bits of the
misa csr. Representing this in the same way inside QEMU
results in overly complex code trying to check that field.
Reviewed-by: LIU Zhiwei <zhiwei_liu@c-sky.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20211020031709.359469-4-richard.henderson@linaro.org
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Qemu doesn't support RISC-V privilege specification v1.9. Remove the
remaining v1.9 specific references from the implementation.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20210319194534.2082397-2-atish.patra@wdc.com>
[Changes by AF:
- Rebase on latest patches
- Bump the vmstate_riscv_cpu version_id and minimum_version_id
]
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
In the case of supporting V extension, add V extension description
to vmstate_riscv_cpu.
Signed-off-by: Yifei Jiang <jiangyifei@huawei.com>
Signed-off-by: Yipeng Yin <yinyipeng1@huawei.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20201026115530.304-6-jiangyifei@huawei.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
In the case of supporting H extension, add H extension description
to vmstate_riscv_cpu.
Signed-off-by: Yifei Jiang <jiangyifei@huawei.com>
Signed-off-by: Yipeng Yin <yinyipeng1@huawei.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20201026115530.304-5-jiangyifei@huawei.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
In the case of supporting PMP feature, add PMP state description
to vmstate_riscv_cpu.
'vmstate_pmp_addr' and 'num_rules' could be regenerated by
pmp_update_rule(). But there exists the problem of updating
num_rules repeatedly in pmp_update_rule(). So here extracts
pmp_update_rule_addr() and pmp_update_rule_nums() to update
'vmstate_pmp_addr' and 'num_rules' respectively.
Signed-off-by: Yifei Jiang <jiangyifei@huawei.com>
Signed-off-by: Yipeng Yin <yinyipeng1@huawei.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20201026115530.304-4-jiangyifei@huawei.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Add basic CPU state description to the newly created machine.c
Signed-off-by: Yifei Jiang <jiangyifei@huawei.com>
Signed-off-by: Yipeng Yin <yinyipeng1@huawei.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20201026115530.304-3-jiangyifei@huawei.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
