Commit Graph
100 Commits
Author SHA1 Message Date
Atish PatraandAnup Patel b8845e4204 lib: sbi: Fix initial value mask while updating the counters
The first 32 bits of the initial value for the counter should be
preserved while updating the mhpmcounter for 32bit.

Fixes: 13d40f21d5 ("lib: sbi: Add PMU support")
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Dong Du <Dd_nirvana@sjtu.edu.cn>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2021-11-11 17:57:17 +05:30
Atish PatraandAnup Patel 15906a3984 lib: utils: Rename the prefix in PMU DT properties
As per the DT schema rules, the prefix should be vendor. As the PMU
properties are generic for all vendors, change the prefix to riscv
instead of pmu.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-11-11 17:54:46 +05:30
Atish PatraandAnup Patel b28f07005c lib: sbi: Enable PMU extension for platforms without mcountinhibit
Some platforms such as hifive unmatched doesn't implement mcountinhibit
csr. However, it has hardware events that can be monitored using 2
hpmcounter it has (i.e. mhpmcounter3 & mhpmcounter4).

Currently, PMU extension disabled if mcountinhibit is absent. That's not
really necessary as long as the supervisor OS keeps track of the delta
value of the counters. Without mcountinhibit, the delta value won't be
entirely accurate because the counters are freely running. However, that
should be fine to produce an approximate counter value which can help
performance analysis. Perf sampling won't work though as sscof extension
is not present in hifive unmatched.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-11-11 17:54:01 +05:30
Atish PatraandAnup Patel b628cfd6a0 lib: sbi: Counter info width should be zero indexed
The mhpm bits represent the number of bits available in mhpmcounter
while counter width describes a zero indexed value. Fix the counter width
calculation.

Fixes: 13d40f21d5 ("lib: sbi: Add PMU support")
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-11-11 17:52:19 +05:30
Atish PatraandAnup Patel 1e147324f0 lib: sbi: Reset the mhpmevent value upon counter reset
The hardware solely relies on the event selector value in mhpmevent
to figure out what event to monitor using that counter. It should be
reset when counter reset happens.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-11-11 17:50:32 +05:30
Atish PatraandAnup Patel 0c304b6619 lib: sbi: Allow programmable counters to monitor cycle/instret events
A platform may use programmable counters for cycle/instret events.
The priv spec allows that provided that cycle/instret also report those
events in addition to the programmable counters. We should allow that
functionality in OpenSBI.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-11-11 17:48:45 +05:30
Atish PatraandAnup Patel 2363f950bc lib: sbi: Always enable access for all counters
OpenSBI doesn't use any counters for its own usage. Thus, all the counters
can be made accessible for lower privilege mode always. However, the
mcountinhibit must be set so that the counter doesn't increment.
As a result, we don't have to enable/disable mcounteren at every start/stop.

Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-11-11 17:47:52 +05:30
Atish PatraandAnup Patel 730f01bb41 lib: sbi: Support sscofpmf extension in OpenSBI
This patch adds sscofpmf extension in pmu module which includes
following things.

1. Enable overflow irq when starting a counter.
2. Setting the correct event filters passed from supervisor.
3. Delegating the overflow interrupt to the supervisor.
4. Add RV32 support for sscofpmf.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-11-11 17:46:57 +05:30
Atish PatraandAnup Patel 9134c3643e lib: sbi: Delegate PMU counter overflow interrupt to S mode
OpenSBI doesn't handle PMU counters for now.

Delegate the overflow counter to S-mode always.

Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-11-11 17:45:12 +05:30
Atish PatraandAnup Patel 867c65360d lib: sbi: Detect Sscofpmf extension at run time
Sscofpmf ISA extension introduces PMU counter overflow and filtering support.
It introduces a read only `scountovf` csr that can be used to detect if
a hart supports this extension at runtime. However, this feature is only
useful if the hart already supports mcounteren and mcountinhibit.

Add a dynamic detection mechanism and boot time print message if sscofpmf
is present.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-11-11 17:42:59 +05:30
Atish PatraandAnup Patel 7084ad9f42 lib: sbi: Update csr_read/write_num for PMU
The Sscofpmf extension introduces mhpmevent[h] csrs to handle filtering
/overflow bits in RV32. There is no way to read/write mcountinhibit
using mcountinhibit csr using a variable.

Updated the support to read/write mhpmevent[h] and mcountinhibit csr.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-11-11 17:39:38 +05:30
Atish PatraandAnup Patel a74daf2cb9 riscv: Add new CSRs introduced by Sscofpmf[1] extension
[1] https://drive.google.com/file/d/1KcjgbLM5L1ZKY8934aJl8aQwGlMz6Cbo/view

Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-11-11 17:37:34 +05:30
Atish PatraandAnup Patel 0e12aa8dee platform: generic: Add PMU support
Add PMU support for generic platform. Generic platform solely relies on
the device tree to parse all pmu related information. If any event is
not described in device tree, generic platform will not support it.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11 10:39:42 +05:30
Atish PatraandAnup Patel ec1b8bb763 lib: sbi: Improve TLB function naming
Follow the standard conventon for static function names:

	All global functions should be start with sbi_<module name>_
	All static functions should be start with <module name>_

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11 10:38:26 +05:30
Atish PatraandAnup Patel 764a17d852 lib: sbi: Implement firmware counters
RISC-V SBI v0.3 specification defines a set of firmware events that can
provide additional information about the current firmware context. All
of the firmware event monitoring are enabled now. The firmware
events must be defined as raw perf event with MSB set as specified in the
specification.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11 10:38:23 +05:30
Atish PatraandAnup Patel 37f9b0f2f2 lib: sbi: Implement SBI PMU extension
RISC-V SBI specfication 0.3 defines a PMU extension that allows supervisor
mode to start/stop/configure pmu related events. This patch implements
all of the functionality defined in the specification.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11 10:38:02 +05:30
Atish PatraandAnup Patel ae72ec0915 utils: fdt: Add fdt helper functions to parse PMU DT nodes
The PMU DT node bindings are defined in docs/pmu_support.md
Add few fdt helper functions to parse the DT node and update the
event-counter mapping tables.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11 10:27:57 +05:30
Atish PatraandAnup Patel 13d40f21d5 lib: sbi: Add PMU support
RISC-V SBI v0.3 specification defined a PMU extension to configure/start/stop
the hardware/firmware pmu events.

Implement PMU support in OpenSBI library. The implementation is agnostic of
event to counter mapping & mhpmevent value configuration. That means, it
expects platform hooks will be used to set up the mapping and provide
the mhpmevent value at runtime.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11 10:23:18 +05:30
Atish PatraandAnup Patel e7cc7a3ab2 lib: sbi: Add PMU specific platform hooks
A platform hook to initialize PMU allows platform vendors to provide
their own mechanism to define pmu event-counter mappings in addition
to the DT based approach.

Another platform hook that allows platform vendors customize the
final mhpmevent value configuration.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11 10:21:38 +05:30
Atish PatraandAnup Patel 49966db306 lib: sbi: Use csr_read/write_num to read/update PMU counters
Currently, csr_read/write_num functions are used to read/write PMP related
CSRs where CSR value is decided at runtime. Expand this function to include
PMU related CSRs as well.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11 10:20:44 +05:30
Atish PatraandAnup Patel fd9116bd46 lib: sbi: Remove redundant boot time print statement
This patch removes redundant print from sbi_boot_print_hart().

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11 10:19:48 +05:30
Atish PatraandAnup Patel 41ae63cd0a include: Add a list empty check function
Implement a list helper function that checks for empty lists.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11 10:15:29 +05:30
Atish PatraandAnup Patel 9c9b4ad24b lib: sbi: Disable m/scounteren & enable mcountinhibit
Currently, all bits in mcountern are enabled unconditionally at boot time.
With SBI PMU extension, all the programmable counters should enabled only
during performance monitoring for a particular event. However, this is done
only if mcountinhibit is implemented because the supervisor mode can not
start/stop any event without mcountinhibit.

Similarly, supervisor should take care enabling scounteren which allows
U-mode to access programmable pmu counters. All the non-programmable ones
(CY, TM, IR) should be enabled in M-mode because some userspace may rely on
builtins such as __builtin_readcyclecounter. Supervisor OS can still disable
them during initial configuration.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11 10:14:26 +05:30
Atish PatraandAnup Patel 0829f2bc28 lib: sbi: Detect number of bits implemented in mhpmcounter
RISC-V privilege specification allows the implementation to have less
than 64 bits.

Add a function to detect the number of implemented bits in mhpmcounter
dynamically at runtime.

Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11 10:13:04 +05:30
Atish PatraandAnup Patel d3a96cc469 lib: sbi: Remove stray '\' character
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11 10:12:06 +05:30
Atish PatraandAnup Patel fde28fadc2 lib: sbi: Detect mcountinihibit support at runtime
RISC-V ISA specification v1.11 defined mcountinhibit CSR that allows
software to stop any counter from incrementing. The SBI PMU extension
depends on this CSR support in hardware.

Define mcountinhibit as a hart specific feature and detect it at runtime.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11 10:11:10 +05:30
Atish PatraandAnup Patel 3e8b31aca9 docs: Add device tree bindings for SBI PMU extension
SBI PMU extension requires a firmware to be aware of the event to
counter/mhpmevent mappings supported by the hardware. One approach
is to encode that information in the device tree.

Define a device tree binding that allows a hardware to describe
all the PMU mappings required in concise format.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2021-07-11 10:10:16 +05:30
Atish PatraandAnup Patel a809f406b9 lib: sbi: Improve boot time print with additional PMP information
We know about pmp granularity and number of bits supported by PMP.
Show those information in the boot time info print

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-10-26 22:59:09 +05:30
Atish PatraandAnup Patel bf21632860 lib: sbi: Detect PMP granularity and number of address bits
As per RISC-V privilege specification, a platform may choose to implement
a coarser granularity scheme for PMP addresses. In that case, we shouldn't
allow any pmp region size smaller than the platform supports. A platform
may not also implement all the bits for a PMP address specified in the priv
specification.

The pmp range granularity and address bits should be detected dynamically
before detecing PMP regions. Any pmp modification request beyond these detected
value must not succeed.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-10-26 22:44:52 +05:30
Atish PatraandAnup Patel 74c0ea1e83 lib: utils: Implement "ranges" property parsing
The "reg" property in a device node may not be the correct address always.
If a parent node defines a "ranges" property, the child address need to be
translated with respect to parents address. If the ranges property is not
present, it will just use 1:1 translation.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-10-23 17:19:21 +05:30
Atish PatraandAnup Patel 106b888e20 docs: Remove redundant documentation about combined payload use case
U-Boot now supports loading Linux kernel image via network and storage
media. Thus, we don't need to use a combined payload containing both
U-Boot & Linux kernel image to boot Linux from U-Boot prompt.

Remove the old documentation.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-06-08 17:04:12 +05:30
Atish PatraandAnup Patel 79bfd67f9a docs: Use doxygen config to mark the main page
The doxygen config option "USE_MDFILE_AS_MAINPAGE" can be used to set
the main page in doxygen generated pdf. This allows us to remove the
"#mainpage" from the README file which markdown doesn't parse.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-06-08 17:02:41 +05:30
Atish PatraandAnup Patel 36833abfbb lib: Optimize inline assembly for unprivilege access functions
Currently, unprivileged access functions uses few additional instructions
which are redundant. It also uses specific registers which are not necessary.

Remove those additional instructions and let the compiler choose the
registers.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-05-16 17:52:42 +05:30
Atish PatraandAnup Patel 22c4334f5c lib: Add hart features in boot time print
We have now clear distinction between platform and hart features.
Modify the boot print messages to print hart specific features in
a string format.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Jonathan Balkind <jbalkind@cs.princeton.edu>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-05-10 10:30:47 +05:30
Atish PatraandAnup Patel 1f235ec47f lib: Add platform features in boot time print
We have now clear distinction between platform and hart features.
Modify the boot print messages to print platform features in a string
format. In the process, this patch moved relatively larger functions
to its own file from platform.h header file.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Jonathan Balkind <jbalkind@cs.princeton.edu>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-05-10 10:24:08 +05:30
Atish PatraandAnup Patel ec0d2a7d7d lib: timer: Provide a hart based timer feature
As per the RISC-V specification, time value can be obtained from a time
CSR implemented in hardware or a MMIO based IP block. Qemu virt machine
already supports timer csr while CLINT provides the timer for other
platforms.

Implement a hart specific timer feature that can be detected at runtime.
As CSR based timer implementation are faster than MMIO address based, it
is always preferred over MMIO based one.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Jonathan Balkind <jbalkind@cs.princeton.edu>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-05-10 10:14:54 +05:30
Atish PatraandAnup Patel 4938024420 platform: fpga: Remove redundant platform specific features
Any platform feature that belongs to a hart, have already been moved to
hart features and are detected at run time. The remaining platform features
are identical to platform default features.

Use the platform default features instead of defining a separate copy of it.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Jonathan Balkind <jbalkind@cs.princeton.edu>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-05-10 10:09:29 +05:30
Atish PatraandAnup Patel b2df751acf platform: Move platform features to hart
PMP & performance counters belong to a hart rather than a platform.
In addition to that, these features enable reading/writing from a
particular csr. Thus, they can be detected and set at runtime rather
than compile time.

Move PMP/MCOUNTEREN/SCOUNTEREN features to hart and detect them at runtime.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Jonathan Balkind <jbalkind@cs.princeton.edu>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-05-10 10:05:41 +05:30
Atish PatraandAnup Patel 6a053f6e6c lib: Add support for hart specific features
There may be some features which are hart specific rather than a platform
specific feature. Add a framework to support that.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Jonathan Balkind <jbalkind@cs.princeton.edu>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-05-10 10:02:49 +05:30
Atish PatraandAnup Patel 79d0fadb06 lib: utils: Update reserved memory fdt node even if PMP is not present
As per RISC-V ISA, pmp is not mandatory. Currently, we only add reserved
memory node in DT only if PMP is present. That allows supervisor to access
the memory where OpenSBI continue to exist without realizing it for non-pmp
based platforms. It may result in corrupting OpenSBI. That's why OpenSBI
should at least let the supervisor know where it continue to exist.
This a best effort service provided by OpenSBI expecting that supervisor
software is not buggy and properly sets up its memory after parsing the
reserved-memory device tree node.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-05-10 10:00:02 +05:30
Atish PatraandAnup Patel 13ca20d8df lib: Create a separate math helper function file
There may be few common mathematics helper functions which can be used
anywhere in OpenSBI project.

Add a separate math helper function file to add these functions.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-05-10 09:59:24 +05:30
Atish PatraandAnup Patel aef9a60d52 lib: Add csr detect support
As RISC-V ISA allows many CSRs such as pmp, s/mcounteren to be optional
in hardware, OpenSBI should provide an option to dynamically detect
these csr access capability at run time.

Implement a csr read/write access check helper macros.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Jonathan Balkind <jbalkind@cs.princeton.edu>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-05-10 09:59:20 +05:30
Atish PatraandAnup Patel 63a513edec lib: Rename unprivileged trap handler
Unprivileged trap handler can be reused for any cases where the executing
code expects a trap.

Rename it to "expected" trap handler as it will be used in other cases in
future.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Jonathan Balkind <jbalkind@cs.princeton.edu>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-05-10 09:59:16 +05:30
Atish PatraandAnup Patel 615587c336 docs: Update README about supported SBI versions
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-04-17 09:32:06 +05:30
Atish PatraandAnup Patel 6c7922e23b lib: Support vector extension
Enable vector context in mstatus by updating the corresponding bits
in mstatus if vector extension is supported by the hart.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-04-17 09:30:17 +05:30
Atish PatraandAnup Patel f281de885e lib: irqchip/plic: Fix maximum priority threshold value
As per the PLIC specification, maximum priority threshold value is 0x7.
Even though, writing a higher value doesn't cause any error in qemu
hifive unleashed, there may be some implementation which checks the upper
and may result in an illegal access.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-04-06 08:58:56 +05:30
Atish PatraandAnup Patel 4c374511fd platform: openpiton: Read the device configurations from device tree
OpenPiton is designed to run on different FPGAs with different
configurations. Use the fdt parser to retrieve the required values
from device tree instead of using fixed values.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Jonathan Balkind <jbalkind@cs.princeton.edu>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-03-24 13:33:39 +05:30
Atish PatraandAnup Patel 040e4e2ec2 lib: utils: Move fdt fixup helper routines to a different file
FDT helper file contain both fdt fixup and parsing functions.

Split the fixup related functions to a separate file for a better code
organization.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-03-24 13:30:32 +05:30
Atish PatraandAnup Patel d1d6560a87 platform: fpga/common: Add a fdt parsing helper functions
Different DT based platforms from the sam family may reuse IP blocks with
different configurations. These different configurations can be obtained
by parsing the device tree.

Add a FDT parser framework that can parse various device configurations from
device tree. Currently, the parsing algorithms doesn't cover all the use cases
or possible combination of DT configurations. It will be improved over time.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-03-24 13:29:07 +05:30
Atish PatraandAnup Patel fb84879e66 platform: Add OpenPiton platform support
OpenPiton is a research platform from Princeton University [1].

"OpenPiton is the world's first open source, general purpose,
multithreaded manycore processor. It is a tiled manycore
framework scalable from one to 1/2 billion cores."

Add OpenSBI support for OpenPiton. As it is based on ariane core,
it reuses the platform code from arine project.

[1]. https://github.com/PrincetonUniversity/openpiton

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-03-24 13:18:38 +05:30
Atish PatraandAnup Patel ed265b4498 platform: fpga/ariane: Remove redundant plic address macros
All the common PLIC specific macros are already defined in plic.c.

Remove it from platform code. While at it, Fix the other coding style
issues.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-03-24 13:15:52 +05:30
Atish PatraandAnup Patel 5968894842 platform: Move ariane standalone fpga project to its own project
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-03-24 13:12:17 +05:30
Atish PatraandAnup Patel 9a74a64ae0 lib: Check MSIP bit after returning from WFI
Commit 71d2b837c4 (lib: Move all coldboot wait APIs to sbi_init.c)
caused a regression while moving the code from sbi_hart.c to sbi_init.c.

As per original commit text, WFI can be implemented as a NOP according
to the RISC-V privilege specification. Software should ensure that
relevant interrupt pending bits are set. Otherwise, loop back to WFI.
Fix the regression by applying the original patch to sbi_init.c.

Fixes: 71d2b837c4 ("lib: Move all coldboot wait APIs to sbi_init.c")

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-03-21 09:21:47 +05:30
Atish PatraandAnup Patel 757bb44e6e docs: Remove out-of-date documentation
Upstream U-Boot now have SMP support and doesn't require any additional
patches for HiFive Unleashed.

Update the documentation.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-03-11 17:09:36 +05:30
Atish PatraandAnup Patel 6704216732 lib: Check MSIP bit after returning from WFI
As per the RISC-V privilege specification, WFI can be implemented as
a NOP. Software should ensure that relevant interrupt pending bits
are set. Otherwise, loop back to WFI.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-03-07 13:15:56 +05:30
Atish PatraandAnup Patel e3f69fc1e9 lib: Implement Hart State Management (HSM) SBI extension
This patch adds support HSM extension. The specification is available
at https://github.com/riscv/riscv-sbi-doc.

It allows to implement hart hotplug and fixed ordered hart booting in
supervisor.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-02-24 18:13:23 +05:30
Atish PatraandAnup Patel 5b4824082f lib: Add possible hart status values
SBI HSM extension defines possible hart status values in the
specification.

Define all possible status values. Add a helper function to
convert hart state to status because hart states are internal
to OpenSBI only and may not match the status values defined in
the specification.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-02-24 18:11:47 +05:30
Atish PatraandAnup Patel b677a9b8d6 lib: Implement hart hotplug
This patch adds support for hart hotplug in OpenSBI using a generic WFI
based approach. Hart hotplug can be achieved via SBI HSM extension which
allows supervisor mode software to start or stop any harts anytime.

Any platform wishes to implement platform specific hart hotplug must
implement both hart_start and hart_stop in addition to enable platform
feature SBI_PLATFORM_HAS_HART_HOTPLUG.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-02-24 18:07:55 +05:30
Atish PatraandAnup Patel f64f4b92e4 lib: Add a new platform feature to bringup secondary harts
A platform may have a specific method to bring-up secondary harts for the
first time but may rely on generic WFI based approach for hart hotplug in
absence of a platform specific hart hotplug method.

Define a platform feature flag for such platforms. The platform needs to
implement platform specific bring-up method in hart_start and not define
hart_stop method in this case. They must only define
SBI_PLATFORM_HAS_HART_SECONDARY_BOOT.

SBI_PLATFORM_HAS_HART_HOTPLUG should only be defined when the platform
intend to support both hart_start and hart_stop and do not intend to rely
on generic WFI based approach.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-02-24 18:04:23 +05:30
Atish PatraandAnup Patel 393624377a lib: Use available hart mask for correct hbase value
As per the latest SBI specification, all online harts should receive
IPI if hbase is set to -1.

Set the target mask to all available hart mask if hbase is -1.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-02-22 10:06:51 +05:30
Atish PatraandAnup Patel c3b3b8f43b lib: Fix typo in atomic exchange functions
There is a typo in atomic operations code which prevents the
usage of riscv atomic instructions even if it is supported.

Fix the typo.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-02-22 10:04:38 +05:30
Atish PatraandAnup Patel c2bfa2bff3 lib: irqchip/plic: Disable all contexts and IRQs
To initialize PLIC in sane state, we should:
1. set maximum threshold value of M-mode PLIC contexts
2. set maximum threshold value of S-mode PLIC contexts
3. set irq priorities to miniumum

Fix the comment and initialize the threshold/priorities correctly.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2020-02-13 09:58:27 +05:30
Atish PatraandAnup Patel 1a8ca08cc0 lib: Initialize out value in SBI calls
As per the SBI specification, the return value in sbiret is undefined
if not explicitly described in the function. However, supervisor may
check this value by mistake and get a garbage value.

Initialize it to zero to avoid nasty supervisor bugs.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-02-13 09:57:22 +05:30
Atish PatraandAnup Patel 2c2bbe7374 platform: sifive/fu540: Set tlb range flush limit to zero
It was reported that tlb range flush is not working on fu540.
Only tlb full flush seems to work on fu540 probably due to some
hardware errata.

Set the tlb flush limit to zero so that all tlb flush requests
are converted to full flush.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-02-05 10:46:29 +05:30
Atish PatraandAnup Patel d79173b4b7 platform: Add an platform ops to return platform specific tlb flush limit
If a platform requires to perform a tlb full flush, they should set
the tlb_range_flush_limit value to zero. However, corresponding platform
API ignore the value and continue to return the default value.

Add a platform ops to retrieve platform specific tlb range flush limit.
The platform variable becomes redundant in presence of the platform ops.
Take this opportunity to remove the variable as well.

The default is still set to smallest page size in RISC-V (4KB), as there
is no way to figure out a best value for all platforms. Individual platform
should set it to the optimal value for their platform.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-02-05 10:37:11 +05:30
Atish PatraandAnup Patel 86a31f5437 lib: Implement RFENCE extension
This patch adds RFENCE extension support in OpenSBI.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-12-23 09:12:23 +05:30
Atish PatraandAnup Patel 331ff6a162 lib: Support stage1 and stage2 tlb flushing
The hypervisor specification support hfence calls which can be used
issue tlb flush requests at both level of address translation. Currently,
these requests are issued only via SBI which are defined in v0.2.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-12-23 09:12:19 +05:30
Atish PatraandAnup Patel 9407202532 lib: Add hfence instruction encoding
Currently, the toolchains do not have support for hfence instruction.
Hence, the instruction are hardcode until we have toolchain support.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-12-23 09:12:16 +05:30
Atish PatraandAnup Patel 9777aeef41 lib: Add IPI extension in SBI
This patch adds new IPI extension which replaces ipi related
v0.1 extensions. This also adds a new API for ipi sending as trap
handling is not necessary in v0.2 SBI IPI related extensions.

It also modifies the IPI sending code which now accepts hart mask as a value
instead of S-mode virtual address. Thus, the caller should set it to exact hart
mask value everytime.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-12-23 09:12:13 +05:30
Atish PatraandAnup Patel 109266397a lib: Add TIME extension in SBI
This patch adds support for TIME extension which replaces v0.1
timer extension.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-12-23 09:12:11 +05:30
Atish PatraandAnup Patel aa0ed1d733 lib: Remove redundant IPI types
We just need to distinguish only between FENCE and non FENCE related
IPIs as all of the fence related requests are handled via fifo now.

Remove the unnecessary IPI types related to individual fence types.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-12-23 09:12:08 +05:30
Atish PatraandAnup Patel b8732feaf7 lib: Add replacement extension and function ids
Take this opportunity to move the enums to macros as enums make
sbi_ecall_interface.h unusable in assembly files.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-12-23 09:12:04 +05:30
Atish PatraandAnup Patel ab14f94a8c lib: Fix probe extension
The break statement is missing in base extension function handling.

Fix the typo.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Xiang Wang <merle@hardenedlinux.org>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-11-26 16:17:52 +05:30
Atish PatraandAnup Patel 30f09fbfd1 lib: Provide a platform hook to implement vendor specific SBI extensions.
SBI v0.2 specification allows vendor extensions and it should be
implemented in a independent of the core sbi library.

Introduce a single platform callback that will let platforms handle
all vendor extensions in platform specific code if they want.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-10-03 08:58:51 +05:30
Atish PatraandAnup Patel 0790be0f2c lib: Implement SBI v0.2
SBI v0.2 introduces a base specification which is mandatory to
implement for any SBI implementations that is not legacy.

Add support for the base extension.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-10-03 08:56:55 +05:30
Atish PatraandAnup Patel 848ed4f644 lib: Remove redundant variable assignment
An ecall handler should only return error if valid SBI function
fails. Otherwise, it should succeed with appropriate error in a0.

Get rid of unnecessary setting of the temporary return variable to
zero for the cases where errors are not expected.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-10-03 08:55:25 +05:30
Atish PatraandAnup Patel 26aec6afed lib: Rename existing SBI implementation as 0.1.
Current SBI implementation is now considered as version 0.1 and will be
removed/replaced with newer extension/functions in future.

Rename the existing implementations accordingly to be in sync with the
specification.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Zong Li <zong.li@sifive.com>
2019-10-03 08:53:52 +05:30
Atish PatraandAnup Patel 3d335bc54b lib: Align error codes as per SBI specification.
Follow the SBI specification for error codes.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-10-03 08:52:54 +05:30
Atish PatraandAnup Patel 8925e3865c Test: Move test payload related code out of interface header
Test payload uses an SBI call and uses the macros defined in interface
header which is not the correct place to have these definitions.
The interface header file should be used to keep SBI specification
related macros.

Keep all the test payload related code in test itself.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-10-03 08:51:39 +05:30
Atish PatraandAnup Patel 0a482e2edb lib: Fix tlb flush range limit value
Use platform defined flush range limit value only if it is non-zero.
Otherwise, use the default value.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2019-09-28 18:21:34 +05:30
Atish PatraandAnup Patel 98ee15ca3a lib: provide a platform specific tlb range flush threshold
Currently, the tlb range flush threshold is fixed and set to 4k for
all platforms. However, it should be platform specific as it completely
depends upon how platform actually implements sfence instruction.

Define a platform feature that allows every individual platform to set
different values. If a platform doesn't define it, just use a page size as
the threshold.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-09-10 17:44:10 +05:30
Atish PatraandAnup Patel f2e82c3d79 lib: Change tlb range flush threshold to 4k page instead of 1G
In RISC-V, tlb flush happens at a page granularity. That's why OpenSBI
also have a tlb range flush limit which decides the which tlb flush
requests should be upgraded to full flush to avoid long delays.
Currently, this is set to 1G which would result in a many sfence.vma
execution in a tight loop for a large range.

Change the threshold to 4k to speed things up.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-09-10 17:44:07 +05:30
Atish PatraandAnup Patel 6ed2bc154f docs: Update the fu540 platform guide as per U-Boot documents.
U-Boot readme for fu540 platform suggest that fdt_addr_r should be used
as DT address after DT is copied via tftpboot.

Update the OpenSBI docs to reflect that. Remove other stale informations
as well.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-08-31 13:16:44 +05:30
Atish PatraandAnup Patel 7b7690ed9c lib: Upgrade to full flush if size is at least threshold
Currently, we upgrade to a full tlb flush only If a tlb flush request
size is greater than the threshold. This is done as sfence in RISC-V
can only flush 4KB at a time. Doing a large number of flushes page by
page impacts the performance. It is better to do a full tlbflush if the
request size is at least equal to the threshold size.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-08-31 13:15:21 +05:30
Atish PatraandAnup Patel 6bd1512024 lib: Support atomic swap instructions
If compiler supports riscv atomic instructions, we should
use them instead of legacy gcc built-in macros
__sync_lock_test_and_set in atomic exchange functions.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-08-31 13:13:47 +05:30
Atish PatraandAnup Patel 2e5cc9051b lib: Fix timer for 32 bit
To read 64bit time in 32 bit we have to read lower & upper half
separately and 'or' them together. However, upper half time may
have changed by the time we read lower half. Thus, the resultant
64 bit time may not be accurate.

Consider lower half time value only if upper half time value has
not changed.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-08-31 13:13:12 +05:30
Atish PatraandAnup Patel 75229705a0 platform: Remove the ipi_sync method from all platforms.
OpenSBI manages outstanding TLB flush requests by queueing
them in a fifo synchronously. An ipi sync which uses an
atomic operation on MMIO address is no longer required.

Remove the ipi sync method from platform header and all usage.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2019-08-16 08:42:58 +05:30
Atish PatraandAnup Patel 897a97a6af lib: Fix race conditions in tlb fifo access.
Linux kernel expects tlb flush SBI call to be completely synchronous i.e.
the SBI call should only return once corresponding *fence* instruction is
executed.

OpenSBI manages the outstanding TLB flush requests by keeping them in a
per hart based fifo. However, there are few corner cases that may lead to
race conditions while updating the fifo.

Currently, the caller hart waits for IPI acknowledgement via clint
address which is not a very good method as synchronization on MMIO may not
be supported in every platform. Moreover, the waiter doesn't have any way of
identifying if the IPI is received for specific tlb flush request or any
other IPI. This may lead to unpredictable behavior in supervisor/user space.

Fix this by waiting on individual fifo entries rather than MMIO address.
Currently, a relaxed loop is being used because wfi again involves MMIO write
which would be slower compared to relaxed loop. To avoid deadlock, fifo
is processed every time a hart loops for fifo enqueue or fifo sync to consume
the tlb flush requests sent by other harts.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2019-08-16 08:42:55 +05:30
Atish PatraandAnup Patel f6e13e0dd3 lib: Provide an atomic exchange function unsigned long
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2019-08-16 08:42:52 +05:30
Atish PatraandAnup Patel 42c938e3f0 platform: Remove the HiFive Unleashed expansion board DT.
The Linux kernel will maintain the device tree (DT) for HiFive Unleashed
from release v5.2-rc6. This DT is incompatible with previous DT
present for Microsemi expansion board in OpenSBI.

Since, OpenSBI will directly load the pre-built DTB from kernel now onwards,
no need to keep the out-of-date DT in openSBI. Remove this DT and
it's related documentation.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
2019-07-02 10:16:00 +05:30
Atish PatraandAnup Patel d44bc16e4b docs: Update the fu540 platform guide for new DT.
With 5.2-rc6 release, Linux kernel hosts the DT for Unleashed board
which is incompatible with the default DT from FSBL.

Update the document to use the DT from kernel.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
2019-06-30 11:56:57 +05:30
Atish PatraandAnup Patel cd2dfdc870 docs: Update docs as per new static library.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
2019-06-19 09:56:24 +05:30
Atish PatraandAnup Patel 5dd93e88fe utils: Remove tinyfdt.c
tinyfdt.c was originally added to provide a minimal implementation of
fdt parsing. However, we have already included libfdt in OpenSBI for
more complicated operations.

Remove tinfdt and replace its functiolity using libfdt.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
2019-06-19 09:55:13 +05:30
Atish PatraandAnup Patel b2d0caf86b platform: Enable all drivers by default.
The drivers and libfdt are built as libsbiutils.a
instead of libplatsbi.a.

libsbiutils.a are not built per platform specific. Thus,
enable all drivers by default.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
2019-06-19 09:49:05 +05:30
Atish PatraandAnup Patel 200ed7c1bd lib: Rename string.x to sbi_string.x
All string functions are part of libsbi. It makes more sense
to rename them to sbi_string.x as the libsbi can be linked
with external libraries that can have similar implementation.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
2019-06-19 09:48:59 +05:30
Atish PatraandAnup Patel 793e5e1184 platform: Move platform common to lib/utils.
Currently, platform/common contains platform/non-platform specific
common minimal drivers and libraries. This is helpful is all platforms
are built within opensbi framework.

Move them to lib/utils so that any external platform code also can
reuse the minimalistic drivers or other common libraries.

This patch doesn't introduce any functional changes.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
2019-06-19 09:48:56 +05:30
Atish PatraandAnup Patel 98aaf8317b lib: Include helper libc functions directly in libsbi.
libsbi needs some of the custom libc functions. It should be directly
included in libsbi instead of platform specific libraries.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
2019-06-19 09:48:54 +05:30
Atish PatraandAnup Patel 749b0b0932 lib: Move sbi core library to lib/sbi
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
2019-06-19 09:48:51 +05:30
Atish PatraandAnup Patel 194dbbe5a1 doc: Update docs as per latest kernel/u-boot status.
All dependant patches are merged in U-Boot and Linux kernel now.
Update the unleashed guide to reflect that and fix the documentation
about tftp loading path as well.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2019-04-15 10:00:04 +05:30
Atish PatraandAnup Patel 999823c597 lib: Optimize TLB flush IPIs
Simulatenous requests for tlbflush IPIs can have overlapping address
ranges.

Ignore if address range is same or within already existing fifo entries.
Update the tlb flush info in fifo directly if the one of the existing
entry lies within the new flush request.
Delete all entries if flush all request is recieved for the vma.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
2019-04-10 15:46:35 +05:30