Commit Graph

99 Commits

Author SHA1 Message Date
Anup Patel
7d4420bd69 include: Extend get_insn() to read instruction from VS/VU mode
Current implementation of get_insn() is not suitable for reading
instruction from VS/VU mode because we have to set SSTATUS_MXR bit
in VSSTATUS CSR for reading instruction from VS/VU mode.

This patch extends get_insn() to read instruction from VS/VU mode.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2019-09-30 15:35:43 +05:30
Anup Patel
a14e7ee82c lib: Redirect WFI trapped from VS/VU mode to HS-mode
The WFI will trap as illegal instruction trap when executed
in VS/VU mode so we just forward/redirect it to HS-mode so
that hypervisor can deal with it appropriately.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
2019-09-30 15:32:00 +05:30
Anup Patel
bbeb8e619d lib: Extend sbi_trap_redirect() for hypervisor extension
When hypervisor extension is available, we can get traps from VS/VU
modes. We should be able to force redirect some of these traps to
HS-mode. In other words, we should be able forward traps from VS/VU
mode to HS-mode using sbi_trap_redirect() hence this patch.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2019-09-30 15:29:37 +05:30
Anup Patel
1a5614e971 lib: Extend sbi_hart_switch_mode() to support hypervisor extension
This patch extends sbi_hart_switch_mode() to support entering
VS/VU modes when hypervisor extension is available.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
2019-09-30 15:18:06 +05:30
Atish Patra
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 Patra
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 Patra
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 Patra
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 Patra
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 Patra
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
Anup Patel
a88e424f6c lib: Handle traps when doing unpriv load/store in get_insn()
We can get a page/access trap when doing unpriv load/store in
get_insn() function because on a SMP system Linux swapper running
on HART A can unmap pages from page table used by HART B.

To tackle this we extend get_insn() implementation so that if
we get trap in get_insn() then we redirect it to S-mode as fetch
page/access fault.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
2019-08-13 09:48:40 +05:30
Anup Patel
dbff3e9f12 lib: Introduce sbi_dprintf() API
This patch introduces new sbi_dprintf() API for runtime debug
prints. The sbi_dprintf() will print to console for a given
HART only when SBI_SCRATCH_DEBUG_PRINTS option in enabled in
sbi_scratch for this HART.

We can now add debug prints using sbi_dprintf() at important
places in OpenSBI sources. These debug prints will only show
up when previous booting stage or compile time parameter sets
the SBI_SCRATCH_DEBUG_PRINTS option in scratch space.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2019-08-09 12:38:33 +05:30
Anup Patel
0f18b3fe0a lib: Allow compiling without FP support
Currently, we mandate 'F' and 'D' extension in riscv_fp.h so that
misaligned load/store emulation has access to FP registers.

The above is too restrictive and we should certainly allow compilation
for soft-FP toolchains and explicit PLATFORM_RISCV_ISA not having 'F'
and 'D' extensions.

This patch extends riscv_fp.h and misaligned load/store emulation to
allow compiling OpenSBI without FP support.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2019-07-26 15:49:49 +05:30
Bin Meng
85546a5477 treewide: Use conventional names for 32-bit and 64-bit
There are several places in the source tree that have:

  32bit, 32 bit, 64bit, 64 bit

Fix by using the conventional names with a hyphen.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Acked-by: Anup Patel <anup.patel@wdc.com>
2019-07-25 09:14:58 +05:30
Anup Patel
ce228ee091 include: Bump-up version to 0.4
This patch updates OpenSBI version to 0.4 as part of
release preparation.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
2019-07-02 11:11:08 +05:30
Abner Chang
9c18c2c610 include: Add firmware context to sbi_platform
Add firmware context field struct sbi_platform to carry firmware
specific information.

Signed-off-by: Abner Chang <abner.chang@hpe.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
2019-06-29 20:59:45 +05:30
Abner Chang
08b196956d include: Add version info to struct sbi_platform
Add version control of sbi_platform structure
- Add opensbi_version, this gives information of opensbi revision on
which the sbi_platform table was created.
- Add platform_version field in sbi_platform structure for platform
level version control.

Signed-off-by: Abner Chang <abner.chang@hpe.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
2019-06-29 19:26:26 +05:30
Abner Chang
fa6fd6bf86 include: Move callbacks in sbi_platform to separate struct
Move platform opensbi functions to sbi_platform_operations structure.
Both sbi_platform and sbi_platform_operations structures are maintained
by platform vendors.

Signed-off-by: Abner Chang <abner.chang@hpe.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
2019-06-29 18:20:00 +05:30
Panagiotis Peristerakis
c6d06a9448 Changed plic_set_thresh() and plic_set_ie() to public
Signed-off-by: Panagiotis Peristerakis <perister@ics.forth.gr>
2019-06-29 17:04:06 +05:30
Atish Patra
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 Patra
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 Patra
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 Patra
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
Anup Patel
a6395acd6c lib: Handle page/access fault caused by unpriv load/store
The unpriv load/store instruction from M-mode can cause page/access
fault to M-mode if S-mode page table did not have mappings OR it did
not have PMP access permission.

To tackle this, we redirect trap back to S-mode if unpriv load/store
instruction traps in M-mode.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2019-05-24 08:22:47 +05:30
Anup Patel
bb915780ac lib: Add per-HART trap info pointer
This patch adds per-HART trap info pointer which can be used to
communicate trap information to sbi_trap_handler().

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2019-05-24 08:22:47 +05:30
Anup Patel
a22c6891b7 include: Make unprivilege load/store functions as non-inline functions
Currently, the unprivilege load/store functions are inline functions.

We will be extending these functions to track whether a page/access
fault occurs when we execute unprivilege load/store instruction.

To make things simpler and debugable, we reduce number of places which
can potentially generate a page/access fault by making all unprivilege
load/store functions as regular (non-inline) functions.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2019-05-24 08:22:47 +05:30
Anup Patel
95b7480ab4 lib: Factor-out TLB management from IPI management
This patch factor-out TLB management from IPI management to separate
sources sbi_tlb.c and sbi_tlb.h.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2019-05-24 08:22:47 +05:30
Anup Patel
2dfed32c46 lib: Add a simple brain-dead allocator to manage extra scratch space
We have extra space above scratch space (sbi_scratch) which we are
currently using to manage per-HART IPI data and TLB request management.

In future, more parts of OpenSBI will use the extra scratch space so
it will become difficult to manage extra scratch space using just
defines and macros.

This patch adds a simple brain-dead allocator to manage extra scratch
space. This allocator never expects anything to be free-ed hence it
keeps incrementing to next allocation offset until it runs-out of space.

In future, we can have more sophisticated allocator which will allow
us to re-claim free-ed space and also allows us to track owner of
allocated space.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2019-05-24 08:22:47 +05:30
Anup Patel
4e2cd47820 lib: Flush everything when remote TLB flush range is too large
On latest Linux kernel (i.e. 5.2-rc1), we get large TLB flush
request for user space addresses (typically, start=x and end=-1).
This is caused by Linux kernel commit a21344dfc6 ("riscv: fix
sbi_remote_sfence_vma{,_asid}").

It's not practical to execute large number of sfence instructions
for a large TLB flush range because it takes too much time and
eventually causes CPU stall in Linux kernel.

This patch addresses above issue by upgrading TLB flush range to
TLB flush all whenever TLB flush range is greater than 1GB.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2019-05-21 10:06:08 +05:30
Anup Patel
bae54f7645 firmware: Add fw_dynamic firmware
This patch provides first-cut implementation of fw_dynamic firmware.

As compared to fw_jump and fw_payload, the fw_dynamic obtains next
address, next mode and OpenSBI options from struct fw_dynamic_info.

The previous booting stage can create struct fw_dynamic_info in memory
and pass address of struct fw_dynamic_info in 'a2' register. Also, the
struct fw_dynamic_info has versioning as well so changes to the struct
fw_dynamic_info can be done in a backward compatible manner.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2019-05-10 12:26:22 +05:30
Olof Johansson
10baa64c02 all: run clang-format and update checked-in files
Noisy commit, no functional changes.

Generated with an current upstream clang-format and:

clang-format -i $(find . -name \*.[ch])

Signed-off-by: Olof Johansson <olof@lixom.net>
2019-04-24 09:49:46 +05:30
Olof Johansson
fbf986ac2a all: Annotate some tables to have clang-format leave them alone
One of the shortcomings of clang-format is that it doesn't allow
for aligned define tables, which is used for a number of constants.

Add annotation to disable the automatic formatting where needed.

Signed-off-by: Olof Johansson <olof@lixom.net>
2019-04-24 09:49:46 +05:30
Atish Patra
110eef44f0 lib: Provide a lock enabled iteration of fifo.
Implement a lock enabled iteration for fifo so that
caller can determine if next entry can be skipped or
any existing entries in fifo can be updated before enqueue.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
2019-04-10 15:46:35 +05:30
Alistair Francis
40086daa62 lib: Fix the ecall macro definitions
Fix the ECALL definitions to matc the latest information in the
privlidge spec table 5.5.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2019-04-06 19:06:22 +05:30
Anup Patel
3fbe233a15 lib: Pack struct sbi_fifo
This patch reduces memory consumed by struct sbi_fifo by droping
redundant "head" member and using u16 in-place of "unsigned long".

Signed-off-by: Anup Patel <anup.patel@wdc.com>
2019-04-03 13:48:38 -07:00
Anup Patel
9dc95021db lib: More improvements to sbi_fifo
This patch does following improvements to sbi_fifo:
1. Use valid SBI_Exxxx error codes instead of -1
2. The sbi_fifo_is_full() and sbi_fifo_is_empty() did
   not acquire qlock before accessing head and tail
   hence fixed it
3. Added avail member for ease in debugging and simplifying
   head/tail updates.

Due to above changes size of sbi_fifo changes from 48 bytes
to 56 bytes.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
2019-04-03 13:48:38 -07:00
Atish Patra
f700216cb5 lib: Use a fifo to keep track of sfence related IPIs.
Currently, there is no provision for tracking multiple IPIs sent
to a single hart at the same time by different harts.

Use a fifo manage the outstanding requests. While dequeueing, read all
the entries once, because we have only 1 bit to track the type of IPI.
Once the queue is full, busy wait until the there is space available in
queue. This is not the most elegant approach. It should be changed in
favor of a wakeup event once available in opensbi.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
2019-04-03 09:57:42 +05:30
Atish Patra
1eba298b0d lib: Increase the scratch space to 512 bytes.
Currently scratch space per hart is 256 bytes. Increase it to 512 bytes
to accomodate ipi queue.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
2019-04-03 09:57:42 +05:30
Atish Patra
fd5418d92c lib: Introduce a tlb info type.
Add a tlb info to distinguish between different type of tlb flush
request pending.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
2019-04-03 09:57:42 +05:30
Atish Patra
8334a88c63 lib: Add a fifo implementation.
Implement a fifo to accomodate outstanding IPIs for a specific hart
at the same time.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
2019-04-03 09:57:42 +05:30
Anup Patel
78c87cd13a include: Make mstatus parameter optional for get_insn()
The mstatus parameter of get_insn() is used to return MSTATUS CSR
value which get_insn() saw. Most of the get_insn() callers don't
use the value returned in mstatus so this patch makes mstatus
parameter optional for get_insn().

Signed-off-by: Anup Patel <anup.patel@wdc.com>
2019-04-01 10:10:38 +05:30
Anup Patel
13877c3a67 include: Rename sbi_unpriv.h to riscv_unpriv.h
The sbi_unpriv.h has quite a few load_xyz() and store_xyz() helper
routines based on RISC-V inline assembly for unpriviledged accesses
from M-mode. These helper routines are similar to helper routines
present in riscv_locks.h, riscv_io.h, and riscv_atomic.h so let's
rename sbi_unpriv.h to riscv_unpriv.h.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
2019-04-01 10:10:38 +05:30
Anup Patel
cfff0126ab lib: Remove unused mepc arg from load_xyz() and store_xyz() functions
This patch removes unused mepc arg from load_xyz() and store_xyz()
unpriviledge access functions.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
2019-04-01 10:10:38 +05:30
Bin Meng
f9cfe301c9 lib: Disable the boot prints if SBI_SCRATCH_NO_BOOT_PRINTS is set
Use the newly introduced "options" in "struct sbi_scratch" to
conditionally disable the boot prints.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
2019-03-29 15:49:11 +05:30
Bin Meng
132f3e024b firmware: Introduce "options" in "struct sbi_scratch"
Introduce "options" in "struct sbi_scratch" and firmware can update
it based on optional compile time flags before calling sbi_init().

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
2019-03-29 15:49:11 +05:30
Atish Patra
90cb4917b5 lib: Implement sfence.vma correctly.
Currently, OpenSBI doesn't distinguish between sfence.vma
and sfence.vm asid calls. Moreover, it ignores the page
ranges and just flush entire TLB everytime.

Fix the sfence implementation by keeping all the tlb flush
info in scratch area.

The relevant Linux kernel code was added by
https://patchwork.kernel.org/project/linux-riscv/list/?series=89695

However, this patch is backward compatible with older version kernel
that doesn't have the above patches as well.

Fixes #87
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2019-03-12 22:07:25 +05:30
Alistair Francis
508a27204c lib: Create a sbi_ipi_data structure
Create a sbi_ipi_data structure that holds unpacked IPI information. At
the same time remove ipi_type from the sbi_scratch struct and use a
fixed offset to access it.

This structure fits in behind the sbi_scratch structure.

This fixes https://github.com/riscv/opensbi/issues/81

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
2019-03-10 21:08:21 +05:30
Xiang Wang
9eb8f0f90d platform: Make the platform read-only
platform should be a read-only variable, if it is placed in the data
segment, it may be exploited.

Signed-off-by: Xiang Wang <wxjstz@126.com>
2019-03-06 11:10:35 -08:00
Atish Patra
86cc9b8633 lib:platform: Fix sbi_getc return type.
As per the current SBI specification, sbi_getc should return
an int instead of char.

In case of FIFO is empty, return -1 as per the specification.

Reported-by: Sergi Granell <xerpi.g.12@gmail.com>
Suggested-by:Thadeu Lima de Souza Cascardo <cascardo@cascardo.eti.br>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
2019-03-05 14:05:12 +05:30
Anup Patel
ca20ac0cd4 include: Bump-up version to 0.3
This patch updates OpenSBI version to 0.3 as part of
release preparation.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
2019-02-26 22:24:59 +05:30