1206 Commits

Author SHA1 Message Date
Atish Patra
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
Palmer Dabbelt
a2a7763ac7 Include git describe in OpenSBI
OpenSBI includes a version, but that is only updated when tagged.  For
users that are using the git releases we instead end up with an
ambiguous version number, which makes it hard to figure out what
everyone is using.  This patch checks for a git directory and prints out
the result of `git describe`, which is a mix of pretty and unambiguous.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
2019-08-19 10:58:21 +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
Jacob Garber
6c24193293 lib: Correct null pointer check
In order to prevent a possible null pointer dereference, return early if
either one of 'in' or 'data' is null.

Signed-off-by: Jacob Garber <jgarber1@ualberta.ca>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2019-08-12 09:27:47 +05:30
Jacob Garber
5e4021a2f5 lib: Prevent unintended sign extensions
In the last argument to sbi_memset() we essentially have the following
multiplication:

    size_t = u16 * u16

Due to C's integer semantics, both u16's are implicitly converted to int
before the multiplication, which cannot hold all possible values of a
u16 * u16. If the multiplication overflows, the intermediate result will
be a negative number. On 64-bit platforms, this will be sign-extended to
a huge integer in the conversion to a u64 (aka size_t). Being the size
argument to sbi_memset(), this could potentially cause a large
out-of-bounds write. The solution is to manually cast one of the u16 to
a size_t, which will make it large enough to avoid the implicit
conversion and any overflow.

Signed-off-by: Jacob Garber <jgarber1@ualberta.ca>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2019-08-12 09:26:38 +05:30
Jacob Garber
6ddf71e6e9 lib: Use correct type for return value
The error check 'plic_off < 0' does nothing, since plic_off is stored as
a u32. Fix this by changing it to an int, which matches the return type of
fdt_node_offset_by_compatible().

Signed-off-by: Jacob Garber <jgarber1@ualberta.ca>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2019-08-12 09:23:28 +05:30
Jacob Garber
3f738f5897 lib: Use bitwise & instead of boolean &&
!(mipval && MIP_MSIP) simplifies to !mipval, which checks if the entire
variable is zero, not just a single bit. Fix this to use bitwise &
instead.

Signed-off-by: Jacob Garber <jgarber1@ualberta.ca>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2019-08-12 09:22:20 +05:30
Anup Patel
88c87f0af4 lib: Use sbi_dprintf() for invalid CSRs
We should sbi_dprintf() instead of sbi_printf() for invalid CSRs
because we are forwarding invalid CSR access back to S-mode.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2019-08-09 12:38:36 +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
Georg Kotheimer
bf2ee7bcdc utils: Use cpu_to_fdt32() when writing to fdt
Although it does not make a functional difference, both cpu_to_fdt32()
and fdt32_to_cpu() pass on to CPU_TO_FDT32, we should use cpu_to_fdt32()
to be semantically correct.

Signed-off-by: Georg Kotheimer <georg.kotheimer@kernkonzept.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
2019-07-25 08:59:50 +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
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 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
Atish Patra
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
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
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
Nick Kossifidis
804b997ed4 lib: Redirect unhandled traps from non-M modes to S mode
In case we didn't handle a trap with one of the available
handlers, check if the trap comes from S or U mode and
redirect it to S mode's trap handler.

Signed-off-by: Nick Kossifidis <mick@ics.forth.gr>
2019-04-22 09:56:20 +05:30
Atish Patra
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
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
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
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
215c200ccb lib: Group all prints during boot into sbi_boot_prints()
Refactor the codes a little bit to put all prints during boot into
sbi_boot_prints().

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
2019-03-29 15:49:11 +05:30
Atish Patra
6c39ea99ee lib: Return ENOTSUPP incase of invalid SBI function ID
OpenSBI should show error trace only if any valid SBI function
does not perform as expected.

However, OpenSBI should show notify the caller with a negative
error if given SBI function ID is not valid.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
2019-03-14 20:44:22 +05:30
Atish Patra
1e24e21d56 lib: Fix full tlb flush behavior
Currently, global page mappings are not flushed if start and size
arguments are zero.

Flush entire TLB if both size and start argument is passed as zero.

Fixes : 90cb491 (lib: Implement sfence.vma correctly)

Signed-off-by: Atish Patra <atish.patra@wdc.com>
2019-03-14 20:41:13 +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
ce6189f7a5 include: Add PRILX define to help print unsigned long
The unsigned long is always machine word size. This means it is
4 bytes on 32bit system and 8 bytes on 64bit system.

This patch adds PRILX define for sbi_printf() which will help us
print unsigned long without worrying whether it is 32bit or 64bit
system.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
2019-02-20 12:02:40 +05:30
Anup Patel
4e774f5470 lib: Fix mask shift in sbi_ipi_send_many()
The mask shift in for-loop of sbi_ipi_send_many() is
broken with commit 918c1354b7
("lib: Improve delivery of SBI_IPI_EVENT_HALT")

This patch fix it.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
2019-02-18 18:39:02 +05:30
Nick Kossifidis
148423d141 lib: Fix small typo on sbi_ipi.c 2019-02-18 09:21:58 +05:30
Nick Kossifidis
918c1354b7 lib: Improve delivery of SBI_IPI_EVENT_HALT
When sbi_ipi_send_many gets called with the current hartid
included on pmask (or when pmask is NULL), and we send
a HALT event, since the for loop works sequentially over
all hartids on the mask, we may send a HALT event to the
current hart before the loop finishes. So we will halt
the current hart before it can deliver a HALT IPI to the
rest and some harts will remain active.

Make sure we send an IPI to the current hart after we've
finished with everybody else.

Signed-off-by: Nick Kossifidis <mick@ics.forth.gr>
2019-02-18 09:21:58 +05:30