Currently, we have fixed TLB flush types supported by the
remote TLB library. This approach is not flexible and does
not allow custom local TLB flush function. For example,
after updating PMP entries on a set of HARTs at runtime,
we have to flush TLB on these HARTs as well.
To support custom local TLB flush function, we replace the
"type" field of "struct sbi_tlb_info" with a local TLB flush
function pointer. We also provide definitions of standard TLB
flush operations (such as fence_i, sfence.vma, hfence.vvma,
hfence.gvma, etc).
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
The HFENCE VVMA instructions flushes TLB based on the VMID
present in HGATP CSR. To handle this, we get the current
VMID for SBI HFENCE VVMA call and we use this current VMID
to do remote TLB HFENCE VVMA on desired set of HARTs.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
The sbi_ipi_send_many() should get current HART scratch pointer
on it's own using eventually hence removing scratch parameter from
sbi_tlb_request().
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Instead of using single ulong as source mask for sbi_tlb_info,
we use sbi_hartmask. This way sbi_tlb_info can easily scale
for large number of HARTs.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
We introduce SBI_TLB_INFO_INIT() helper macro to help easy
initialization of struct sbi_tlb_info which is passed to the
sbi_tlb_request() API.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
This patch drops _fifo from the name of various sbi_tlb_fifo_xyz()
functions because all these functions deal with remote TLB managment
and FIFO is the per-HART data structure used internally by remote
TLB implementation.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
This patch introduces sbi_ipi_event_create/destroy() APIs and
struct sbi_ipi_event_ops for creating/destroying IPI events
at runtime based of event operations.
This new APIs will help platform code and utils code to create
custom IPI events which are not part of generic OpenSBI library.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Instead of directly calling sbi_ipi_send_many(), we introduce
sbi_tlb_fifo_request() for halting a set of HARTs.
This way in future we can assign any IPI event number for remote
FENCE within sbi_tlb.c only.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
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>
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>
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>
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>
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>
