This patch adds shadow mapping to the MMU module. The shadow mapping
allows traversing the page table in host memory rather reading each PTE
from the device memory.
It brings better performance and avoids reading from invalid device
address upon PCI errors.
Only at the end of map/unmap flow, writings to the device are performed in
order to sync the H/W page tables with the shadow ones.
Signed-off-by: Omer Shpigelman <oshpigelman@habana.ai>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
This patch provides a workaround for a H/W bug in Goya, where access to
RAZWI from TPC can cause PCI completion timeout.
The WA is to use the device MMU to map any unmapped DRAM memory to a
default page in the DRAM. That way, the TPC will never reach RAZWI upon
accessing a bad address in the DRAM.
When a DRAM page is mapped by the user, its default mapping is
overwritten. Once that page is unmapped, the MMU driver will map that page
to the default page.
To help debugging, the driver will set the default page area to 0x99 on
device initialization.
Signed-off-by: Omer Shpigelman <oshpigelman@habana.ai>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds the Virtual Memory and MMU modules.
Goya has an internal MMU which provides process isolation on the internal
DDR. The internal MMU also performs translations for transactions that go
from Goya to the Host.
The driver is responsible for allocating and freeing memory on the DDR
upon user request. It also provides an interface to map and unmap DDR and
Host memory to the device address space.
The MMU in Goya supports 3-level and 4-level page tables. With 3-level, the
size of each page is 2MB, while with 4-level the size of each page is 4KB.
In the DDR, the physical pages are always 2MB.
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Omer Shpigelman <oshpigelman@habana.ai>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
