[PATCH V4 0/5] ocxl: Mmio invalidation support

Christophe Lombard clombard at linux.vnet.ibm.com
Thu Nov 26 02:50:08 AEDT 2020


OpenCAPI 4.0/5.0 with TLBI/SLBI Snooping, is not used due to performance
problems caused by the PAU having to process all incoming TLBI/SLBI
commands which will cause them to back up on the PowerBus.

When the Address Translation Mode requires TLB operations to be initiated
using MMIO registers, a set of registers like the following is used:
• XTS MMIO ATSD0 LPARID register
• XTS MMIO ATSD0 AVA register
• XTS MMIO ATSD0 launch register, write access initiates a shoot down
• XTS MMIO ATSD0 status register

The MMIO based mechanism also blocks the NPU/PAU from snooping TLBIE
commands from the PowerBus.

The Shootdown commands (ATSD) will be generated using MMIO registers
in the NPU/PAU and sent to the device.

Signed-off-by: Christophe Lombard <clombard at linux.vnet.ibm.com>

---
Changelog[v4]
 - Rebase to latest upstream.
 - Correct a typo in page size

Changelog[v3]
 - Rebase to latest upstream.
 - Add page_size argument in pnv_ocxl_tlb_invalidate()
 - Remove double pointer
 
Changelog[v2]
 - Rebase to latest upstream.
 - Create a set of smaller patches
 - Move the device tree parsing and ioremap() for the shootdown page in a
   platform-specific file (powernv)
 - Release the shootdown page in release_xsl()
 - Initialize atsd_lock
 - Move the code to initiate the TLB Invalidate command in a
   platform-specific file (powernv)
 - Use the notifier invalidate_range
---

Christophe Lombard (5):
  ocxl: Assign a register set to a Logical Partition
  ocxl: Initiate a TLB invalidate command
  ocxl: Update the Process Element Entry
  ocxl: Add mmu notifier
  ocxl: Add new kernel traces

 arch/powerpc/include/asm/pnv-ocxl.h   |  54 ++++++++++++
 arch/powerpc/platforms/powernv/ocxl.c | 114 ++++++++++++++++++++++++++
 drivers/misc/ocxl/context.c           |   4 +-
 drivers/misc/ocxl/link.c              |  70 +++++++++++++++-
 drivers/misc/ocxl/ocxl_internal.h     |   9 +-
 drivers/misc/ocxl/trace.h             |  64 +++++++++++++++
 drivers/scsi/cxlflash/ocxl_hw.c       |   6 +-
 include/misc/ocxl.h                   |   2 +-
 8 files changed, 314 insertions(+), 9 deletions(-)

-- 
2.28.0



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