[PATCH v17 00/10] LPC: legacy ISA I/O support

From: John Garry
Date: Wed Mar 14 2018 - 14:19:02 EST

This patchset supports the IPMI-bt device attached to the Low-Pin-Count
interface implemented on Hisilicon Hip06/Hip07 SoC.
-----------
| LPC host|
| |
-----------
|
_____________V_______________LPC
| |
V V
------------
| BT(ipmi)|
------------

When master accesses those peripherals beneath the Hip06/Hip07 LPC, a specific
LPC driver is needed to make LPC host generate the standard LPC I/O cycles with
the target peripherals'I/O port addresses. But on curent arm64 world, there is
no real I/O accesses. All the I/O operations through in/out accessors are based
on MMIO ranges; on Hip06/Hip07 LPC the I/O accesses are performed through driver
specific accessors rather than MMIO.
To solve this issue and keep the relevant existing peripherals' drivers untouched,
this patchset:
- introduces a generic I/O space management framework, logical PIO, to support
I/O operations on host controllers operating either on MMIO buses or on buses
requiring specific driver I/O accessors;
- redefines the in/out accessors to provide a unified interface for both MMIO
and driver specific I/O operations. Using logical PIO, th call of in/out() from
the host children drivers, such as ipmi-si, will be redirected to the
corresponding device-specific I/O hooks to perform the I/O accesses.

Based on this patch-set, all the I/O accesses to Hip06/Hip07 LPC peripherals can
be supported without any changes on the existing ipmi-si driver.

The whole patchset has been tested on Hip07 D05 board both using DTB and ACPI.

Differences to v16:
- Add patch to rename acpi_is_serial_bus_slave()
Note: Could not rebase on recent linux-next as either build broken or fails
to boot.

Differences to v15:
- addressed further coding style comments in LLDD and logic PIO code
from Andy
- rebased to linux next 20180302

Differences to v14:
- addressed coding style comments from Andy
- applied tags from Rafael, Andy, and Dann
- rebased to linux next 20180223 (had to fix locally arm64 build issue)

Differences to v13:
- dropped ACPI scan handler and added patch to not enumerate children
of indirect IO hosts in ACPI code
- tidied up logic_pio.c a bit for kerneldoc and made some APIs clearer
to understand
- tided (and simplified) hisi_lpc.c and added new ACPI probe code
(same as previous ACPI scan handler code, so comments from Rafael
and Andy included)
- reinstated PCI range upper limit check in pci_pio_to_address()
- dropped Dann Frazier's "tested-by" tag in light of changes
- rebase to linuxnext 20180219 (had to fix locally arm64 build issue)

Differences to v12:
- Addressed ACPI comments from Rafael and Andy, including:
- added SPDX license identifiers (other new files in the series got this also)
- fixed style issues, like superflous newlines and symbol naming
- add fuller acpi_indirectio.c patch commit message
- dropped acpi_indirectio_host_data (author's decision) to simplify
- added Rob Herring's tag
- rebase to linux-next 20180212

Differences to v11:
- fixed build errors for i386, m68k, and tile
- added a comment in LPC driver commit log why we set
the kernel config as bool
- some tidying logic_pio code

Differences to v10:
- dropped CONFIG_LOGIC_PIO. Reason is that CONFIG_PCI
depends on this, and CONFIG_PCI is a per-arch CONFIG.
So we would require all arch's kconfig to select this.
- Addressed Dann Frazier's comments on LPC driver, and
sopme other cleanup
- Moved logic_pio.h to be included in generic asm io.h
- Fixed ACPI indirect IO host setup to handle >1 child
- Relocated ACPI indirect IO host setup code to
drivers/acpi
- Rebased to linux next-20180118

Changes from v9:
- patch 2 has been split into 3 patches according to Bjorn comments on
v9 thread
- patch 1 has been reworked accordign to Bjorn comments on v9
- now logic_pio_trans_hwaddr() has a sanity check to make sure the resource
size fits into the assigned range
- in patch 5 the MFD framework has been used to probe the LPC children
according to the suggestion from Mika Westerberg
- Maintaner has changed to Huawei Linuxarm mailing list

Changes from v8:
- Simplified LIB IO framewrok
- Moved INDIRECT PIO ACPI framework under acpi/arm64
- Renamed occurrences of "lib io" and "indirect io" to "lib pio" and
"indirect pio" to keep the patchset nomenclature consistent
- Removed Alignment reuqirements
- Moved LPC specific code out of ACPI common framework
- Now PIO indirect HW ranges can overlap
- Changed HiSilicon LPC driver maintainer (Gabriele Paoloni now) and split
maintaner file modifications in a separate commit
- Removed the commit with the DT nodes support for hip06 and hip07 (to be
pushed separately)
- Added a checking on ioport_map() not to break that function as Arnd points
out in V7 review thread;
- fixed the compile issues on alpha, m68k;

Changes from V7:
- Based on Arnd's comment, rename the LIBIO as LOGIC_PIO;
- Improved the mapping process in LOGIC_PIO to gain better efficiency when
redirecting the I/O accesses to right device driver;
- To reduce the impact on PCI MMIO to a minimum, add a new
CONFIG_INDIRECT_PIO for indirect-IO hosts/devices;
- Added a new ACPI handler for indirect-IO hosts/devices;
- Fixed the compile issues on V6;

Changes from V6:
- According to the comments from Bjorn and Alex, merge PCI IO and indirect-IO
into a generic I/O space management, LIBIO;
- Adopted the '_DEP' to replace the platform bus notifier. In this way, we can
ensure the LPC peripherals' I/O resources had been translated to logical IO
before the LPC peripheral enumeration;
- Replaced the rwlock with rcu list based on Alex's suggestion;
- Applied relaxed write/read to LPC driver;
- Some bugs fixing and some optimazations based on the comments of V6;

Changes from V5:
- Made the extio driver more generic and locate in lib/;
- Supported multiple indirect-IO bus instances;
- Extended the pci_register_io_range() to support indirect-IO, then dropped
the I/O reservation used in previous patchset;
- Reimplemented the ACPI LPC support;
- Fixed some bugs, including the compile error on other archs, the module
building failure found by Ming Lei, etc;

Changes from V4:
- Some revises based on the comments from Bjorn, Rob on V4;
- Fixed the compile error on some platforms, such as openrisc;

Changes from V3:
- UART support deferred to a separate patchset; This patchset only support
ipmi device under LPC;
- LPC bus I/O range is fixed to 0 ~ (PCIBIOS_MIN_IO - 1), which is separeted
from PCI/PCIE PIO space;
- Based on Arnd's remarks, removed the ranges property from Hip06 lpc dts and
added a new fixup function, of_isa_indirect_io(), to get the I/O address
directly from LPC dts configurations;
- Support in(w,l)/out(w,l) for Hip06 lpc I/O;
- Decouple the header file dependency on the gerenic io.h by defining in/out
as normal functions in c file;
- removed unused macro definitions in the LPC driver;

Changes from V2:
- Support the PIO retrieval from the linux PIO generated by
pci_address_to_pio. This method replace the 4K PIO reservation in V2;
- Support the flat-tree earlycon;
- Some revises based on Arnd's remarks;
- Make sure the linux PIO range allocated to Hip06 LPC peripherals starts
from non-ZERO;

Changes from V1:
- Support the ACPI LPC device;
- Optimize the dts LPC driver in ISA compatible mode;
- Reserve the IO range below 4K in avoid the possible conflict with PCI host
IO ranges;
- Support the LPC uart and relevant earlycon;

V16 thread here: https://lkml.org/lkml/2018/2/26/584
V15 thread here: https://lkml.org/lkml/2018/2/26/584
V14 thread here: https://lkml.org/lkml/2018/2/19/460
V13 thread here: https://lkml.org/lkml/2018/2/13/744
V12 thread here: https://lkml.org/lkml/2018/1/23/508
V11 thread here: https://lkml.org/lkml/2018/1/21/38
V10 thread here: https://lkml.org/lkml/2017/10/27/465
V9 thread here: https://lkml.org/lkml/2017/5/25/263
V8 thread here: https://lkml.org/lkml/2017/3/30/619
V7 thread here: https://lkml.org/lkml/2017/3/12/279
v6 thread here: https://lkml.org/lkml/2017/1/24/25
v5 thread here: https://lkml.org/lkml/2016/11/7/955
v4 thread here: https://lkml.org/lkml/2016/10/20/149
v3 thread here: https://lkml.org/lkml/2016/9/14/326
v2 thread here: https://lkml.org/lkml/2016/9/7/356
v1 thread here: https://lkml.org/lkml/2015/12/29/154

Gabriele Paoloni (2):
PCI: Remove unused __weak attribute in pci_register_io_range()
PCI: Add fwnode handler as input param of pci_register_io_range()

John Garry (4):
ACPI / scan: rename acpi_is_serial_bus_slave() to widen use
ACPI / scan: do not enumerate Indirect IO host children
HISI LPC: Add ACPI support
MAINTAINERS: Add maintainer for HiSilicon LPC driver

Zhichang Yuan (4):
LIB: Introduce a generic PIO mapping method
PCI: Apply the new generic I/O management on PCI IO hosts
OF: Add missing I/O range exception for indirect-IO devices
HISI LPC: Support the LPC host on Hip06/Hip07 with DT bindings

.../arm/hisilicon/hisilicon-low-pin-count.txt | 33 ++
MAINTAINERS | 7 +
drivers/acpi/pci_root.c | 8 +-
drivers/acpi/scan.c | 33 +-
drivers/bus/Kconfig | 8 +
drivers/bus/Makefile | 2 +
drivers/bus/hisi_lpc.c | 623 +++++++++++++++++++++
drivers/of/address.c | 96 +++-
drivers/pci/pci.c | 95 +---
include/acpi/acpi_bus.h | 2 +-
include/asm-generic/io.h | 4 +-
include/linux/logic_pio.h | 124 ++++
include/linux/pci.h | 3 +-
lib/Kconfig | 15 +
lib/Makefile | 2 +
lib/logic_pio.c | 282 ++++++++++
16 files changed, 1229 insertions(+), 108 deletions(-)
create mode 100644 Documentation/devicetree/bindings/arm/hisilicon/hisilicon-low-pin-count.txt
create mode 100644 drivers/bus/hisi_lpc.c
create mode 100644 include/linux/logic_pio.h
create mode 100644 lib/logic_pio.c

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1.9.1