[Xen-devel] [PATCH v3 0/6] ARM: add PSCI host support

[Andre Przywara <andre.przywara@xxxxxxxxxx>]

This is a smaller bug fix release of the major rework of last
week's ARM PSCI host support.
-----------

Xen did not make use of the host provided ARM PSCI (Power State
Coordination Interface [1]) functionality so far, but relied on
platform specific SMP bringup functions.
This series adds support for PSCI on the host by reading the required
information from the DTB and invoking the appropriate handler when
bringing up each single CPU.
Since PSCI is defined for both ARM32 and ARM64, I added code for both
architectures, though only ARM32 is tested on Midway and VExpress
(without any PSCI support on the latter, just a regression test).
ARM64 code was compile tested only.

The ARM32 SMP boot flow is now as following:
The DTB is scanned for a node announcing PSCI support. If that is
available, call the PSCI handler via SMC to bringup the secondary
cores. If no PSCI has been found, call the platform specific cpu_up()
function. It is now the responsibility of those functions to do the
GIC SGI call to kick the secondary CPUs. For that a function is now
provided which does this, so three platforms now reference this
generic function instead of coding up an empty one and relying on the
GIC kick in Xen code later.

The ARM64 SMP boot flow is different: PSCI is not only described in a
root DTB node, but also advertised in each core's node as the
preferred SMP bringup method. So the PSCI call wrapper function is
registered as the cpu_up function when the DTB is scanned.

This patch series is split up as follows:
1/6) rename psci.c to vpsci.c to make room for the new, host-related
     code
2/6) move the GIC SGI kick into a separate function and call it now
     directly from the platform code, removing the empty cpu_up()
3/6) parse the DTB for a PSCI node and store the needed function index
4/6) add a function to actually invoke the firmware's PSCI handler
5/6) enable PSCI on ARM32 by adding the call to the PSCI handler
6/6) enable PSCI on ARM64 by registering the PSCI handler function


Changes from v2:
- change type of psci_available from int to bool_t
- const-ify device tree node pointer in psci_init()
- use 64-bit arguments in ARM64 smc call
- move setting of psci_available and printk into psci_init() itself
- hard-code SMP start address into call_psci_cpu_on

Changes from v1:
- much rework, PSCI host DTB scanning unchanged (v1: 1/4, v2: 3/6)
- moved host PSCI code to psci.c, renaming the old one to vpsci.c
- have a separate psci_available variable
- removing explicit "host" from function names
- returning standard error codes on DTB scanning
- do the ARM64 PSCI call from a registered function pointer
- move the GIC kick into a separate function
- more change to the code flow in general


Signed-off-by: Andre Przywara <andre.przywara@xxxxxxxxxx>

[1]: 
http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0022b/index.html

Andre Przywara (6):
  arm: rename xen/arch/arm/psci.c into vpsci.c
  arm: move GIC SGI kicking into separate function
  arm: parse PSCI node from the host device-tree
  arm: add a function to invoke the PSCI handler
  arm32: enable PSCI secondary CPU bringup
  arm64: enable PSCI secondary CPU bringup

 xen/arch/arm/Makefile             |   1 +
 xen/arch/arm/arm32/smpboot.c      |   4 +-
 xen/arch/arm/arm64/smpboot.c      |  18 ++++-
 xen/arch/arm/platform.c           |   6 +-
 xen/arch/arm/platforms/exynos5.c  |  11 +--
 xen/arch/arm/platforms/omap5.c    |  11 +--
 xen/arch/arm/platforms/vexpress.c |  10 +--
 xen/arch/arm/psci.c               | 141 ++++++++++++++++++++------------------
 xen/arch/arm/smpboot.c            |  19 +++--
 xen/arch/arm/vpsci.c              |  93 +++++++++++++++++++++++++
 xen/include/asm-arm/psci.h        |   7 ++
 xen/include/asm-arm/smp.h         |   2 +
 12 files changed, 217 insertions(+), 106 deletions(-)
 create mode 100644 xen/arch/arm/vpsci.c

-- 
1.7.12.1


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