powerpc/xive: add missing iounmap() in error path in xive_spapr_populate_irq_data()

If remapping 'data->trig_page' fails, the 'data->eoi_mmio' need be unmapped
before returning from xive_spapr_populate_irq_data().

Fixes: eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221017032333.1852406-1-yangyingliang@huawei.com

powerpc/xive: Fix refcount leak in xive_get_max_prio

of_find_node_by_path() returns a node pointer with
refcount incremented, we should use of_node_put() on it when done.
Add missing of_node_put() to avoid refcount leak.

Fixes: eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220605053225.56125-1-linmq006@gmail.com

powerpc/xive/spapr: correct bitmap allocation size

kasan detects access beyond the end of the xibm->bitmap allocation:

BUG: KASAN: slab-out-of-bounds in _find_first_zero_bit+0x40/0x140
Read of size 8 at addr c00000001d1d0118 by task swapper/0/1

CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc2-00001-g90df023b36dd #28
Call Trace:
[c00000001d98f770] [c0000000012baab8] dump_stack_lvl+0xac/0x108 (unreliable)
[c00000001d98f7b0] [c00000000068faac] print_report+0x37c/0x710
[c00000001d98f880] [c0000000006902c0] kasan_report+0x110/0x354
[c00000001d98f950] [c000000000692324] __asan_load8+0xa4/0xe0
[c00000001d98f970] [c0000000011c6ed0] _find_first_zero_bit+0x40/0x140
[c00000001d98f9b0] [c0000000000dbfbc] xive_spapr_get_ipi+0xcc/0x260
[c00000001d98fa70] [c0000000000d6d28] xive_setup_cpu_ipi+0x1e8/0x450
[c00000001d98fb30] [c000000004032a20] pSeries_smp_probe+0x5c/0x118
[c00000001d98fb60] [c000000004018b44] smp_prepare_cpus+0x944/0x9ac
[c00000001d98fc90] [c000000004009f9c] kernel_init_freeable+0x2d4/0x640
[c00000001d98fd90] [c0000000000131e8] kernel_init+0x28/0x1d0
[c00000001d98fe10] [c00000000000cd54] ret_from_kernel_thread+0x5c/0x64

Allocated by task 0:
kasan_save_stack+0x34/0x70
__kasan_kmalloc+0xb4/0xf0
__kmalloc+0x268/0x540
xive_spapr_init+0x4d0/0x77c
pseries_init_irq+0x40/0x27c
init_IRQ+0x44/0x84
start_kernel+0x2a4/0x538
start_here_common+0x1c/0x20

The buggy address belongs to the object at c00000001d1d0118
which belongs to the cache kmalloc-8 of size 8
The buggy address is located 0 bytes inside of
8-byte region [c00000001d1d0118, c00000001d1d0120)

The buggy address belongs to the physical page:
page:c00c000000074740 refcount:1 mapcount:0 mapping:0000000000000000 index:0xc00000001d1d0558 pfn:0x1d1d
flags: 0x7ffff000000200(slab|node=0|zone=0|lastcpupid=0x7ffff)
raw: 007ffff000000200 c00000001d0003c8 c00000001d0003c8 c00000001d010480
raw: c00000001d1d0558 0000000001e1000a 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
c00000001d1d0000: fc 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
c00000001d1d0080: fc fc 00 fc fc fc fc fc fc fc fc fc fc fc fc fc
>c00000001d1d0100: fc fc fc 02 fc fc fc fc fc fc fc fc fc fc fc fc
^
c00000001d1d0180: fc fc fc fc 04 fc fc fc fc fc fc fc fc fc fc fc
c00000001d1d0200: fc fc fc fc fc 04 fc fc fc fc fc fc fc fc fc fc

This happens because the allocation uses the wrong unit (bits) when it
should pass (BITS_TO_LONGS(count) * sizeof(long)) or equivalent. With small
numbers of bits, the allocated object can be smaller than sizeof(long),
which results in invalid accesses.

Use bitmap_zalloc() to allocate and initialize the irq bitmap, paired with
bitmap_free() for consistency.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220623182509.3985625-1-nathanl@linux.ibm.com

powerpc/xive: Fix refcount leak in xive_spapr_init

of_find_compatible_node() returns a node pointer with refcount
incremented, we should use of_node_put() on it when done.
Add missing of_node_put() to avoid refcount leak.

Fixes: eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220512090535.33397-1-linmq006@gmail.com

powerpc: Add missing headers

Don't inherit headers "by chances" from asm/prom.h, asm/mpc52xx.h,
asm/pci.h etc...

Include the needed headers, and remove asm/prom.h when it was
needed exclusively for pulling necessary headers.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/be8bdc934d152a7d8ee8d1a840d5596e2f7d85e0.1646767214.git.christophe.leroy@csgroup.eu

powerpc/xive: Add some error handling code to 'xive_spapr_init()'

'xive_irq_bitmap_add()' can return -ENOMEM.
In this case, we should free the memory already allocated and return
'false' to the caller.

Also add an error path which undoes the 'tima = ioremap(...)'

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/564998101804886b151235c8a9f93020923bfd2c.1643718324.git.christophe.jaillet@wanadoo.fr

powerpc/xive: Add missing null check after calling kmalloc

Commit 930914b7d528fc ("powerpc/xive: Add a debugfs file to dump
internal XIVE state") forgot to add a null check.

Add it.

Fixes: 930914b7d528fc6b0249bffc00564100bcf6ef75 ("powerpc/xive: Add a debugfs file to dump internal XIVE state")
Signed-off-by: Ammar Faizi <ammarfaizi2@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211226135314.251221-1-ammar.faizi@intel.com

powerpc/sysdev: Add __init attribute to eligible functions

Some files functions in 'arch/powerpc/sysdev' are deserving of an `__init`
macro attribute. These functions are only called by other initialization
functions and therefore should inherit the attribute.
Also, change function declarations in header files to include `__init`.

Signed-off-by: Nick Child <nick.child@ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211216220035.605465-6-nick.child@ibm.com

powerpc/xive: Replace pr_devel() by pr_debug() to ease debug

These routines are not on hot code paths and pr_debug() is easier to
activate. Also add a '0x' prefix to hex printed values (HW IRQ number).

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211105102636.1016378-2-clg@kaod.org

powerpc/xive: use true and false for bool variable

fixed the following coccicheck:
./arch/powerpc/sysdev/xive/spapr.c:552:8-9: WARNING: return of 0/1 in
function 'xive_spapr_match' with return type bool

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1615793096-83758-1-git-send-email-yang.lee@linux.alibaba.com

powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_EOI_FW

This flag was used to support the P9 DD1 and we have stopped
supporting this CPU when DD2 came out. See skiboot commit:

https://github.com/open-power/skiboot/commit/0b0d15e3c170

Also, remove eoi handler which is now unused.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201210171450.1933725-11-clg@kaod.org

powerpc/xive: Add a name to the IRQ domain

We hope one day to handle multiple irq_domain in the XIVE driver.
Start simple by setting the name using the DT node.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201210171450.1933725-6-clg@kaod.org

powerpc: fix function annotations to avoid section mismatch warnings with gcc-10

Certain warnings are emitted for powerpc code when building with a gcc-10
toolset:

WARNING: modpost: vmlinux.o(.text.unlikely+0x377c): Section mismatch in
reference from the function remove_pmd_table() to the function
.meminit.text:split_kernel_mapping()
The function remove_pmd_table() references
the function __meminit split_kernel_mapping().
This is often because remove_pmd_table lacks a __meminit
annotation or the annotation of split_kernel_mapping is wrong.

Add the appropriate __init and __meminit annotations to make modpost not
complain. In all the cases there are just a single callsite from another
__init or __meminit function:

__meminit remove_pagetable() -> remove_pud_table() -> remove_pmd_table()
__init prom_init() -> setup_secure_guest()
__init xive_spapr_init() -> xive_spapr_disabled()

Signed-off-by: Vladis Dronov <vdronov@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200729133741.62789-1-vdronov@redhat.com

powerpc/xive: Share the event-queue page with the Hypervisor.

XIVE interrupt controller uses an Event Queue (EQ) to enqueue event
notifications when an exception occurs. The EQ is a single memory page
provided by the O/S defining a circular buffer, one per server and
priority couple.

On baremetal, the EQ page is configured with an OPAL call. On pseries,
an extra hop is necessary and the guest OS uses the hcall
H_INT_SET_QUEUE_CONFIG to configure the XIVE interrupt controller.

The XIVE controller being Hypervisor privileged, it will not be allowed
to enqueue event notifications for a Secure VM unless the EQ pages are
shared by the Secure VM.

Hypervisor/Ultravisor still requires support for the TIMA and ESB page
fault handlers. Until this is complete, QEMU can use the emulated XIVE
device for Secure VMs, option "kernel_irqchip=off" on the QEMU pseries
machine.

Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Reviewed-by: Cedric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200426020518.GC5853@oc0525413822.ibm.com

powerpc/xive: Add a debugfs file to dump internal XIVE state

As does XMON, the debugfs file /sys/kernel/debug/powerpc/xive exposes
the XIVE internal state of the machine CPUs and interrupts. Available
on the PowerNV and sPAPR platforms.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
[mpe: Make the debugfs file 0400]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306150143.5551-5-clg@kaod.org

powerpc/xive: Use XIVE_BAD_IRQ instead of zero to catch non configured IPIs

When a CPU is brought up, an IPI number is allocated and recorded
under the XIVE CPU structure. Invalid IPI numbers are tracked with
interrupt number 0x0.

On the PowerNV platform, the interrupt number space starts at 0x10 and
this works fine. However, on the sPAPR platform, it is possible to
allocate the interrupt number 0x0 and this raises an issue when CPU 0
is unplugged. The XIVE spapr driver tracks allocated interrupt numbers
in a bitmask and it is not correctly updated when interrupt number 0x0
is freed. It stays allocated and it is then impossible to reallocate.

Fix by using the XIVE_BAD_IRQ value instead of zero on both platforms.

Reported-by: David Gibson <david@gibson.dropbear.id.au>
Fixes: eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Tested-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306150143.5551-2-clg@kaod.org

powerpc/xive: Skip ioremap() of ESB pages for LSI interrupts

The PCI INTx interrupts and other LSI interrupts are handled differently
under a sPAPR platform. When the interrupt source characteristics are
queried, the hypervisor returns an H_INT_ESB flag to inform the OS
that it should be using the H_INT_ESB hcall for interrupt management
and not loads and stores on the interrupt ESB pages.

A default -1 value is returned for the addresses of the ESB pages. The
driver ignores this condition today and performs a bogus IO mapping.
Recent changes and the DEBUG_VM configuration option make the bug
visible with :

kernel BUG at arch/powerpc/include/asm/book3s/64/pgtable.h:612!
Oops: Exception in kernel mode, sig: 5 [#1]
LE PAGE_SIZE=64K MMU=Radix MMU=Hash SMP NR_CPUS=1024 NUMA pSeries
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.4.0-0.rc6.git0.1.fc32.ppc64le #1
NIP: c000000000f63294 LR: c000000000f62e44 CTR: 0000000000000000
REGS: c0000000fa45f0d0 TRAP: 0700 Not tainted (5.4.0-0.rc6.git0.1.fc32.ppc64le)
...
NIP ioremap_page_range+0x4c4/0x6e0
LR ioremap_page_range+0x74/0x6e0
Call Trace:
ioremap_page_range+0x74/0x6e0 (unreliable)
do_ioremap+0x8c/0x120
__ioremap_caller+0x128/0x140
ioremap+0x30/0x50
xive_spapr_populate_irq_data+0x170/0x260
xive_irq_domain_map+0x8c/0x170
irq_domain_associate+0xb4/0x2d0
irq_create_mapping+0x1e0/0x3b0
irq_create_fwspec_mapping+0x27c/0x3e0
irq_create_of_mapping+0x98/0xb0
of_irq_parse_and_map_pci+0x168/0x230
pcibios_setup_device+0x88/0x250
pcibios_setup_bus_devices+0x54/0x100
__of_scan_bus+0x160/0x310
pcibios_scan_phb+0x330/0x390
pcibios_init+0x8c/0x128
do_one_initcall+0x60/0x2c0
kernel_init_freeable+0x290/0x378
kernel_init+0x2c/0x148
ret_from_kernel_thread+0x5c/0x80

Fixes: bed81ee181dd ("powerpc/xive: introduce H_INT_ESB hcall")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191203163642.2428-1-clg@kaod.org

powerpc/xive: Fix dump of XIVE interrupt under pseries

The xmon 'dxi' command calls OPAL to query the XIVE configuration of a
interrupt. This can only be done on baremetal (PowerNV) and it will
crash a pseries machine.

Introduce a new XIVE get_irq_config() operation which implements a
different query depending on the platform, PowerNV or pseries, and
modify xmon to use a top level wrapper.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190814154754.23682-3-clg@kaod.org

powerpc/xive: Add a check for memory allocation failure

The result of this kzalloc is not checked. Add a check and corresponding
error handling code.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/cc53462734dfeaf15b6bad0e626b483de18656b4.1564647619.git.christophe.jaillet@wanadoo.fr

powerpc/xive: Use GFP_KERNEL instead of GFP_ATOMIC in 'xive_irq_bitmap_add()'

There is no need to use GFP_ATOMIC here. GFP_KERNEL should be enough.
GFP_KERNEL is also already used for another allocation just a few lines
below.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/85d5d247ce753befd6aa63c473f7823de6520ccd.1564647619.git.christophe.jaillet@wanadoo.fr

powerpc/pseries: Fix xive=off command line

On POWER9, if the hypervisor supports XIVE exploitation mode, the
guest OS will unconditionally requests for the XIVE interrupt mode
even if XIVE was deactivated with the kernel command line xive=off.
Later on, when the spapr XIVE init code handles xive=off, it disables
XIVE and tries to fall back on the legacy mode XICS.

This discrepency causes a kernel panic because the hypervisor is
configured to provide the XIVE interrupt mode to the guest :

kernel BUG at arch/powerpc/sysdev/xics/xics-common.c:135!
...
NIP xics_smp_probe+0x38/0x98
LR xics_smp_probe+0x2c/0x98
Call Trace:
xics_smp_probe+0x2c/0x98 (unreliable)
pSeries_smp_probe+0x40/0xa0
smp_prepare_cpus+0x62c/0x6ec
kernel_init_freeable+0x148/0x448
kernel_init+0x2c/0x148
ret_from_kernel_thread+0x5c/0x68

Look for xive=off during prom_init and don't ask for XIVE in this
case. One exception though: if the host only supports XIVE, we still
want to boot so we ignore xive=off.

Similarly, have the spapr XIVE init code to looking at the interrupt
mode negotiated during CAS, and ignore xive=off if the hypervisor only
supports XIVE.

Fixes: eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller")
Cc: stable@vger.kernel.org # v4.20
Reported-by: Pavithra R. Prakash <pavrampu@in.ibm.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

powerpc/xive: prepare all hcalls to support long busy delays

This is not the case for the moment, but future releases of pHyp might
need to introduce some synchronisation routines under the hood which
would make the XIVE hcalls longer to complete.

As this was done for H_INT_RESET, let's wrap the other hcalls in a
loop catching the H_LONG_BUSY_* codes.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/xive: fix hcall H_INT_RESET to support long busy delays

The hcall H_INT_RESET can take some time to complete and in such cases
it returns H_LONG_BUSY_* codes requiring the machine to sleep for a
while before retrying.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/xive: Use hw CPU ids when configuring the CPU queues

The CPU event notification queues on sPAPR should be configured using
a hardware CPU identifier.

The problem did not show up on the Power Hypervisor because pHyp
supports 8 threads per core which keeps CPU number contiguous. This is
not the case on all sPAPR virtual machines, some use SMT=1.

Also improve error logging by adding the CPU number.

Fixes: eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/xive: Fix IPI reset

When resetting an IPI, hw_ipi should also be set to zero.

Fixes: eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/xive: Fix section __init warning

xive_spapr_init() is called from a __init routine and calls __init
routines.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/xive: introduce H_INT_ESB hcall

The H_INT_ESB hcall() is used to issue a load or store to the ESB page
instead of using the MMIO pages. This can be used as a workaround on
some HW issues. The OS knows that this hcall should be used on an
interrupt source when the ESB hcall flag is set to 1 in the hcall
H_INT_GET_SOURCE_INFO.

To maintain the frontier between the xive frontend and backend, we
introduce a new xive operation 'esb_rw' to be used in the routines
doing memory accesses on the ESBs.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/xive: add the HW IRQ number under xive_irq_data

It will be required later by the H_INT_ESB hcall.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/xive: guest exploitation of the XIVE interrupt controller

This is the framework for using XIVE in a PowerVM guest. The support
is very similar to the native one in a much simpler form.

Each source is associated with an Event State Buffer (ESB). This is a
two bit state machine which is used to trigger events. The bits are
named "P" (pending) and "Q" (queued) and can be controlled by MMIO.
The Guest OS registers event (or notifications) queues on which the HW
will post event data for a target to notify.

Instead of OPAL calls, a set of Hypervisors call are used to configure
the interrupt sources and the event/notification queues of the guest:

- H_INT_GET_SOURCE_INFO

used to obtain the address of the MMIO page of the Event State
Buffer (PQ bits) entry associated with the source.

- H_INT_SET_SOURCE_CONFIG

assigns a source to a "target".

- H_INT_GET_SOURCE_CONFIG

determines to which "target" and "priority" is assigned to a source

- H_INT_GET_QUEUE_INFO

returns the address of the notification management page associated
with the specified "target" and "priority".

- H_INT_SET_QUEUE_CONFIG

sets or resets the event queue for a given "target" and "priority".
It is also used to set the notification config associated with the
queue, only unconditional notification for the moment. Reset is
performed with a queue size of 0 and queueing is disabled in that
case.

- H_INT_GET_QUEUE_CONFIG

returns the queue settings for a given "target" and "priority".

- H_INT_RESET

resets all of the partition's interrupt exploitation structures to
their initial state, losing all configuration set via the hcalls
H_INT_SET_SOURCE_CONFIG and H_INT_SET_QUEUE_CONFIG.

- H_INT_SYNC

issue a synchronisation on a source to make sure sure all
notifications have reached their queue.

As for XICS, the XIVE interface for the guest is described in the
device tree under the "interrupt-controller" node. A couple of new
properties are specific to XIVE :

- "reg"

contains the base address and size of the thread interrupt
managnement areas (TIMA), also called rings, for the User level and
for the Guest OS level. Only the Guest OS level is taken into
account today.

- "ibm,xive-eq-sizes"

the size of the event queues. One cell per size supported, contains
log2 of size, in ascending order.

- "ibm,xive-lisn-ranges"

the interrupt numbers ranges assigned to the guest. These are
allocated using a simple bitmap.

and also :

- "/ibm,plat-res-int-priorities"

contains a list of priorities that the hypervisor has reserved for
its own use.

Tested with a QEMU XIVE model for pseries and with the Power hypervisor.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>