linux_dsm_epyc7002/arch/powerpc
Oliver O'Halloran a4b4f61db8 powerpc/eeh: Do early EEH init only when required
The pci hotplug helper (pci_hp_add_devices()) calls
eeh_add_device_tree_early() to scan the device-tree for new PCI devices and
do the early EEH probe before the device is scanned. This early probe is a
no-op in a lot of cases because:

a) The early init is only required to satisfy a PAPR requirement that EEH
   be configured before we start doing config accesses. On PowerNV it is
   a no-op.

b) It's a no-op for devices that have already had their eeh_dev
   initialised.

There are four callers of pci_hp_add_devices():

1. arch/powerpc/kernel/eeh_driver.c
	Here the hotplug helper is called when re-scanning pci_devs that
	were removed during an EEH recovery pass. The EEH stat for each
	removed device (the eeh_dev) is retained across a recovery pass
	so the early init is a no-op in this case.

2. drivers/pci/hotplug/pnv_php.c
	This is also a no-op since the PowerNV hotplug driver is, suprisingly,
	PowerNV specific.

3. drivers/pci/hotplug/rpaphp_core.c
4. drivers/pci/hotplug/rpaphp_pci.c
	In these two cases new devices have been hotplugged and FW has
	provided new DT nodes for each. These are the only two cases where
	the EEH we might have new PCI device nodes in the DT so these are
	the only two cases where the early EEH probe needs to be done.

We can move the calls to eeh_add_device_tree_early() to the locations where
it's needed and remove it from the generic path. This is preparation for
making the early EEH probe pseries specific.

Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-3-oohall@gmail.com
2020-03-25 12:09:38 +11:00
..
boot powerpc/Makefile: Mark phony targets as PHONY 2020-03-04 22:44:27 +11:00
configs virtio: fixes, cleanups 2020-02-07 12:26:34 -08:00
crypto crypto: remove CRYPTO_TFM_RES_BAD_KEY_LEN 2020-01-09 11:30:53 +08:00
include powerpc/eeh: Remove eeh_add_device_tree_late() 2020-03-25 12:09:38 +11:00
kernel powerpc/eeh: Do early EEH init only when required 2020-03-25 12:09:38 +11:00
kexec powerpc: Avoid clang warnings around setjmp and longjmp 2019-11-25 21:45:43 +11:00
kvm powerpc/kvm: no need to check return value of debugfs_create functions 2020-03-04 22:44:25 +11:00
lib powerpc/sstep: Fix DS operand in ld encoding to appropriate value 2020-03-25 12:06:46 +11:00
math-emu treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
mm powerpc/32s: reorder Linux PTE bits to better match Hash PTE bits. 2020-03-25 12:09:27 +11:00
net treewide: Use sizeof_field() macro 2019-12-09 10:36:44 -08:00
oprofile powerpc updates for 5.6 2020-02-04 13:06:46 +00:00
perf powerpc/8xx: Use alternative scratch registers in DTLB miss handler 2020-01-27 22:36:16 +11:00
platforms powerpc/eeh: Add sysfs files in late probe 2020-03-25 12:09:38 +11:00
purgatory treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
sysdev powerpc updates for 5.6 2020-02-04 13:06:46 +00:00
tools powerpc: Do not consider weak unresolved symbol relocations as bad 2020-01-31 20:17:22 +11:00
xmon powerpc/xmon: Lower limits on nidump and ndump 2020-03-25 12:07:58 +11:00
Kbuild powerpc/kexec: Move kexec files into a dedicated subdir. 2019-11-21 15:41:34 +11:00
Kconfig powerpc updates for 5.6 2020-02-04 13:06:46 +00:00
Kconfig.debug powerpc/ptdump: Only enable PPC_CHECK_WX with STRICT_KERNEL_RWX 2020-01-23 21:31:13 +11:00
Makefile powerpc/Makefile: Mark phony targets as PHONY 2020-03-04 22:44:27 +11:00
Makefile.postlink powerpc: Do not consider weak unresolved symbol relocations as bad 2020-01-31 20:17:22 +11:00