[F][PATCH 2/11] powerpc/powernv/ioda: Protect PE list

[frank.heimes at canonical.com]

From: Frederic Barrat <fbarrat at linux.ibm.com>

BugLink: https://bugs.launchpad.net/bugs/1862121

Protect the PHB's list of PE. Probably not needed as long as it was
populated during PHB creation, but it feels right and will become
required once we can add/remove opencapi devices on hotplug.

Reviewed-by: Andrew Donnellan <ajd at linux.ibm.com>
Signed-off-by: Frederic Barrat <fbarrat at linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
Link: https://lore.kernel.org/r/20191121134918.7155-3-fbarrat@linux.ibm.com
(cherry picked from commit 80f1ff83fa113aa718ff4009684981386c574954)
Signed-off-by: Frank Heimes <frank.heimes at canonical.com>
---
 arch/powerpc/platforms/powernv/pci-ioda.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 155333872cb4..fbcc765d444c 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -1087,8 +1087,9 @@ static struct pnv_ioda_pe *pnv_ioda_setup_dev_PE(struct pci_dev *dev)
 	}
 
 	/* Put PE to the list */
+	mutex_lock(&phb->ioda.pe_list_mutex);
 	list_add_tail(&pe->list, &phb->ioda.pe_list);
-
+	mutex_unlock(&phb->ioda.pe_list_mutex);
 	return pe;
 }
 
@@ -3517,7 +3518,10 @@ static void pnv_ioda_release_pe(struct pnv_ioda_pe *pe)
 	struct pnv_phb *phb = pe->phb;
 	struct pnv_ioda_pe *slave, *tmp;
 
+	mutex_lock(&phb->ioda.pe_list_mutex);
 	list_del(&pe->list);
+	mutex_unlock(&phb->ioda.pe_list_mutex);
+
 	switch (phb->type) {
 	case PNV_PHB_IODA1:
 		pnv_pci_ioda1_release_pe_dma(pe);
-- 
2.25.0