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Subject[PATCH 4.9 077/152] arm64: PCI: Manage controller-specific data on per-controller basis
Date
4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Tomasz Nowicki <tn@semihalf.com>

[ Upstream commit 093d24a204425f71f4f106b7e62c8df4b456e1cc ]

Currently we use one shared global acpi_pci_root_ops structure to keep
controller-specific ops. We pass its pointer to acpi_pci_root_create() and
associate it with a host bridge instance for good. Such a design implies
serious drawback. Any potential manipulation on the single system-wide
acpi_pci_root_ops leads to kernel crash. The structure content is not
really changing even across multiple host bridges creation; thus it was not
an issue so far.

In preparation for adding ECAM quirks mechanism (where controller-specific
PCI ops may be different for each host bridge) allocate new
acpi_pci_root_ops and fill in with data for each bridge. Now it is safe to
have different controller-specific info. As a consequence free
acpi_pci_root_ops when host bridge is released.

No functional changes in this patch.

Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/arm64/kernel/pci.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)

--- a/arch/arm64/kernel/pci.c
+++ b/arch/arm64/kernel/pci.c
@@ -159,33 +159,36 @@ static void pci_acpi_generic_release_inf

ri = container_of(ci, struct acpi_pci_generic_root_info, common);
pci_ecam_free(ri->cfg);
+ kfree(ci->ops);
kfree(ri);
}

-static struct acpi_pci_root_ops acpi_pci_root_ops = {
- .release_info = pci_acpi_generic_release_info,
-};
-
/* Interface called from ACPI code to setup PCI host controller */
struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
{
int node = acpi_get_node(root->device->handle);
struct acpi_pci_generic_root_info *ri;
struct pci_bus *bus, *child;
+ struct acpi_pci_root_ops *root_ops;

ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
if (!ri)
return NULL;

+ root_ops = kzalloc_node(sizeof(*root_ops), GFP_KERNEL, node);
+ if (!root_ops)
+ return NULL;
+
ri->cfg = pci_acpi_setup_ecam_mapping(root);
if (!ri->cfg) {
kfree(ri);
+ kfree(root_ops);
return NULL;
}

- acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops;
- bus = acpi_pci_root_create(root, &acpi_pci_root_ops, &ri->common,
- ri->cfg);
+ root_ops->release_info = pci_acpi_generic_release_info;
+ root_ops->pci_ops = &ri->cfg->ops->pci_ops;
+ bus = acpi_pci_root_create(root, root_ops, &ri->common, ri->cfg);
if (!bus)
return NULL;


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