[RFC] x86/pci: Mark pci_root_ops as const
From: Zubin Mithra
Date: Thu Nov 08 2018 - 12:11:27 EST
pci_root_ops is only written to from within intel_mid_pci_init. This
is linked in only when CONFIG_X86_INTEL_MID is set. If not for this,
pci_root_ops could be marked as const.
Fix this by replacing pci_root_ops usage with pci_root_ops_ptr. If
CONFIG_X86_INTEL_MID is set, pci_root_ops_ptr will be set to
intel_mid_pci_ops inside intel_mid_pci_init.
Introduce pci_acpi_set_ops for intel_mid_pci_init to set
acpi_pci_root_ops.pci_ops.
This also means that intel_mid_pci_ops cannot be freed after init, hence
remove __initconst.
Signed-off-by: Zubin Mithra <zsm@xxxxxxxxxxxx>
---
arch/x86/include/asm/pci_x86.h | 4 +++-
arch/x86/pci/acpi.c | 5 +++++
arch/x86/pci/common.c | 5 +++--
arch/x86/pci/intel_mid_pci.c | 5 +++--
drivers/pci/access.c | 4 ++--
drivers/pci/probe.c | 4 ++--
include/linux/pci-acpi.h | 2 +-
include/linux/pci.h | 11 ++++++-----
8 files changed, 25 insertions(+), 15 deletions(-)
diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
index 959d618dbb17..1e82ddaeb52f 100644
--- a/arch/x86/include/asm/pci_x86.h
+++ b/arch/x86/include/asm/pci_x86.h
@@ -58,7 +58,8 @@ void pcibios_set_cache_line_size(void);
/* pci-pc.c */
extern int pcibios_last_bus;
-extern struct pci_ops pci_root_ops;
+extern const struct pci_ops pci_root_ops;
+extern const struct pci_ops *pci_root_ops_ptr;
void pcibios_scan_specific_bus(int busn);
@@ -122,6 +123,7 @@ extern void __init dmi_check_skip_isa_align(void);
/* some common used subsys_initcalls */
extern int __init pci_acpi_init(void);
+extern void __init pci_acpi_set_ops(const struct pci_ops *ops);
extern void __init pcibios_irq_init(void);
extern int __init pcibios_init(void);
extern int pci_legacy_init(void);
diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index 948656069cdd..63ebac5fa212 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -397,6 +397,11 @@ int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
return 0;
}
+void __init pci_acpi_set_ops(const struct pci_ops *ops)
+{
+ acpi_pci_root_ops.pci_ops = ops;
+}
+
int __init pci_acpi_init(void)
{
struct pci_dev *dev = NULL;
diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index d4ec117c1142..747a8e9fd430 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -67,10 +67,11 @@ static int pci_write(struct pci_bus *bus, unsigned int devfn, int where, int siz
devfn, where, size, value);
}
-struct pci_ops pci_root_ops = {
+const struct pci_ops pci_root_ops = {
.read = pci_read,
.write = pci_write,
};
+const struct pci_ops *pci_root_ops_ptr = &pci_root_ops;
/*
* This interrupt-safe spinlock protects all accesses to PCI configuration
@@ -467,7 +468,7 @@ void pcibios_scan_root(int busnum)
sd->node = x86_pci_root_bus_node(busnum);
x86_pci_root_bus_resources(busnum, &resources);
printk(KERN_DEBUG "PCI: Probing PCI hardware (bus %02x)\n", busnum);
- bus = pci_scan_root_bus(NULL, busnum, &pci_root_ops, sd, &resources);
+ bus = pci_scan_root_bus(NULL, busnum, pci_root_ops_ptr, sd, &resources);
if (!bus) {
pci_free_resource_list(&resources);
kfree(sd);
diff --git a/arch/x86/pci/intel_mid_pci.c b/arch/x86/pci/intel_mid_pci.c
index 43867bc85368..b79c469afd57 100644
--- a/arch/x86/pci/intel_mid_pci.c
+++ b/arch/x86/pci/intel_mid_pci.c
@@ -280,7 +280,7 @@ static void intel_mid_pci_irq_disable(struct pci_dev *dev)
}
}
-static const struct pci_ops intel_mid_pci_ops __initconst = {
+static const struct pci_ops intel_mid_pci_ops = {
.read = pci_read,
.write = pci_write,
};
@@ -297,7 +297,8 @@ int __init intel_mid_pci_init(void)
pci_mmcfg_late_init();
pcibios_enable_irq = intel_mid_pci_irq_enable;
pcibios_disable_irq = intel_mid_pci_irq_disable;
- pci_root_ops = intel_mid_pci_ops;
+ pci_root_ops_ptr = &intel_mid_pci_ops;
+ pci_acpi_set_ops(&intel_mid_pci_ops);
pci_soc_mode = 1;
/* Continue with standard init */
acpi_noirq_set();
diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index 544922f097c0..ca9d3cbc5541 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -180,9 +180,9 @@ EXPORT_SYMBOL_GPL(pci_generic_config_write32);
*
* Return previous raw operations
*/
-struct pci_ops *pci_bus_set_ops(struct pci_bus *bus, struct pci_ops *ops)
+const struct pci_ops *pci_bus_set_ops(struct pci_bus *bus, const struct pci_ops *ops)
{
- struct pci_ops *old_ops;
+ const struct pci_ops *old_ops;
unsigned long flags;
raw_spin_lock_irqsave(&pci_lock, flags);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index b1c05b5054a0..c66c84ef070a 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2915,7 +2915,7 @@ void __weak pcibios_remove_bus(struct pci_bus *bus)
}
struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
- struct pci_ops *ops, void *sysdata, struct list_head *resources)
+ const struct pci_ops *ops, void *sysdata, struct list_head *resources)
{
int error;
struct pci_host_bridge *bridge;
@@ -3079,7 +3079,7 @@ int pci_scan_root_bus_bridge(struct pci_host_bridge *bridge)
EXPORT_SYMBOL(pci_scan_root_bus_bridge);
struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
- struct pci_ops *ops, void *sysdata, struct list_head *resources)
+ const struct pci_ops *ops, void *sysdata, struct list_head *resources)
{
struct resource_entry *window;
bool found = false;
diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
index 8082b612f561..e2c80f2edbe8 100644
--- a/include/linux/pci-acpi.h
+++ b/include/linux/pci-acpi.h
@@ -69,7 +69,7 @@ struct acpi_pci_root_info {
};
struct acpi_pci_root_ops {
- struct pci_ops *pci_ops;
+ const struct pci_ops *pci_ops;
int (*init_info)(struct acpi_pci_root_info *info);
void (*release_info)(struct acpi_pci_root_info *info);
int (*prepare_resources)(struct acpi_pci_root_info *info);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 11c71c4ecf75..994a4418a3c4 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -474,7 +474,7 @@ static inline int pci_channel_offline(struct pci_dev *pdev)
struct pci_host_bridge {
struct device dev;
struct pci_bus *bus; /* Root bus */
- struct pci_ops *ops;
+ const struct pci_ops *ops;
void *sysdata;
int busnr;
struct list_head windows; /* resource_entry */
@@ -558,7 +558,7 @@ struct pci_bus {
struct list_head resources; /* Address space routed to this bus */
struct resource busn_res; /* Bus numbers routed to this bus */
- struct pci_ops *ops; /* Configuration access functions */
+ const struct pci_ops *ops; /* Configuration access functions */
struct msi_controller *msi; /* MSI controller */
void *sysdata; /* Hook for sys-specific extension */
struct proc_dir_entry *procdir; /* Directory entry in /proc/bus/pci */
@@ -913,14 +913,14 @@ struct pci_bus *pci_find_bus(int domain, int busnr);
void pci_bus_add_devices(const struct pci_bus *bus);
struct pci_bus *pci_scan_bus(int bus, struct pci_ops *ops, void *sysdata);
struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
- struct pci_ops *ops, void *sysdata,
+ const struct pci_ops *ops, void *sysdata,
struct list_head *resources);
int pci_host_probe(struct pci_host_bridge *bridge);
int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int busmax);
int pci_bus_update_busn_res_end(struct pci_bus *b, int busmax);
void pci_bus_release_busn_res(struct pci_bus *b);
struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
- struct pci_ops *ops, void *sysdata,
+ const struct pci_ops *ops, void *sysdata,
struct list_head *resources);
int pci_scan_root_bus_bridge(struct pci_host_bridge *bridge);
struct pci_bus *pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev,
@@ -1010,7 +1010,8 @@ int pci_generic_config_read32(struct pci_bus *bus, unsigned int devfn,
int pci_generic_config_write32(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 val);
-struct pci_ops *pci_bus_set_ops(struct pci_bus *bus, struct pci_ops *ops);
+const struct pci_ops *pci_bus_set_ops(struct pci_bus *bus,
+ const struct pci_ops *ops);
int pci_read_config_byte(const struct pci_dev *dev, int where, u8 *val);
int pci_read_config_word(const struct pci_dev *dev, int where, u16 *val);
--
2.19.1.930.g4563a0d9d0-goog