[PATCH 5.4 01/50] PCI: pci-bridge-emul: Fix big-endian support

From: Greg Kroah-Hartman
Date: Fri Sep 24 2021 - 08:52:59 EST


From: Grzegorz Jaszczyk <jaz@xxxxxxxxxxxx>

commit e0d9d30b73548fbfe5c024ed630169bdc9a08aee upstream.

Perform conversion to little-endian before every write to configuration
space and convert it back to CPU endianness on reads.

Additionally, initialise every multiple byte field of config space with
the cpu_to_le* macro, which is required since the structure describing
config space of emulated bridge assumes little-endian convention.

Signed-off-by: Grzegorz Jaszczyk <jaz@xxxxxxxxxxxx>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/pci/pci-bridge-emul.c | 25 +++++++------
drivers/pci/pci-bridge-emul.h | 78 +++++++++++++++++++++---------------------
2 files changed, 52 insertions(+), 51 deletions(-)

--- a/drivers/pci/pci-bridge-emul.c
+++ b/drivers/pci/pci-bridge-emul.c
@@ -270,10 +270,10 @@ static const struct pci_bridge_reg_behav
int pci_bridge_emul_init(struct pci_bridge_emul *bridge,
unsigned int flags)
{
- bridge->conf.class_revision |= PCI_CLASS_BRIDGE_PCI << 16;
+ bridge->conf.class_revision |= cpu_to_le32(PCI_CLASS_BRIDGE_PCI << 16);
bridge->conf.header_type = PCI_HEADER_TYPE_BRIDGE;
bridge->conf.cache_line_size = 0x10;
- bridge->conf.status = PCI_STATUS_CAP_LIST;
+ bridge->conf.status = cpu_to_le16(PCI_STATUS_CAP_LIST);
bridge->pci_regs_behavior = kmemdup(pci_regs_behavior,
sizeof(pci_regs_behavior),
GFP_KERNEL);
@@ -284,8 +284,9 @@ int pci_bridge_emul_init(struct pci_brid
bridge->conf.capabilities_pointer = PCI_CAP_PCIE_START;
bridge->pcie_conf.cap_id = PCI_CAP_ID_EXP;
/* Set PCIe v2, root port, slot support */
- bridge->pcie_conf.cap = PCI_EXP_TYPE_ROOT_PORT << 4 | 2 |
- PCI_EXP_FLAGS_SLOT;
+ bridge->pcie_conf.cap =
+ cpu_to_le16(PCI_EXP_TYPE_ROOT_PORT << 4 | 2 |
+ PCI_EXP_FLAGS_SLOT);
bridge->pcie_cap_regs_behavior =
kmemdup(pcie_cap_regs_behavior,
sizeof(pcie_cap_regs_behavior),
@@ -327,7 +328,7 @@ int pci_bridge_emul_conf_read(struct pci
int reg = where & ~3;
pci_bridge_emul_read_status_t (*read_op)(struct pci_bridge_emul *bridge,
int reg, u32 *value);
- u32 *cfgspace;
+ __le32 *cfgspace;
const struct pci_bridge_reg_behavior *behavior;

if (bridge->has_pcie && reg >= PCI_CAP_PCIE_END) {
@@ -343,11 +344,11 @@ int pci_bridge_emul_conf_read(struct pci
if (bridge->has_pcie && reg >= PCI_CAP_PCIE_START) {
reg -= PCI_CAP_PCIE_START;
read_op = bridge->ops->read_pcie;
- cfgspace = (u32 *) &bridge->pcie_conf;
+ cfgspace = (__le32 *) &bridge->pcie_conf;
behavior = bridge->pcie_cap_regs_behavior;
} else {
read_op = bridge->ops->read_base;
- cfgspace = (u32 *) &bridge->conf;
+ cfgspace = (__le32 *) &bridge->conf;
behavior = bridge->pci_regs_behavior;
}

@@ -357,7 +358,7 @@ int pci_bridge_emul_conf_read(struct pci
ret = PCI_BRIDGE_EMUL_NOT_HANDLED;

if (ret == PCI_BRIDGE_EMUL_NOT_HANDLED)
- *value = cfgspace[reg / 4];
+ *value = le32_to_cpu(cfgspace[reg / 4]);

/*
* Make sure we never return any reserved bit with a value
@@ -387,7 +388,7 @@ int pci_bridge_emul_conf_write(struct pc
int mask, ret, old, new, shift;
void (*write_op)(struct pci_bridge_emul *bridge, int reg,
u32 old, u32 new, u32 mask);
- u32 *cfgspace;
+ __le32 *cfgspace;
const struct pci_bridge_reg_behavior *behavior;

if (bridge->has_pcie && reg >= PCI_CAP_PCIE_END)
@@ -414,11 +415,11 @@ int pci_bridge_emul_conf_write(struct pc
if (bridge->has_pcie && reg >= PCI_CAP_PCIE_START) {
reg -= PCI_CAP_PCIE_START;
write_op = bridge->ops->write_pcie;
- cfgspace = (u32 *) &bridge->pcie_conf;
+ cfgspace = (__le32 *) &bridge->pcie_conf;
behavior = bridge->pcie_cap_regs_behavior;
} else {
write_op = bridge->ops->write_base;
- cfgspace = (u32 *) &bridge->conf;
+ cfgspace = (__le32 *) &bridge->conf;
behavior = bridge->pci_regs_behavior;
}

@@ -431,7 +432,7 @@ int pci_bridge_emul_conf_write(struct pc
/* Clear the W1C bits */
new &= ~((value << shift) & (behavior[reg / 4].w1c & mask));

- cfgspace[reg / 4] = new;
+ cfgspace[reg / 4] = cpu_to_le32(new);

if (write_op)
write_op(bridge, reg, old, new, mask);
--- a/drivers/pci/pci-bridge-emul.h
+++ b/drivers/pci/pci-bridge-emul.h
@@ -6,65 +6,65 @@

/* PCI configuration space of a PCI-to-PCI bridge. */
struct pci_bridge_emul_conf {
- u16 vendor;
- u16 device;
- u16 command;
- u16 status;
- u32 class_revision;
+ __le16 vendor;
+ __le16 device;
+ __le16 command;
+ __le16 status;
+ __le32 class_revision;
u8 cache_line_size;
u8 latency_timer;
u8 header_type;
u8 bist;
- u32 bar[2];
+ __le32 bar[2];
u8 primary_bus;
u8 secondary_bus;
u8 subordinate_bus;
u8 secondary_latency_timer;
u8 iobase;
u8 iolimit;
- u16 secondary_status;
- u16 membase;
- u16 memlimit;
- u16 pref_mem_base;
- u16 pref_mem_limit;
- u32 prefbaseupper;
- u32 preflimitupper;
- u16 iobaseupper;
- u16 iolimitupper;
+ __le16 secondary_status;
+ __le16 membase;
+ __le16 memlimit;
+ __le16 pref_mem_base;
+ __le16 pref_mem_limit;
+ __le32 prefbaseupper;
+ __le32 preflimitupper;
+ __le16 iobaseupper;
+ __le16 iolimitupper;
u8 capabilities_pointer;
u8 reserve[3];
- u32 romaddr;
+ __le32 romaddr;
u8 intline;
u8 intpin;
- u16 bridgectrl;
+ __le16 bridgectrl;
};

/* PCI configuration space of the PCIe capabilities */
struct pci_bridge_emul_pcie_conf {
u8 cap_id;
u8 next;
- u16 cap;
- u32 devcap;
- u16 devctl;
- u16 devsta;
- u32 lnkcap;
- u16 lnkctl;
- u16 lnksta;
- u32 slotcap;
- u16 slotctl;
- u16 slotsta;
- u16 rootctl;
- u16 rsvd;
- u32 rootsta;
- u32 devcap2;
- u16 devctl2;
- u16 devsta2;
- u32 lnkcap2;
- u16 lnkctl2;
- u16 lnksta2;
- u32 slotcap2;
- u16 slotctl2;
- u16 slotsta2;
+ __le16 cap;
+ __le32 devcap;
+ __le16 devctl;
+ __le16 devsta;
+ __le32 lnkcap;
+ __le16 lnkctl;
+ __le16 lnksta;
+ __le32 slotcap;
+ __le16 slotctl;
+ __le16 slotsta;
+ __le16 rootctl;
+ __le16 rsvd;
+ __le32 rootsta;
+ __le32 devcap2;
+ __le16 devctl2;
+ __le16 devsta2;
+ __le32 lnkcap2;
+ __le16 lnkctl2;
+ __le16 lnksta2;
+ __le32 slotcap2;
+ __le16 slotctl2;
+ __le16 slotsta2;
};

struct pci_bridge_emul;