Implement generic pci access functions to read/write the configuration
space.
Signed-off-by: Rahul Singh <rahul.si...@arm.com>
---
Change in v2: Fixed comments
---
xen/arch/arm/pci/pci-access.c | 58 ++++++++++++++++++++++++++++++
xen/arch/arm/pci/pci-host-common.c | 19 ++++++++++
xen/include/asm-arm/pci.h | 2 ++
3 files changed, 79 insertions(+)
diff --git a/xen/arch/arm/pci/pci-access.c b/xen/arch/arm/pci/pci-access.c
index 04fe9fbf92..45500cec2a 100644
--- a/xen/arch/arm/pci/pci-access.c
+++ b/xen/arch/arm/pci/pci-access.c
@@ -16,6 +16,7 @@
#include <asm/io.h>
#define INVALID_VALUE (~0U)
+#define PCI_ERR_VALUE(len) GENMASK(0, len * 8)
int pci_generic_config_read(struct pci_host_bridge *bridge, uint32_t sbdf,
uint32_t reg, uint32_t len, uint32_t *value)
@@ -72,6 +73,63 @@ int pci_generic_config_write(struct pci_host_bridge *bridge,
uint32_t sbdf,
return 0;
}
+static uint32_t pci_config_read(pci_sbdf_t sbdf, unsigned int reg,
+ unsigned int len)
+{
+ uint32_t val = PCI_ERR_VALUE(len);
+
+ struct pci_host_bridge *bridge = pci_find_host_bridge(sbdf.seg, sbdf.bus);
+
+ if ( unlikely(!bridge) )
+ return val;
+
+ if ( unlikely(!bridge->ops->read) )
+ return val;
+
+ bridge->ops->read(bridge, (uint32_t) sbdf.sbdf, reg, len, &val);
+
+ return val;
+}
+
+static void pci_config_write(pci_sbdf_t sbdf, unsigned int reg,
+ unsigned int len, uint32_t val)
+{
+ struct pci_host_bridge *bridge = pci_find_host_bridge(sbdf.seg, sbdf.bus);
+
+ if ( unlikely(!bridge) )
+ return;
+
+ if ( unlikely(!bridge->ops->write) )
+ return;
+
+ bridge->ops->write(bridge, (uint32_t) sbdf.sbdf, reg, len, val);
+}
+
+/*
+ * Wrappers for all PCI configuration access functions.
+ */
+
+#define PCI_OP_WRITE(size, type) \
+ void pci_conf_write##size(pci_sbdf_t sbdf, \
+ unsigned int reg, type val) \
+{ \
+ pci_config_write(sbdf, reg, size / 8, val); \
+}
+
+#define PCI_OP_READ(size, type) \
+ type pci_conf_read##size(pci_sbdf_t sbdf, \
+ unsigned int reg) \
+{ \
+ return pci_config_read(sbdf, reg, size / 8); \
+}
+
+PCI_OP_READ(8, uint8_t)
+PCI_OP_READ(16, uint16_t)
+PCI_OP_READ(32, uint32_t)
+PCI_OP_WRITE(8, uint8_t)
+PCI_OP_WRITE(16, uint16_t)
+PCI_OP_WRITE(32, uint32_t)
+
/*
* Local variables:
* mode: C
diff --git a/xen/arch/arm/pci/pci-host-common.c
b/xen/arch/arm/pci/pci-host-common.c
index 4beec14f2f..3bdc336268 100644
--- a/xen/arch/arm/pci/pci-host-common.c
+++ b/xen/arch/arm/pci/pci-host-common.c
@@ -243,6 +243,25 @@ err_exit:
return err;
}
+/*
+ * This function will lookup an hostbridge based on the segment and bus
+ * number.
+ */
+struct pci_host_bridge *pci_find_host_bridge(uint16_t segment, uint8_t bus)
+{
+ struct pci_host_bridge *bridge;
+
+ list_for_each_entry( bridge, &pci_host_bridges, node )
+ {
+ if ( bridge->segment != segment )
+ continue;
+ if ( (bus < bridge->bus_start) || (bus > bridge->bus_end) )
+ continue;
+ return bridge;
+ }
+
+ return NULL;
+}
/*
* Local variables:
* mode: C
diff --git a/xen/include/asm-arm/pci.h b/xen/include/asm-arm/pci.h
index 4b32c7088a..5406daecda 100644
--- a/xen/include/asm-arm/pci.h
+++ b/xen/include/asm-arm/pci.h
@@ -18,6 +18,7 @@
#ifdef CONFIG_HAS_PCI
#define pci_to_dev(pcidev) (&(pcidev)->arch.dev)
+#define PRI_pci "%04x:%02x:%02x.%u"
extern bool_t pci_passthrough_enabled;
@@ -84,6 +85,7 @@ int pci_generic_config_write(struct pci_host_bridge *bridge,
uint32_t sbdf,
uint32_t reg, uint32_t len, uint32_t value);
void __iomem *pci_ecam_map_bus(struct pci_host_bridge *bridge,
uint32_t sbdf, uint32_t where);
+struct pci_host_bridge *pci_find_host_bridge(uint16_t segment, uint8_t bus);
static always_inline bool is_pci_passthrough_enabled(void)
{
--
2.17.1
