[RFC PATCH v2 02/21] RISC-V: ACPI: Implement PCI related functionality

Sunil V L
2023-10-25T20:24:22Z

Replace the dummy implementation for PCI related functions with actual
implementation. This needs ECAM and MCFG CONFIG options to be enabled
for RISC-V.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
---
arch/riscv/Kconfig | 2 ++
arch/riscv/kernel/acpi.c | 31 ++++++++++++++-----------------
drivers/pci/pci-acpi.c | 2 +-
3 files changed, 17 insertions(+), 18 deletions(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index c3c3f3562082..8c105a151e12 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -13,6 +13,7 @@ config 32BIT
config RISCV
def_bool y
select ACPI_GENERIC_GSI if ACPI
+ select ACPI_MCFG if (ACPI && PCI)
select ACPI_REDUCED_HARDWARE_ONLY if ACPI
select ARCH_DMA_DEFAULT_COHERENT
select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
@@ -152,6 +153,7 @@ config RISCV
select OF_EARLY_FLATTREE
select OF_IRQ
select PCI_DOMAINS_GENERIC if PCI
+ select PCI_ECAM if (ACPI && PCI)
select PCI_MSI if PCI
select RISCV_ALTERNATIVE if !XIP_KERNEL
select RISCV_APLIC
diff --git a/arch/riscv/kernel/acpi.c b/arch/riscv/kernel/acpi.c
index e619edc8b0cc..41aa77c8484b 100644
--- a/arch/riscv/kernel/acpi.c
+++ b/arch/riscv/kernel/acpi.c
@@ -306,29 +306,26 @@ void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
#ifdef CONFIG_PCI

/*
- * These interfaces are defined just to enable building ACPI core.
- * TODO: Update it with actual implementation when external interrupt
- * controller support is added in RISC-V ACPI.
+ * raw_pci_read/write - Platform-specific PCI config space access.
*/
-int raw_pci_read(unsigned int domain, unsigned int bus, unsigned int devfn,
- int reg, int len, u32 *val)
+int raw_pci_read(unsigned int domain, unsigned int bus,
+ unsigned int devfn, int reg, int len, u32 *val)
{
- return PCIBIOS_DEVICE_NOT_FOUND;
-}
+ struct pci_bus *b = pci_find_bus(domain, bus);

-int raw_pci_write(unsigned int domain, unsigned int bus, unsigned int devfn,
- int reg, int len, u32 val)
-{
- return PCIBIOS_DEVICE_NOT_FOUND;
+ if (!b)
+ return PCIBIOS_DEVICE_NOT_FOUND;
+ return b->ops->read(b, devfn, reg, len, val);
}

-int acpi_pci_bus_find_domain_nr(struct pci_bus *bus)
+int raw_pci_write(unsigned int domain, unsigned int bus,
+ unsigned int devfn, int reg, int len, u32 val)
{
- return -1;
-}
+ struct pci_bus *b = pci_find_bus(domain, bus);

-struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
-{
- return NULL;
+ if (!b)
+ return PCIBIOS_DEVICE_NOT_FOUND;
+ return b->ops->write(b, devfn, reg, len, val);
}
+
#endif /* CONFIG_PCI */
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 58497b25d2ab..c8c3369fd69f 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -1520,7 +1520,7 @@ static int __init acpi_pci_init(void)
}
arch_initcall(acpi_pci_init);

-#if defined(CONFIG_ARM64)
+#if defined(CONFIG_ARM64) || defined(CONFIG_RISCV)

/*
* Try to assign the IRQ number when probing a new device
--
2.39.2