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From: Sunil V L <sunilvl@ventanamicro.com>
To: linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	linux-riscv@lists.infradead.org,
	linux-acpi@vger.kernel.org,
	linux-pci@vger.kernel.org
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	"Rafael J . Wysocki" <rafael@kernel.org>,
	Len Brown <lenb@kernel.org>,
	Anup Patel <anup@brainfault.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Haibo Xu <haibo1.xu@intel.com>,
	Conor Dooley <conor.dooley@microchip.com>,
	Andrew Jones <ajones@ventanamicro.com>,
	=?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= <bjorn@kernel.org>,
	Marc Zyngier <maz@kernel.org>,
	Sunil V L <sunilvl@ventanamicro.com>
Subject: [RFC PATCH v3 02/17] RISC-V: ACPI: Implement PCI related functionality
Date: Tue, 19 Dec 2023 23:15:11 +0530
Message-Id: <20231219174526.2235150-3-sunilvl@ventanamicro.com>
In-Reply-To: <20231219174526.2235150-1-sunilvl@ventanamicro.com>
References: <20231219174526.2235150-1-sunilvl@ventanamicro.com>
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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 45c660f1219d..d939fff5b5b1 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
@@ -151,6 +152,7 @@ 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 56cb2c986c48..b7bf1678241a 100644
--- a/arch/riscv/kernel/acpi.c
+++ b/arch/riscv/kernel/acpi.c
@@ -223,29 +223,26 @@ 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