From 00a5bf3a8ca30d19f24219fc3cfb74f4eab3600d Mon Sep 17 00:00:00 2001
From: Yash Shah <yash.shah@sifive.com>
Date: Fri, 25 Oct 2019 08:30:03 +0000
Subject: [PATCH] RISC-V: Add PCIe I/O BAR memory mapping
For legacy I/O BARs (non-MMIO BARs) to work correctly on RISC-V Linux,
we need to establish a reserved memory region for them, so that drivers
that wish to use the legacy I/O BARs can issue reads and writes against
a memory region that is mapped to the host PCIe controller's I/O BAR
mapping.
Signed-off-by: Yash Shah <yash.shah@sifive.com>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
---
arch/riscv/include/asm/io.h | 7 +++++++
arch/riscv/include/asm/pgtable.h | 7 ++++++-
2 files changed, 13 insertions(+), 1 deletion(-)
diff --git a/arch/riscv/include/asm/io.h b/arch/riscv/include/asm/io.h
index fc1189ad37772..3ba4d93721d30 100644
--- a/arch/riscv/include/asm/io.h
+++ b/arch/riscv/include/asm/io.h
@@ -13,6 +13,7 @@
#include <linux/types.h>
#include <asm/mmiowb.h>
+#include <asm/pgtable.h>
extern void __iomem *ioremap(phys_addr_t offset, unsigned long size);
@@ -161,6 +162,12 @@ static inline u64 __raw_readq(const volatile void __iomem *addr)
#define writeq(v,c) ({ __io_bw(); writeq_cpu((v),(c)); __io_aw(); })
#endif
+/*
+ * I/O port access constants.
+ */
+#define IO_SPACE_LIMIT (PCI_IO_SIZE - 1)
+#define PCI_IOBASE ((void __iomem *)PCI_IO_START)
+
/*
* Emulation routines for the port-mapped IO space used by some PCI drivers.
* These are defined as being "fully synchronous", but also "not guaranteed to
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 0352f20c29f42..d3221017194dd 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -7,6 +7,7 @@
#define _ASM_RISCV_PGTABLE_H
#include <linux/mmzone.h>
+#include <linux/sizes.h>
#include <asm/pgtable-bits.h>
@@ -86,6 +87,7 @@ extern pgd_t swapper_pg_dir[];
#define VMALLOC_SIZE (KERN_VIRT_SIZE >> 1)
#define VMALLOC_END (PAGE_OFFSET - 1)
#define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE)
+#define PCI_IO_SIZE SZ_16M
/*
* Roughly size the vmemmap space to be large enough to fit enough
@@ -100,7 +102,10 @@ extern pgd_t swapper_pg_dir[];
#define vmemmap ((struct page *)VMEMMAP_START)
-#define FIXADDR_TOP (VMEMMAP_START)
+#define PCI_IO_END VMEMMAP_START
+#define PCI_IO_START (PCI_IO_END - PCI_IO_SIZE)
+#define FIXADDR_TOP PCI_IO_START
+
#ifdef CONFIG_64BIT
#define FIXADDR_SIZE PMD_SIZE
#else
--
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