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authorYash Shah <yash.shah@sifive.com>2019-10-25 08:30:03 +0000
committerPaul Walmsley <paul.walmsley@sifive.com>2019-10-28 10:43:32 -0700
commit00a5bf3a8ca30d19f24219fc3cfb74f4eab3600d (patch)
treeca4482fe65348fc5321ed6093a9f5352fe70bb5b /arch/riscv
parentf307307992bf63e609fe5395953048e81c9ebc54 (diff)
downloadlinux-00a5bf3a8ca30d19f24219fc3cfb74f4eab3600d.tar.gz
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>
Diffstat (limited to 'arch/riscv')
-rw-r--r--arch/riscv/include/asm/io.h7
-rw-r--r--arch/riscv/include/asm/pgtable.h7
2 files changed, 13 insertions, 1 deletions
diff --git a/arch/riscv/include/asm/io.h b/arch/riscv/include/asm/io.h
index fc1189ad3777..3ba4d93721d3 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);
@@ -162,6 +163,12 @@ static inline u64 __raw_readq(const volatile void __iomem *addr)
#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
* be fully ordered with respect to other memory and I/O operations". We're
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 0352f20c29f4..d3221017194d 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