Commit 00a5bf3a authored by Yash Shah's avatar Yash Shah Committed by Paul Walmsley
Browse files

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: default avatarYash Shah <yash.shah@sifive.com>
Signed-off-by: default avatarPaul Walmsley <paul.walmsley@sifive.com>
parent f3073079

arch/riscv/include/asm/io.h

+7 −0
Original line number Diff line number Diff line
@@ -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

arch/riscv/include/asm/pgtable.h

+6 −1
Original line number Diff line number Diff line
@@ -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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