Commit 1d4454e7 authored by Roland Dreier's avatar Roland Dreier Committed by Paul Mackerras
Browse files

[POWERPC] Define pci_unmap_addr() et al. when CONFIG_NOT_COHERENT_CACHE=y 



The current PowerPC code makes pci_unmap_addr(), pci_unmap_addr_set(),
and friends trivial for all 32-bit kernels.  This is reasonable, since
for those kernels it is true that pci_unmap_single() does not need the
DMA address from the original DMA mapping -- in fact, it is a NOP.

However, I recently tried the tg3 driver on a PowerPC 440SPe machine,
which runs a 32-bit kernel and has non-cache-coherent PCI DMA.  I
found that the tg3 driver crashed in pci_dma_sync_single_for_cpu(),
since for non-coherent systems, that function must invalidate the
cache for the DMA address range requested, and therefore it does use
the address passed in.  tg3 uses a DMA address it stashes away with
pci_unmap_addr_set() and retrieves with pci_unmap_addr().  Of course,
since pci_unmap_addr() is defined to (0) right now, this doesn't work.

It seems to me that the tg3 driver is using pci_unmap_addr() in a
legitimate way -- I wouldn't want to have to teach all drivers that
they should use pci_unmap_addr() if they only need the address for
unmapping functions, but if they want the pci_dma_sync functions, then
they have to store the DMA address without the helper macros.
The right fix therefore seems to be in the definition of the macros in
<asm/pci.h> -- we should use the trivial versions only for 32-bit
kernels for coherent systems, and the real versions for both 64-bit
kernels and non-coherent systems.

Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 885ed0fb

include/asm-powerpc/pci.h

+22 −11
Original line number Diff line number Diff line
@@ -143,8 +143,13 @@ int pci_mmap_page_range(struct pci_dev *pdev, struct vm_area_struct *vma, 
/* Tell drivers/pci/proc.c that we have pci_mmap_page_range() */

#define HAVE_PCI_MMAP	1



#ifdef CONFIG_PPC64

/* pci_unmap_{single,page} is not a nop, thus... */

#if defined(CONFIG_PPC64) || defined(CONFIG_NOT_COHERENT_CACHE)

/*

 * For 64-bit kernels, pci_unmap_{single,page} is not a nop.

 * For 32-bit non-coherent kernels, pci_dma_sync_single_for_cpu() and

 * so on are not nops.

 * and thus...

 */

#define DECLARE_PCI_UNMAP_ADDR(ADDR_NAME)	\

	dma_addr_t ADDR_NAME;

#define DECLARE_PCI_UNMAP_LEN(LEN_NAME)		\
@@ -158,6 +163,20 @@ int pci_mmap_page_range(struct pci_dev *pdev, struct vm_area_struct *vma, 
#define pci_unmap_len_set(PTR, LEN_NAME, VAL)		\

	(((PTR)->LEN_NAME) = (VAL))



#else /* 32-bit && coherent */



/* pci_unmap_{page,single} is a nop so... */

#define DECLARE_PCI_UNMAP_ADDR(ADDR_NAME)

#define DECLARE_PCI_UNMAP_LEN(LEN_NAME)

#define pci_unmap_addr(PTR, ADDR_NAME)		(0)

#define pci_unmap_addr_set(PTR, ADDR_NAME, VAL)	do { } while (0)

#define pci_unmap_len(PTR, LEN_NAME)		(0)

#define pci_unmap_len_set(PTR, LEN_NAME, VAL)	do { } while (0)



#endif /* CONFIG_PPC64 || CONFIG_NOT_COHERENT_CACHE */



#ifdef CONFIG_PPC64



/* The PCI address space does not equal the physical memory address

 * space (we have an IOMMU).  The IDE and SCSI device layers use

 * this boolean for bounce buffer decisions.
@@ -172,14 +191,6 @@ int pci_mmap_page_range(struct pci_dev *pdev, struct vm_area_struct *vma, 
 */

#define PCI_DMA_BUS_IS_PHYS     (1)



/* pci_unmap_{page,single} is a nop so... */

#define DECLARE_PCI_UNMAP_ADDR(ADDR_NAME)

#define DECLARE_PCI_UNMAP_LEN(LEN_NAME)

#define pci_unmap_addr(PTR, ADDR_NAME)		(0)

#define pci_unmap_addr_set(PTR, ADDR_NAME, VAL)	do { } while (0)

#define pci_unmap_len(PTR, LEN_NAME)		(0)

#define pci_unmap_len_set(PTR, LEN_NAME, VAL)	do { } while (0)



#endif /* CONFIG_PPC64 */



extern void pcibios_resource_to_bus(struct pci_dev *dev,

include/asm-ppc/pci.h

+23 −0
Original line number Diff line number Diff line
@@ -61,6 +61,27 @@ extern unsigned long pci_bus_to_phys(unsigned int ba, int busnr); 
 */

#define PCI_DMA_BUS_IS_PHYS     (1)



#ifdef CONFIG_NOT_COHERENT_CACHE

/*

 * pci_unmap_{page,single} are NOPs but pci_dma_sync_single_for_cpu()

 * and so on are not, so...

 */



#define DECLARE_PCI_UNMAP_ADDR(ADDR_NAME)	\

	dma_addr_t ADDR_NAME;

#define DECLARE_PCI_UNMAP_LEN(LEN_NAME)		\

	__u32 LEN_NAME;

#define pci_unmap_addr(PTR, ADDR_NAME)			\

	((PTR)->ADDR_NAME)

#define pci_unmap_addr_set(PTR, ADDR_NAME, VAL)		\

	(((PTR)->ADDR_NAME) = (VAL))

#define pci_unmap_len(PTR, LEN_NAME)			\

	((PTR)->LEN_NAME)

#define pci_unmap_len_set(PTR, LEN_NAME, VAL)		\

	(((PTR)->LEN_NAME) = (VAL))



#else /* coherent */



/* pci_unmap_{page,single} is a nop so... */

#define DECLARE_PCI_UNMAP_ADDR(ADDR_NAME)

#define DECLARE_PCI_UNMAP_LEN(LEN_NAME)
@@ -69,6 +90,8 @@ extern unsigned long pci_bus_to_phys(unsigned int ba, int busnr); 
#define pci_unmap_len(PTR, LEN_NAME)		(0)

#define pci_unmap_len_set(PTR, LEN_NAME, VAL)	do { } while (0)



#endif /* CONFIG_NOT_COHERENT_CACHE */



#ifdef CONFIG_PCI

static inline void pci_dma_burst_advice(struct pci_dev *pdev,

					enum pci_dma_burst_strategy *strat,

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