Re: [PATCH 13/22] nds32: use generic dma_noncoherent_ops

Greentime Hu
2018-04-23T06:50:30Z

2018-04-20 16:03 GMT+08:00 Christoph Hellwig <hch@lst.de>:
> Switch to the generic noncoherent direct mapping implementation.
>
> This makes sure kmap_atomic_pfn is consistently used for access to
> virtual addresses instead of either using the slower plain kmap
> or blindly expecting page_address() to work.
>
> This makes sure the cache_sync routines is called in the unmap_sg
> case, to match the unmap_single and sync_{single,sg}_to_cpu cases.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
> arch/nds32/Kconfig | 3 +
> arch/nds32/include/asm/Kbuild | 1 +
> arch/nds32/include/asm/dma-mapping.h | 14 ---
> arch/nds32/kernel/dma.c | 182 ++++++---------------------
> 4 files changed, 39 insertions(+), 161 deletions(-)
> delete mode 100644 arch/nds32/include/asm/dma-mapping.h
>
> diff --git a/arch/nds32/Kconfig b/arch/nds32/Kconfig
> index 249f38d3388f..67d0ac0a989c 100644
> --- a/arch/nds32/Kconfig
> +++ b/arch/nds32/Kconfig
> @@ -5,10 +5,13 @@
>
> config NDS32
> def_bool y
> + select ARCH_HAS_SYNC_DMA_FOR_CPU
> + select ARCH_HAS_SYNC_DMA_FOR_DEVICE
> select ARCH_WANT_FRAME_POINTERS if FTRACE
> select CLKSRC_MMIO
> select CLONE_BACKWARDS
> select COMMON_CLK
> + select DMA_NONCOHERENT_OPS
> select GENERIC_ATOMIC64
> select GENERIC_CPU_DEVICES
> select GENERIC_CLOCKEVENTS
> diff --git a/arch/nds32/include/asm/Kbuild b/arch/nds32/include/asm/Kbuild
> index 06bdf8167f5a..b3e951f805f8 100644
> --- a/arch/nds32/include/asm/Kbuild
> +++ b/arch/nds32/include/asm/Kbuild
> @@ -13,6 +13,7 @@ generic-y += cputime.h
> generic-y += device.h
> generic-y += div64.h
> generic-y += dma.h
> +generic-y += dma-mapping.h
> generic-y += emergency-restart.h
> generic-y += errno.h
> generic-y += exec.h
> diff --git a/arch/nds32/include/asm/dma-mapping.h b/arch/nds32/include/asm/dma-mapping.h
> deleted file mode 100644
> index 2dd47d245c25..000000000000
> --- a/arch/nds32/include/asm/dma-mapping.h
> +++ /dev/null
> @@ -1,14 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0
> -// Copyright (C) 2005-2017 Andes Technology Corporation
> -
> -#ifndef ASMNDS32_DMA_MAPPING_H
> -#define ASMNDS32_DMA_MAPPING_H
> -
> -extern struct dma_map_ops nds32_dma_ops;
> -
> -static inline struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
> -{
> - return &nds32_dma_ops;
> -}
> -
> -#endif
> diff --git a/arch/nds32/kernel/dma.c b/arch/nds32/kernel/dma.c
> index d291800fc621..688f1a03dee6 100644
> --- a/arch/nds32/kernel/dma.c
> +++ b/arch/nds32/kernel/dma.c
> @@ -3,17 +3,14 @@
>
> #include <linux/types.h>
> #include <linux/mm.h>
> -#include <linux/export.h>
> #include <linux/string.h>
> -#include <linux/scatterlist.h>
> -#include <linux/dma-mapping.h>
> +#include <linux/dma-noncoherent.h>
> #include <linux/io.h>
> #include <linux/cache.h>
> #include <linux/highmem.h>
> #include <linux/slab.h>
> #include <asm/cacheflush.h>
> #include <asm/tlbflush.h>
> -#include <asm/dma-mapping.h>
> #include <asm/proc-fns.h>
>
> /*
> @@ -22,11 +19,6 @@
> static pte_t *consistent_pte;
> static DEFINE_RAW_SPINLOCK(consistent_lock);
>
> -enum master_type {
> - FOR_CPU = 0,
> - FOR_DEVICE = 1,
> -};
> -
> /*
> * VM region handling support.
> *
> @@ -124,10 +116,8 @@ static struct arch_vm_region *vm_region_find(struct arch_vm_region *head,
> return c;
> }
>
> -/* FIXME: attrs is not used. */
> -static void *nds32_dma_alloc_coherent(struct device *dev, size_t size,
> - dma_addr_t * handle, gfp_t gfp,
> - unsigned long attrs)
> +void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
> + gfp_t gfp, unsigned long attrs)
> {
> struct page *page;
> struct arch_vm_region *c;
> @@ -232,8 +222,8 @@ static void *nds32_dma_alloc_coherent(struct device *dev, size_t size,
> return NULL;
> }
>
> -static void nds32_dma_free(struct device *dev, size_t size, void *cpu_addr,
> - dma_addr_t handle, unsigned long attrs)
> +void arch_dma_free(struct device *dev, size_t size, void *cpu_addr,
> + dma_addr_t handle, unsigned long attrs)
> {
> struct arch_vm_region *c;
> unsigned long flags, addr;
> @@ -333,145 +323,43 @@ static int __init consistent_init(void)
> }
>
> core_initcall(consistent_init);
> -static void consistent_sync(void *vaddr, size_t size, int direction, int master_type);
> -static dma_addr_t nds32_dma_map_page(struct device *dev, struct page *page,
> - unsigned long offset, size_t size,
> - enum dma_data_direction dir,
> - unsigned long attrs)
> -{
> - if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
> - consistent_sync((void *)(page_address(page) + offset), size, dir, FOR_DEVICE);
> - return page_to_phys(page) + offset;
> -}
> -
> -static void nds32_dma_unmap_page(struct device *dev, dma_addr_t handle,
> - size_t size, enum dma_data_direction dir,
> - unsigned long attrs)
> -{
> - if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
> - consistent_sync(phys_to_virt(handle), size, dir, FOR_CPU);
> -}
>
> -/*
> - * Make an area consistent for devices.
> - */
> -static void consistent_sync(void *vaddr, size_t size, int direction, int master_type)
> +void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr,
> + size_t size, enum dma_data_direction dir)
> {
> - unsigned long start = (unsigned long)vaddr;
> - unsigned long end = start + size;
> -
> - if (master_type == FOR_CPU) {
> - switch (direction) {
> - case DMA_TO_DEVICE:
> - break;
> - case DMA_FROM_DEVICE:
> - case DMA_BIDIRECTIONAL:
> - cpu_dma_inval_range(start, end);
> - break;
> - default:
> - BUG();
> - }
> - } else {
> - /* FOR_DEVICE */
> - switch (direction) {
> - case DMA_FROM_DEVICE:
> - break;
> - case DMA_TO_DEVICE:
> - case DMA_BIDIRECTIONAL:
> - cpu_dma_wb_range(start, end);
> - break;
> - default:
> - BUG();
> - }
> + void *addr = kmap_atomic_pfn(PHYS_PFN(paddr));
> + unsigned long start = (unsigned long)addr;
> +
> + switch (direction) {
> + case DMA_FROM_DEVICE:
> + break;
> + case DMA_TO_DEVICE:
> + case DMA_BIDIRECTIONAL:
> + cpu_dma_wb_range(start, start + size);
> + break;
> + default:
> + BUG();
> }
> -}
>
> -static int nds32_dma_map_sg(struct device *dev, struct scatterlist *sg,
> - int nents, enum dma_data_direction dir,
> - unsigned long attrs)
> -{
> - int i;
> -
> - for (i = 0; i < nents; i++, sg++) {
> - void *virt;
> - unsigned long pfn;
> - struct page *page = sg_page(sg);
> -
> - sg->dma_address = sg_phys(sg);
> - pfn = page_to_pfn(page) + sg->offset / PAGE_SIZE;
> - page = pfn_to_page(pfn);
> - if (PageHighMem(page)) {
> - virt = kmap_atomic(page);
> - consistent_sync(virt, sg->length, dir, FOR_CPU);
> - kunmap_atomic(virt);
> - } else {
> - if (sg->offset > PAGE_SIZE)
> - panic("sg->offset:%08x > PAGE_SIZE\n",
> - sg->offset);
> - virt = page_address(page) + sg->offset;
> - consistent_sync(virt, sg->length, dir, FOR_CPU);
> - }
> - }
> - return nents;
> -}
> -
> -static void nds32_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
> - int nhwentries, enum dma_data_direction dir,
> - unsigned long attrs)
> -{
> + kunmap_atomic(addr);
> }
>
> -static void
> -nds32_dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle,
> - size_t size, enum dma_data_direction dir)
> +void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr,
> + size_t size, enum dma_data_direction dir)
> {
> - consistent_sync((void *)phys_to_virt(handle), size, dir, FOR_CPU);
> -}
> -
> -static void
> -nds32_dma_sync_single_for_device(struct device *dev, dma_addr_t handle,
> - size_t size, enum dma_data_direction dir)
> -{
> - consistent_sync((void *)phys_to_virt(handle), size, dir, FOR_DEVICE);
> -}
> -
> -static void
> -nds32_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents,
> - enum dma_data_direction dir)
> -{
> - int i;
> -
> - for (i = 0; i < nents; i++, sg++) {
> - char *virt =
> - page_address((struct page *)sg->page_link) + sg->offset;
> - consistent_sync(virt, sg->length, dir, FOR_CPU);
> + void *addr = kmap_atomic_pfn(PHYS_PFN(paddr));
> + unsigned long start = (unsigned long)addr;
> +
> + switch (direction) {
> + case DMA_TO_DEVICE:
> + break;
> + case DMA_FROM_DEVICE:
> + case DMA_BIDIRECTIONAL:
> + cpu_dma_inval_range(start, end);
> + break;
> + default:
> + BUG();
> }

CC arch/nds32/kernel/dma.o
arch/nds32/kernel/dma.c: In function 'arch_sync_dma_for_device':
arch/nds32/kernel/dma.c:333:10: error: 'direction' undeclared (first
use in this function)
switch (direction) {
^~~~~~~~~
arch/nds32/kernel/dma.c:333:10: note: each undeclared identifier is
reported only once for each function it appears in
arch/nds32/kernel/dma.c: In function 'arch_sync_dma_for_cpu':
arch/nds32/kernel/dma.c:353:10: error: 'direction' undeclared (first
use in this function)
switch (direction) {
^~~~~~~~~
arch/nds32/kernel/dma.c:358:30: error: 'end' undeclared (first use in
this function)
cpu_dma_inval_range(start, end);
^~~
make[1]: *** [arch/nds32/kernel/dma.o] Error 1
make: *** [arch/nds32/kernel] Error 2

After this building error, the ftmac100.c driver is broken. Not sure
what happened.