On Tue, Jun 19, 2018 at 04:19:25PM -0700, Paul Burton wrote:
> Hi Christoph,
>
> On Fri, Jun 15, 2018 at 01:08:47PM +0200, Christoph Hellwig wrote:
> > -static inline unsigned long plat_dma_addr_to_phys(struct device *dev,
> > - dma_addr_t dma_addr)
> > -{
> > -#if defined(CONFIG_CPU_LOONGSON2F) && defined(CONFIG_64BIT)
> > - return (dma_addr > 0x8fffffff) ? dma_addr : (dma_addr & 0x0fffffff);
> > -#else
> > - return dma_addr & 0x7fffffff;
> > -#endif
> > -}
>
> ...
>
> > +phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dma_addr)
> > +{
> > +#if defined(CONFIG_CPU_LOONGSON2F) && defined(CONFIG_64BIT)
> > + if (dma_addr > 0x8fffffff)
> > + return dma_addr;
> > +#endif
> > + return dma_addr & 0x0fffffff;
> > +}
>
> Thanks for putting in the work here - I've applied patches 1-17 to
> mips-next so far, but I'm struggling to convince myself that the above
> is correct.
>
> In the original code we have 3 distinct cases:
>
> 64b Loongson2F, dma_addr > 0x8fffffff -> dma_addr
> 64b Loongson2F, dma_addr <= 0x8fffffff -> dma_addr & 0x0fffffff
> Everything else -> dma_addr & 0x7fffffff
>
> In the new __dma_to_phys() though only the first case remains the same.
>
> Is this intentional or a mixup?
No, this is a mixup. I hadn't noticed one case was 0x0fffffff and
the other 0x7fffffff.
Below is the minimal fixup that keeps things as much as it was before.
---
>From 174213f535c07774cdbbccd42c76164893729cf5 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@xxxxxx>
Date: Wed, 20 Jun 2018 09:11:15 +0200
Subject: MIPS: loongson64: use generic dma noncoherent ops
Provide phys_to_dma/dma_to_phys helpers, everything else is generic.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
arch/mips/Kconfig | 1 +
.../asm/mach-loongson64/dma-coherence.h | 69 -------------------
arch/mips/loongson64/Kconfig | 2 -
arch/mips/loongson64/common/Makefile | 1 +
arch/mips/loongson64/common/dma.c | 18 +++++
5 files changed, 20 insertions(+), 71 deletions(-)
delete mode 100644 arch/mips/include/asm/mach-loongson64/dma-coherence.h
create mode 100644 arch/mips/loongson64/common/dma.c
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 326bd73bc5bf..e192e484b1b8 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1827,6 +1827,7 @@ config CPU_LOONGSON2
select CPU_SUPPORTS_64BIT_KERNEL
select CPU_SUPPORTS_HIGHMEM
select CPU_SUPPORTS_HUGEPAGES
+ select ARCH_HAS_PHYS_TO_DMA
config CPU_LOONGSON1
bool
diff --git a/arch/mips/include/asm/mach-loongson64/dma-coherence.h b/arch/mips/include/asm/mach-loongson64/dma-coherence.h
deleted file mode 100644
index 651dd2eb3ee5..000000000000
--- a/arch/mips/include/asm/mach-loongson64/dma-coherence.h
+++ /dev/null
@@ -1,69 +0,0 @@
-/*
- * This file is subject to the terms and conditions of the GNU General Public
- * License. See the file "COPYING" in the main directory of this archive
- * for more details.
- *
- * Copyright (C) 2006, 07 Ralf Baechle <ralf@xxxxxxxxxxxxxx>
- * Copyright (C) 2007 Lemote, Inc. & Institute of Computing Technology
- * Author: Fuxin Zhang, zhangfx@xxxxxxxxxx
- *
- */
-#ifndef __ASM_MACH_LOONGSON64_DMA_COHERENCE_H
-#define __ASM_MACH_LOONGSON64_DMA_COHERENCE_H
-
-#ifdef CONFIG_SWIOTLB
-#include <linux/swiotlb.h>
-#endif
-
-struct device;
-
-static inline dma_addr_t plat_map_dma_mem(struct device *dev, void *addr,
- size_t size)
-{
- return virt_to_phys(addr) | 0x80000000;
-}
-
-static inline dma_addr_t plat_map_dma_mem_page(struct device *dev,
- struct page *page)
-{
- return page_to_phys(page) | 0x80000000;
-}
-
-static inline unsigned long plat_dma_addr_to_phys(struct device *dev,
- dma_addr_t dma_addr)
-{
-#if defined(CONFIG_CPU_LOONGSON2F) && defined(CONFIG_64BIT)
- return (dma_addr > 0x8fffffff) ? dma_addr : (dma_addr & 0x0fffffff);
-#else
- return dma_addr & 0x7fffffff;
-#endif
-}
-
-static inline void plat_unmap_dma_mem(struct device *dev, dma_addr_t dma_addr,
- size_t size, enum dma_data_direction direction)
-{
-}
-
-static inline int plat_dma_supported(struct device *dev, u64 mask)
-{
- /*
- * we fall back to GFP_DMA when the mask isn't all 1s,
- * so we can't guarantee allocations that must be
- * within a tighter range than GFP_DMA..
- */
- if (mask < DMA_BIT_MASK(24))
- return 0;
-
- return 1;
-}
-
-static inline int plat_device_is_coherent(struct device *dev)
-{
- return 0;
-}
-
-static inline void plat_post_dma_flush(struct device *dev)
-{
-}
-
-#endif /* __ASM_MACH_LOONGSON64_DMA_COHERENCE_H */
diff --git a/arch/mips/loongson64/Kconfig b/arch/mips/loongson64/Kconfig
index a785bf8da3f3..c865b4b9b775 100644
--- a/arch/mips/loongson64/Kconfig
+++ b/arch/mips/loongson64/Kconfig
@@ -13,7 +13,6 @@ config LEMOTE_FULOONG2E
select CSRC_R4K
select SYS_HAS_CPU_LOONGSON2E
select DMA_NONCOHERENT
- select MIPS_DMA_DEFAULT
select BOOT_ELF32
select BOARD_SCACHE
select HW_HAS_PCI
@@ -45,7 +44,6 @@ config LEMOTE_MACH2F
select CS5536
select CSRC_R4K if ! MIPS_EXTERNAL_TIMER
select DMA_NONCOHERENT
- select MIPS_DMA_DEFAULT
select GENERIC_ISA_DMA_SUPPORT_BROKEN
select HAVE_CLK
select HW_HAS_PCI
diff --git a/arch/mips/loongson64/common/Makefile b/arch/mips/loongson64/common/Makefile
index 684624f61f5a..57ee03022941 100644
--- a/arch/mips/loongson64/common/Makefile
+++ b/arch/mips/loongson64/common/Makefile
@@ -6,6 +6,7 @@
obj-y += setup.o init.o cmdline.o env.o time.o reset.o irq.o \
bonito-irq.o mem.o machtype.o platform.o serial.o
obj-$(CONFIG_PCI) += pci.o
+obj-$(CONFIG_CPU_LOONGSON2) += dma.o
#
# Serial port support
diff --git a/arch/mips/loongson64/common/dma.c b/arch/mips/loongson64/common/dma.c
new file mode 100644
index 000000000000..48f04126bde2
--- /dev/null
+++ b/arch/mips/loongson64/common/dma.c
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/dma-direct.h>
+
+dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
+{
+ return paddr | 0x80000000;
+}
+
+phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dma_addr)
+{
+#if defined(CONFIG_CPU_LOONGSON2F) && defined(CONFIG_64BIT)
+ if (dma_addr > 0x8fffffff)
+ return dma_addr;
+ return dma_addr & 0x0fffffff;
+#else
+ return dma_addr & 0x7fffffff;
+#endif
+}
--
2.17.1
