From: Yann Sionneau <ysionneau@xxxxxxxxx>
Signed-off-by: Jules Maselbas <jmaselbas@xxxxxxxxx>
---
changes v1 -> v2:
- add BUILD_BUG_ON_MSG in dma_alloc_coherent
- renamed kvx_dcache_invalidate_mem_area to invalidate_dcache_range
- add comment on dcache beeing write-through
---
arch/kvx/Kconfig | 1 +
arch/kvx/include/asm/dma.h | 32 +++++++++++
arch/kvx/include/asm/sys_arch.h | 3 ++
arch/kvx/lib/Makefile | 2 +-
arch/kvx/lib/dma-default.c | 94 +++++++++++++++++++++++++++++++++
5 files changed, 131 insertions(+), 1 deletion(-)
create mode 100644 arch/kvx/include/asm/dma.h
create mode 100644 arch/kvx/lib/dma-default.c
diff --git a/arch/kvx/Kconfig b/arch/kvx/Kconfig
index 4e02613ec..093444088 100644
--- a/arch/kvx/Kconfig
+++ b/arch/kvx/Kconfig
@@ -13,6 +13,7 @@ config KVX
select GENERIC_FIND_NEXT_BIT
select HAS_ARCH_SJLJ
select HAS_CACHE
+ select HAS_DMA
select LIBFDT
select MFD_SYSCON
select OF_BAREBOX_DRIVERS
diff --git a/arch/kvx/include/asm/dma.h b/arch/kvx/include/asm/dma.h
new file mode 100644
index 000000000..a7ecf279a
--- /dev/null
+++ b/arch/kvx/include/asm/dma.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* SPDX-FileCopyrightText: 2021 Yann Sionneau <ysionneau@xxxxxxxxx>, Kalray Inc. */
+
+#ifndef __ASM_DMA_H
+#define __ASM_DMA_H
+
+#include <common.h>
+
+#define KVX_DDR_32BIT_RAM_WINDOW_BA (0x80000000ULL)
+#define KVX_DDR_64BIT_RAM_WINDOW_BA (0x100000000ULL)
+#define MAX_32BIT_ADDR (0xffffffffULL)
+
+#define dma_alloc dma_alloc
+static inline void *dma_alloc(size_t size)
+{
+ return xmemalign(64, ALIGN(size, 64));
+}
+
+static inline void *dma_alloc_coherent(size_t size, dma_addr_t *dma_handle)
+{
+ BUILD_BUG_ON_MSG(1, "dma_alloc_coherent not supported: "
+ "MMU support is required to map uncached pages");
+ return NULL;
+}
+
+static inline void dma_free_coherent(void *mem, dma_addr_t dma_handle,
+ size_t size)
+{
+ free(mem);
+}
+
+#endif /* __ASM_DMA_H */
diff --git a/arch/kvx/include/asm/sys_arch.h b/arch/kvx/include/asm/sys_arch.h
index 9df32c4e7..ce07a5598 100644
--- a/arch/kvx/include/asm/sys_arch.h
+++ b/arch/kvx/include/asm/sys_arch.h
@@ -11,6 +11,9 @@
#define EXCEPTION_STRIDE 0x40
#define EXCEPTION_ALIGNMENT 0x100
+#define kvx_cluster_id() ((int) \
+ ((kvx_sfr_get(PCR) & KVX_SFR_PCR_CID_MASK) \
+ >> KVX_SFR_PCR_CID_SHIFT))
#define KVX_SFR_START(__sfr_reg) \
(KVX_SFR_## __sfr_reg ## _SHIFT)
diff --git a/arch/kvx/lib/Makefile b/arch/kvx/lib/Makefile
index d271ebccf..c730e1c23 100644
--- a/arch/kvx/lib/Makefile
+++ b/arch/kvx/lib/Makefile
@@ -3,4 +3,4 @@
# Copyright (C) 2019 Kalray Inc.
#
-obj-y += cpuinfo.o board.o dtb.o poweroff.o bootm.o setjmp.o cache.o
+obj-y += cpuinfo.o board.o dtb.o poweroff.o bootm.o setjmp.o cache.o dma-default.o
diff --git a/arch/kvx/lib/dma-default.c b/arch/kvx/lib/dma-default.c
new file mode 100644
index 000000000..2a4144696
--- /dev/null
+++ b/arch/kvx/lib/dma-default.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// SPDX-FileCopyrightText: 2021 Yann Sionneau <ysionneau@xxxxxxxxx>, Kalray Inc.
+
+#include <dma.h>
+#include <asm/barrier.h>
+#include <asm/io.h>
+#include <asm/cache.h>
+#include <asm/sfr.h>
+#include <asm/sys_arch.h>
+
+/*
+ * The implementation of arch should follow the following rules:
+ * map for_cpu for_device unmap
+ * TO_DEV writeback none writeback none
+ * FROM_DEV invalidate invalidate(*) invalidate invalidate(*)
+ * BIDIR writeback invalidate writeback invalidate
+ *
+ * (*) - only necessary if the CPU speculatively prefetches.
+ *
+ * (see https://lkml.org/lkml/2018/5/18/979)
+ */
+
+void dma_sync_single_for_device(dma_addr_t addr, size_t size,
+ enum dma_data_direction dir)
+{
+ /* dcache is Write-Through: no need to flush to force writeback */
+ switch (dir) {
+ case DMA_FROM_DEVICE:
+ invalidate_dcache_range(addr, addr + size);
+ break;
+ case DMA_TO_DEVICE:
+ case DMA_BIDIRECTIONAL:
+ /* allow device to read buffer written by CPU */
+ wmb();
+ break;
+ default:
+ BUG();
+ }
+}
+
+void dma_sync_single_for_cpu(dma_addr_t addr, size_t size,
+ enum dma_data_direction dir)
+{
+ /* CPU does not speculatively prefetches */
+ switch (dir) {
+ case DMA_FROM_DEVICE:
+ /* invalidate has been done during map/for_device */
+ case DMA_TO_DEVICE:
+ break;
+ case DMA_BIDIRECTIONAL:
+ invalidate_dcache_range(addr, addr + size);
+ break;
+ default:
+ BUG();
+ }
+}
+
+#define KVX_DDR_ALIAS_OFFSET \
+ (KVX_DDR_64BIT_RAM_WINDOW_BA - KVX_DDR_32BIT_RAM_WINDOW_BA)
+#define KVX_DDR_ALIAS_WINDOW \
+ (KVX_DDR_64BIT_RAM_WINDOW_BA + KVX_DDR_ALIAS_OFFSET)
+
+/* Local smem is aliased between 0 and 16MB */
+#define KVX_SMEM_LOCAL_ALIAS 0x1000000ULL
+
+dma_addr_t dma_map_single(struct device_d *dev, void *ptr, size_t size,
+ enum dma_data_direction dir)
+{
+ uintptr_t addr = (uintptr_t) ptr;
+
+ dma_sync_single_for_device(addr, size, dir);
+
+ /* Local smem alias should never be used for dma */
+ if (addr < KVX_SMEM_LOCAL_ALIAS)
+ return addr + (1 + kvx_cluster_id()) * KVX_SMEM_LOCAL_ALIAS;
+
+ if (dev->dma_mask && addr <= dev->dma_mask)
+ return addr;
+
+ if (addr >= KVX_DDR_ALIAS_WINDOW)
+ return DMA_ERROR_CODE;
+
+ addr -= KVX_DDR_ALIAS_OFFSET;
+ if (dev->dma_mask && addr > dev->dma_mask)
+ return DMA_ERROR_CODE;
+
+ return addr;
+}
+
+void dma_unmap_single(struct device_d *dev, dma_addr_t addr, size_t size,
+ enum dma_data_direction dir)
+{
+ dma_sync_single_for_cpu(addr, size, dir);
+}
--
2.17.1
_______________________________________________
barebox mailing list
barebox@xxxxxxxxxxxxxxxxxxx
http://lists.infradead.org/mailman/listinfo/barebox
