summaryrefslogtreecommitdiffstats
path: root/arch/mips/sgi-ip32/ip32-dma.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/mips/sgi-ip32/ip32-dma.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/mips/sgi-ip32/ip32-dma.c')
-rw-r--r--arch/mips/sgi-ip32/ip32-dma.c37
1 files changed, 37 insertions, 0 deletions
diff --git a/arch/mips/sgi-ip32/ip32-dma.c b/arch/mips/sgi-ip32/ip32-dma.c
new file mode 100644
index 000000000..20c6da9d7
--- /dev/null
+++ b/arch/mips/sgi-ip32/ip32-dma.c
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2006 Ralf Baechle <ralf@linux-mips.org>
+ */
+#include <linux/dma-direct.h>
+#include <asm/ip32/crime.h>
+
+/*
+ * Few notes.
+ * 1. CPU sees memory as two chunks: 0-256M@0x0, and the rest @0x40000000+256M
+ * 2. PCI sees memory as one big chunk @0x0 (or we could use 0x40000000 for
+ * native-endian)
+ * 3. All other devices see memory as one big chunk at 0x40000000
+ * 4. Non-PCI devices will pass NULL as struct device*
+ *
+ * Thus we translate differently, depending on device.
+ */
+
+#define RAM_OFFSET_MASK 0x3fffffffUL
+
+dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
+{
+ dma_addr_t dma_addr = paddr & RAM_OFFSET_MASK;
+
+ if (!dev)
+ dma_addr += CRIME_HI_MEM_BASE;
+ return dma_addr;
+}
+
+phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
+{
+ phys_addr_t paddr = dma_addr & RAM_OFFSET_MASK;
+
+ if (dma_addr >= 256*1024*1024)
+ paddr += CRIME_HI_MEM_BASE;
+ return paddr;
+}