[PATCH v1 3/4] MIPS: bmips: Remove obsolete DMA mapping support

Jim Quinlan
2021-12-09T20:47:44Z

The code in 'arch/mips/bmips/dma.c' performed DMA mapping for inbound
regions. This mapping was and is required for the Broadcom STB PCIe
controller HW. This code is removed as the current 'struct device' has a
@dma_range_map field which performs the same functionality by processing
the "dma-ranges" DT property.

Subsequently, ARCH_HAS_PHYS_TO_DMA is now unset since the dma_to_phys()
and phys_to_dma() functions are removed.

Signed-off-by: Jim Quinlan <jim2101024@gmail.com>
---
arch/mips/Kconfig | 1 -
arch/mips/bmips/dma.c | 106 +-----------------------------------------
2 files changed, 2 insertions(+), 105 deletions(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 0215dc1529e9..eb1184a7254b 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -264,7 +264,6 @@ config BMIPS_GENERIC
bool "Broadcom Generic BMIPS kernel"
select ARCH_HAS_RESET_CONTROLLER
select ARCH_HAS_SYNC_DMA_FOR_CPU_ALL
- select ARCH_HAS_PHYS_TO_DMA
select BOOT_RAW
select NO_EXCEPT_FILL
select USE_OF
diff --git a/arch/mips/bmips/dma.c b/arch/mips/bmips/dma.c
index 915ce4b189c1..c535f9cb75ec 100644
--- a/arch/mips/bmips/dma.c
+++ b/arch/mips/bmips/dma.c
@@ -1,68 +1,8 @@
-/*
- * 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) 2014 Kevin Cernekee <cernekee@gmail.com>
- */
+// SPDX-License-Identifier: GPL-2.0+

-#define pr_fmt(fmt) "bmips-dma: " fmt
-
-#include <linux/device.h>
-#include <linux/dma-direction.h>
-#include <linux/dma-direct.h>
-#include <linux/init.h>
-#include <linux/io.h>
-#include <linux/of.h>
-#include <linux/printk.h>
-#include <linux/slab.h>
#include <linux/types.h>
#include <asm/bmips.h>
-
-/*
- * BCM338x has configurable address translation windows which allow the
- * peripherals' DMA addresses to be different from the Zephyr-visible
- * physical addresses. e.g. usb_dma_addr = zephyr_pa ^ 0x08000000
- *
- * If the "brcm,ubus" node has a "dma-ranges" property we will enable this
- * translation globally using the provided information. This implements a
- * very limited subset of "dma-ranges" support and it will probably be
- * replaced by a more generic version later.
- */
-
-struct bmips_dma_range {
- u32 child_addr;
- u32 parent_addr;
- u32 size;
-};
-
-static struct bmips_dma_range *bmips_dma_ranges;
-
-#define FLUSH_RAC 0x100
-
-dma_addr_t phys_to_dma(struct device *dev, phys_addr_t pa)
-{
- struct bmips_dma_range *r;
-
- for (r = bmips_dma_ranges; r && r->size; r++) {
- if (pa >= r->child_addr &&
- pa < (r->child_addr + r->size))
- return pa - r->child_addr + r->parent_addr;
- }
- return pa;
-}
-
-phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr)
-{
- struct bmips_dma_range *r;
-
- for (r = bmips_dma_ranges; r && r->size; r++) {
- if (dma_addr >= r->parent_addr &&
- dma_addr < (r->parent_addr + r->size))
- return dma_addr - r->parent_addr + r->child_addr;
- }
- return dma_addr;
-}
+#include <asm/io.h>

void arch_sync_dma_for_cpu_all(void)
{
@@ -79,45 +19,3 @@ void arch_sync_dma_for_cpu_all(void)
__raw_writel(cfg | 0x100, cbr + BMIPS_RAC_CONFIG);
__raw_readl(cbr + BMIPS_RAC_CONFIG);
}
-
-static int __init bmips_init_dma_ranges(void)
-{
- struct device_node *np =
- of_find_compatible_node(NULL, NULL, "brcm,ubus");
- const __be32 *data;
- struct bmips_dma_range *r;
- int len;
-
- if (!np)
- return 0;
-
- data = of_get_property(np, "dma-ranges", &len);
- if (!data)
- goto out_good;
-
- len /= sizeof(*data) * 3;
- if (!len)
- goto out_bad;
-
- /* add a dummy (zero) entry at the end as a sentinel */
- bmips_dma_ranges = kcalloc(len + 1, sizeof(struct bmips_dma_range),
- GFP_KERNEL);
- if (!bmips_dma_ranges)
- goto out_bad;
-
- for (r = bmips_dma_ranges; len; len--, r++) {
- r->child_addr = be32_to_cpup(data++);
- r->parent_addr = be32_to_cpup(data++);
- r->size = be32_to_cpup(data++);
- }
-
-out_good:
- of_node_put(np);
- return 0;
-
-out_bad:
- pr_err("error parsing dma-ranges property\n");
- of_node_put(np);
- return -EINVAL;
-}
-arch_initcall(bmips_init_dma_ranges);
--
2.17.1