c6x: remove architecture

The c6x architecture was added to the kernel in 2011 at a time when
running Linux on DSPs was widely seen as the logical evolution.
It appears the trend has gone back to running Linux on Arm based SoCs
with DSP, using a better supported software ecosystem, and having better
real-time behavior for the DSP code. An example of this is TI's own
Keystone2 platform.

The upstream kernel port appears to no longer have any users. Mark
Salter remained avaialable to review patches, but mentioned that
he no longer has access to working hardware himself. Without any
users, it's best to just remove the code completely to reduce the
work for cross-architecture code changes.

Many thanks to Mark for maintaining the code for the past ten years.

Link: https://lore.kernel.org/lkml/41dc7795afda9f776d8cd0d3075f776cf586e97c.camel@redhat.com/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

3 files changed, 0 insertions, 244 deletions

diff --git a/arch/c6x/mm/Makefile b/arch/c6x/mm/Makefile
deleted file mode 100644
index 19d05e972dd1..000000000000
--- a/arch/c6x/mm/Makefile
+++ /dev/null
@@ -1,6 +0,0 @@
-# SPDX-License-Identifier: GPL-2.0-only
-#
-# Makefile for the linux c6x-specific parts of the memory manager.
-#
-
-obj-y := init.o dma-coherent.o
diff --git a/arch/c6x/mm/dma-coherent.c b/arch/c6x/mm/dma-coherent.c
deleted file mode 100644
index 03df07a831fc..000000000000
--- a/arch/c6x/mm/dma-coherent.c
+++ /dev/null
@@ -1,173 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- *  Port on Texas Instruments TMS320C6x architecture
- *
- *  Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated
- *  Author: Aurelien Jacquiot <aurelien.jacquiot@ti.com>
- *
- *  DMA uncached mapping support.
- *
- *  Using code pulled from ARM
- *  Copyright (C) 2000-2004 Russell King
- */
-#include <linux/slab.h>
-#include <linux/bitmap.h>
-#include <linux/bitops.h>
-#include <linux/module.h>
-#include <linux/interrupt.h>
-#include <linux/dma-map-ops.h>
-#include <linux/memblock.h>
-
-#include <asm/cacheflush.h>
-#include <asm/page.h>
-#include <asm/setup.h>
-
-/*
- * DMA coherent memory management, can be redefined using the memdma=
- * kernel command line
- */
-
-/* none by default */
-static phys_addr_t dma_base;
-static u32 dma_size;
-static u32 dma_pages;
-
-static unsigned long *dma_bitmap;
-
-/* bitmap lock */
-static DEFINE_SPINLOCK(dma_lock);
-
-/*
- * Return a DMA coherent and contiguous memory chunk from the DMA memory
- */
-static inline u32 __alloc_dma_pages(int order)
-{
-	unsigned long flags;
-	u32 pos;
-
-	spin_lock_irqsave(&dma_lock, flags);
-	pos = bitmap_find_free_region(dma_bitmap, dma_pages, order);
-	spin_unlock_irqrestore(&dma_lock, flags);
-
-	return dma_base + (pos << PAGE_SHIFT);
-}
-
-static void __free_dma_pages(u32 addr, int order)
-{
-	unsigned long flags;
-	u32 pos = (addr - dma_base) >> PAGE_SHIFT;
-
-	if (addr < dma_base || (pos + (1 << order)) >= dma_pages) {
-		printk(KERN_ERR "%s: freeing outside range.\n", __func__);
-		BUG();
-	}
-
-	spin_lock_irqsave(&dma_lock, flags);
-	bitmap_release_region(dma_bitmap, pos, order);
-	spin_unlock_irqrestore(&dma_lock, flags);
-}
-
-/*
- * Allocate DMA coherent memory space and return both the kernel
- * virtual and DMA address for that space.
- */
-void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
-		gfp_t gfp, unsigned long attrs)
-{
-	void *ret;
-	u32 paddr;
-	int order;
-
-	if (!dma_size || !size)
-		return NULL;
-
-	order = get_count_order(((size - 1) >> PAGE_SHIFT) + 1);
-
-	paddr = __alloc_dma_pages(order);
-
-	if (handle)
-		*handle = paddr;
-
-	if (!paddr)
-		return NULL;
-
-	ret = phys_to_virt(paddr);
-	memset(ret, 0, 1 << order);
-	return ret;
-}
-
-/*
- * Free DMA coherent memory as defined by the above mapping.
- */
-void arch_dma_free(struct device *dev, size_t size, void *vaddr,
-		dma_addr_t dma_handle, unsigned long attrs)
-{
-	int order;
-
-	if (!dma_size || !size)
-		return;
-
-	order = get_count_order(((size - 1) >> PAGE_SHIFT) + 1);
-
-	__free_dma_pages(virt_to_phys(vaddr), order);
-}
-
-/*
- * Initialise the coherent DMA memory allocator using the given uncached region.
- */
-void __init coherent_mem_init(phys_addr_t start, u32 size)
-{
-	if (!size)
-		return;
-
-	printk(KERN_INFO
-	       "Coherent memory (DMA) region start=0x%x size=0x%x\n",
-	       start, size);
-
-	dma_base = start;
-	dma_size = size;
-
-	/* allocate bitmap */
-	dma_pages = dma_size >> PAGE_SHIFT;
-	if (dma_size & (PAGE_SIZE - 1))
-		++dma_pages;
-
-	dma_bitmap = memblock_alloc(BITS_TO_LONGS(dma_pages) * sizeof(long),
-				    sizeof(long));
-	if (!dma_bitmap)
-		panic("%s: Failed to allocate %zu bytes align=0x%zx\n",
-		      __func__, BITS_TO_LONGS(dma_pages) * sizeof(long),
-		      sizeof(long));
-}
-
-static void c6x_dma_sync(phys_addr_t paddr, size_t size,
-		enum dma_data_direction dir)
-{
-	BUG_ON(!valid_dma_direction(dir));
-
-	switch (dir) {
-	case DMA_FROM_DEVICE:
-		L2_cache_block_invalidate(paddr, paddr + size);
-		break;
-	case DMA_TO_DEVICE:
-		L2_cache_block_writeback(paddr, paddr + size);
-		break;
-	case DMA_BIDIRECTIONAL:
-		L2_cache_block_writeback_invalidate(paddr, paddr + size);
-		break;
-	default:
-		break;
-	}
-}
-
-void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
-		enum dma_data_direction dir)
-{
-	return c6x_dma_sync(paddr, size, dir);
-}
-
-void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
-		enum dma_data_direction dir)
-{
-	return c6x_dma_sync(paddr, size, dir);
-}
diff --git a/arch/c6x/mm/init.c b/arch/c6x/mm/init.c
deleted file mode 100644
index a97e51a3e26d..000000000000
--- a/arch/c6x/mm/init.c
+++ /dev/null
@@ -1,65 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- *  Port on Texas Instruments TMS320C6x architecture
- *
- *  Copyright (C) 2004, 2009, 2010, 2011 Texas Instruments Incorporated
- *  Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
- */
-#include <linux/mm.h>
-#include <linux/swap.h>
-#include <linux/module.h>
-#include <linux/memblock.h>
-#ifdef CONFIG_BLK_DEV_RAM
-#include <linux/blkdev.h>
-#endif
-#include <linux/initrd.h>
-
-#include <asm/sections.h>
-#include <linux/uaccess.h>
-
-/*
- * ZERO_PAGE is a special page that is used for zero-initialized
- * data and COW.
- */
-unsigned long empty_zero_page;
-EXPORT_SYMBOL(empty_zero_page);
-
-/*
- * paging_init() continues the virtual memory environment setup which
- * was begun by the code in arch/head.S.
- * The parameters are pointers to where to stick the starting and ending
- * addresses  of available kernel virtual memory.
- */
-void __init paging_init(void)
-{
-	struct pglist_data *pgdat = NODE_DATA(0);
-	unsigned long max_zone_pfn[MAX_NR_ZONES] = {0, };
-
-	empty_zero_page      = (unsigned long) memblock_alloc(PAGE_SIZE,
-							      PAGE_SIZE);
-	if (!empty_zero_page)
-		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
-		      __func__, PAGE_SIZE, PAGE_SIZE);
-
-	/*
-	 * Set up user data space
-	 */
-	set_fs(KERNEL_DS);
-
-	/*
-	 * Define zones
-	 */
-	max_zone_pfn[ZONE_NORMAL] = memory_end >> PAGE_SHIFT;
-
-	free_area_init(max_zone_pfn);
-}
-
-void __init mem_init(void)
-{
-	high_memory = (void *)(memory_end & PAGE_MASK);
-
-	/* this will put all memory onto the freelists */
-	memblock_free_all();
-
-	mem_init_print_info(NULL);
-}