metag: Remove arch/metag/

The earliest Meta architecture port of Linux I have a record of was an
import of a Meta port of Linux v2.4.1 in February 2004, which was worked
on significantly over the next few years by Graham Whaley, Will Newton,
Matt Fleming, myself and others.

Eventually the port was merged into mainline in v3.9 in March 2013, not
long after Imagination Technologies bought MIPS Technologies and shifted
its CPU focus over to the MIPS architecture.

As a result, though the port was maintained for a while, kept on life
support for a while longer, and useful for testing a few specific
drivers for which I don't have ready access to the equivalent MIPS
hardware, it is now essentially dead with no users.

It is also stuck using an out-of-tree toolchain based on GCC 4.2.4 which
is no longer maintained, now struggles to build modern kernels due to
toolchain bugs, and doesn't itself build with a modern GCC. The latest
buildroot port is still using an old uClibc snapshot which is no longer
served, and the latest uClibc doesn't build with GCC 4.2.4.

So lets call it a day and drop the Meta architecture port from the
kernel. RIP Meta.

Signed-off-by: James Hogan <jhogan@kernel.org>
Link: https://lkml.kernel.org/r/95906b76-6ce1-3f84-eaba-c29b4ae952eb@roeck-us.net
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Graham Whaley <graham.whaley@gmail.com>
Cc: linux-metag@vger.kernel.org

1 files changed, 0 insertions, 588 deletions

diff --git a/arch/metag/kernel/dma.c b/arch/metag/kernel/dma.c
deleted file mode 100644
index f0ab3a4..0000000
--- a/arch/metag/kernel/dma.c
+++ /dev/null
@@ -1,588 +0,0 @@
-/*
- *  Meta version derived from arch/powerpc/lib/dma-noncoherent.c
- *    Copyright (C) 2008 Imagination Technologies Ltd.
- *
- *  PowerPC version derived from arch/arm/mm/consistent.c
- *    Copyright (C) 2001 Dan Malek (dmalek@jlc.net)
- *
- *  Copyright (C) 2000 Russell King
- *
- * Consistent memory allocators.  Used for DMA devices that want to
- * share uncached memory with the processor core.  The function return
- * is the virtual address and 'dma_handle' is the physical address.
- * Mostly stolen from the ARM port, with some changes for PowerPC.
- *						-- Dan
- *
- * Reorganized to get rid of the arch-specific consistent_* functions
- * and provide non-coherent implementations for the DMA API. -Matt
- *
- * Added in_interrupt() safe dma_alloc_coherent()/dma_free_coherent()
- * implementation. This is pulled straight from ARM and barely
- * modified. -Matt
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-
-#include <linux/sched.h>
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/export.h>
-#include <linux/string.h>
-#include <linux/types.h>
-#include <linux/highmem.h>
-#include <linux/dma-mapping.h>
-#include <linux/slab.h>
-
-#include <asm/tlbflush.h>
-#include <asm/mmu.h>
-
-#define CONSISTENT_OFFSET(x)	(((unsigned long)(x) - CONSISTENT_START) \
-					>> PAGE_SHIFT)
-
-static u64 get_coherent_dma_mask(struct device *dev)
-{
-	u64 mask = ~0ULL;
-
-	if (dev) {
-		mask = dev->coherent_dma_mask;
-
-		/*
-		 * Sanity check the DMA mask - it must be non-zero, and
-		 * must be able to be satisfied by a DMA allocation.
-		 */
-		if (mask == 0) {
-			dev_warn(dev, "coherent DMA mask is unset\n");
-			return 0;
-		}
-	}
-
-	return mask;
-}
-/*
- * This is the page table (2MB) covering uncached, DMA consistent allocations
- */
-static pte_t *consistent_pte;
-static DEFINE_SPINLOCK(consistent_lock);
-
-/*
- * VM region handling support.
- *
- * This should become something generic, handling VM region allocations for
- * vmalloc and similar (ioremap, module space, etc).
- *
- * I envisage vmalloc()'s supporting vm_struct becoming:
- *
- *  struct vm_struct {
- *    struct metag_vm_region	region;
- *    unsigned long	flags;
- *    struct page	**pages;
- *    unsigned int	nr_pages;
- *    unsigned long	phys_addr;
- *  };
- *
- * get_vm_area() would then call metag_vm_region_alloc with an appropriate
- * struct metag_vm_region head (eg):
- *
- *  struct metag_vm_region vmalloc_head = {
- *	.vm_list	= LIST_HEAD_INIT(vmalloc_head.vm_list),
- *	.vm_start	= VMALLOC_START,
- *	.vm_end		= VMALLOC_END,
- *  };
- *
- * However, vmalloc_head.vm_start is variable (typically, it is dependent on
- * the amount of RAM found at boot time.)  I would imagine that get_vm_area()
- * would have to initialise this each time prior to calling
- * metag_vm_region_alloc().
- */
-struct metag_vm_region {
-	struct list_head vm_list;
-	unsigned long vm_start;
-	unsigned long vm_end;
-	struct page		*vm_pages;
-	int			vm_active;
-};
-
-static struct metag_vm_region consistent_head = {
-	.vm_list = LIST_HEAD_INIT(consistent_head.vm_list),
-	.vm_start = CONSISTENT_START,
-	.vm_end = CONSISTENT_END,
-};
-
-static struct metag_vm_region *metag_vm_region_alloc(struct metag_vm_region
-						     *head, size_t size,
-						     gfp_t gfp)
-{
-	unsigned long addr = head->vm_start, end = head->vm_end - size;
-	unsigned long flags;
-	struct metag_vm_region *c, *new;
-
-	new = kmalloc(sizeof(struct metag_vm_region), gfp);
-	if (!new)
-		goto out;
-
-	spin_lock_irqsave(&consistent_lock, flags);
-
-	list_for_each_entry(c, &head->vm_list, vm_list) {
-		if ((addr + size) < addr)
-			goto nospc;
-		if ((addr + size) <= c->vm_start)
-			goto found;
-		addr = c->vm_end;
-		if (addr > end)
-			goto nospc;
-	}
-
-found:
-	/*
-	 * Insert this entry _before_ the one we found.
-	 */
-	list_add_tail(&new->vm_list, &c->vm_list);
-	new->vm_start = addr;
-	new->vm_end = addr + size;
-	new->vm_active = 1;
-
-	spin_unlock_irqrestore(&consistent_lock, flags);
-	return new;
-
-nospc:
-	spin_unlock_irqrestore(&consistent_lock, flags);
-	kfree(new);
-out:
-	return NULL;
-}
-
-static struct metag_vm_region *metag_vm_region_find(struct metag_vm_region
-						    *head, unsigned long addr)
-{
-	struct metag_vm_region *c;
-
-	list_for_each_entry(c, &head->vm_list, vm_list) {
-		if (c->vm_active && c->vm_start == addr)
-			goto out;
-	}
-	c = NULL;
-out:
-	return c;
-}
-
-/*
- * Allocate DMA-coherent memory space and return both the kernel remapped
- * virtual and bus address for that space.
- */
-static void *metag_dma_alloc(struct device *dev, size_t size,
-		dma_addr_t *handle, gfp_t gfp, unsigned long attrs)
-{
-	struct page *page;
-	struct metag_vm_region *c;
-	unsigned long order;
-	u64 mask = get_coherent_dma_mask(dev);
-	u64 limit;
-
-	if (!consistent_pte) {
-		pr_err("%s: not initialised\n", __func__);
-		dump_stack();
-		return NULL;
-	}
-
-	if (!mask)
-		goto no_page;
-	size = PAGE_ALIGN(size);
-	limit = (mask + 1) & ~mask;
-	if ((limit && size >= limit)
-	    || size >= (CONSISTENT_END - CONSISTENT_START)) {
-		pr_warn("coherent allocation too big (requested %#x mask %#Lx)\n",
-			size, mask);
-		return NULL;
-	}
-
-	order = get_order(size);
-
-	if (mask != 0xffffffff)
-		gfp |= GFP_DMA;
-
-	page = alloc_pages(gfp, order);
-	if (!page)
-		goto no_page;
-
-	/*
-	 * Invalidate any data that might be lurking in the
-	 * kernel direct-mapped region for device DMA.
-	 */
-	{
-		void *kaddr = page_address(page);
-		memset(kaddr, 0, size);
-		flush_dcache_region(kaddr, size);
-	}
-
-	/*
-	 * Allocate a virtual address in the consistent mapping region.
-	 */
-	c = metag_vm_region_alloc(&consistent_head, size,
-				  gfp & ~(__GFP_DMA | __GFP_HIGHMEM));
-	if (c) {
-		unsigned long vaddr = c->vm_start;
-		pte_t *pte = consistent_pte + CONSISTENT_OFFSET(vaddr);
-		struct page *end = page + (1 << order);
-
-		c->vm_pages = page;
-		split_page(page, order);
-
-		/*
-		 * Set the "dma handle"
-		 */
-		*handle = page_to_bus(page);
-
-		do {
-			BUG_ON(!pte_none(*pte));
-
-			SetPageReserved(page);
-			set_pte_at(&init_mm, vaddr,
-				   pte, mk_pte(page,
-					       pgprot_writecombine
-					       (PAGE_KERNEL)));
-			page++;
-			pte++;
-			vaddr += PAGE_SIZE;
-		} while (size -= PAGE_SIZE);
-
-		/*
-		 * Free the otherwise unused pages.
-		 */
-		while (page < end) {
-			__free_page(page);
-			page++;
-		}
-
-		return (void *)c->vm_start;
-	}
-
-	if (page)
-		__free_pages(page, order);
-no_page:
-	return NULL;
-}
-
-/*
- * free a page as defined by the above mapping.
- */
-static void metag_dma_free(struct device *dev, size_t size, void *vaddr,
-		dma_addr_t dma_handle, unsigned long attrs)
-{
-	struct metag_vm_region *c;
-	unsigned long flags, addr;
-	pte_t *ptep;
-
-	size = PAGE_ALIGN(size);
-
-	spin_lock_irqsave(&consistent_lock, flags);
-
-	c = metag_vm_region_find(&consistent_head, (unsigned long)vaddr);
-	if (!c)
-		goto no_area;
-
-	c->vm_active = 0;
-	if ((c->vm_end - c->vm_start) != size) {
-		pr_err("%s: freeing wrong coherent size (%ld != %d)\n",
-		       __func__, c->vm_end - c->vm_start, size);
-		dump_stack();
-		size = c->vm_end - c->vm_start;
-	}
-
-	ptep = consistent_pte + CONSISTENT_OFFSET(c->vm_start);
-	addr = c->vm_start;
-	do {
-		pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep);
-		unsigned long pfn;
-
-		ptep++;
-		addr += PAGE_SIZE;
-
-		if (!pte_none(pte) && pte_present(pte)) {
-			pfn = pte_pfn(pte);
-
-			if (pfn_valid(pfn)) {
-				struct page *page = pfn_to_page(pfn);
-				__free_reserved_page(page);
-				continue;
-			}
-		}
-
-		pr_crit("%s: bad page in kernel page table\n",
-			__func__);
-	} while (size -= PAGE_SIZE);
-
-	flush_tlb_kernel_range(c->vm_start, c->vm_end);
-
-	list_del(&c->vm_list);
-
-	spin_unlock_irqrestore(&consistent_lock, flags);
-
-	kfree(c);
-	return;
-
-no_area:
-	spin_unlock_irqrestore(&consistent_lock, flags);
-	pr_err("%s: trying to free invalid coherent area: %p\n",
-	       __func__, vaddr);
-	dump_stack();
-}
-
-static int metag_dma_mmap(struct device *dev, struct vm_area_struct *vma,
-		void *cpu_addr, dma_addr_t dma_addr, size_t size,
-		unsigned long attrs)
-{
-	unsigned long flags, user_size, kern_size;
-	struct metag_vm_region *c;
-	int ret = -ENXIO;
-
-	if (attrs & DMA_ATTR_WRITE_COMBINE)
-		vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
-	else
-		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
-
-	user_size = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
-
-	spin_lock_irqsave(&consistent_lock, flags);
-	c = metag_vm_region_find(&consistent_head, (unsigned long)cpu_addr);
-	spin_unlock_irqrestore(&consistent_lock, flags);
-
-	if (c) {
-		unsigned long off = vma->vm_pgoff;
-
-		kern_size = (c->vm_end - c->vm_start) >> PAGE_SHIFT;
-
-		if (off < kern_size &&
-		    user_size <= (kern_size - off)) {
-			ret = remap_pfn_range(vma, vma->vm_start,
-					      page_to_pfn(c->vm_pages) + off,
-					      user_size << PAGE_SHIFT,
-					      vma->vm_page_prot);
-		}
-	}
-
-
-	return ret;
-}
-
-/*
- * Initialise the consistent memory allocation.
- */
-static int __init dma_alloc_init(void)
-{
-	pgd_t *pgd, *pgd_k;
-	pud_t *pud, *pud_k;
-	pmd_t *pmd, *pmd_k;
-	pte_t *pte;
-	int ret = 0;
-
-	do {
-		int offset = pgd_index(CONSISTENT_START);
-		pgd = pgd_offset(&init_mm, CONSISTENT_START);
-		pud = pud_alloc(&init_mm, pgd, CONSISTENT_START);
-		pmd = pmd_alloc(&init_mm, pud, CONSISTENT_START);
-		WARN_ON(!pmd_none(*pmd));
-
-		pte = pte_alloc_kernel(pmd, CONSISTENT_START);
-		if (!pte) {
-			pr_err("%s: no pte tables\n", __func__);
-			ret = -ENOMEM;
-			break;
-		}
-
-		pgd_k = ((pgd_t *) mmu_get_base()) + offset;
-		pud_k = pud_offset(pgd_k, CONSISTENT_START);
-		pmd_k = pmd_offset(pud_k, CONSISTENT_START);
-		set_pmd(pmd_k, *pmd);
-
-		consistent_pte = pte;
-	} while (0);
-
-	return ret;
-}
-early_initcall(dma_alloc_init);
-
-/*
- * make an area consistent to devices.
- */
-static void dma_sync_for_device(void *vaddr, size_t size, int dma_direction)
-{
-	/*
-	 * Ensure any writes get through the write combiner. This is necessary
-	 * even with DMA_FROM_DEVICE, or the write may dirty the cache after
-	 * we've invalidated it and get written back during the DMA.
-	 */
-
-	barrier();
-
-	switch (dma_direction) {
-	case DMA_BIDIRECTIONAL:
-		/*
-		 * Writeback to ensure the device can see our latest changes and
-		 * so that we have no dirty lines, and invalidate the cache
-		 * lines too in preparation for receiving the buffer back
-		 * (dma_sync_for_cpu) later.
-		 */
-		flush_dcache_region(vaddr, size);
-		break;
-	case DMA_TO_DEVICE:
-		/*
-		 * Writeback to ensure the device can see our latest changes.
-		 * There's no need to invalidate as the device shouldn't write
-		 * to the buffer.
-		 */
-		writeback_dcache_region(vaddr, size);
-		break;
-	case DMA_FROM_DEVICE:
-		/*
-		 * Invalidate to ensure we have no dirty lines that could get
-		 * written back during the DMA. It's also safe to flush
-		 * (writeback) here if necessary.
-		 */
-		invalidate_dcache_region(vaddr, size);
-		break;
-	case DMA_NONE:
-		BUG();
-	}
-
-	wmb();
-}
-
-/*
- * make an area consistent to the core.
- */
-static void dma_sync_for_cpu(void *vaddr, size_t size, int dma_direction)
-{
-	/*
-	 * Hardware L2 cache prefetch doesn't occur across 4K physical
-	 * boundaries, however according to Documentation/DMA-API-HOWTO.txt
-	 * kmalloc'd memory is DMA'able, so accesses in nearby memory could
-	 * trigger a cache fill in the DMA buffer.
-	 *
-	 * This should never cause dirty lines, so a flush or invalidate should
-	 * be safe to allow us to see data from the device.
-	 */
-	if (_meta_l2c_pf_is_enabled()) {
-		switch (dma_direction) {
-		case DMA_BIDIRECTIONAL:
-		case DMA_FROM_DEVICE:
-			invalidate_dcache_region(vaddr, size);
-			break;
-		case DMA_TO_DEVICE:
-			/* The device shouldn't have written to the buffer */
-			break;
-		case DMA_NONE:
-			BUG();
-		}
-	}
-
-	rmb();
-}
-
-static dma_addr_t metag_dma_map_page(struct device *dev, struct page *page,
-		unsigned long offset, size_t size,
-		enum dma_data_direction direction, unsigned long attrs)
-{
-	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
-		dma_sync_for_device((void *)(page_to_phys(page) + offset),
-				    size, direction);
-	return page_to_phys(page) + offset;
-}
-
-static void metag_dma_unmap_page(struct device *dev, dma_addr_t dma_address,
-		size_t size, enum dma_data_direction direction,
-		unsigned long attrs)
-{
-	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
-		dma_sync_for_cpu(phys_to_virt(dma_address), size, direction);
-}
-
-static int metag_dma_map_sg(struct device *dev, struct scatterlist *sglist,
-		int nents, enum dma_data_direction direction,
-		unsigned long attrs)
-{
-	struct scatterlist *sg;
-	int i;
-
-	for_each_sg(sglist, sg, nents, i) {
-		BUG_ON(!sg_page(sg));
-
-		sg->dma_address = sg_phys(sg);
-
-		if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
-			continue;
-
-		dma_sync_for_device(sg_virt(sg), sg->length, direction);
-	}
-
-	return nents;
-}
-
-
-static void metag_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
-		int nhwentries, enum dma_data_direction direction,
-		unsigned long attrs)
-{
-	struct scatterlist *sg;
-	int i;
-
-	for_each_sg(sglist, sg, nhwentries, i) {
-		BUG_ON(!sg_page(sg));
-
-		sg->dma_address = sg_phys(sg);
-
-		if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
-			continue;
-
-		dma_sync_for_cpu(sg_virt(sg), sg->length, direction);
-	}
-}
-
-static void metag_dma_sync_single_for_cpu(struct device *dev,
-		dma_addr_t dma_handle, size_t size,
-		enum dma_data_direction direction)
-{
-	dma_sync_for_cpu(phys_to_virt(dma_handle), size, direction);
-}
-
-static void metag_dma_sync_single_for_device(struct device *dev,
-		dma_addr_t dma_handle, size_t size,
-		enum dma_data_direction direction)
-{
-	dma_sync_for_device(phys_to_virt(dma_handle), size, direction);
-}
-
-static void metag_dma_sync_sg_for_cpu(struct device *dev,
-		struct scatterlist *sglist, int nelems,
-		enum dma_data_direction direction)
-{
-	int i;
-	struct scatterlist *sg;
-
-	for_each_sg(sglist, sg, nelems, i)
-		dma_sync_for_cpu(sg_virt(sg), sg->length, direction);
-}
-
-static void metag_dma_sync_sg_for_device(struct device *dev,
-		struct scatterlist *sglist, int nelems,
-		enum dma_data_direction direction)
-{
-	int i;
-	struct scatterlist *sg;
-
-	for_each_sg(sglist, sg, nelems, i)
-		dma_sync_for_device(sg_virt(sg), sg->length, direction);
-}
-
-const struct dma_map_ops metag_dma_ops = {
-	.alloc			= metag_dma_alloc,
-	.free			= metag_dma_free,
-	.map_page		= metag_dma_map_page,
-	.map_sg			= metag_dma_map_sg,
-	.sync_single_for_device	= metag_dma_sync_single_for_device,
-	.sync_single_for_cpu	= metag_dma_sync_single_for_cpu,
-	.sync_sg_for_cpu	= metag_dma_sync_sg_for_cpu,
-	.mmap			= metag_dma_mmap,
-};
-EXPORT_SYMBOL(metag_dma_ops);