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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/microblaze/mm/consistent.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/microblaze/mm/consistent.c')
-rw-r--r--arch/microblaze/mm/consistent.c222
1 files changed, 222 insertions, 0 deletions
diff --git a/arch/microblaze/mm/consistent.c b/arch/microblaze/mm/consistent.c
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+/*
+ * Microblaze support for cache consistent memory.
+ * Copyright (C) 2010 Michal Simek <monstr@monstr.eu>
+ * Copyright (C) 2010 PetaLogix
+ * Copyright (C) 2005 John Williams <jwilliams@itee.uq.edu.au>
+ *
+ * Based on PowerPC version derived from arch/arm/mm/consistent.c
+ * Copyright (C) 2001 Dan Malek (dmalek@jlc.net)
+ * Copyright (C) 2000 Russell King
+ *
+ * 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/export.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/stddef.h>
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/bootmem.h>
+#include <linux/highmem.h>
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+#include <linux/gfp.h>
+#include <linux/dma-noncoherent.h>
+
+#include <asm/pgalloc.h>
+#include <linux/io.h>
+#include <linux/hardirq.h>
+#include <linux/mmu_context.h>
+#include <asm/mmu.h>
+#include <linux/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/cpuinfo.h>
+#include <asm/tlbflush.h>
+
+#ifndef CONFIG_MMU
+/* I have to use dcache values because I can't relate on ram size */
+# define UNCACHED_SHADOW_MASK (cpuinfo.dcache_high - cpuinfo.dcache_base + 1)
+#endif
+
+/*
+ * Consistent memory allocators. Used for DMA devices that want to
+ * share uncached memory with the processor core.
+ * My crufty no-MMU approach is simple. In the HW platform we can optionally
+ * mirror the DDR up above the processor cacheable region. So, memory accessed
+ * in this mirror region will not be cached. It's alloced from the same
+ * pool as normal memory, but the handle we return is shifted up into the
+ * uncached region. This will no doubt cause big problems if memory allocated
+ * here is not also freed properly. -- JW
+ */
+void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
+ gfp_t gfp, unsigned long attrs)
+{
+ unsigned long order, vaddr;
+ void *ret;
+ unsigned int i, err = 0;
+ struct page *page, *end;
+
+#ifdef CONFIG_MMU
+ phys_addr_t pa;
+ struct vm_struct *area;
+ unsigned long va;
+#endif
+
+ if (in_interrupt())
+ BUG();
+
+ /* Only allocate page size areas. */
+ size = PAGE_ALIGN(size);
+ order = get_order(size);
+
+ vaddr = __get_free_pages(gfp, order);
+ if (!vaddr)
+ return NULL;
+
+ /*
+ * we need to ensure that there are no cachelines in use,
+ * or worse dirty in this area.
+ */
+ flush_dcache_range(virt_to_phys((void *)vaddr),
+ virt_to_phys((void *)vaddr) + size);
+
+#ifndef CONFIG_MMU
+ ret = (void *)vaddr;
+ /*
+ * Here's the magic! Note if the uncached shadow is not implemented,
+ * it's up to the calling code to also test that condition and make
+ * other arranegments, such as manually flushing the cache and so on.
+ */
+# ifdef CONFIG_XILINX_UNCACHED_SHADOW
+ ret = (void *)((unsigned) ret | UNCACHED_SHADOW_MASK);
+# endif
+ if ((unsigned int)ret > cpuinfo.dcache_base &&
+ (unsigned int)ret < cpuinfo.dcache_high)
+ pr_warn("ERROR: Your cache coherent area is CACHED!!!\n");
+
+ /* dma_handle is same as physical (shadowed) address */
+ *dma_handle = (dma_addr_t)ret;
+#else
+ /* Allocate some common virtual space to map the new pages. */
+ area = get_vm_area(size, VM_ALLOC);
+ if (!area) {
+ free_pages(vaddr, order);
+ return NULL;
+ }
+ va = (unsigned long) area->addr;
+ ret = (void *)va;
+
+ /* This gives us the real physical address of the first page. */
+ *dma_handle = pa = __virt_to_phys(vaddr);
+#endif
+
+ /*
+ * free wasted pages. We skip the first page since we know
+ * that it will have count = 1 and won't require freeing.
+ * We also mark the pages in use as reserved so that
+ * remap_page_range works.
+ */
+ page = virt_to_page(vaddr);
+ end = page + (1 << order);
+
+ split_page(page, order);
+
+ for (i = 0; i < size && err == 0; i += PAGE_SIZE) {
+#ifdef CONFIG_MMU
+ /* MS: This is the whole magic - use cache inhibit pages */
+ err = map_page(va + i, pa + i, _PAGE_KERNEL | _PAGE_NO_CACHE);
+#endif
+
+ SetPageReserved(page);
+ page++;
+ }
+
+ /* Free the otherwise unused pages. */
+ while (page < end) {
+ __free_page(page);
+ page++;
+ }
+
+ if (err) {
+ free_pages(vaddr, order);
+ return NULL;
+ }
+
+ return ret;
+}
+
+#ifdef CONFIG_MMU
+static pte_t *consistent_virt_to_pte(void *vaddr)
+{
+ unsigned long addr = (unsigned long)vaddr;
+
+ return pte_offset_kernel(pmd_offset(pgd_offset_k(addr), addr), addr);
+}
+
+unsigned long consistent_virt_to_pfn(void *vaddr)
+{
+ pte_t *ptep = consistent_virt_to_pte(vaddr);
+
+ if (pte_none(*ptep) || !pte_present(*ptep))
+ return 0;
+
+ return pte_pfn(*ptep);
+}
+#endif
+
+/*
+ * free page(s) as defined by the above mapping.
+ */
+void arch_dma_free(struct device *dev, size_t size, void *vaddr,
+ dma_addr_t dma_addr, unsigned long attrs)
+{
+ struct page *page;
+
+ if (in_interrupt())
+ BUG();
+
+ size = PAGE_ALIGN(size);
+
+#ifndef CONFIG_MMU
+ /* Clear SHADOW_MASK bit in address, and free as per usual */
+# ifdef CONFIG_XILINX_UNCACHED_SHADOW
+ vaddr = (void *)((unsigned)vaddr & ~UNCACHED_SHADOW_MASK);
+# endif
+ page = virt_to_page(vaddr);
+
+ do {
+ __free_reserved_page(page);
+ page++;
+ } while (size -= PAGE_SIZE);
+#else
+ do {
+ pte_t *ptep = consistent_virt_to_pte(vaddr);
+ unsigned long pfn;
+
+ if (!pte_none(*ptep) && pte_present(*ptep)) {
+ pfn = pte_pfn(*ptep);
+ pte_clear(&init_mm, (unsigned int)vaddr, ptep);
+ if (pfn_valid(pfn)) {
+ page = pfn_to_page(pfn);
+ __free_reserved_page(page);
+ }
+ }
+ vaddr += PAGE_SIZE;
+ } while (size -= PAGE_SIZE);
+
+ /* flush tlb */
+ flush_tlb_all();
+#endif
+}