// SPDX-License-Identifier: GPL-2.0
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/*
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* DMABUF System heap exporter
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*
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* Copyright (C) 2011 Google, Inc.
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* Copyright (C) 2019, 2020 Linaro Ltd.
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*
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* Portions based off of Andrew Davis' SRAM heap:
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* Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
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* Andrew F. Davis <afd@ti.com>
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*/
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#include <linux/dma-buf.h>
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#include <linux/dma-mapping.h>
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#include <linux/dma-heap.h>
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#include <linux/err.h>
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#include <linux/highmem.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/scatterlist.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include "page_pool.h"
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#include "deferred-free-helper.h"
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static struct dma_heap *sys_heap;
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static struct dma_heap *sys_uncached_heap;
|
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struct system_heap_buffer {
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struct dma_heap *heap;
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struct list_head attachments;
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struct mutex lock;
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unsigned long len;
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struct sg_table sg_table;
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int vmap_cnt;
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void *vaddr;
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struct deferred_freelist_item deferred_free;
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bool uncached;
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};
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struct dma_heap_attachment {
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struct device *dev;
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struct sg_table *table;
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struct list_head list;
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bool mapped;
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bool uncached;
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};
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#define LOW_ORDER_GFP (GFP_HIGHUSER | __GFP_ZERO)
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#define HIGH_ORDER_GFP (((GFP_HIGHUSER | __GFP_ZERO | __GFP_NOWARN \
|
| __GFP_NORETRY) & ~__GFP_RECLAIM) \
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| __GFP_COMP)
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static gfp_t order_flags[] = {HIGH_ORDER_GFP, HIGH_ORDER_GFP, LOW_ORDER_GFP};
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/*
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* The selection of the orders used for allocation (1MB, 64K, 4K) is designed
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* to match with the sizes often found in IOMMUs. Using order 4 pages instead
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* of order 0 pages can significantly improve the performance of many IOMMUs
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* by reducing TLB pressure and time spent updating page tables.
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*/
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static const unsigned int orders[] = {8, 4, 0};
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#define NUM_ORDERS ARRAY_SIZE(orders)
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struct dmabuf_page_pool *pools[NUM_ORDERS];
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static struct sg_table *dup_sg_table(struct sg_table *table)
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{
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struct sg_table *new_table;
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int ret, i;
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struct scatterlist *sg, *new_sg;
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new_table = kzalloc(sizeof(*new_table), GFP_KERNEL);
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if (!new_table)
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return ERR_PTR(-ENOMEM);
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ret = sg_alloc_table(new_table, table->orig_nents, GFP_KERNEL);
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if (ret) {
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kfree(new_table);
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return ERR_PTR(-ENOMEM);
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}
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new_sg = new_table->sgl;
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for_each_sgtable_sg(table, sg, i) {
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sg_set_page(new_sg, sg_page(sg), sg->length, sg->offset);
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new_sg = sg_next(new_sg);
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}
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return new_table;
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}
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static int system_heap_attach(struct dma_buf *dmabuf,
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struct dma_buf_attachment *attachment)
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{
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struct system_heap_buffer *buffer = dmabuf->priv;
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struct dma_heap_attachment *a;
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struct sg_table *table;
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a = kzalloc(sizeof(*a), GFP_KERNEL);
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if (!a)
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return -ENOMEM;
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table = dup_sg_table(&buffer->sg_table);
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if (IS_ERR(table)) {
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kfree(a);
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return -ENOMEM;
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}
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a->table = table;
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a->dev = attachment->dev;
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INIT_LIST_HEAD(&a->list);
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a->mapped = false;
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a->uncached = buffer->uncached;
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attachment->priv = a;
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mutex_lock(&buffer->lock);
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list_add(&a->list, &buffer->attachments);
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mutex_unlock(&buffer->lock);
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return 0;
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}
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static void system_heap_detach(struct dma_buf *dmabuf,
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struct dma_buf_attachment *attachment)
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{
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struct system_heap_buffer *buffer = dmabuf->priv;
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struct dma_heap_attachment *a = attachment->priv;
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mutex_lock(&buffer->lock);
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list_del(&a->list);
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mutex_unlock(&buffer->lock);
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sg_free_table(a->table);
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kfree(a->table);
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kfree(a);
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}
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static struct sg_table *system_heap_map_dma_buf(struct dma_buf_attachment *attachment,
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enum dma_data_direction direction)
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{
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struct dma_heap_attachment *a = attachment->priv;
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struct sg_table *table = a->table;
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int attr = attachment->dma_map_attrs;
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int ret;
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if (a->uncached)
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attr |= DMA_ATTR_SKIP_CPU_SYNC;
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ret = dma_map_sgtable(attachment->dev, table, direction, attr);
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if (ret)
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return ERR_PTR(ret);
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a->mapped = true;
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return table;
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}
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static void system_heap_unmap_dma_buf(struct dma_buf_attachment *attachment,
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struct sg_table *table,
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enum dma_data_direction direction)
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{
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struct dma_heap_attachment *a = attachment->priv;
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int attr = attachment->dma_map_attrs;
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if (a->uncached)
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attr |= DMA_ATTR_SKIP_CPU_SYNC;
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a->mapped = false;
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dma_unmap_sgtable(attachment->dev, table, direction, attr);
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}
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static int system_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
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enum dma_data_direction direction)
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{
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struct system_heap_buffer *buffer = dmabuf->priv;
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struct dma_heap_attachment *a;
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mutex_lock(&buffer->lock);
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if (buffer->vmap_cnt)
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invalidate_kernel_vmap_range(buffer->vaddr, buffer->len);
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if (!buffer->uncached) {
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list_for_each_entry(a, &buffer->attachments, list) {
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if (!a->mapped)
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continue;
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dma_sync_sgtable_for_cpu(a->dev, a->table, direction);
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}
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}
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mutex_unlock(&buffer->lock);
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return 0;
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}
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static int system_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf,
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enum dma_data_direction direction)
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{
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struct system_heap_buffer *buffer = dmabuf->priv;
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struct dma_heap_attachment *a;
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mutex_lock(&buffer->lock);
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if (buffer->vmap_cnt)
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flush_kernel_vmap_range(buffer->vaddr, buffer->len);
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if (!buffer->uncached) {
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list_for_each_entry(a, &buffer->attachments, list) {
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if (!a->mapped)
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continue;
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dma_sync_sgtable_for_device(a->dev, a->table, direction);
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}
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}
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mutex_unlock(&buffer->lock);
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return 0;
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}
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static int system_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
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{
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struct system_heap_buffer *buffer = dmabuf->priv;
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struct sg_table *table = &buffer->sg_table;
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unsigned long addr = vma->vm_start;
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struct sg_page_iter piter;
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int ret;
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if (buffer->uncached)
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vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
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for_each_sgtable_page(table, &piter, vma->vm_pgoff) {
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struct page *page = sg_page_iter_page(&piter);
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ret = remap_pfn_range(vma, addr, page_to_pfn(page), PAGE_SIZE,
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vma->vm_page_prot);
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if (ret)
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return ret;
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addr += PAGE_SIZE;
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if (addr >= vma->vm_end)
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return 0;
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}
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return 0;
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}
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static void *system_heap_do_vmap(struct system_heap_buffer *buffer)
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{
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struct sg_table *table = &buffer->sg_table;
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int npages = PAGE_ALIGN(buffer->len) / PAGE_SIZE;
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struct page **pages = vmalloc(sizeof(struct page *) * npages);
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struct page **tmp = pages;
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struct sg_page_iter piter;
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pgprot_t pgprot = PAGE_KERNEL;
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void *vaddr;
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if (!pages)
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return ERR_PTR(-ENOMEM);
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if (buffer->uncached)
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pgprot = pgprot_writecombine(PAGE_KERNEL);
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for_each_sgtable_page(table, &piter, 0) {
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WARN_ON(tmp - pages >= npages);
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*tmp++ = sg_page_iter_page(&piter);
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}
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vaddr = vmap(pages, npages, VM_MAP, pgprot);
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vfree(pages);
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if (!vaddr)
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return ERR_PTR(-ENOMEM);
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return vaddr;
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}
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static void *system_heap_vmap(struct dma_buf *dmabuf)
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{
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struct system_heap_buffer *buffer = dmabuf->priv;
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void *vaddr;
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mutex_lock(&buffer->lock);
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if (buffer->vmap_cnt) {
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buffer->vmap_cnt++;
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vaddr = buffer->vaddr;
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goto out;
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}
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vaddr = system_heap_do_vmap(buffer);
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if (IS_ERR(vaddr))
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goto out;
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buffer->vaddr = vaddr;
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buffer->vmap_cnt++;
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out:
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mutex_unlock(&buffer->lock);
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return vaddr;
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}
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static void system_heap_vunmap(struct dma_buf *dmabuf, void *vaddr)
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{
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struct system_heap_buffer *buffer = dmabuf->priv;
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mutex_lock(&buffer->lock);
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if (!--buffer->vmap_cnt) {
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vunmap(buffer->vaddr);
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buffer->vaddr = NULL;
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}
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mutex_unlock(&buffer->lock);
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}
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static int system_heap_zero_buffer(struct system_heap_buffer *buffer)
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{
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struct sg_table *sgt = &buffer->sg_table;
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struct sg_page_iter piter;
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struct page *p;
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void *vaddr;
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int ret = 0;
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for_each_sgtable_page(sgt, &piter, 0) {
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p = sg_page_iter_page(&piter);
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vaddr = kmap_atomic(p);
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memset(vaddr, 0, PAGE_SIZE);
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kunmap_atomic(vaddr);
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}
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return ret;
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}
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static void system_heap_buf_free(struct deferred_freelist_item *item,
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enum df_reason reason)
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{
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struct system_heap_buffer *buffer;
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struct sg_table *table;
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struct scatterlist *sg;
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int i, j;
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buffer = container_of(item, struct system_heap_buffer, deferred_free);
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/* Zero the buffer pages before adding back to the pool */
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if (reason == DF_NORMAL)
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if (system_heap_zero_buffer(buffer))
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reason = DF_UNDER_PRESSURE; // On failure, just free
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table = &buffer->sg_table;
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for_each_sgtable_sg(table, sg, i) {
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struct page *page = sg_page(sg);
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if (reason == DF_UNDER_PRESSURE) {
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__free_pages(page, compound_order(page));
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} else {
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for (j = 0; j < NUM_ORDERS; j++) {
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if (compound_order(page) == orders[j])
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break;
|
}
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dmabuf_page_pool_free(pools[j], page);
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}
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}
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sg_free_table(table);
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kfree(buffer);
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}
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static void system_heap_dma_buf_release(struct dma_buf *dmabuf)
|
{
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struct system_heap_buffer *buffer = dmabuf->priv;
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int npages = PAGE_ALIGN(buffer->len) / PAGE_SIZE;
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|
deferred_free(&buffer->deferred_free, system_heap_buf_free, npages);
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}
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static const struct dma_buf_ops system_heap_buf_ops = {
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.attach = system_heap_attach,
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.detach = system_heap_detach,
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.map_dma_buf = system_heap_map_dma_buf,
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.unmap_dma_buf = system_heap_unmap_dma_buf,
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.begin_cpu_access = system_heap_dma_buf_begin_cpu_access,
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.end_cpu_access = system_heap_dma_buf_end_cpu_access,
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.mmap = system_heap_mmap,
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.vmap = system_heap_vmap,
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.vunmap = system_heap_vunmap,
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.release = system_heap_dma_buf_release,
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};
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static struct page *alloc_largest_available(unsigned long size,
|
unsigned int max_order)
|
{
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struct page *page;
|
int i;
|
|
for (i = 0; i < NUM_ORDERS; i++) {
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if (size < (PAGE_SIZE << orders[i]))
|
continue;
|
if (max_order < orders[i])
|
continue;
|
page = dmabuf_page_pool_alloc(pools[i]);
|
if (!page)
|
continue;
|
return page;
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}
|
return NULL;
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}
|
|
static struct dma_buf *system_heap_do_allocate(struct dma_heap *heap,
|
unsigned long len,
|
unsigned long fd_flags,
|
unsigned long heap_flags,
|
bool uncached)
|
{
|
struct system_heap_buffer *buffer;
|
DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
|
unsigned long size_remaining = len;
|
unsigned int max_order = orders[0];
|
struct dma_buf *dmabuf;
|
struct sg_table *table;
|
struct scatterlist *sg;
|
struct list_head pages;
|
struct page *page, *tmp_page;
|
int i, ret = -ENOMEM;
|
|
buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
|
if (!buffer)
|
return ERR_PTR(-ENOMEM);
|
|
INIT_LIST_HEAD(&buffer->attachments);
|
mutex_init(&buffer->lock);
|
buffer->heap = heap;
|
buffer->len = len;
|
buffer->uncached = uncached;
|
|
INIT_LIST_HEAD(&pages);
|
i = 0;
|
while (size_remaining > 0) {
|
/*
|
* Avoid trying to allocate memory if the process
|
* has been killed by SIGKILL
|
*/
|
if (fatal_signal_pending(current))
|
goto free_buffer;
|
|
page = alloc_largest_available(size_remaining, max_order);
|
if (!page)
|
goto free_buffer;
|
|
list_add_tail(&page->lru, &pages);
|
size_remaining -= page_size(page);
|
max_order = compound_order(page);
|
i++;
|
}
|
|
table = &buffer->sg_table;
|
if (sg_alloc_table(table, i, GFP_KERNEL))
|
goto free_buffer;
|
|
sg = table->sgl;
|
list_for_each_entry_safe(page, tmp_page, &pages, lru) {
|
sg_set_page(sg, page, page_size(page), 0);
|
sg = sg_next(sg);
|
list_del(&page->lru);
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}
|
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/* create the dmabuf */
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exp_info.exp_name = dma_heap_get_name(heap);
|
exp_info.ops = &system_heap_buf_ops;
|
exp_info.size = buffer->len;
|
exp_info.flags = fd_flags;
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exp_info.priv = buffer;
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dmabuf = dma_buf_export(&exp_info);
|
if (IS_ERR(dmabuf)) {
|
ret = PTR_ERR(dmabuf);
|
goto free_pages;
|
}
|
|
/*
|
* For uncached buffers, we need to initially flush cpu cache, since
|
* the __GFP_ZERO on the allocation means the zeroing was done by the
|
* cpu and thus it is likely cached. Map (and implicitly flush) and
|
* unmap it now so we don't get corruption later on.
|
*/
|
if (buffer->uncached) {
|
dma_map_sgtable(dma_heap_get_dev(heap), table, DMA_BIDIRECTIONAL, 0);
|
dma_unmap_sgtable(dma_heap_get_dev(heap), table, DMA_BIDIRECTIONAL, 0);
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}
|
|
return dmabuf;
|
|
free_pages:
|
for_each_sgtable_sg(table, sg, i) {
|
struct page *p = sg_page(sg);
|
|
__free_pages(p, compound_order(p));
|
}
|
sg_free_table(table);
|
free_buffer:
|
list_for_each_entry_safe(page, tmp_page, &pages, lru)
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__free_pages(page, compound_order(page));
|
kfree(buffer);
|
|
return ERR_PTR(ret);
|
}
|
|
static struct dma_buf *system_heap_allocate(struct dma_heap *heap,
|
unsigned long len,
|
unsigned long fd_flags,
|
unsigned long heap_flags)
|
{
|
return system_heap_do_allocate(heap, len, fd_flags, heap_flags, false);
|
}
|
|
static long system_get_pool_size(struct dma_heap *heap)
|
{
|
int i;
|
long num_pages = 0;
|
struct dmabuf_page_pool **pool;
|
|
pool = pools;
|
for (i = 0; i < NUM_ORDERS; i++, pool++) {
|
num_pages += ((*pool)->count[POOL_LOWPAGE] +
|
(*pool)->count[POOL_HIGHPAGE]) << (*pool)->order;
|
}
|
|
return num_pages << PAGE_SHIFT;
|
}
|
|
static const struct dma_heap_ops system_heap_ops = {
|
.allocate = system_heap_allocate,
|
.get_pool_size = system_get_pool_size,
|
};
|
|
static struct dma_buf *system_uncached_heap_allocate(struct dma_heap *heap,
|
unsigned long len,
|
unsigned long fd_flags,
|
unsigned long heap_flags)
|
{
|
return system_heap_do_allocate(heap, len, fd_flags, heap_flags, true);
|
}
|
|
/* Dummy function to be used until we can call coerce_mask_and_coherent */
|
static struct dma_buf *system_uncached_heap_not_initialized(struct dma_heap *heap,
|
unsigned long len,
|
unsigned long fd_flags,
|
unsigned long heap_flags)
|
{
|
return ERR_PTR(-EBUSY);
|
}
|
|
static struct dma_heap_ops system_uncached_heap_ops = {
|
/* After system_heap_create is complete, we will swap this */
|
.allocate = system_uncached_heap_not_initialized,
|
};
|
|
static int set_heap_dev_dma(struct device *heap_dev)
|
{
|
int err = 0;
|
|
if (!heap_dev)
|
return -EINVAL;
|
|
dma_coerce_mask_and_coherent(heap_dev, DMA_BIT_MASK(64));
|
|
if (!heap_dev->dma_parms) {
|
heap_dev->dma_parms = devm_kzalloc(heap_dev,
|
sizeof(*heap_dev->dma_parms),
|
GFP_KERNEL);
|
if (!heap_dev->dma_parms)
|
return -ENOMEM;
|
|
err = dma_set_max_seg_size(heap_dev, (unsigned int)DMA_BIT_MASK(64));
|
if (err) {
|
devm_kfree(heap_dev, heap_dev->dma_parms);
|
dev_err(heap_dev, "Failed to set DMA segment size, err:%d\n", err);
|
return err;
|
}
|
}
|
|
return 0;
|
}
|
|
static int system_heap_create(void)
|
{
|
struct dma_heap_export_info exp_info;
|
int i, err = 0;
|
|
for (i = 0; i < NUM_ORDERS; i++) {
|
pools[i] = dmabuf_page_pool_create(order_flags[i], orders[i]);
|
|
if (!pools[i]) {
|
int j;
|
|
pr_err("%s: page pool creation failed!\n", __func__);
|
for (j = 0; j < i; j++)
|
dmabuf_page_pool_destroy(pools[j]);
|
return -ENOMEM;
|
}
|
}
|
|
exp_info.name = "system";
|
exp_info.ops = &system_heap_ops;
|
exp_info.priv = NULL;
|
|
sys_heap = dma_heap_add(&exp_info);
|
if (IS_ERR(sys_heap))
|
return PTR_ERR(sys_heap);
|
|
exp_info.name = "system-uncached";
|
exp_info.ops = &system_uncached_heap_ops;
|
exp_info.priv = NULL;
|
|
sys_uncached_heap = dma_heap_add(&exp_info);
|
if (IS_ERR(sys_uncached_heap))
|
return PTR_ERR(sys_uncached_heap);
|
|
err = set_heap_dev_dma(dma_heap_get_dev(sys_uncached_heap));
|
if (err)
|
return err;
|
|
mb(); /* make sure we only set allocate after dma_mask is set */
|
system_uncached_heap_ops.allocate = system_uncached_heap_allocate;
|
|
return 0;
|
}
|
module_init(system_heap_create);
|
MODULE_LICENSE("GPL v2");
|
