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path: root/drivers/misc/bcm-vk/bcm_vk_sg.c
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Diffstat (limited to 'drivers/misc/bcm-vk/bcm_vk_sg.c')
-rw-r--r--drivers/misc/bcm-vk/bcm_vk_sg.c275
1 files changed, 275 insertions, 0 deletions
diff --git a/drivers/misc/bcm-vk/bcm_vk_sg.c b/drivers/misc/bcm-vk/bcm_vk_sg.c
new file mode 100644
index 000000000000..2e9daaf3e492
--- /dev/null
+++ b/drivers/misc/bcm-vk/bcm_vk_sg.c
@@ -0,0 +1,275 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2018-2020 Broadcom.
+ */
+#include <linux/dma-mapping.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
+#include <linux/pgtable.h>
+#include <linux/vmalloc.h>
+
+#include <asm/page.h>
+#include <asm/unaligned.h>
+
+#include <uapi/linux/misc/bcm_vk.h>
+
+#include "bcm_vk.h"
+#include "bcm_vk_msg.h"
+#include "bcm_vk_sg.h"
+
+/*
+ * Valkyrie has a hardware limitation of 16M transfer size.
+ * So limit the SGL chunks to 16M.
+ */
+#define BCM_VK_MAX_SGL_CHUNK SZ_16M
+
+static int bcm_vk_dma_alloc(struct device *dev,
+ struct bcm_vk_dma *dma,
+ int dir,
+ struct _vk_data *vkdata);
+static int bcm_vk_dma_free(struct device *dev, struct bcm_vk_dma *dma);
+
+/* Uncomment to dump SGLIST */
+/* #define BCM_VK_DUMP_SGLIST */
+
+static int bcm_vk_dma_alloc(struct device *dev,
+ struct bcm_vk_dma *dma,
+ int direction,
+ struct _vk_data *vkdata)
+{
+ dma_addr_t addr, sg_addr;
+ int err;
+ int i;
+ int offset;
+ u32 size;
+ u32 remaining_size;
+ u32 transfer_size;
+ u64 data;
+ unsigned long first, last;
+ struct _vk_data *sgdata;
+
+ /* Get 64-bit user address */
+ data = get_unaligned(&vkdata->address);
+
+ /* offset into first page */
+ offset = offset_in_page(data);
+
+ /* Calculate number of pages */
+ first = (data & PAGE_MASK) >> PAGE_SHIFT;
+ last = ((data + vkdata->size - 1) & PAGE_MASK) >> PAGE_SHIFT;
+ dma->nr_pages = last - first + 1;
+
+ /* Allocate DMA pages */
+ dma->pages = kmalloc_array(dma->nr_pages,
+ sizeof(struct page *),
+ GFP_KERNEL);
+ if (!dma->pages)
+ return -ENOMEM;
+
+ dev_dbg(dev, "Alloc DMA Pages [0x%llx+0x%x => %d pages]\n",
+ data, vkdata->size, dma->nr_pages);
+
+ dma->direction = direction;
+
+ /* Get user pages into memory */
+ err = get_user_pages_fast(data & PAGE_MASK,
+ dma->nr_pages,
+ direction == DMA_FROM_DEVICE,
+ dma->pages);
+ if (err != dma->nr_pages) {
+ dma->nr_pages = (err >= 0) ? err : 0;
+ dev_err(dev, "get_user_pages_fast, err=%d [%d]\n",
+ err, dma->nr_pages);
+ return err < 0 ? err : -EINVAL;
+ }
+
+ /* Max size of sg list is 1 per mapped page + fields at start */
+ dma->sglen = (dma->nr_pages * sizeof(*sgdata)) +
+ (sizeof(u32) * SGLIST_VKDATA_START);
+
+ /* Allocate sglist */
+ dma->sglist = dma_alloc_coherent(dev,
+ dma->sglen,
+ &dma->handle,
+ GFP_KERNEL);
+ if (!dma->sglist)
+ return -ENOMEM;
+
+ dma->sglist[SGLIST_NUM_SG] = 0;
+ dma->sglist[SGLIST_TOTALSIZE] = vkdata->size;
+ remaining_size = vkdata->size;
+ sgdata = (struct _vk_data *)&dma->sglist[SGLIST_VKDATA_START];
+
+ /* Map all pages into DMA */
+ size = min_t(size_t, PAGE_SIZE - offset, remaining_size);
+ remaining_size -= size;
+ sg_addr = dma_map_page(dev,
+ dma->pages[0],
+ offset,
+ size,
+ dma->direction);
+ transfer_size = size;
+ if (unlikely(dma_mapping_error(dev, sg_addr))) {
+ __free_page(dma->pages[0]);
+ return -EIO;
+ }
+
+ for (i = 1; i < dma->nr_pages; i++) {
+ size = min_t(size_t, PAGE_SIZE, remaining_size);
+ remaining_size -= size;
+ addr = dma_map_page(dev,
+ dma->pages[i],
+ 0,
+ size,
+ dma->direction);
+ if (unlikely(dma_mapping_error(dev, addr))) {
+ __free_page(dma->pages[i]);
+ return -EIO;
+ }
+
+ /*
+ * Compress SG list entry when pages are contiguous
+ * and transfer size less or equal to BCM_VK_MAX_SGL_CHUNK
+ */
+ if ((addr == (sg_addr + transfer_size)) &&
+ ((transfer_size + size) <= BCM_VK_MAX_SGL_CHUNK)) {
+ /* pages are contiguous, add to same sg entry */
+ transfer_size += size;
+ } else {
+ /* pages are not contiguous, write sg entry */
+ sgdata->size = transfer_size;
+ put_unaligned(sg_addr, (u64 *)&sgdata->address);
+ dma->sglist[SGLIST_NUM_SG]++;
+
+ /* start new sg entry */
+ sgdata++;
+ sg_addr = addr;
+ transfer_size = size;
+ }
+ }
+ /* Write last sg list entry */
+ sgdata->size = transfer_size;
+ put_unaligned(sg_addr, (u64 *)&sgdata->address);
+ dma->sglist[SGLIST_NUM_SG]++;
+
+ /* Update pointers and size field to point to sglist */
+ put_unaligned((u64)dma->handle, &vkdata->address);
+ vkdata->size = (dma->sglist[SGLIST_NUM_SG] * sizeof(*sgdata)) +
+ (sizeof(u32) * SGLIST_VKDATA_START);
+
+#ifdef BCM_VK_DUMP_SGLIST
+ dev_dbg(dev,
+ "sgl 0x%llx handle 0x%llx, sglen: 0x%x sgsize: 0x%x\n",
+ (u64)dma->sglist,
+ dma->handle,
+ dma->sglen,
+ vkdata->size);
+ for (i = 0; i < vkdata->size / sizeof(u32); i++)
+ dev_dbg(dev, "i:0x%x 0x%x\n", i, dma->sglist[i]);
+#endif
+
+ return 0;
+}
+
+int bcm_vk_sg_alloc(struct device *dev,
+ struct bcm_vk_dma *dma,
+ int dir,
+ struct _vk_data *vkdata,
+ int num)
+{
+ int i;
+ int rc = -EINVAL;
+
+ /* Convert user addresses to DMA SG List */
+ for (i = 0; i < num; i++) {
+ if (vkdata[i].size && vkdata[i].address) {
+ /*
+ * If both size and address are non-zero
+ * then DMA alloc.
+ */
+ rc = bcm_vk_dma_alloc(dev,
+ &dma[i],
+ dir,
+ &vkdata[i]);
+ } else if (vkdata[i].size ||
+ vkdata[i].address) {
+ /*
+ * If one of size and address are zero
+ * there is a problem.
+ */
+ dev_err(dev,
+ "Invalid vkdata %x 0x%x 0x%llx\n",
+ i, vkdata[i].size, vkdata[i].address);
+ rc = -EINVAL;
+ } else {
+ /*
+ * If size and address are both zero
+ * don't convert, but return success.
+ */
+ rc = 0;
+ }
+
+ if (rc)
+ goto fail_alloc;
+ }
+ return rc;
+
+fail_alloc:
+ while (i > 0) {
+ i--;
+ if (dma[i].sglist)
+ bcm_vk_dma_free(dev, &dma[i]);
+ }
+ return rc;
+}
+
+static int bcm_vk_dma_free(struct device *dev, struct bcm_vk_dma *dma)
+{
+ dma_addr_t addr;
+ int i;
+ int num_sg;
+ u32 size;
+ struct _vk_data *vkdata;
+
+ dev_dbg(dev, "free sglist=%p sglen=0x%x\n", dma->sglist, dma->sglen);
+
+ /* Unmap all pages in the sglist */
+ num_sg = dma->sglist[SGLIST_NUM_SG];
+ vkdata = (struct _vk_data *)&dma->sglist[SGLIST_VKDATA_START];
+ for (i = 0; i < num_sg; i++) {
+ size = vkdata[i].size;
+ addr = get_unaligned(&vkdata[i].address);
+
+ dma_unmap_page(dev, addr, size, dma->direction);
+ }
+
+ /* Free allocated sglist */
+ dma_free_coherent(dev, dma->sglen, dma->sglist, dma->handle);
+
+ /* Release lock on all pages */
+ for (i = 0; i < dma->nr_pages; i++)
+ put_page(dma->pages[i]);
+
+ /* Free allocated dma pages */
+ kfree(dma->pages);
+ dma->sglist = NULL;
+
+ return 0;
+}
+
+int bcm_vk_sg_free(struct device *dev, struct bcm_vk_dma *dma, int num,
+ int *proc_cnt)
+{
+ int i;
+
+ *proc_cnt = 0;
+ /* Unmap and free all pages and sglists */
+ for (i = 0; i < num; i++) {
+ if (dma[i].sglist) {
+ bcm_vk_dma_free(dev, &dma[i]);
+ *proc_cnt += 1;
+ }
+ }
+
+ return 0;
+}
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-26 05:57:35 +0300