Hi Andrew,
kernel test robot noticed the following build warnings:
[auto build test WARNING on char-misc/char-misc-testing]
[also build test WARNING on char-misc/char-misc-next char-misc/char-misc-linus soc/for-next pza/reset/next linus/master v6.3-rc5 next-20230403]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Andrew-Davis/misc-sram-Add-DMA-BUF-Heap-exporting-of-SRAM-areas/20230404-032607
patch link: https://lore.kernel.org/r/20230403192433.26648-1-afd%40ti.com
patch subject: [PATCH v2] misc: sram: Add DMA-BUF Heap exporting of SRAM areas
config: loongarch-allyesconfig (https://download.01.org/0day-ci/archive/20230404/202304041144.t5JCOGsE-lkp@intel.com/config)
compiler: loongarch64-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/6fcaa3c7cfbc144dd982f9abaa1c5af50dde24a8
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Andrew-Davis/misc-sram-Add-DMA-BUF-Heap-exporting-of-SRAM-areas/20230404-032607
git checkout 6fcaa3c7cfbc144dd982f9abaa1c5af50dde24a8
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=loongarch olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=loongarch SHELL=/bin/bash drivers/
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202304041144.t5JCOGsE-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> drivers/misc/sram-dma-heap.c:161:17: warning: no previous prototype for 'sram_dma_heap_allocate' [-Wmissing-prototypes]
161 | struct dma_buf *sram_dma_heap_allocate(struct dma_heap *heap,
| ^~~~~~~~~~~~~~~~~~~~~~
vim +/sram_dma_heap_allocate +161 drivers/misc/sram-dma-heap.c
160
> 161 struct dma_buf *sram_dma_heap_allocate(struct dma_heap *heap,
162 unsigned long len,
163 unsigned long fd_flags,
164 unsigned long heap_flags)
165 {
166 struct sram_dma_heap *sram_dma_heap = dma_heap_get_drvdata(heap);
167 struct sram_dma_heap_buffer *buffer;
168
169 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
170 struct dma_buf *dmabuf;
171 int ret;
172
173 buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
174 if (!buffer)
175 return ERR_PTR(-ENOMEM);
176 buffer->pool = sram_dma_heap->pool;
177 INIT_LIST_HEAD(&buffer->attachments);
178 mutex_init(&buffer->attachments_lock);
179 buffer->len = len;
180
181 buffer->vaddr = (void *)gen_pool_alloc(buffer->pool, buffer->len);
182 if (!buffer->vaddr) {
183 ret = -ENOMEM;
184 goto free_buffer;
185 }
186
187 buffer->paddr = gen_pool_virt_to_phys(buffer->pool, (unsigned long)buffer->vaddr);
188 if (buffer->paddr == -1) {
189 ret = -ENOMEM;
190 goto free_pool;
191 }
192
193 /* create the dmabuf */
194 exp_info.exp_name = dma_heap_get_name(heap);
195 exp_info.ops = &sram_dma_heap_buf_ops;
196 exp_info.size = buffer->len;
197 exp_info.flags = fd_flags;
198 exp_info.priv = buffer;
199 dmabuf = dma_buf_export(&exp_info);
200 if (IS_ERR(dmabuf)) {
201 ret = PTR_ERR(dmabuf);
202 goto free_pool;
203 }
204
205 return dmabuf;
206
207 free_pool:
208 gen_pool_free(buffer->pool, (unsigned long)buffer->vaddr, buffer->len);
209 free_buffer:
210 kfree(buffer);
211
212 return ERR_PTR(ret);
213 }
214
@@ -448,6 +448,13 @@ config SRAM
config SRAM_EXEC
bool
+config SRAM_DMA_HEAP
+ bool "Export on-chip SRAM pools using DMA-Heaps"
+ depends on DMABUF_HEAPS && SRAM
+ help
+ This driver allows the export of on-chip SRAM marked as both pool
+ and exportable to userspace using the DMA-Heaps interface.
+
config DW_XDATA_PCIE
depends on PCI
tristate "Synopsys DesignWare xData PCIe driver"
@@ -47,6 +47,7 @@ obj-$(CONFIG_VMWARE_VMCI) += vmw_vmci/
obj-$(CONFIG_LATTICE_ECP3_CONFIG) += lattice-ecp3-config.o
obj-$(CONFIG_SRAM) += sram.o
obj-$(CONFIG_SRAM_EXEC) += sram-exec.o
+obj-$(CONFIG_SRAM_DMA_HEAP) += sram-dma-heap.o
obj-$(CONFIG_GENWQE) += genwqe/
obj-$(CONFIG_ECHO) += echo/
obj-$(CONFIG_CXL_BASE) += cxl/
new file mode 100644
@@ -0,0 +1,245 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SRAM DMA-Heap userspace exporter
+ *
+ * Copyright (C) 2019-2022 Texas Instruments Incorporated - https://www.ti.com/
+ * Andrew Davis <afd@ti.com>
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/genalloc.h>
+#include <linux/io.h>
+#include <linux/mm.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/dma-buf.h>
+#include <linux/dma-heap.h>
+
+#include "sram.h"
+
+struct sram_dma_heap {
+ struct dma_heap *heap;
+ struct gen_pool *pool;
+};
+
+struct sram_dma_heap_buffer {
+ struct gen_pool *pool;
+ struct list_head attachments;
+ struct mutex attachments_lock;
+ unsigned long len;
+ void *vaddr;
+ phys_addr_t paddr;
+};
+
+struct dma_heap_attachment {
+ struct device *dev;
+ struct sg_table *table;
+ struct list_head list;
+};
+
+static int dma_heap_attach(struct dma_buf *dmabuf,
+ struct dma_buf_attachment *attachment)
+{
+ struct sram_dma_heap_buffer *buffer = dmabuf->priv;
+ struct dma_heap_attachment *a;
+ struct sg_table *table;
+
+ a = kzalloc(sizeof(*a), GFP_KERNEL);
+ if (!a)
+ return -ENOMEM;
+
+ table = kmalloc(sizeof(*table), GFP_KERNEL);
+ if (!table) {
+ kfree(a);
+ return -ENOMEM;
+ }
+ if (sg_alloc_table(table, 1, GFP_KERNEL)) {
+ kfree(table);
+ kfree(a);
+ return -ENOMEM;
+ }
+ sg_set_page(table->sgl, pfn_to_page(PFN_DOWN(buffer->paddr)), buffer->len, 0);
+
+ a->table = table;
+ a->dev = attachment->dev;
+ INIT_LIST_HEAD(&a->list);
+
+ attachment->priv = a;
+
+ mutex_lock(&buffer->attachments_lock);
+ list_add(&a->list, &buffer->attachments);
+ mutex_unlock(&buffer->attachments_lock);
+
+ return 0;
+}
+
+static void dma_heap_detatch(struct dma_buf *dmabuf,
+ struct dma_buf_attachment *attachment)
+{
+ struct sram_dma_heap_buffer *buffer = dmabuf->priv;
+ struct dma_heap_attachment *a = attachment->priv;
+
+ mutex_lock(&buffer->attachments_lock);
+ list_del(&a->list);
+ mutex_unlock(&buffer->attachments_lock);
+
+ sg_free_table(a->table);
+ kfree(a->table);
+ kfree(a);
+}
+
+static struct sg_table *dma_heap_map_dma_buf(struct dma_buf_attachment *attachment,
+ enum dma_data_direction direction)
+{
+ struct dma_heap_attachment *a = attachment->priv;
+ struct sg_table *table = a->table;
+
+ /*
+ * As this heap is backed by uncached SRAM memory we do not need to
+ * perform any sync operations on the buffer before allowing device
+ * domain access. For this reason we use SKIP_CPU_SYNC and also do
+ * not use or provide begin/end_cpu_access() dma-buf functions.
+ */
+ if (!dma_map_sg_attrs(attachment->dev, table->sgl, table->nents,
+ direction, DMA_ATTR_SKIP_CPU_SYNC))
+ return ERR_PTR(-ENOMEM);
+
+ return table;
+}
+
+static void dma_heap_unmap_dma_buf(struct dma_buf_attachment *attachment,
+ struct sg_table *table,
+ enum dma_data_direction direction)
+{
+ dma_unmap_sg_attrs(attachment->dev, table->sgl, table->nents,
+ direction, DMA_ATTR_SKIP_CPU_SYNC);
+}
+
+static void dma_heap_dma_buf_release(struct dma_buf *dmabuf)
+{
+ struct sram_dma_heap_buffer *buffer = dmabuf->priv;
+
+ gen_pool_free(buffer->pool, (unsigned long)buffer->vaddr, buffer->len);
+ kfree(buffer);
+}
+
+static int dma_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
+{
+ struct sram_dma_heap_buffer *buffer = dmabuf->priv;
+ int ret;
+
+ /* SRAM mappings are not cached */
+ vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
+
+ ret = vm_iomap_memory(vma, buffer->paddr, buffer->len);
+ if (ret)
+ pr_err("Could not map buffer to userspace\n");
+
+ return ret;
+}
+
+static int dma_heap_vmap(struct dma_buf *dmabuf, struct iosys_map *map)
+{
+ struct sram_dma_heap_buffer *buffer = dmabuf->priv;
+
+ iosys_map_set_vaddr(map, buffer->vaddr);
+
+ return 0;
+}
+
+static const struct dma_buf_ops sram_dma_heap_buf_ops = {
+ .attach = dma_heap_attach,
+ .detach = dma_heap_detatch,
+ .map_dma_buf = dma_heap_map_dma_buf,
+ .unmap_dma_buf = dma_heap_unmap_dma_buf,
+ .release = dma_heap_dma_buf_release,
+ .mmap = dma_heap_mmap,
+ .vmap = dma_heap_vmap,
+};
+
+struct dma_buf *sram_dma_heap_allocate(struct dma_heap *heap,
+ unsigned long len,
+ unsigned long fd_flags,
+ unsigned long heap_flags)
+{
+ struct sram_dma_heap *sram_dma_heap = dma_heap_get_drvdata(heap);
+ struct sram_dma_heap_buffer *buffer;
+
+ DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+ struct dma_buf *dmabuf;
+ int ret;
+
+ buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
+ if (!buffer)
+ return ERR_PTR(-ENOMEM);
+ buffer->pool = sram_dma_heap->pool;
+ INIT_LIST_HEAD(&buffer->attachments);
+ mutex_init(&buffer->attachments_lock);
+ buffer->len = len;
+
+ buffer->vaddr = (void *)gen_pool_alloc(buffer->pool, buffer->len);
+ if (!buffer->vaddr) {
+ ret = -ENOMEM;
+ goto free_buffer;
+ }
+
+ buffer->paddr = gen_pool_virt_to_phys(buffer->pool, (unsigned long)buffer->vaddr);
+ if (buffer->paddr == -1) {
+ ret = -ENOMEM;
+ goto free_pool;
+ }
+
+ /* create the dmabuf */
+ exp_info.exp_name = dma_heap_get_name(heap);
+ exp_info.ops = &sram_dma_heap_buf_ops;
+ exp_info.size = buffer->len;
+ exp_info.flags = fd_flags;
+ exp_info.priv = buffer;
+ dmabuf = dma_buf_export(&exp_info);
+ if (IS_ERR(dmabuf)) {
+ ret = PTR_ERR(dmabuf);
+ goto free_pool;
+ }
+
+ return dmabuf;
+
+free_pool:
+ gen_pool_free(buffer->pool, (unsigned long)buffer->vaddr, buffer->len);
+free_buffer:
+ kfree(buffer);
+
+ return ERR_PTR(ret);
+}
+
+static struct dma_heap_ops sram_dma_heap_ops = {
+ .allocate = sram_dma_heap_allocate,
+};
+
+int sram_add_dma_heap(struct sram_dev *sram,
+ struct sram_reserve *block,
+ phys_addr_t start,
+ struct sram_partition *part)
+{
+ struct sram_dma_heap *sram_dma_heap;
+ struct dma_heap_export_info exp_info;
+
+ dev_info(sram->dev, "Exporting SRAM Heap '%s'\n", block->label);
+
+ sram_dma_heap = kzalloc(sizeof(*sram_dma_heap), GFP_KERNEL);
+ if (!sram_dma_heap)
+ return -ENOMEM;
+ sram_dma_heap->pool = part->pool;
+
+ exp_info.name = kasprintf(GFP_KERNEL, "sram_%s", block->label);
+ exp_info.ops = &sram_dma_heap_ops;
+ exp_info.priv = sram_dma_heap;
+ sram_dma_heap->heap = dma_heap_add(&exp_info);
+ if (IS_ERR(sram_dma_heap->heap)) {
+ int ret = PTR_ERR(sram_dma_heap->heap);
+ kfree(sram_dma_heap);
+ return ret;
+ }
+
+ return 0;
+}
@@ -120,6 +120,12 @@ static int sram_add_partition(struct sram_dev *sram, struct sram_reserve *block,
ret = sram_add_pool(sram, block, start, part);
if (ret)
return ret;
+
+ if (block->export) {
+ ret = sram_add_dma_heap(sram, block, start, part);
+ if (ret)
+ return ret;
+ }
}
if (block->export) {
ret = sram_add_export(sram, block, start, part);
@@ -61,4 +61,20 @@ static inline int sram_add_protect_exec(struct sram_partition *part)
return -ENODEV;
}
#endif /* CONFIG_SRAM_EXEC */
+
+#ifdef CONFIG_SRAM_DMA_HEAP
+int sram_add_dma_heap(struct sram_dev *sram,
+ struct sram_reserve *block,
+ phys_addr_t start,
+ struct sram_partition *part);
+#else
+static inline int sram_add_dma_heap(struct sram_dev *sram,
+ struct sram_reserve *block,
+ phys_addr_t start,
+ struct sram_partition *part)
+{
+ return 0;
+}
+#endif /* CONFIG_SRAM_DMA_HEAP */
+
#endif /* __SRAM_H */