Re: [PATCH v2] misc: sram: Add DMA-BUF Heap exporting of SRAM areas
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-...@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
| Link:
https://lore.kernel.org/oe-kbuild-all/202304041144.t5jcogse-...@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(>attachments);
178 mutex_init(>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 = _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(_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
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests
[PATCH v2] misc: sram: Add DMA-BUF Heap exporting of SRAM areas
This new export type exposes to userspace the SRAM area as a DMA-BUF Heap,
this allows for allocations of DMA-BUFs that can be consumed by various
DMA-BUF supporting devices.
Signed-off-by: Andrew Davis
---
Changes from v1:
- Use existing DT flags, if both pool(device usable) and export(userspace
usable) properties are in the SRAM node then export as a DMA-BUF Heap
- Rebase on 6.3-rc5
drivers/misc/Kconfig | 7 +
drivers/misc/Makefile| 1 +
drivers/misc/sram-dma-heap.c | 245 +++
drivers/misc/sram.c | 6 +
drivers/misc/sram.h | 16 +++
5 files changed, 275 insertions(+)
create mode 100644 drivers/misc/sram-dma-heap.c
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 433aa41977852..8b4c111a6493b 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -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"
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 56de43943cd51..bbdc64aa8af1a 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -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/
diff --git a/drivers/misc/sram-dma-heap.c b/drivers/misc/sram-dma-heap.c
new file mode 100644
index 0..c511f4ac1280e
--- /dev/null
+++ b/drivers/misc/sram-dma-heap.c
@@ -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
+ */
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#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(>list);
+
+ attachment->priv = a;
+
+ mutex_lock(>attachments_lock);
+ list_add(>list, >attachments);
+ mutex_unlock(>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(>attachments_lock);
+ list_del(>list);
+ mutex_unlock(>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))
+
