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
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 <afd@ti.com>
---
Changes from v2:
- Make sram_dma_heap_allocate static (kernel test robot)
- Rebase on v6.5-rc1
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 75e427f124b28..ee34dfb61605f 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 f2a4d1ff65d46..5e7516bfaa8de 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 0000000000000..c054c04dff33e
--- /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 <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,
+};
+
+static 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 = 0;
+
+ 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;
+}
diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c
index 5757adf418b1d..6dd173a2fba8e 100644
--- a/drivers/misc/sram.c
+++ b/drivers/misc/sram.c
@@ -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);
diff --git a/drivers/misc/sram.h b/drivers/misc/sram.h
index 397205b8bf6ff..062bdd25fa068 100644
--- a/drivers/misc/sram.h
+++ b/drivers/misc/sram.h
@@ -60,4 +60,20 @@ 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 */
--
2.39.2On Thu, Jul 13, 2023 at 02:13:16PM -0500, Andrew Davis wrote:
> +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);
When drivers are working properly, they are quiet.
thanks,
greg k-h
On 7/13/23 2:27 PM, Greg Kroah-Hartman wrote:
> On Thu, Jul 13, 2023 at 02:13:16PM -0500, Andrew Davis wrote:
>> +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);
>
> When drivers are working properly, they are quiet.
>
This should only be printed once in early boot when the memory is added,
I was wanting this to match the other memory exporters/output at the
beginning of boot logs.
But quiet is fine too, will change this to dev_dbg() for v4.
Thanks,
Andrew
> thanks,
>
> greg k-h
On Thu, Jul 13, 2023 at 02:13:16PM -0500, Andrew Davis wrote: > 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. What devices exactly? And what userspace tools/programs are going to use this api? > > Signed-off-by: Andrew Davis <afd@ti.com> > --- > > Changes from v2: > - Make sram_dma_heap_allocate static (kernel test robot) > - Rebase on v6.5-rc1 > > 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 75e427f124b28..ee34dfb61605f 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. Module name? > config DW_XDATA_PCIE > depends on PCI > tristate "Synopsys DesignWare xData PCIe driver" > diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile > index f2a4d1ff65d46..5e7516bfaa8de 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 0000000000000..c054c04dff33e > --- /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 <afd@ti.com> It's 2023 :( And this needs review from the dma-buf maintainers before I could do anything with it. thanks, greg k-h
Am 13.07.23 um 21:28 schrieb Greg Kroah-Hartman: > On Thu, Jul 13, 2023 at 02:13:16PM -0500, Andrew Davis wrote: >> 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. > What devices exactly? > > And what userspace tools/programs are going to use this api? > >> Signed-off-by: Andrew Davis <afd@ti.com> >> --- >> >> Changes from v2: >> - Make sram_dma_heap_allocate static (kernel test robot) >> - Rebase on v6.5-rc1 >> >> 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 75e427f124b28..ee34dfb61605f 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. > Module name? > >> config DW_XDATA_PCIE >> depends on PCI >> tristate "Synopsys DesignWare xData PCIe driver" >> diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile >> index f2a4d1ff65d46..5e7516bfaa8de 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 0000000000000..c054c04dff33e >> --- /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 <afd@ti.com> > It's 2023 :( > > And this needs review from the dma-buf maintainers before I could do > anything with it. Yeah, agree. Thanks Greg. It would be nice if you explicitly CC the maintainers for DMA-buf and DMA-buf heaps as well. Of hand I can only find the version from 2020 in the LKML archives. Regards, Christian. > > thanks, > > greg k-h > _______________________________________________ > Linaro-mm-sig mailing list -- linaro-mm-sig@lists.linaro.org > To unsubscribe send an email to linaro-mm-sig-leave@lists.linaro.org
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