kmap() is being deprecated in favor of kmap_local_page().
There are two main problems with kmap(): (1) It comes with an overhead as
mapping space is restricted and protected by a global lock for
synchronization and (2) it also requires global TLB invalidation when the
kmap’s pool wraps and it might block when the mapping space is fully
utilized until a slot becomes available.
With kmap_local_page() the mappings are per thread, CPU local, can take
page faults, and can be called from any context (including interrupts).
It is faster than kmap() in kernels with HIGHMEM enabled. Furthermore,
the tasks can be preempted and, when they are scheduled to run again, the
kernel virtual addresses are restored and are still valid.
Since its use in amdgpu/amdgpu_ttm.c is safe, it should be preferred.
Therefore, replace kmap() with kmap_local_page() in amdgpu/amdgpu_ttm.c.
Suggested-by: Ira Weiny <ira.weiny(a)intel.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco(a)gmail.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 3b4c19412625..c11657b5915f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -2301,9 +2301,9 @@ static ssize_t amdgpu_iomem_read(struct file *f, char __user *buf,
if (p->mapping != adev->mman.bdev.dev_mapping)
return -EPERM;
- ptr = kmap(p);
+ ptr = kmap_local_page(p);
r = copy_to_user(buf, ptr + off, bytes);
- kunmap(p);
+ kunmap_local(ptr);
if (r)
return -EFAULT;
@@ -2352,9 +2352,9 @@ static ssize_t amdgpu_iomem_write(struct file *f, const char __user *buf,
if (p->mapping != adev->mman.bdev.dev_mapping)
return -EPERM;
- ptr = kmap(p);
+ ptr = kmap_local_page(p);
r = copy_from_user(ptr + off, buf, bytes);
- kunmap(p);
+ kunmap_local(ptr);
if (r)
return -EFAULT;
--
2.37.1
Add a new ioctl called TEE_IOC_SHM_REGISTER_FD to register a
shared memory from a dmabuf file descriptor.
Etienne Carriere (1):
tee: new ioctl to a register tee_shm from a dmabuf file descriptor
drivers/tee/tee_core.c | 38 +++++++++++++++
drivers/tee/tee_shm.c | 99 +++++++++++++++++++++++++++++++++++++++-
include/linux/tee_drv.h | 11 +++++
include/uapi/linux/tee.h | 29 ++++++++++++
4 files changed, 175 insertions(+), 2 deletions(-)
--
2.25.0
Hello,
This series moves all drivers to a dynamic dma-buf locking specification.
From now on all dma-buf importers are made responsible for holding
dma-buf's reservation lock around all operations performed over dma-bufs
in accordance to the locking specification. This allows us to utilize
reservation lock more broadly around kernel without fearing of a potential
deadlocks.
This patchset passes all i915 selftests. It was also tested using VirtIO,
Panfrost, Lima and Tegra drivers. I tested cases of display+GPU,
display+V4L and GPU+V4L dma-buf sharing, which covers majority of kernel
drivers since rest of the drivers share same or similar code paths.
Changelog:
v2: - Changed locking specification to avoid problems with a cross-driver
ww locking, like was suggested by Christian König. Now the attach/detach
callbacks are invoked without the held lock and exporter should take the
lock.
- Added "locking convention" documentation that explains which dma-buf
functions and callbacks are locked/unlocked for importers and exporters,
which was requested by Christian König.
- Added ack from Tomasz Figa to the V4L patches that he gave to v1.
Dmitry Osipenko (5):
dma-buf: Add _unlocked postfix to function names
drm/gem: Take reservation lock for vmap/vunmap operations
dma-buf: Move all dma-bufs to dynamic locking specification
media: videobuf2: Stop using internal dma-buf lock
dma-buf: Remove internal lock
Documentation/driver-api/dma-buf.rst | 6 +
drivers/dma-buf/dma-buf.c | 253 +++++++++++++-----
drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 4 +-
drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 4 +-
drivers/gpu/drm/armada/armada_gem.c | 14 +-
drivers/gpu/drm/drm_client.c | 4 +-
drivers/gpu/drm/drm_gem.c | 24 ++
drivers/gpu/drm/drm_gem_cma_helper.c | 6 +-
drivers/gpu/drm/drm_gem_framebuffer_helper.c | 6 +-
drivers/gpu/drm/drm_gem_shmem_helper.c | 6 +-
drivers/gpu/drm/drm_prime.c | 12 +-
drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c | 6 +-
drivers/gpu/drm/exynos/exynos_drm_gem.c | 2 +-
drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 14 +-
.../drm/i915/gem/selftests/i915_gem_dmabuf.c | 20 +-
drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c | 8 +-
drivers/gpu/drm/qxl/qxl_object.c | 17 +-
drivers/gpu/drm/qxl/qxl_prime.c | 4 +-
drivers/gpu/drm/tegra/gem.c | 27 +-
drivers/infiniband/core/umem_dmabuf.c | 11 +-
.../common/videobuf2/videobuf2-dma-contig.c | 26 +-
.../media/common/videobuf2/videobuf2-dma-sg.c | 23 +-
.../common/videobuf2/videobuf2-vmalloc.c | 17 +-
.../platform/nvidia/tegra-vde/dmabuf-cache.c | 12 +-
drivers/misc/fastrpc.c | 12 +-
drivers/xen/gntdev-dmabuf.c | 14 +-
include/drm/drm_gem.h | 3 +
include/linux/dma-buf.h | 71 ++---
28 files changed, 372 insertions(+), 254 deletions(-)
--
2.36.1
Fix i2c transfers using GPI DMA mode for all message types that do not set
the I2C_M_DMA_SAFE flag (e.g. SMBus "read byte").
In this case a bounce buffer is returned by i2c_get_dma_safe_msg_buf(),
and it has to synced back to the message after the transfer is done.
Add missing assignment of dma buffer in geni_i2c_gpi().
Set xferred in i2c_put_dma_safe_msg_buf() to true in case of no error to
ensure the sync-back of this dma buffer to the message.
Signed-off-by: Robin Reckmann <robin.reckmann(a)gmail.com>
---
drivers/i2c/busses/i2c-qcom-geni.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
index 6ac402ea58fb..d3541e94794e 100644
--- a/drivers/i2c/busses/i2c-qcom-geni.c
+++ b/drivers/i2c/busses/i2c-qcom-geni.c
@@ -484,12 +484,12 @@ static void geni_i2c_gpi_unmap(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
{
if (tx_buf) {
dma_unmap_single(gi2c->se.dev->parent, tx_addr, msg->len, DMA_TO_DEVICE);
- i2c_put_dma_safe_msg_buf(tx_buf, msg, false);
+ i2c_put_dma_safe_msg_buf(tx_buf, msg, !gi2c->err);
}
if (rx_buf) {
dma_unmap_single(gi2c->se.dev->parent, rx_addr, msg->len, DMA_FROM_DEVICE);
- i2c_put_dma_safe_msg_buf(rx_buf, msg, false);
+ i2c_put_dma_safe_msg_buf(rx_buf, msg, !gi2c->err);
}
}
@@ -553,6 +553,7 @@ static int geni_i2c_gpi(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
desc->callback_param = gi2c;
dmaengine_submit(desc);
+ *buf = dma_buf;
*dma_addr_p = addr;
return 0;
--
2.25.1