2022-02-19 09:49:35

by Baoquan He

Subject: [PATCH 20/22] HID: intel-ish-hid: Use dma_alloc_noncoherent() for dma buffer

GFP_DMA32 is an illegal flag to pass when calling kmalloc(), please see
GFP_SLAB_BUG_MASK definition.

Allocating dma buffer using kmalloc() is not recommended. Use
dma_alloc_noncoherent() instead. DMA API will assume the device has
32 bit addressing limitation when allocating buffer.

[ [email protected]: Use dma_alloc_noncoherent() instead of
__get_free_pages ]

Signed-off-by: Baoquan He <[email protected]>
Signed-off-by: Hyeonggon Yoo <[email protected]>
Cc: Srinivas Pandruvada <[email protected]>
Cc: Jiri Kosina <[email protected]>
Cc: Benjamin Tissoires <[email protected]>
Cc: Sumit Semwal <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
drivers/hid/intel-ish-hid/ishtp-fw-loader.c | 23 +++++++--------------
1 file changed, 8 insertions(+), 15 deletions(-)

diff --git a/drivers/hid/intel-ish-hid/ishtp-fw-loader.c b/drivers/hid/intel-ish-hid/ishtp-fw-loader.c
index e24988586710..3be1e3329962 100644
--- a/drivers/hid/intel-ish-hid/ishtp-fw-loader.c
+++ b/drivers/hid/intel-ish-hid/ishtp-fw-loader.c
@@ -661,21 +661,15 @@ static int ish_fw_xfer_direct_dma(struct ishtp_cl_data *client_data,
*/
payload_max_size &= ~(L1_CACHE_BYTES - 1);

- dma_buf = kmalloc(payload_max_size, GFP_KERNEL | GFP_DMA32);
+ dma_buf = dma_alloc_noncoherent(devc, get_order(payload_max_size),
+ &dma_buf_phy, DMA_TO_DEVICE,
+ GFP_KERNEL);
if (!dma_buf) {
+ dev_err(cl_data_to_dev(client_data), "DMA alloc failed\n");
client_data->flag_retry = true;
return -ENOMEM;
}

- dma_buf_phy = dma_map_single(devc, dma_buf, payload_max_size,
- DMA_TO_DEVICE);
- if (dma_mapping_error(devc, dma_buf_phy)) {
- dev_err(cl_data_to_dev(client_data), "DMA map failed\n");
- client_data->flag_retry = true;
- rv = -ENOMEM;
- goto end_err_dma_buf_release;
- }
-
ldr_xfer_dma_frag.fragment.hdr.command = LOADER_CMD_XFER_FRAGMENT;
ldr_xfer_dma_frag.fragment.xfer_mode = LOADER_XFER_MODE_DIRECT_DMA;
ldr_xfer_dma_frag.ddr_phys_addr = (u64)dma_buf_phy;
@@ -725,15 +719,14 @@ static int ish_fw_xfer_direct_dma(struct ishtp_cl_data *client_data,
fragment_offset += fragment_size;
}

- dma_unmap_single(devc, dma_buf_phy, payload_max_size, DMA_TO_DEVICE);
- kfree(dma_buf);
+ dma_free_noncoherent(devc, get_order(payload_max_size), dma_buf,
+ dma_buf_phy, DMA_TO_DEVICE);
return 0;

end_err_resp_buf_release:
/* Free ISH buffer if not done already, in error case */
- dma_unmap_single(devc, dma_buf_phy, payload_max_size, DMA_TO_DEVICE);
-end_err_dma_buf_release:
- kfree(dma_buf);
+ dma_free_noncoherent(devc, get_order(payload_max_size), dma_buf,
+ dma_buf_phy, DMA_TO_DEVICE);
return rv;
}

--
2.17.2

2022-02-20 13:28:31

by Christoph Hellwig

Subject: Re: [PATCH 20/22] HID: intel-ish-hid: Use dma_alloc_noncoherent() for dma buffer

Looks good,

Reviewed-by: Christoph Hellwig <[email protected]>