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Subject[PATCH v2] tpm: ibmvtpm: Make use of dma_alloc_noncoherent()
Date
Replacing kmalloc/kfree/get_zeroed_page/free_page/dma_map_single/
dma_unmap_single() with dma_alloc_noncoherent/dma_free_noncoherent()
helps to reduce code size, and simplify the code, and the hardware
can keep DMA coherent itself.

Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
---
v1->v2:
*Change to dma_alloc/free_noncoherent from dma_alloc/free_coherent.
*Update changelog.

drivers/char/tpm/tpm_ibmvtpm.c | 63 +++++++++++-----------------------
1 file changed, 20 insertions(+), 43 deletions(-)

diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c
index 3af4c07a9342..b4552f8400b8 100644
--- a/drivers/char/tpm/tpm_ibmvtpm.c
+++ b/drivers/char/tpm/tpm_ibmvtpm.c
@@ -356,15 +356,13 @@ static void tpm_ibmvtpm_remove(struct vio_dev *vdev)
rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
} while (rc == H_BUSY || H_IS_LONG_BUSY(rc));

- dma_unmap_single(ibmvtpm->dev, ibmvtpm->crq_dma_handle,
- CRQ_RES_BUF_SIZE, DMA_BIDIRECTIONAL);
- free_page((unsigned long)ibmvtpm->crq_queue.crq_addr);
-
- if (ibmvtpm->rtce_buf) {
- dma_unmap_single(ibmvtpm->dev, ibmvtpm->rtce_dma_handle,
- ibmvtpm->rtce_size, DMA_BIDIRECTIONAL);
- kfree(ibmvtpm->rtce_buf);
- }
+ dma_free_noncoherent(ibmvtpm->dev, CRQ_RES_BUF_SIZE, crq_q->crq_addr,
+ crq_q->crq_dma_handle, DMA_BIDIRECTIONAL);
+
+ if (ibmvtpm->rtce_buf)
+ dma_free_noncoherent(ibmvtpm->dev,
+ ibmvtpm->rtce_size, ibmvtpm->rtce_buf,
+ ibmvtpm->rtce_dma_handle, DMA_BIDIRECTIONAL);

kfree(ibmvtpm);
/* For tpm_ibmvtpm_get_desired_dma */
@@ -522,23 +520,12 @@ static void ibmvtpm_crq_process(struct ibmvtpm_crq *crq,
return;
}
ibmvtpm->rtce_size = be16_to_cpu(crq->len);
- ibmvtpm->rtce_buf = kmalloc(ibmvtpm->rtce_size,
- GFP_ATOMIC);
- if (!ibmvtpm->rtce_buf) {
- dev_err(ibmvtpm->dev, "Failed to allocate memory for rtce buffer\n");
- return;
- }
-
- ibmvtpm->rtce_dma_handle = dma_map_single(ibmvtpm->dev,
- ibmvtpm->rtce_buf, ibmvtpm->rtce_size,
- DMA_BIDIRECTIONAL);
-
- if (dma_mapping_error(ibmvtpm->dev,
- ibmvtpm->rtce_dma_handle)) {
- kfree(ibmvtpm->rtce_buf);
- ibmvtpm->rtce_buf = NULL;
- dev_err(ibmvtpm->dev, "Failed to dma map rtce buffer\n");
- }
+ ibmvtpm->rtce_buf = dma_alloc_noncoherent(ibmvtpm->dev,
+ ibmvtpm->rtce_size,
+ &ibmvtpm->rtce_dma_handle,
+ DMA_BIDIRECTIONAL, GFP_ATOMIC);
+ if (!ibmvtpm->rtce_buf)
+ dev_err(ibmvtpm->dev, "Failed to dma allocate rtce buffer\n");

return;
case VTPM_GET_VERSION_RES:
@@ -618,22 +605,14 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev,
ibmvtpm->vdev = vio_dev;

crq_q = &ibmvtpm->crq_queue;
- crq_q->crq_addr = (struct ibmvtpm_crq *)get_zeroed_page(GFP_KERNEL);
- if (!crq_q->crq_addr) {
- dev_err(dev, "Unable to allocate memory for crq_addr\n");
- goto cleanup;
- }

crq_q->num_entry = CRQ_RES_BUF_SIZE / sizeof(*crq_q->crq_addr);
init_waitqueue_head(&crq_q->wq);
- ibmvtpm->crq_dma_handle = dma_map_single(dev, crq_q->crq_addr,
- CRQ_RES_BUF_SIZE,
- DMA_BIDIRECTIONAL);
-
- if (dma_mapping_error(dev, ibmvtpm->crq_dma_handle)) {
- dev_err(dev, "dma mapping failed\n");
+ crq_q->crq_addr = dma_alloc_noncoherent(dev, CRQ_RES_BUF_SIZE,
+ &ibmvtpm->crq_dma_handle,
+ DMA_BIDIRECTIONAL, GFP_KERNEL);
+ if (!crq_q->crq_addr)
goto cleanup;
- }

rc = plpar_hcall_norets(H_REG_CRQ, vio_dev->unit_address,
ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE);
@@ -642,7 +621,7 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev,

if (rc) {
dev_err(dev, "Unable to register CRQ rc=%d\n", rc);
- goto reg_crq_cleanup;
+ goto cleanup;
}

rc = request_irq(vio_dev->irq, ibmvtpm_interrupt, 0,
@@ -704,13 +683,11 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev,
do {
rc1 = plpar_hcall_norets(H_FREE_CRQ, vio_dev->unit_address);
} while (rc1 == H_BUSY || H_IS_LONG_BUSY(rc1));
-reg_crq_cleanup:
- dma_unmap_single(dev, ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE,
- DMA_BIDIRECTIONAL);
cleanup:
if (ibmvtpm) {
if (crq_q->crq_addr)
- free_page((unsigned long)crq_q->crq_addr);
+ dma_free_noncoherent(dev, CRQ_RES_BUF_SIZE, crq_q->crq_addr,
+ crq_q->crq_dma_handle, DMA_BIDIRECTIONAL);
kfree(ibmvtpm);
}

--
2.25.1
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