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Subject[char-misc-next 06/12] mei: dma ring buffers allocation
Date
Allocate DMA ring buffers from managed coherent memory.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
---
drivers/misc/mei/Makefile | 1 +
drivers/misc/mei/dma-ring.c | 103 ++++++++++++++++++++++++++++++++++++++++++++
drivers/misc/mei/hw-me.c | 6 +++
drivers/misc/mei/mei_dev.h | 20 +++++++++
4 files changed, 130 insertions(+)
create mode 100644 drivers/misc/mei/dma-ring.c

diff --git a/drivers/misc/mei/Makefile b/drivers/misc/mei/Makefile
index cd6825afa8e1..d9215fc4e499 100644
--- a/drivers/misc/mei/Makefile
+++ b/drivers/misc/mei/Makefile
@@ -9,6 +9,7 @@ mei-objs += hbm.o
mei-objs += interrupt.o
mei-objs += client.o
mei-objs += main.o
+mei-objs += dma-ring.o
mei-objs += bus.o
mei-objs += bus-fixup.o
mei-$(CONFIG_DEBUG_FS) += debugfs.o
diff --git a/drivers/misc/mei/dma-ring.c b/drivers/misc/mei/dma-ring.c
new file mode 100644
index 000000000000..368012116196
--- /dev/null
+++ b/drivers/misc/mei/dma-ring.c
@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/*
+ * Copyright(c) 2016 - 2018 Intel Corporation. All rights reserved.
+ */
+#include <linux/dma-mapping.h>
+#include <linux/mei.h>
+
+#include "mei_dev.h"
+
+/**
+ * mei_dmam_dscr_alloc - allocate a managed coherent buffer
+ * for the dma descriptor
+ *
+ * @dev: mei_device
+ * @dscr: dma descriptor
+ *
+ * Return: 0 on success or zero allocation request
+ * -EINVAL if size is not power of 2
+ * -ENOMEM of allocation has failed
+ */
+static int mei_dmam_dscr_alloc(struct mei_device *dev,
+ struct mei_dma_dscr *dscr)
+{
+ if (!dscr->size)
+ return 0;
+
+ if (WARN_ON(!is_power_of_2(dscr->size)))
+ return -EINVAL;
+
+ if (dscr->vaddr)
+ return 0;
+
+ dscr->vaddr = dmam_alloc_coherent(dev->dev, dscr->size, &dscr->daddr,
+ GFP_KERNEL);
+ if (!dscr->vaddr)
+ return -ENOMEM;
+
+ return 0;
+}
+
+/**
+ * mei_dmam_dscr_free - free a managed coherent buffer
+ * from the dma descriptor
+ *
+ * @dev: mei_device
+ * @dscr: dma descriptor
+ */
+static void mei_dmam_dscr_free(struct mei_device *dev,
+ struct mei_dma_dscr *dscr)
+{
+ if (!dscr->vaddr)
+ return;
+
+ dmam_free_coherent(dev->dev, dscr->size, dscr->vaddr, dscr->daddr);
+ dscr->vaddr = NULL;
+}
+
+/**
+ * mei_dmam_ring_free - free dma ring buffers
+ *
+ * @dev: mei device
+ */
+void mei_dmam_ring_free(struct mei_device *dev)
+{
+ int i;
+
+ for (i = 0; i < DMA_DSCR_NUM; i++)
+ mei_dmam_dscr_free(dev, &dev->dr_dscr[i]);
+}
+
+/**
+ * mei_dmam_ring_alloc - allocate dma ring buffers
+ *
+ * @dev: mei device
+ *
+ * Return: -ENOMEM on allocation failure 0 otherwise
+ */
+int mei_dmam_ring_alloc(struct mei_device *dev)
+{
+ int i;
+
+ for (i = 0; i < DMA_DSCR_NUM; i++)
+ if (mei_dmam_dscr_alloc(dev, &dev->dr_dscr[i]))
+ goto err;
+
+ return 0;
+
+err:
+ mei_dmam_ring_free(dev);
+ return -ENOMEM;
+}
+
+/**
+ * mei_dma_ring_is_allocated - check if dma ring is allocated
+ *
+ * @dev: mei device
+ *
+ * Return: true if dma ring is allocated
+ */
+bool mei_dma_ring_is_allocated(struct mei_device *dev)
+{
+ return !!dev->dr_dscr[DMA_DSCR_HOST].vaddr;
+}
diff --git a/drivers/misc/mei/hw-me.c b/drivers/misc/mei/hw-me.c
index 0759c3a668de..3fbbadfa2ae1 100644
--- a/drivers/misc/mei/hw-me.c
+++ b/drivers/misc/mei/hw-me.c
@@ -1471,15 +1471,21 @@ struct mei_device *mei_me_dev_init(struct pci_dev *pdev,
{
struct mei_device *dev;
struct mei_me_hw *hw;
+ int i;

dev = devm_kzalloc(&pdev->dev, sizeof(struct mei_device) +
sizeof(struct mei_me_hw), GFP_KERNEL);
if (!dev)
return NULL;
+
hw = to_me_hw(dev);

+ for (i = 0; i < DMA_DSCR_NUM; i++)
+ dev->dr_dscr[i].size = cfg->dma_size[i];
+
mei_device_init(dev, &pdev->dev, &mei_me_hw_ops);
hw->cfg = cfg;
+
return dev;
}

diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index 377397e1b5a5..a6796e3f712b 100644
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -122,6 +122,19 @@ struct mei_msg_data {
unsigned char *data;
};

+/**
+ * struct mei_dma_dscr - dma address descriptor
+ *
+ * @vaddr: dma buffer virtual address
+ * @daddr: dma buffer physical address
+ * @size : dma buffer size
+ */
+struct mei_dma_dscr {
+ void *vaddr;
+ dma_addr_t daddr;
+ size_t size;
+};
+
/* Maximum number of processed FW status registers */
#define MEI_FW_STATUS_MAX 6
/* Minimal buffer for FW status string (8 bytes in dw + space or '\0') */
@@ -409,6 +422,7 @@ struct mei_fw_version {
* @rd_msg_hdr : read message header storage
*
* @hbuf_is_ready : query if the host host/write buffer is ready
+ * @dr_dscr: DMA ring descriptors: TX, RX, and CTRL
*
* @version : HBM protocol version in use
* @hbm_f_pg_supported : hbm feature pgi protocol
@@ -488,6 +502,8 @@ struct mei_device {
/* write buffer */
bool hbuf_is_ready;

+ struct mei_dma_dscr dr_dscr[DMA_DSCR_NUM];
+
struct hbm_version version;
unsigned int hbm_f_pg_supported:1;
unsigned int hbm_f_dc_supported:1;
@@ -578,6 +594,10 @@ int mei_restart(struct mei_device *dev);
void mei_stop(struct mei_device *dev);
void mei_cancel_work(struct mei_device *dev);

+int mei_dmam_ring_alloc(struct mei_device *dev);
+void mei_dmam_ring_free(struct mei_device *dev);
+bool mei_dma_ring_is_allocated(struct mei_device *dev);
+
/*
* MEI interrupt functions prototype
*/
--
2.14.4
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