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[RFC] Virtio mmio i2c #1

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b347ce3
drivers: mailbox: add interrupt controller to manage interrupt context
arnopo Jun 22, 2023
86c425c
dma-direct: prevent incorrect check of min dma address
Nicolas62x Jun 22, 2023
65f2333
remoteproc: virtio: Added mmio device populate
Nicolas62x Jun 22, 2023
ae47a1c
i2c: virtio: Use dma api instead of kalloc
Nicolas62x Jun 22, 2023
30ab589
virtio_mmio: Added compatiblility with remote processor
Nicolas62x Jun 22, 2023
e882ba4
ARM: dts: stm32: declare interrupt controller for the IPCC node on st…
arnopo Aug 29, 2023
debad54
ARM: dts: stm32: declare interrupt controller for the IPCC node on st…
arnopo Aug 29, 2023
752412d
ARM: dts: stm32: Add virtio mmio device to the stm32mp15xx-dkx board
arnopo Aug 28, 2023
0a0db9c
ARM: dts: stm32: Add virtio mmio device to the stm32mp157c-ed1 board
arnopo Aug 29, 2023
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29 changes: 28 additions & 1 deletion arch/arm/boot/dts/st/stm32mp157c-ed1.dts
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Original file line number Diff line number Diff line change
Expand Up @@ -58,6 +58,18 @@
no-map;
};

mmio0: mmio0@10050000 {
compatible = "shared-dma-pool";
reg = <0x10050000 0x200>;
no-map;
};

virtio0mem: virtio0mem@10050200 {
compatible = "shared-dma-pool";
reg = <0x10050200 0x7E00>;
no-map;
};

mcuram: mcuram@30000000 {
compatible = "shared-dma-pool";
reg = <0x30000000 0x40000>;
Expand Down Expand Up @@ -304,6 +316,8 @@

&ipcc {
status = "okay";
#interrupt-cells = <1>;
interrupt-controller;
};

&iwdg2 {
Expand All @@ -313,12 +327,25 @@

&m4_rproc {
memory-region = <&retram>, <&mcuram>, <&mcuram2>, <&vdev0vring0>,
<&vdev0vring1>, <&vdev0buffer>;
<&vdev0vring1>, <&vdev0buffer>, <&mmio0>;
mboxes = <&ipcc 0>, <&ipcc 1>, <&ipcc 2>, <&ipcc 3>;
mbox-names = "vq0", "vq1", "shutdown", "detach";
interrupt-parent = <&exti>;
interrupts = <68 1>;
status = "okay";

ranges;

#address-cells = <1>;
#size-cells = <1>;
mmio@10050000 {
compatible = "virtio,mmio-remoteproc";
reg = <0x10050000 0x100>;
interrupts-extended = <&ipcc 4>;
memory-region = <&virtio0mem>;
mboxes = <&ipcc 5>;
mbox-names = "sync_mb";
};
};

&pwr_regulators {
Expand Down
29 changes: 28 additions & 1 deletion arch/arm/boot/dts/st/stm32mp15xx-dkx.dtsi
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Original file line number Diff line number Diff line change
Expand Up @@ -48,6 +48,18 @@
no-map;
};

mmio0: mmio0@10050000 {
compatible = "shared-dma-pool";
reg = <0x10050000 0x200>;
no-map;
};

virtio0mem: virtio0mem@10050200 {
compatible = "shared-dma-pool";
reg = <0x10050200 0x7E00>;
no-map;
};

mcuram: mcuram@30000000 {
compatible = "shared-dma-pool";
reg = <0x30000000 0x40000>;
Expand Down Expand Up @@ -454,6 +466,8 @@

&ipcc {
status = "okay";
#interrupt-cells = <1>;
interrupt-controller;
};

&iwdg2 {
Expand All @@ -476,12 +490,25 @@

&m4_rproc {
memory-region = <&retram>, <&mcuram>, <&mcuram2>, <&vdev0vring0>,
<&vdev0vring1>, <&vdev0buffer>;
<&vdev0vring1>, <&vdev0buffer>, <&mmio0>;
mboxes = <&ipcc 0>, <&ipcc 1>, <&ipcc 2>, <&ipcc 3>;
mbox-names = "vq0", "vq1", "shutdown", "detach";
interrupt-parent = <&exti>;
interrupts = <68 1>;
status = "okay";

ranges;

#address-cells = <1>;
#size-cells = <1>;
mmio@10050000 {
compatible = "virtio,mmio-remoteproc";
reg = <0x10050000 0x100>;
interrupts-extended = <&ipcc 4>;
memory-region = <&virtio0mem>;
mboxes = <&ipcc 5>;
mbox-names = "sync_mb";
};
};

&pwr_regulators {
Expand Down
74 changes: 61 additions & 13 deletions drivers/i2c/busses/i2c-virtio.c
View file
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Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,7 @@
#include <linux/virtio_ids.h>
#include <linux/virtio_config.h>
#include <linux/virtio_i2c.h>
#include <linux/dma-mapping.h>

/**
* struct virtio_i2c - virtio I2C data
Expand All @@ -39,7 +40,8 @@ struct virtio_i2c {
* @in_hdr: the IN header of the virtio I2C message
*/
struct virtio_i2c_req {
struct completion completion;
struct completion *completion;
dma_addr_t dma_handle;
struct virtio_i2c_out_hdr out_hdr ____cacheline_aligned;
uint8_t *buf ____cacheline_aligned;
struct virtio_i2c_in_hdr in_hdr ____cacheline_aligned;
Expand All @@ -51,7 +53,35 @@ static void virtio_i2c_msg_done(struct virtqueue *vq)
unsigned int len;

while ((req = virtqueue_get_buf(vq, &len)))
complete(&req->completion);
complete(req->completion);
}

static void virtio_sg_init(struct scatterlist *sg, void *cpu_addr, unsigned int len)
{
if (likely(is_vmalloc_addr(cpu_addr))) {
sg_init_table(sg, 1);
sg_set_page(sg, vmalloc_to_page(cpu_addr), len,
offset_in_page(cpu_addr));
} else {
WARN_ON(!virt_addr_valid(cpu_addr));
sg_init_one(sg, cpu_addr, len);
}
}

static void get_dma_buffer(struct device *dma_dev, struct virtio_i2c_req *req, struct i2c_msg *msg)
{
req->buf = dma_alloc_coherent(dma_dev, msg->len, &req->dma_handle, GFP_KERNEL);

if (req->buf)
memcpy(req->buf, msg->buf, msg->len);
}

static void put_dma_buffer(struct device *dma_dev, struct virtio_i2c_req *req, struct i2c_msg *msg)
{
if (msg->flags & I2C_M_RD)
memcpy(msg->buf, req->buf, msg->len);

dma_free_coherent(dma_dev, msg->len, req->buf, req->dma_handle);
}

static int virtio_i2c_prepare_reqs(struct virtqueue *vq,
Expand All @@ -64,7 +94,11 @@ static int virtio_i2c_prepare_reqs(struct virtqueue *vq,
for (i = 0; i < num; i++) {
int outcnt = 0, incnt = 0;

init_completion(&reqs[i].completion);
reqs[i].completion = kcalloc(1, sizeof(struct completion), GFP_KERNEL);
if (!reqs[i].completion)
break;

init_completion(reqs[i].completion);

/*
* Only 7-bit mode supported for this moment. For the address
Expand All @@ -78,27 +112,33 @@ static int virtio_i2c_prepare_reqs(struct virtqueue *vq,
if (i != num - 1)
reqs[i].out_hdr.flags |= cpu_to_le32(VIRTIO_I2C_FLAGS_FAIL_NEXT);

sg_init_one(&out_hdr, &reqs[i].out_hdr, sizeof(reqs[i].out_hdr));
virtio_sg_init(&out_hdr, &reqs[i].out_hdr, sizeof(reqs[i].out_hdr));
sgs[outcnt++] = &out_hdr;

if (msgs[i].len) {
reqs[i].buf = i2c_get_dma_safe_msg_buf(&msgs[i], 1);
if (!reqs[i].buf)
get_dma_buffer(vq->vdev->dev.parent, &reqs[i], &msgs[i]);

if (!reqs[i].buf) {
kfree(reqs[i].completion);
break;
}

sg_init_one(&msg_buf, reqs[i].buf, msgs[i].len);
virtio_sg_init(&msg_buf, reqs[i].buf, msgs[i].len);

if (msgs[i].flags & I2C_M_RD)
sgs[outcnt + incnt++] = &msg_buf;
else
sgs[outcnt++] = &msg_buf;
}

sg_init_one(&in_hdr, &reqs[i].in_hdr, sizeof(reqs[i].in_hdr));
virtio_sg_init(&in_hdr, &reqs[i].in_hdr, sizeof(reqs[i].in_hdr));
sgs[outcnt + incnt++] = &in_hdr;

if (virtqueue_add_sgs(vq, sgs, outcnt, incnt, &reqs[i], GFP_KERNEL)) {
i2c_put_dma_safe_msg_buf(reqs[i].buf, &msgs[i], false);
put_dma_buffer(vq->vdev->dev.parent, &reqs[i], &msgs[i]);

kfree(reqs[i].completion);

break;
}
}
Expand All @@ -116,12 +156,14 @@ static int virtio_i2c_complete_reqs(struct virtqueue *vq,
for (i = 0; i < num; i++) {
struct virtio_i2c_req *req = &reqs[i];

wait_for_completion(&req->completion);
wait_for_completion(req->completion);

if (!failed && req->in_hdr.status != VIRTIO_I2C_MSG_OK)
failed = true;

i2c_put_dma_safe_msg_buf(reqs[i].buf, &msgs[i], !failed);
put_dma_buffer(vq->vdev->dev.parent, req, &msgs[i]);

kfree(req->completion);

if (!failed)
j++;
Expand All @@ -137,8 +179,12 @@ static int virtio_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
struct virtqueue *vq = vi->vq;
struct virtio_i2c_req *reqs;
int count;
dma_addr_t dma_handle;

reqs = dma_alloc_coherent(vq->vdev->dev.parent,
sizeof(struct virtio_i2c_req) * num,
&dma_handle, GFP_KERNEL);

reqs = kcalloc(num, sizeof(*reqs), GFP_KERNEL);
if (!reqs)
return -ENOMEM;

Expand All @@ -159,7 +205,9 @@ static int virtio_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
count = virtio_i2c_complete_reqs(vq, reqs, msgs, count);

err_free:
kfree(reqs);
dma_free_coherent(vq->vdev->dev.parent,
sizeof(struct virtio_i2c_req) * num,
reqs, dma_handle);
return count;
}

Expand Down
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