On Wed, Apr 15, 2020 at 10:27 AM Alan Mikhak <alan.mikhak@xxxxxxxxxx> wrote:
>
> From: Alan Mikhak <alan.mikhak@xxxxxxxxxx>
>
> Decouple dw-edma-core.c from struct pci_dev as a step toward integration
> of dw-edma with pci-epf-test so the latter can initiate dma operations
> locally from the endpoint side. A barrier to such integration is the
> dependency of dw_edma_probe() and other functions in dw-edma-core.c on
> struct pci_dev.
>
> The Synopsys DesignWare dw-edma driver was designed to run on host side
> of PCIe link to initiate DMA operations remotely using eDMA channels of
> PCIe controller on the endpoint side. This can be inferred from seeing
> that dw-edma uses struct pci_dev and accesses hardware registers of dma
> channels across the bus using BAR0 and BAR2.
>
> The ops field of struct dw_edma in dw-edma-core.h is currenty undefined:
>
> const struct dw_edma_core_ops *ops;
>
> However, the kernel builds without failure even when dw-edma driver is
> enabled. Instead of removing the currently undefined and usued ops field,
> define struct dw_edma_core_ops and use the ops field to decouple
> dw-edma-core.c from struct pci_dev.
>
> Signed-off-by: Alan Mikhak <alan.mikhak@xxxxxxxxxx>
Adding the ACK from RFC patch
Acked-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
> ---
> drivers/dma/dw-edma/dw-edma-core.c | 29 ++++++++++++++++++++---------
> drivers/dma/dw-edma/dw-edma-core.h | 4 ++++
> drivers/dma/dw-edma/dw-edma-pcie.c | 10 ++++++++++
> 3 files changed, 34 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
> index ff392c01bad1..db401eb11322 100644
> --- a/drivers/dma/dw-edma/dw-edma-core.c
> +++ b/drivers/dma/dw-edma/dw-edma-core.c
> @@ -14,7 +14,7 @@
> #include <linux/err.h>
> #include <linux/interrupt.h>
> #include <linux/dma/edma.h>
> -#include <linux/pci.h>
> +#include <linux/dma-mapping.h>
>
> #include "dw-edma-core.h"
> #include "dw-edma-v0-core.h"
> @@ -781,7 +781,7 @@ static int dw_edma_irq_request(struct dw_edma_chip *chip,
>
> if (dw->nr_irqs == 1) {
> /* Common IRQ shared among all channels */
> - err = request_irq(pci_irq_vector(to_pci_dev(dev), 0),
> + err = request_irq(dw->ops->irq_vector(dev, 0),
> dw_edma_interrupt_common,
> IRQF_SHARED, dw->name, &dw->irq[0]);
> if (err) {
> @@ -789,7 +789,7 @@ static int dw_edma_irq_request(struct dw_edma_chip *chip,
> return err;
> }
>
> - get_cached_msi_msg(pci_irq_vector(to_pci_dev(dev), 0),
> + get_cached_msi_msg(dw->ops->irq_vector(dev, 0),
> &dw->irq[0].msi);
> } else {
> /* Distribute IRQs equally among all channels */
> @@ -804,7 +804,7 @@ static int dw_edma_irq_request(struct dw_edma_chip *chip,
> dw_edma_add_irq_mask(&rd_mask, *rd_alloc, dw->rd_ch_cnt);
>
> for (i = 0; i < (*wr_alloc + *rd_alloc); i++) {
> - err = request_irq(pci_irq_vector(to_pci_dev(dev), i),
> + err = request_irq(dw->ops->irq_vector(dev, i),
> i < *wr_alloc ?
> dw_edma_interrupt_write :
> dw_edma_interrupt_read,
> @@ -815,7 +815,7 @@ static int dw_edma_irq_request(struct dw_edma_chip *chip,
> return err;
> }
>
> - get_cached_msi_msg(pci_irq_vector(to_pci_dev(dev), i),
> + get_cached_msi_msg(dw->ops->irq_vector(dev, i),
> &dw->irq[i].msi);
> }
>
> @@ -827,12 +827,23 @@ static int dw_edma_irq_request(struct dw_edma_chip *chip,
>
> int dw_edma_probe(struct dw_edma_chip *chip)
> {
> - struct device *dev = chip->dev;
> - struct dw_edma *dw = chip->dw;
> + struct device *dev;
> + struct dw_edma *dw;
> u32 wr_alloc = 0;
> u32 rd_alloc = 0;
> int i, err;
>
> + if (!chip)
> + return -EINVAL;
> +
> + dev = chip->dev;
> + if (!dev)
> + return -EINVAL;
> +
> + dw = chip->dw;
> + if (!dw || !dw->irq || !dw->ops || !dw->ops->irq_vector)
> + return -EINVAL;
> +
> raw_spin_lock_init(&dw->lock);
>
> /* Find out how many write channels are supported by hardware */
> @@ -884,7 +895,7 @@ int dw_edma_probe(struct dw_edma_chip *chip)
>
> err_irq_free:
> for (i = (dw->nr_irqs - 1); i >= 0; i--)
> - free_irq(pci_irq_vector(to_pci_dev(dev), i), &dw->irq[i]);
> + free_irq(dw->ops->irq_vector(dev, i), &dw->irq[i]);
>
> dw->nr_irqs = 0;
>
> @@ -904,7 +915,7 @@ int dw_edma_remove(struct dw_edma_chip *chip)
>
> /* Free irqs */
> for (i = (dw->nr_irqs - 1); i >= 0; i--)
> - free_irq(pci_irq_vector(to_pci_dev(dev), i), &dw->irq[i]);
> + free_irq(dw->ops->irq_vector(dev, i), &dw->irq[i]);
>
> /* Power management */
> pm_runtime_disable(dev);
> diff --git a/drivers/dma/dw-edma/dw-edma-core.h b/drivers/dma/dw-edma/dw-edma-core.h
> index 4e5f9f6e901b..31fc50d31792 100644
> --- a/drivers/dma/dw-edma/dw-edma-core.h
> +++ b/drivers/dma/dw-edma/dw-edma-core.h
> @@ -103,6 +103,10 @@ struct dw_edma_irq {
> struct dw_edma *dw;
> };
>
> +struct dw_edma_core_ops {
> + int (*irq_vector)(struct device *dev, unsigned int nr);
> +};
> +
> struct dw_edma {
> char name[20];
>
> diff --git a/drivers/dma/dw-edma/dw-edma-pcie.c b/drivers/dma/dw-edma/dw-edma-pcie.c
> index dc85f55e1bb8..1eafc602e17e 100644
> --- a/drivers/dma/dw-edma/dw-edma-pcie.c
> +++ b/drivers/dma/dw-edma/dw-edma-pcie.c
> @@ -54,6 +54,15 @@ static const struct dw_edma_pcie_data snps_edda_data = {
> .irqs = 1,
> };
>
> +static int dw_edma_pcie_irq_vector(struct device *dev, unsigned int nr)
> +{
> + return pci_irq_vector(to_pci_dev(dev), nr);
> +}
> +
> +static const struct dw_edma_core_ops dw_edma_pcie_core_ops = {
> + .irq_vector = dw_edma_pcie_irq_vector,
> +};
> +
> static int dw_edma_pcie_probe(struct pci_dev *pdev,
> const struct pci_device_id *pid)
> {
> @@ -151,6 +160,7 @@ static int dw_edma_pcie_probe(struct pci_dev *pdev,
> dw->version = pdata->version;
> dw->mode = pdata->mode;
> dw->nr_irqs = nr_irqs;
> + dw->ops = &dw_edma_pcie_core_ops;
>
> /* Debug info */
> pci_dbg(pdev, "Version:\t%u\n", dw->version);
> --
> 2.7.4
>
