On Thu, Apr 30, 2020 at 01:18:07PM -0700, Bjorn Andersson wrote:
> On Wed 29 Apr 23:30 PDT 2020, Manivannan Sadhasivam wrote:
>
> > From: Venkata Narendra Kumar Gutta <vnkgutta@xxxxxxxxxxxxxx>
> >
> > Add support for the Inter-Processor Communication Controller (IPCC)
> > driver that coordinates the interrupts (inbound & outbound) for
> > Multiprocessor (MPROC), COMPUTE-Level0 (COMPUTE-L0) & COMPUTE-Level1
> > (COMPUTE-L1) protocols for the Application Processor Subsystem (APSS).
> >
> > As a part of its inbound communication, the driver would be responsible
> > for forwarding the interrupts from various clients, such as Modem, DSPs,
> > PCIe, and so on, to the entities running on the APPS. As a result, it's
> > implemented as an irq_chip driver.
> >
> > On the other hand, the driver also registers as a mailbox controller
> > that provides a mailbox interface to interrupt other clients connected
> > to the IPCC, acting as an outbound communication channel.
> >
> > Signed-off-by: Raghavendra Rao Ananta <rananta@xxxxxxxxxxxxxx>
> > Signed-off-by: Venkata Narendra Kumar Gutta <vnkgutta@xxxxxxxxxxxxxx>
> > Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> > [mani: cleaned up for upstream]
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> > ---
> > drivers/soc/qcom/Kconfig | 11 +
> > drivers/soc/qcom/Makefile | 1 +
> > drivers/soc/qcom/qcom_ipcc.c | 410 +++++++++++++++++++++++++++++++++++
>
> I think the driver should be moved to either drivers/irqchip or
> drivers/mailbox.
>
As said in bindings patch, mailbox seems to be a better location if we don't
want this to be under drivers/soc.
> > 3 files changed, 422 insertions(+)
> > create mode 100644 drivers/soc/qcom/qcom_ipcc.c
> >
> > diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
> > index bf42a17a45de..97c380c3fa09 100644
> > --- a/drivers/soc/qcom/Kconfig
> > +++ b/drivers/soc/qcom/Kconfig
> > @@ -53,6 +53,17 @@ config QCOM_GSBI
> > functions for connecting the underlying serial UART, SPI, and I2C
> > devices to the output pins.
> >
> > +config QCOM_IPCC
> > + tristate "Qualcomm Technologies, Inc. IPCC driver"
> > + depends on MAILBOX
> > + help
> > + Qualcomm Technologies, Inc. IPCC driver for MSM devices. The drivers
> > + acts as an interrupt controller for the clients interested in
> > + talking to the IPCC (inbound-communication). On the other hand, the
> > + driver also provides a mailbox channel for outbound-communications.
> > + Say Y here to compile the driver as a part of kernel or M to compile
> > + as a module.
> > +
> > config QCOM_LLCC
> > tristate "Qualcomm Technologies, Inc. LLCC driver"
> > depends on ARCH_QCOM || COMPILE_TEST
> > diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
> > index 5d6b83dc58e8..b7658b007040 100644
> > --- a/drivers/soc/qcom/Makefile
> > +++ b/drivers/soc/qcom/Makefile
> > @@ -24,5 +24,6 @@ obj-$(CONFIG_QCOM_SOCINFO) += socinfo.o
> > obj-$(CONFIG_QCOM_WCNSS_CTRL) += wcnss_ctrl.o
> > obj-$(CONFIG_QCOM_APR) += apr.o
> > obj-$(CONFIG_QCOM_LLCC) += llcc-qcom.o
> > +obj-$(CONFIG_QCOM_IPCC) += qcom_ipcc.o
> > obj-$(CONFIG_QCOM_RPMHPD) += rpmhpd.o
> > obj-$(CONFIG_QCOM_RPMPD) += rpmpd.o
> > diff --git a/drivers/soc/qcom/qcom_ipcc.c b/drivers/soc/qcom/qcom_ipcc.c
> > new file mode 100644
> > index 000000000000..5906a70220e0
> > --- /dev/null
> > +++ b/drivers/soc/qcom/qcom_ipcc.c
> > @@ -0,0 +1,410 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
> > + */
> > +
> > +#include <linux/interrupt.h>
> > +#include <linux/irq.h>
> > +#include <linux/irqdomain.h>
> > +#include <linux/mailbox_controller.h>
> > +#include <linux/module.h>
> > +#include <linux/platform_device.h>
> > +
> > +#include <dt-bindings/soc/qcom,ipcc.h>
> > +
> > +/* IPCC Register offsets */
> > +#define IPCC_REG_SEND_ID 0x0c
> > +#define IPCC_REG_RECV_ID 0x10
> > +#define IPCC_REG_RECV_SIGNAL_ENABLE 0x14
> > +#define IPCC_REG_RECV_SIGNAL_DISABLE 0x18
> > +#define IPCC_REG_RECV_SIGNAL_CLEAR 0x1c
> > +#define IPCC_REG_CLIENT_CLEAR 0x38
> > +
> > +#define IPCC_SIGNAL_ID_MASK GENMASK(15, 0)
> > +#define IPCC_CLIENT_ID_MASK GENMASK(31, 16)
> > +#define IPCC_CLIENT_ID_SHIFT 16
> > +
> > +#define IPCC_NO_PENDING_IRQ 0xffffffff
> > +
> > +/**
> > + * struct qcom_ipcc_proto_data - Per-protocol data
> > + * @irq_domain: irq_domain associated with this protocol-id
> > + * @mbox: mailbox-controller interface
> > + * @chans: The mailbox clients channel array (created dynamically)
> > + * @base: Base address of the IPCC frame associated to APSS
> > + * @dev: Device associated with this instance
> > + * @irq: Summary irq
> > + */
> > +struct qcom_ipcc_proto_data {
>
> There's only one of these per IPCC hardware block, so I would suggest
> that you shorten in to just "struct qcom_ipcc" and then throughout the
> implementation replace "proto_data" with just "ipcc".
>
okay
> > + struct irq_domain *irq_domain;
> > + struct mbox_controller mbox;
> > + struct mbox_chan *chans;
> > + void __iomem *base;
> > + struct device *dev;
> > + int irq;
> > +};
> > +
> > +/**
> > + * struct qcom_ipcc_mbox_chan - Per-mailbox-channel data. Associated to
> > + * channel when requested by the clients
> > + * @chan: Points to this channel's array element for this protocol's
> > + * ipcc_protocol_data->chans[]
> > + * @proto_data: The pointer to per-protocol data associated to this channel
> > + * @client_id: The client-id to which the interrupt has to be triggered
> > + * @signal_id: The signal-id to which the interrupt has to be triggered
> > + */
> > +struct qcom_ipcc_mbox_chan {
> > + struct mbox_chan *chan;
> > + struct qcom_ipcc_proto_data *proto_data;
> > + u16 client_id;
> > + u16 signal_id;
> > +};
> > +
> > +static struct qcom_ipcc_proto_data *ipcc_proto_data;
> > +
> > +static inline u32 qcom_ipcc_get_packed_id(u16 client_id, u16 signal_id)
>
> qcom_ipcc_pack_ids()
>
> and please omit the "inline", the compiler will inline it if it's a good
> thing to do.
>
But the usual convention is to give the hint to compiler isn't it?
> > +{
> > + return (client_id << IPCC_CLIENT_ID_SHIFT) | signal_id;
>
> How about:
>
> return FIELD_PREP(IPCC_CLIENT_ID_MASK, client_id) |
> FIELD_PREP(IPCC_SIGNAL_ID_MASK, signal_id);
>
okay
> > +}
> > +
> > +static inline u16 qcom_ipcc_get_client_id(u32 packed_id)
>
> This is used only to extract the field for a dev_dbg print. How about
> dropping this for now and if this kind of debugging is beneficial lets
> add some tracepoint that internally can extract the fields.
>
okay, will drop.
> > +{
> > + return packed_id >> IPCC_CLIENT_ID_SHIFT;
> > +}
> > +
> > +static inline u16 qcom_ipcc_get_signal_id(u32 packed_id)
>
> Ditto.
>
> > +{
> > + return packed_id & IPCC_SIGNAL_ID_MASK;
> > +}
> > +
> > +static irqreturn_t qcom_ipcc_irq_fn(int irq, void *data)
> > +{
> > + struct qcom_ipcc_proto_data *proto_data = data;
> > + u32 packed_id;
> > + int virq;
> > +
> > + for (;;) {
> > + packed_id = readl(proto_data->base + IPCC_REG_RECV_ID);
> > + if (packed_id == IPCC_NO_PENDING_IRQ)
> > + break;
> > +
> > + virq = irq_find_mapping(proto_data->irq_domain, packed_id);
> > +
> > + dev_dbg(proto_data->dev,
> > + "IRQ for client_id: %u; signal_id: %u; virq: %d\n",
> > + qcom_ipcc_get_client_id(packed_id),
> > + qcom_ipcc_get_signal_id(packed_id), virq);
>
> As above, I think this is useful either during development of the driver
> (now done) or in a system debugging case as a tracepoint. So please omit
> this debug print.
>
okay
> > +
> > + writel(packed_id,
>
> If you're consistently with naming this "hwirq" you don't need to wrap
> this line.
>
> > + proto_data->base + IPCC_REG_RECV_SIGNAL_CLEAR);
> > +
> > + generic_handle_irq(virq);
> > + }
> > +
> > + return IRQ_HANDLED;
> > +}
> > +
> > +static void qcom_ipcc_mask_irq(struct irq_data *irqd)
> > +{
> > + struct qcom_ipcc_proto_data *proto_data;
> > + irq_hw_number_t hwirq = irqd_to_hwirq(irqd);
> > + u16 sender_client_id = qcom_ipcc_get_client_id(hwirq);
> > + u16 sender_signal_id = qcom_ipcc_get_signal_id(hwirq);
> > +
> > + proto_data = irq_data_get_irq_chip_data(irqd);
>
> struct qcom_ipcc *ipcc = irq_data_get_irq_chip_data(irqd);
> irq_hw_number_t hwirq = irqd_to_hwirq(irqd);
>
> Looks better.
>
> > +
> > + dev_dbg(proto_data->dev,
> > + "Disabling interrupts for: client_id: %u; signal_id: %u\n",
> > + sender_client_id, sender_signal_id);
>
> Pushing out field dissection and "logging" to a tracepoint would make
> this function prettier as well.
>
okay
> > +
> > + writel(hwirq, proto_data->base + IPCC_REG_RECV_SIGNAL_DISABLE);
> > +}
> > +
> > +static void qcom_ipcc_unmask_irq(struct irq_data *irqd)
> > +{
> > + struct qcom_ipcc_proto_data *proto_data;
> > + irq_hw_number_t hwirq = irqd_to_hwirq(irqd);
> > + u16 sender_client_id = qcom_ipcc_get_client_id(hwirq);
> > + u16 sender_signal_id = qcom_ipcc_get_signal_id(hwirq);
> > +
> > + proto_data = irq_data_get_irq_chip_data(irqd);
>
> As above.
>
> > +
> > + dev_dbg(proto_data->dev,
> > + "Enabling interrupts for: client_id: %u; signal_id: %u\n",
> > + sender_client_id, sender_signal_id);
> > +
> > + writel(hwirq, proto_data->base + IPCC_REG_RECV_SIGNAL_ENABLE);
> > +}
> > +
> > +static struct irq_chip qcom_ipcc_irq_chip = {
> > + .name = "ipcc",
> > + .irq_mask = qcom_ipcc_mask_irq,
> > + .irq_unmask = qcom_ipcc_unmask_irq,
> > + .flags = IRQCHIP_SKIP_SET_WAKE,
> > +};
> > +
> > +static int qcom_ipcc_domain_map(struct irq_domain *d, unsigned int irq,
> > + irq_hw_number_t hw)
> > +{
> > + struct qcom_ipcc_proto_data *proto_data = d->host_data;
> > +
> > + irq_set_chip_and_handler(irq, &qcom_ipcc_irq_chip, handle_level_irq);
> > + irq_set_chip_data(irq, proto_data);
> > + irq_set_noprobe(irq);
> > +
> > + return 0;
> > +}
> > +
> > +static int qcom_ipcc_domain_xlate(struct irq_domain *d,
> > + struct device_node *node, const u32 *intspec,
> > + unsigned int intsize,
> > + unsigned long *out_hwirq,
> > + unsigned int *out_type)
> > +{
> > + struct qcom_ipcc_proto_data *proto_data = d->host_data;
> > + struct device *dev = proto_data->dev;
> > +
> > + if (intsize != 3)
> > + return -EINVAL;
> > +
> > + *out_hwirq = qcom_ipcc_get_packed_id(intspec[0], intspec[1]);
> > + *out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
> > +
> > + dev_dbg(dev, "hwirq: 0x%lx\n", *out_hwirq);
> > +
> > + return 0;
> > +}
> > +
> > +static const struct irq_domain_ops qcom_ipcc_irq_ops = {
> > + .map = qcom_ipcc_domain_map,
> > + .xlate = qcom_ipcc_domain_xlate,
> > +};
> > +
> > +static int qcom_ipcc_mbox_send_data(struct mbox_chan *chan, void *data)
> > +{
> > + struct qcom_ipcc_mbox_chan *ipcc_mbox_chan = chan->con_priv;
> > + struct qcom_ipcc_proto_data *proto_data = ipcc_mbox_chan->proto_data;
> > + u32 packed_id;
>
> Although we're in the "mailbox section", I still think it's reasonable
> to name this hwirq for consistency (otherwise please shorten it to "id").
>
okay, will name it as hwirq.
> > +
> > + dev_dbg(proto_data->dev,
> > + "Generating IRQ for client_id: %u; signal_id: %u\n",
> > + ipcc_mbox_chan->client_id, ipcc_mbox_chan->signal_id);
> > +
> > + packed_id = qcom_ipcc_get_packed_id(ipcc_mbox_chan->client_id,
> > + ipcc_mbox_chan->signal_id);
> > + writel(packed_id, proto_data->base + IPCC_REG_SEND_ID);
> > +
> > + return 0;
> > +}
> > +
> > +static void qcom_ipcc_mbox_shutdown(struct mbox_chan *chan)
> > +{
> > + struct qcom_ipcc_mbox_chan *ipcc_mbox_chan = chan->con_priv;
> > +
> > + chan->con_priv = NULL;
> > + kfree(ipcc_mbox_chan);
> > +}
> > +
> > +static struct mbox_chan *qcom_ipcc_mbox_xlate(struct mbox_controller *mbox,
> > + const struct of_phandle_args *ph)
> > +{
> > + struct device *dev;
> > + struct qcom_ipcc_proto_data *proto_data;
> > + struct qcom_ipcc_mbox_chan *ipcc_mbox_chan;
> > + int chan_id;
> > +
> > + proto_data = container_of(mbox, struct qcom_ipcc_proto_data, mbox);
> > + if (WARN_ON(!proto_data))
>
> Is this possible?
>
hmm, not required.
> > + return ERR_PTR(-EINVAL);
> > +
> > + dev = proto_data->dev;
> > +
> > + if (ph->args_count != 2)
> > + return ERR_PTR(-EINVAL);
> > +
> > + /* Check whether the mbox channel is allocated or not */
> > + for (chan_id = 0; chan_id < mbox->num_chans; chan_id++) {
> > + ipcc_mbox_chan = proto_data->chans[chan_id].con_priv;
> > +
> > + if (!ipcc_mbox_chan)
> > + break;
> > + else if (ipcc_mbox_chan->client_id == ph->args[0] &&
> > + ipcc_mbox_chan->signal_id == ph->args[1])
> > + return ERR_PTR(-EBUSY);
>
> I think it would be better to just return the matching chan, and let
> mbox_request_channel() deal with the fact that it's already in use.
>
okay
> > + }
> > +
> > + if (chan_id >= mbox->num_chans)
> > + return ERR_PTR(-EBUSY);
> > +
> > + ipcc_mbox_chan = kzalloc(sizeof(*ipcc_mbox_chan), GFP_KERNEL);
>
> Can we allocate these during initialization time instead of allocating
> and releasing them in of_xlate and shutdown?
>
We should know the max channels supported for allocating statically.
> > + if (!ipcc_mbox_chan)
> > + return ERR_PTR(-ENOMEM);
> > +
> > + ipcc_mbox_chan->client_id = ph->args[0];
> > + ipcc_mbox_chan->signal_id = ph->args[1];
> > + ipcc_mbox_chan->chan = &proto_data->chans[chan_id];
> > + ipcc_mbox_chan->proto_data = proto_data;
> > + ipcc_mbox_chan->chan->con_priv = ipcc_mbox_chan;
> > +
> > + dev_dbg(dev,
> > + "New mailbox channel: %u for client_id: %u; signal_id: %u\n",
> > + chan_id, ipcc_mbox_chan->client_id,
> > + ipcc_mbox_chan->signal_id);
> > +
> > + return ipcc_mbox_chan->chan;
> > +}
> > +
> > +static const struct mbox_chan_ops ipcc_mbox_chan_ops = {
> > + .send_data = qcom_ipcc_mbox_send_data,
> > + .shutdown = qcom_ipcc_mbox_shutdown
> > +};
> > +
> > +static int qcom_ipcc_setup_mbox(struct qcom_ipcc_proto_data *proto_data,
> > + struct device_node *controller_dn)
> > +{
> > + struct mbox_controller *mbox;
> > + struct device_node *client_dn;
> > + struct device *dev = proto_data->dev;
> > + struct of_phandle_args curr_ph;
> > + int i, j, ret;
> > + int num_chans = 0;
> > +
> > + /*
> > + * Find out the number of clients interested in this mailbox
> > + * and create channels accordingly.
> > + */
> > + for_each_node_with_property(client_dn, "mboxes") {
>
> How much memory do we save by doing this, in comparison to just picking
> a max amount?
>
Right, this is what I thought and was hoping that you'll get to it :)
But I don't know the max channels supported by IPCC.
Can someone help to find this?
> > + if (!of_device_is_available(client_dn))
> > + continue;
> > + i = of_count_phandle_with_args(client_dn,
> > + "mboxes", "#mbox-cells");
> > + for (j = 0; j < i; j++) {
> > + ret = of_parse_phandle_with_args(client_dn, "mboxes",
> > + "#mbox-cells", j,
> > + &curr_ph);
> > + of_node_put(curr_ph.np);
> > + if (!ret && curr_ph.np == controller_dn) {
> > + num_chans++;
> > + break;
> > + }
> > + }
> > + }
> > +
> > + /* If no clients are found, skip registering as a mbox controller */
> > + if (!num_chans)
> > + return 0;
> > +
> > + proto_data->chans = devm_kcalloc(dev, num_chans,
> > + sizeof(struct mbox_chan), GFP_KERNEL);
>
> sizeof(*proto_data->chans)
>
> > + if (!proto_data->chans)
> > + return -ENOMEM;
> > +
> > + mbox = &proto_data->mbox;
> > + mbox->dev = dev;
> > + mbox->num_chans = num_chans;
> > + mbox->chans = proto_data->chans;
> > + mbox->ops = &ipcc_mbox_chan_ops;
> > + mbox->of_xlate = qcom_ipcc_mbox_xlate;
> > + mbox->txdone_irq = false;
> > + mbox->txdone_poll = false;
> > +
> > + return devm_mbox_controller_register(dev, mbox);
> > +}
> > +
> > +static int qcom_ipcc_probe(struct platform_device *pdev)
> > +{
> > + struct qcom_ipcc_proto_data *proto_data;
> > + int ret;
> > +
> > + proto_data = devm_kzalloc(&pdev->dev, sizeof(*proto_data), GFP_KERNEL);
> > + if (!proto_data)
> > + return -ENOMEM;
> > +
> > + ipcc_proto_data = proto_data;
>
> ipcc_protocol_data is unused.
>
Ack, this is a leftover.
> > + proto_data->dev = &pdev->dev;
> > +
> > + proto_data->base = devm_platform_ioremap_resource(pdev, 0);
> > + if (IS_ERR(proto_data->base)) {
> > + dev_err(&pdev->dev, "Failed to ioremap the ipcc base addr\n");
> > + return PTR_ERR(proto_data->base);
> > + }
> > +
> > + proto_data->irq = platform_get_irq(pdev, 0);
> > + if (proto_data->irq < 0) {
> > + dev_err(&pdev->dev, "Failed to get the IRQ\n");
>
> platform_get_irq() already did print.
>
> > + return proto_data->irq;
> > + }
> > +
> > + /* Perform a SW reset on this client's protocol state */
> > + writel(0x1, proto_data->base + IPCC_REG_CLIENT_CLEAR);
> > +
> > + proto_data->irq_domain = irq_domain_add_tree(pdev->dev.of_node,
> > + &qcom_ipcc_irq_ops,
> > + proto_data);
> > + if (!proto_data->irq_domain) {
> > + dev_err(&pdev->dev, "Failed to add irq_domain\n");
>
> Afaict this also prints errors.
>
> > + return -ENOMEM;
> > + }
> > +
> > + ret = qcom_ipcc_setup_mbox(proto_data, pdev->dev.of_node);
> > + if (ret) {
> > + dev_err(&pdev->dev, "Failed to create mailbox\n");
>
> Afaict this too will print errors in all code paths (except the ones
> where you pass invalid data to mbox_controller_register() - but we're
> already past that).
>
Okay, will remove.
Thanks,
Mani
> Regards,
> Bjorn
>
> > + goto err_mbox;
> > + }
> > +
> > + ret = devm_request_irq(&pdev->dev, proto_data->irq, qcom_ipcc_irq_fn,
> > + IRQF_TRIGGER_HIGH, "ipcc", proto_data);
> > + if (ret < 0) {
> > + dev_err(&pdev->dev, "Failed to register the irq: %d\n", ret);
> > + goto err_mbox;
> > + }
> > +
> > + enable_irq_wake(proto_data->irq);
> > + platform_set_drvdata(pdev, proto_data);
> > +
> > + return 0;
> > +
> > +err_mbox:
> > + irq_domain_remove(proto_data->irq_domain);
> > +
> > + return ret;
> > +}
> > +
> > +static int qcom_ipcc_remove(struct platform_device *pdev)
> > +{
> > + struct qcom_ipcc_proto_data *proto_data = platform_get_drvdata(pdev);
> > +
> > + disable_irq_wake(proto_data->irq);
> > + irq_domain_remove(proto_data->irq_domain);
> > +
> > + return 0;
> > +}
> > +
> > +static const struct of_device_id qcom_ipcc_of_match[] = {
> > + { .compatible = "qcom,ipcc"},
> > + {}
> > +};
> > +MODULE_DEVICE_TABLE(of, qcom_ipcc_of_match);
> > +
> > +static struct platform_driver qcom_ipcc_driver = {
> > + .probe = qcom_ipcc_probe,
> > + .remove = qcom_ipcc_remove,
> > + .driver = {
> > + .name = "qcom_ipcc",
> > + .of_match_table = qcom_ipcc_of_match,
> > + },
> > +};
> > +
> > +static int __init qcom_ipcc_init(void)
> > +{
> > + return platform_driver_register(&qcom_ipcc_driver);
> > +}
> > +arch_initcall(qcom_ipcc_init);
> > +
> > +static void __exit qcom_ipcc_exit(void)
> > +{
> > + platform_driver_unregister(&qcom_ipcc_driver);
> > +}
> > +module_exit(qcom_ipcc_exit);
> > +
> > +MODULE_LICENSE("GPL v2");
> > --
> > 2.17.1
> >
