[PATCH linux dev-4.10 1/7] drivers/fsi: Add slave interrupt polling
Eddie James
eajames at linux.vnet.ibm.com
Thu May 11 08:26:42 AEST 2017
On 05/09/2017 04:38 PM, Christopher Bostic wrote:
> Scan slaves present for asserting interrupt signals in the
> si1s register and call a registered client's interrupt handler as
> appropriate.
>
> Includes initial code from Eddie James <eajames at us.ibm.com>
>
> Signed-off-by: Eddie James <eajames at us.ibm.com>
> Signed-off-by: Christopher Bostic <cbostic at linux.vnet.ibm.com>
> ---
> drivers/fsi/fsi-core.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++
> drivers/fsi/fsi-master.h | 1 +
> include/linux/fsi.h | 5 +++
> 3 files changed, 116 insertions(+)
>
> diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
> index a6ed34f..73fdb69 100644
> --- a/drivers/fsi/fsi-core.c
> +++ b/drivers/fsi/fsi-core.c
> @@ -15,9 +15,11 @@
>
> #include <linux/device.h>
> #include <linux/fsi.h>
> +#include <linux/kthread.h>
> #include <linux/idr.h>
> #include <linux/module.h>
> #include <linux/slab.h>
> +#include <linux/jiffies.h>
>
> #include "fsi-master.h"
>
> @@ -38,8 +40,11 @@
> #define FSI_PEEK_BASE 0x410
>
> static const int engine_page_size = 0x400;
> +static struct task_struct *master_ipoll;
> +static unsigned int fsi_ipoll_period_ms = 100;
>
> #define FSI_SLAVE_BASE 0x800
> +#define FSI_IPOLL_PERIOD msecs_to_jiffies(fsi_ipoll_period_ms)
>
> /*
> * FSI slave engine control register offsets
> @@ -47,6 +52,8 @@
> #define FSI_SMODE 0x0 /* R/W: Mode register */
> #define FSI_SISC 0x8 /* R/W: Interrupt condition */
> #define FSI_SSTAT 0x14 /* R : Slave status */
> +#define FSI_SI1M 0x18 /* R/W: IRQ mask */
> +#define FSI_SI1S 0x1C /* R : IRQ status */
> #define FSI_LLMODE 0x100 /* R/W: Link layer mode register */
>
> /*
> @@ -342,6 +349,7 @@ static int fsi_slave_scan(struct fsi_slave *slave)
> uint32_t engine_addr;
> uint32_t conf;
> int rc, i;
> + uint8_t si1s_bit = 1;
>
> /*
> * scan engines
> @@ -396,6 +404,7 @@ static int fsi_slave_scan(struct fsi_slave *slave)
> dev->unit = i;
> dev->addr = engine_addr;
> dev->size = slots * engine_page_size;
> + dev->si1s_bit = si1s_bit++;
>
> dev_info(&slave->dev,
> "engine[%i]: type %x, version %x, addr %x size %x\n",
> @@ -761,6 +770,90 @@ static void fsi_master_unscan(struct fsi_master *master)
> device_for_each_child(&master->dev, NULL, __fsi_master_remove_slave);
> }
>
> +static int __fsi_dev_irq(struct device *dev, void *data)
> +{
> + uint32_t *si1s = data;
> + struct fsi_device *fsi_dev = to_fsi_dev(dev);
> +
> + if (!fsi_dev || !si1s) {
> + dev_dbg(dev, "Invalid input: %p %p\n", fsi_dev, si1s);
> + return -EINVAL;
> + }
> +
> + if (*si1s & (0x80000000 >> fsi_dev->si1s_bit) &&
> + fsi_dev->irq_handler) {
> + fsi_dev->irq_handler(0, &fsi_dev->dev);
> + return 1;
> + }
> +
> + return 0;
> +}
> +
> +static int __fsi_slave_irq(struct device *dev, void *data)
> +{
> + return device_for_each_child(dev, data, __fsi_dev_irq);
> +}
> +
> +static void fsi_master_irq(struct fsi_master *master, int link, uint32_t si1s)
> +{
> + device_for_each_child(&master->dev, &si1s, __fsi_slave_irq);
> +}
> +
> +static int fsi_master_ipoll(void *data)
> +{
> + int rc;
> + uint32_t si1s;
> + unsigned long elapsed = 0;
> + unsigned long previous_jiffies = jiffies;
> + struct fsi_master *master = data;
> +
> + while (!kthread_should_stop()) {
> + if (!master->ipoll)
> + goto done;
> +
> + /* Ignore errors for now */
> + rc = master->read(master, 0, 0, FSI_SLAVE_BASE + FSI_SI1S,
> + &si1s, sizeof(uint32_t));
> + if (rc)
> + goto done;
> +
> + if (si1s & master->ipoll)
> + fsi_master_irq(master, 0, si1s);
> +done:
> + elapsed = jiffies = previous_jiffies;
> + if (elapsed < FSI_IPOLL_PERIOD) {
> + set_current_state(TASK_UNINTERRUPTIBLE);
> + schedule_timeout(FSI_IPOLL_PERIOD - elapsed);
> + }
> + previous_jiffies = jiffies;
> + }
> +
> + return 0;
> +}
> +
> +/*
> + * TODO: move this to master->start_ipoll() - each master may have its
> + * own way of doing this
> + */
> +int fsi_master_start_ipoll(struct fsi_master *master)
> +{
> + if (master_ipoll) {
> + dev_err(&master->dev, "Already polling for irqs\n");
> + return -EALREADY;
> + }
> + master_ipoll = kthread_create(fsi_master_ipoll, master,
> + "fsi_master_ipoll");
> + if (IS_ERR(master_ipoll)) {
> + dev_err(&master->dev, "Coudn't create ipoll thread rc:%d\n",
> + (int)PTR_ERR(master_ipoll));
> + return PTR_ERR(master_ipoll);
> + }
> + wake_up_process(master_ipoll);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(fsi_master_start_ipoll);
> +
> static ssize_t master_rescan_store(struct device *dev,
> struct device_attribute *attr, const char *buf, size_t count)
> {
> @@ -768,6 +861,7 @@ static ssize_t master_rescan_store(struct device *dev,
>
> fsi_master_unscan(master);
> fsi_master_scan(master);
> + fsi_master_start_ipoll(master);
I have been having some problems in 4.10 with this patch in the build.
BMC is hanging and requires AC cycle to recover, directly after scanning
fsi. I haven't had time to debug but so far it seems to follow this
patch. I do not think this should be merged until Chris and I have done
more testing.
Thanks,
Eddie
>
> return count;
> }
> @@ -829,6 +923,11 @@ void fsi_master_unregister(struct fsi_master *master)
> master->idx = -1;
> }
>
> + if (master_ipoll) {
> + kthread_stop(master_ipoll);
> + master_ipoll = NULL;
> + }
> +
> device_unregister(&master->dev);
> }
> EXPORT_SYMBOL_GPL(fsi_master_unregister);
> @@ -872,6 +971,17 @@ void fsi_driver_unregister(struct fsi_driver *fsi_drv)
> }
> EXPORT_SYMBOL_GPL(fsi_driver_unregister);
>
> +int fsi_enable_irq(struct fsi_device *dev)
> +{
> + return 0;
> +}
> +EXPORT_SYMBOL(fsi_enable_irq);
> +
> +void fsi_disable_irq(struct fsi_device *dev)
> +{
> +}
> +EXPORT_SYMBOL(fsi_disable_irq);
> +
> struct bus_type fsi_bus_type = {
> .name = "fsi",
> .match = fsi_bus_match,
> diff --git a/drivers/fsi/fsi-master.h b/drivers/fsi/fsi-master.h
> index fd39924..668ab0c 100644
> --- a/drivers/fsi/fsi-master.h
> +++ b/drivers/fsi/fsi-master.h
> @@ -26,6 +26,7 @@ struct fsi_master {
> int idx;
> int n_links;
> int flags;
> + uint32_t ipoll;
> int (*read)(struct fsi_master *, int link, uint8_t id,
> uint32_t addr, void *val, size_t size);
> int (*write)(struct fsi_master *, int link, uint8_t id,
> diff --git a/include/linux/fsi.h b/include/linux/fsi.h
> index 141fd38..bb5c6c6 100644
> --- a/include/linux/fsi.h
> +++ b/include/linux/fsi.h
> @@ -22,9 +22,11 @@ struct fsi_device {
> u8 engine_type;
> u8 version;
> u8 unit;
> + u8 si1s_bit;
> struct fsi_slave *slave;
> uint32_t addr;
> uint32_t size;
> + int (*irq_handler)(int, void *);
> };
>
> extern int fsi_device_read(struct fsi_device *dev, uint32_t addr,
> @@ -80,4 +82,7 @@ extern int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
>
> extern struct bus_type fsi_bus_type;
>
> +extern int fsi_enable_irq(struct fsi_device *dev);
> +extern void fsi_disable_irq(struct fsi_device *dev);
> +
> #endif /* LINUX_FSI_H */
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