Subject: Re: [RFC PATCH 4/5] PTP: Add flag for non-periodic output

From: Felipe Balbi <[email-masked]>
Date: Tue, 13 Aug 2019 10:53:53 +0300

Hi,

Richard Cochran <[email-masked]> writes:

> On Thu, Jul 18, 2019 at 11:59:10AM +0300, Felipe Balbi wrote:
>> no problem, anything in particular in mind? Just create new versions of
>> all the IOCTLs so we can actually use the reserved fields in the future?
>
> Yes, please!

before I send a new series built on top of this change, I thought I'd
check with you if I'm on the right path. Below you can find my current
take at the new IOCTLs. I maintained the same exact structures so that
there's no maintenance burden. Also introduce a new IOCTL for every
single one of the previously existing ones even though not all of them
needed changes. The reason for that was just to make it easier for
libary authors to update their library by a simple sed script adding '2'
to the end of the IOCTL macro.

Let me know if you want anything to be changed or had a different idea
about any of this. Also, if you prefer that I finish the entire series
before you review, no worries either ;-)

Cheers, patch follows:

>From bc2aa511d4c2e2228590fb29604c6c33b56527ad Mon Sep 17 00:00:00 2001
From: Felipe Balbi <[email-masked]>
Date: Tue, 13 Aug 2019 10:32:35 +0300
Subject: [PATCH] PTP: introduce new versions of IOCTLs

The current version of the IOCTL have a small problem which prevents
us from extending the API by making use of reserved fields. In these
new IOCTLs, we are now making sure that flags and rsv fields are zero
which will allow us to extend the API in the future.

Signed-off-by: Felipe Balbi <[email-masked]>
---
 drivers/ptp/ptp_chardev.c      | 105 +++++++++++++++++++++++++++++++++
 include/uapi/linux/ptp_clock.h |  12 ++++
 2 files changed, 117 insertions(+)

diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index 18ffe449efdf..94775073527b 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -126,6 +126,7 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 	switch (cmd) {
 
 	case PTP_CLOCK_GETCAPS:
+	case PTP_CLOCK_GETCAPS2:
 		memset(&caps, 0, sizeof(caps));
 		caps.max_adj = ptp->info->max_adj;
 		caps.n_alarm = ptp->info->n_alarm;
@@ -153,6 +154,28 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 		err = ops->enable(ops, &req, enable);
 		break;
 
+	case PTP_EXTTS_REQUEST2:
+		memset(&req, 0, sizeof(req));
+		if (copy_from_user(&req.extts, (void __user *)arg,
+				   sizeof(req.extts))) {
+			err = -EFAULT;
+			break;
+		}
+		if (req.extts.flags || req.extts.rsv[0]
+				|| req.extts.rsv[1]) {
+			err = -EINVAL;
+			break;
+		}
+			
+		if (req.extts.index >= ops->n_ext_ts) {
+			err = -EINVAL;
+			break;
+		}
+		req.type = PTP_CLK_REQ_EXTTS;
+		enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
+		err = ops->enable(ops, &req, enable);
+		break;
+
 	case PTP_PEROUT_REQUEST:
 		if (copy_from_user(&req.perout, (void __user *)arg,
 				   sizeof(req.perout))) {
@@ -168,6 +191,28 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 		err = ops->enable(ops, &req, enable);
 		break;
 
+	case PTP_PEROUT_REQUEST2:
+		memset(&req, 0, sizeof(req));
+		if (copy_from_user(&req.perout, (void __user *)arg,
+				   sizeof(req.perout))) {
+			err = -EFAULT;
+			break;
+		}
+		if (req.perout.flags || req.perout.rsv[0]
+				|| req.perout.rsv[1] || req.perout.rsv[2]
+				|| req.perout.rsv[3]) {
+			err = -EINVAL;
+			break;
+		}
+		if (req.perout.index >= ops->n_per_out) {
+			err = -EINVAL;
+			break;
+		}
+		req.type = PTP_CLK_REQ_PEROUT;
+		enable = req.perout.period.sec || req.perout.period.nsec;
+		err = ops->enable(ops, &req, enable);
+		break;
+
 	case PTP_ENABLE_PPS:
 		if (!capable(CAP_SYS_TIME))
 			return -EPERM;
@@ -176,7 +221,17 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 		err = ops->enable(ops, &req, enable);
 		break;
 
+	case PTP_ENABLE_PPS2:
+		if (!capable(CAP_SYS_TIME))
+			return -EPERM;
+		memset(&req, 0, sizeof(req));
+		req.type = PTP_CLK_REQ_PPS;
+		enable = arg ? 1 : 0;
+		err = ops->enable(ops, &req, enable);
+		break;
+
 	case PTP_SYS_OFFSET_PRECISE:
+	case PTP_SYS_OFFSET_PRECISE2:
 		if (!ptp->info->getcrosststamp) {
 			err = -EOPNOTSUPP;
 			break;
@@ -201,6 +256,7 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 		break;
 
 	case PTP_SYS_OFFSET_EXTENDED:
+	case PTP_SYS_OFFSET_EXTENDED2:
 		if (!ptp->info->gettimex64) {
 			err = -EOPNOTSUPP;
 			break;
@@ -232,6 +288,7 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 		break;
 
 	case PTP_SYS_OFFSET:
+	case PTP_SYS_OFFSET2:
 		sysoff = memdup_user((void __user *)arg, sizeof(*sysoff));
 		if (IS_ERR(sysoff)) {
 			err = PTR_ERR(sysoff);
@@ -284,6 +341,31 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 			err = -EFAULT;
 		break;
 
+	case PTP_PIN_GETFUNC2:
+		memset(&pd, 0, sizeof(pd));
+		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
+			err = -EFAULT;
+			break;
+		}
+		if (pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
+				|| pd.rsv[3] || pd.rsv[4]) {
+			err = -EINVAL;
+			break;
+		}
+		pin_index = pd.index;
+		if (pin_index >= ops->n_pins) {
+			err = -EINVAL;
+			break;
+		}
+		pin_index = array_index_nospec(pin_index, ops->n_pins);
+		if (mutex_lock_interruptible(&ptp->pincfg_mux))
+			return -ERESTARTSYS;
+		pd = ops->pin_config[pin_index];
+		mutex_unlock(&ptp->pincfg_mux);
+		if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
+			err = -EFAULT;
+		break;
+
 	case PTP_PIN_SETFUNC:
 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
 			err = -EFAULT;
@@ -301,6 +383,29 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 		mutex_unlock(&ptp->pincfg_mux);
 		break;
 
+	case PTP_PIN_SETFUNC2:
+		memset(&pd, 0, sizeof(pd));
+		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
+			err = -EFAULT;
+			break;
+		}
+		if (pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
+				|| pd.rsv[3] || pd.rsv[4]) {
+			err = -EINVAL;
+			break;
+		}
+		pin_index = pd.index;
+		if (pin_index >= ops->n_pins) {
+			err = -EINVAL;
+			break;
+		}
+		pin_index = array_index_nospec(pin_index, ops->n_pins);
+		if (mutex_lock_interruptible(&ptp->pincfg_mux))
+			return -ERESTARTSYS;
+		err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
+		mutex_unlock(&ptp->pincfg_mux);
+		break;
+
 	default:
 		err = -ENOTTY;
 		break;
diff --git a/include/uapi/linux/ptp_clock.h b/include/uapi/linux/ptp_clock.h
index 1bc794ad957a..039cd62ec706 100644
--- a/include/uapi/linux/ptp_clock.h
+++ b/include/uapi/linux/ptp_clock.h
@@ -149,6 +149,18 @@ struct ptp_pin_desc {
 #define PTP_SYS_OFFSET_EXTENDED \
 	_IOWR(PTP_CLK_MAGIC, 9, struct ptp_sys_offset_extended)
 
+#define PTP_CLOCK_GETCAPS2  _IOR(PTP_CLK_MAGIC, 10, struct ptp_clock_caps)
+#define PTP_EXTTS_REQUEST2  _IOW(PTP_CLK_MAGIC, 11, struct ptp_extts_request)
+#define PTP_PEROUT_REQUEST2 _IOW(PTP_CLK_MAGIC, 12, struct ptp_perout_request)
+#define PTP_ENABLE_PPS2     _IOW(PTP_CLK_MAGIC, 13, int)
+#define PTP_SYS_OFFSET2     _IOW(PTP_CLK_MAGIC, 14, struct ptp_sys_offset)
+#define PTP_PIN_GETFUNC2    _IOWR(PTP_CLK_MAGIC, 15, struct ptp_pin_desc)
+#define PTP_PIN_SETFUNC2    _IOW(PTP_CLK_MAGIC, 16, struct ptp_pin_desc)
+#define PTP_SYS_OFFSET_PRECISE2 \
+	_IOWR(PTP_CLK_MAGIC, 17, struct ptp_sys_offset_precise)
+#define PTP_SYS_OFFSET_EXTENDED2 \
+	_IOWR(PTP_CLK_MAGIC, 18, struct ptp_sys_offset_extended)
+
 struct ptp_extts_event {
 	struct ptp_clock_time t; /* Time event occured. */
 	unsigned int index;      /* Which channel produced the event. */
-- 
2.22.0

-- 
balbi