[dpdk-dev,8/9] pci: add a helper to refresh a device
Commit Message
It will be used mainly for hotplug code.
Signed-off-by: David Marchand <david.marchand@6wind.com>
---
lib/librte_eal/bsdapp/eal/eal_pci.c | 49 +++++++++++++++++++++++++++++++++++
lib/librte_eal/common/eal_private.h | 13 ++++++++++
lib/librte_eal/linuxapp/eal/eal_pci.c | 13 ++++++++++
3 files changed, 75 insertions(+)
Comments
On Fri, 29 Jan 2016 15:08:35 +0100
David Marchand <david.marchand@6wind.com> wrote:
> It will be used mainly for hotplug code.
>
> Signed-off-by: David Marchand <david.marchand@6wind.com>
> ---
> lib/librte_eal/bsdapp/eal/eal_pci.c | 49 +++++++++++++++++++++++++++++++++++
> lib/librte_eal/common/eal_private.h | 13 ++++++++++
> lib/librte_eal/linuxapp/eal/eal_pci.c | 13 ++++++++++
> 3 files changed, 75 insertions(+)
>
> diff --git a/lib/librte_eal/bsdapp/eal/eal_pci.c b/lib/librte_eal/bsdapp/eal/eal_pci.c
> index 4584522..5dd89e3 100644
> --- a/lib/librte_eal/bsdapp/eal/eal_pci.c
> +++ b/lib/librte_eal/bsdapp/eal/eal_pci.c
> @@ -396,6 +396,55 @@ error:
> return -1;
> }
>
> +int
> +pci_refresh_device(const struct rte_pci_addr *addr)
What about pci_reload_device or pci_reload_device_info? I don't mind
too much, only the word 'refresh' reminds me other associations.
> +{
> + int fd;
> + struct pci_conf matches[2];
> + struct pci_match_conf match = {
> + .pc_sel = {
> + .pc_domain = addr->domain,
> + .pc_bus = addr->bus,
> + .pc_dev = addr->devid,
> + .pc_func = addr->function,
> + },
> + };
> + struct pci_conf_io conf_io = {
> + .pat_buf_len = 0,
> + .num_patterns = 1,
> + .patterns = { &match },
> + .match_buf_len = sizeof(matches),
> + .matches = &matches[0],
> + };
> +
> + fd = open("/dev/pci", O_RDONLY);
Just courious who provides this special file... is a DPDK-specific
thing? I haven't noticed it anywhere in Linux.
> + if (fd < 0) {
> + RTE_LOG(ERR, EAL, "%s(): error opening /dev/pci\n", __func__);
> + goto error;
If you write:
return -1;
then you can...
> + }
> +
> + if (ioctl(fd, PCIOCGETCONF, &conf_io) < 0) {
> + RTE_LOG(ERR, EAL, "%s(): error with ioctl on /dev/pci: %s\n",
> + __func__, strerror(errno));
> + goto error;
> + }
> +
> + if (conf_io.num_matches != 1)
> + goto error;
> +
> + if (pci_scan_one(fd, &matches[0]) < 0)
> + goto error;
> +
> + close(fd);
> +
> + return 0;
> +
> +error:
...remove this if:
> + if (fd >= 0)
> + close(fd);
Or, do you consider it more stable in the orignal way?
> + return -1;
> +}
> +
> /* Read PCI config space. */
> int rte_eal_pci_read_config(const struct rte_pci_device *dev,
> void *buf, size_t len, off_t offset)
> diff --git a/lib/librte_eal/common/eal_private.h b/lib/librte_eal/common/eal_private.h
> index 072e672..ed1903f 100644
> --- a/lib/librte_eal/common/eal_private.h
> +++ b/lib/librte_eal/common/eal_private.h
> @@ -155,6 +155,19 @@ struct rte_pci_driver;
> struct rte_pci_device;
>
> /**
> + * Refresh a pci device object by asking the kernel for the latest information.
> + *
> + * This function is private to EAL.
> + *
> + * @param addr
> + * The PCI Bus-Device-Function address to look for
> + * @return
> + * - 0 on success.
> + * - negative on error.
I don't know whether this is a convention in DPDK, anyway, I don't
like to restrict errors to just negatives. You cannot write
if ((err = pci_refresh_device(...)) /* < 0 */) {
handle_error(err);
}
as the check for < 0 is required (easy to be avoided).
> + */
> +int pci_refresh_device(const struct rte_pci_addr *addr);
> +
> +/**
> * Unbind kernel driver for this device
> *
> * This function is private to EAL.
> diff --git a/lib/librte_eal/linuxapp/eal/eal_pci.c b/lib/librte_eal/linuxapp/eal/eal_pci.c
> index a354f76..4fe8b60 100644
> --- a/lib/librte_eal/linuxapp/eal/eal_pci.c
> +++ b/lib/librte_eal/linuxapp/eal/eal_pci.c
> @@ -393,6 +393,19 @@ pci_scan_one(const char *dirname, uint16_t domain, uint8_t bus,
> return 0;
> }
>
> +int
> +pci_refresh_device(const struct rte_pci_addr *addr)
> +{
> + char filename[PATH_MAX];
> +
> + snprintf(filename, sizeof(filename), "%s/" PCI_PRI_FMT,
> + SYSFS_PCI_DEVICES, addr->domain, addr->bus, addr->devid,
> + addr->function);
> +
> + return pci_scan_one(filename, addr->domain, addr->bus, addr->devid,
> + addr->function);
> +}
> +
> /*
> * split up a pci address into its constituent parts.
> */
On Wed, Feb 10, 2016 at 12:23 PM, Jan Viktorin <viktorin@rehivetech.com> wrote:
> On Fri, 29 Jan 2016 15:08:35 +0100
> David Marchand <david.marchand@6wind.com> wrote:
>
>> It will be used mainly for hotplug code.
>>
>> Signed-off-by: David Marchand <david.marchand@6wind.com>
>> ---
>> lib/librte_eal/bsdapp/eal/eal_pci.c | 49 +++++++++++++++++++++++++++++++++++
>> lib/librte_eal/common/eal_private.h | 13 ++++++++++
>> lib/librte_eal/linuxapp/eal/eal_pci.c | 13 ++++++++++
>> 3 files changed, 75 insertions(+)
>>
>> diff --git a/lib/librte_eal/bsdapp/eal/eal_pci.c b/lib/librte_eal/bsdapp/eal/eal_pci.c
>> index 4584522..5dd89e3 100644
>> --- a/lib/librte_eal/bsdapp/eal/eal_pci.c
>> +++ b/lib/librte_eal/bsdapp/eal/eal_pci.c
>> @@ -396,6 +396,55 @@ error:
>> return -1;
>> }
>>
>> +int
>> +pci_refresh_device(const struct rte_pci_addr *addr)
>
> What about pci_reload_device or pci_reload_device_info? I don't mind
> too much, only the word 'refresh' reminds me other associations.
Or maybe pci_update_device ?
I added pci_add_device in my other pci patchset, so update sounds better to me.
>> +{
>> + int fd;
>> + struct pci_conf matches[2];
>> + struct pci_match_conf match = {
>> + .pc_sel = {
>> + .pc_domain = addr->domain,
>> + .pc_bus = addr->bus,
>> + .pc_dev = addr->devid,
>> + .pc_func = addr->function,
>> + },
>> + };
>> + struct pci_conf_io conf_io = {
>> + .pat_buf_len = 0,
>> + .num_patterns = 1,
>> + .patterns = { &match },
>> + .match_buf_len = sizeof(matches),
>> + .matches = &matches[0],
>> + };
>> +
>> + fd = open("/dev/pci", O_RDONLY);
>
> Just courious who provides this special file... is a DPDK-specific
> thing? I haven't noticed it anywhere in Linux.
I don't know, just took the bsd pci code and plugged myself in it.
So for me this is a special bsd device.
This is mainly copy/paste.
Look at rte_eal_pci_scan() from lib/librte_eal/bsdapp/eal/eal_pci.c.
>
>> + if (fd < 0) {
>> + RTE_LOG(ERR, EAL, "%s(): error opening /dev/pci\n", __func__);
>> + goto error;
>
> If you write:
> return -1;
>
> then you can...
>
>> + }
>> +
>> + if (ioctl(fd, PCIOCGETCONF, &conf_io) < 0) {
>> + RTE_LOG(ERR, EAL, "%s(): error with ioctl on /dev/pci: %s\n",
>> + __func__, strerror(errno));
>> + goto error;
>> + }
>> +
>> + if (conf_io.num_matches != 1)
>> + goto error;
>> +
>> + if (pci_scan_one(fd, &matches[0]) < 0)
>> + goto error;
>> +
>> + close(fd);
>> +
>> + return 0;
>> +
>> +error:
>
> ...remove this if:
>
>> + if (fd >= 0)
>> + close(fd);
>
> Or, do you consider it more stable in the orignal way?
Well, as said above, this is copy/paste code.
But, anyway, when I write functions with goto statements, I prefer
having a minimal number of return statements, matter of taste.
Another way is to add two label error_close: error: but this is a bit
overkill here.
>> + return -1;
>> +}
>> +
>> /* Read PCI config space. */
>> int rte_eal_pci_read_config(const struct rte_pci_device *dev,
>> void *buf, size_t len, off_t offset)
>> diff --git a/lib/librte_eal/common/eal_private.h b/lib/librte_eal/common/eal_private.h
>> index 072e672..ed1903f 100644
>> --- a/lib/librte_eal/common/eal_private.h
>> +++ b/lib/librte_eal/common/eal_private.h
>> @@ -155,6 +155,19 @@ struct rte_pci_driver;
>> struct rte_pci_device;
>>
>> /**
>> + * Refresh a pci device object by asking the kernel for the latest information.
>> + *
>> + * This function is private to EAL.
>> + *
>> + * @param addr
>> + * The PCI Bus-Device-Function address to look for
>> + * @return
>> + * - 0 on success.
>> + * - negative on error.
>
> I don't know whether this is a convention in DPDK, anyway, I don't
> like to restrict errors to just negatives. You cannot write
>
> if ((err = pci_refresh_device(...)) /* < 0 */) {
> handle_error(err);
> }
>
> as the check for < 0 is required (easy to be avoided).
It is a remnant of a lot of code in eal that tries to have 0 for
success, < 0 for errors, > 0 for special cases.
On Wed, 10 Feb 2016 13:00:50 +0100
David Marchand <david.marchand@6wind.com> wrote:
> On Wed, Feb 10, 2016 at 12:23 PM, Jan Viktorin <viktorin@rehivetech.com> wrote:
> > On Fri, 29 Jan 2016 15:08:35 +0100
> > David Marchand <david.marchand@6wind.com> wrote:
> >
> >> It will be used mainly for hotplug code.
> >>
> >> Signed-off-by: David Marchand <david.marchand@6wind.com>
> >> ---
> >> lib/librte_eal/bsdapp/eal/eal_pci.c | 49 +++++++++++++++++++++++++++++++++++
> >> lib/librte_eal/common/eal_private.h | 13 ++++++++++
> >> lib/librte_eal/linuxapp/eal/eal_pci.c | 13 ++++++++++
> >> 3 files changed, 75 insertions(+)
> >>
> >> diff --git a/lib/librte_eal/bsdapp/eal/eal_pci.c b/lib/librte_eal/bsdapp/eal/eal_pci.c
> >> index 4584522..5dd89e3 100644
> >> --- a/lib/librte_eal/bsdapp/eal/eal_pci.c
> >> +++ b/lib/librte_eal/bsdapp/eal/eal_pci.c
> >> @@ -396,6 +396,55 @@ error:
> >> return -1;
> >> }
> >>
> >> +int
> >> +pci_refresh_device(const struct rte_pci_addr *addr)
> >
> > What about pci_reload_device or pci_reload_device_info? I don't mind
> > too much, only the word 'refresh' reminds me other associations.
>
> Or maybe pci_update_device ?
> I added pci_add_device in my other pci patchset, so update sounds better to me.
>
OK.
>
> >> +{
> >> + int fd;
> >> + struct pci_conf matches[2];
> >> + struct pci_match_conf match = {
> >> + .pc_sel = {
> >> + .pc_domain = addr->domain,
> >> + .pc_bus = addr->bus,
> >> + .pc_dev = addr->devid,
> >> + .pc_func = addr->function,
> >> + },
> >> + };
> >> + struct pci_conf_io conf_io = {
> >> + .pat_buf_len = 0,
> >> + .num_patterns = 1,
> >> + .patterns = { &match },
> >> + .match_buf_len = sizeof(matches),
> >> + .matches = &matches[0],
> >> + };
> >> +
> >> + fd = open("/dev/pci", O_RDONLY);
> >
> > Just courious who provides this special file... is a DPDK-specific
> > thing? I haven't noticed it anywhere in Linux.
>
> I don't know, just took the bsd pci code and plugged myself in it.
> So for me this is a special bsd device.
>
> This is mainly copy/paste.
> Look at rte_eal_pci_scan() from lib/librte_eal/bsdapp/eal/eal_pci.c.
BSD... I didn't notice. That's the answer.
>
> >
> >> + if (fd < 0) {
> >> + RTE_LOG(ERR, EAL, "%s(): error opening /dev/pci\n", __func__);
> >> + goto error;
> >
> > If you write:
> > return -1;
> >
> > then you can...
> >
> >> + }
> >> +
> >> + if (ioctl(fd, PCIOCGETCONF, &conf_io) < 0) {
> >> + RTE_LOG(ERR, EAL, "%s(): error with ioctl on /dev/pci: %s\n",
> >> + __func__, strerror(errno));
> >> + goto error;
> >> + }
> >> +
> >> + if (conf_io.num_matches != 1)
> >> + goto error;
> >> +
> >> + if (pci_scan_one(fd, &matches[0]) < 0)
> >> + goto error;
> >> +
> >> + close(fd);
> >> +
> >> + return 0;
> >> +
> >> +error:
> >
> > ...remove this if:
> >
> >> + if (fd >= 0)
> >> + close(fd);
> >
> > Or, do you consider it more stable in the orignal way?
>
> Well, as said above, this is copy/paste code.
> But, anyway, when I write functions with goto statements, I prefer
> having a minimal number of return statements, matter of taste.
> Another way is to add two label error_close: error: but this is a bit
> overkill here.
All of them are OK. As for me, I prefer to not hide simple returns.
>
>
> >> + return -1;
> >> +}
> >> +
> >> /* Read PCI config space. */
> >> int rte_eal_pci_read_config(const struct rte_pci_device *dev,
> >> void *buf, size_t len, off_t offset)
> >> diff --git a/lib/librte_eal/common/eal_private.h b/lib/librte_eal/common/eal_private.h
> >> index 072e672..ed1903f 100644
> >> --- a/lib/librte_eal/common/eal_private.h
> >> +++ b/lib/librte_eal/common/eal_private.h
> >> @@ -155,6 +155,19 @@ struct rte_pci_driver;
> >> struct rte_pci_device;
> >>
> >> /**
> >> + * Refresh a pci device object by asking the kernel for the latest information.
> >> + *
> >> + * This function is private to EAL.
> >> + *
> >> + * @param addr
> >> + * The PCI Bus-Device-Function address to look for
> >> + * @return
> >> + * - 0 on success.
> >> + * - negative on error.
> >
> > I don't know whether this is a convention in DPDK, anyway, I don't
> > like to restrict errors to just negatives. You cannot write
> >
> > if ((err = pci_refresh_device(...)) /* < 0 */) {
> > handle_error(err);
> > }
> >
> > as the check for < 0 is required (easy to be avoided).
>
> It is a remnant of a lot of code in eal that tries to have 0 for
> success, < 0 for errors, > 0 for special cases.
>
OK, makes sense.
>
@@ -396,6 +396,55 @@ error:
return -1;
}
+int
+pci_refresh_device(const struct rte_pci_addr *addr)
+{
+ int fd;
+ struct pci_conf matches[2];
+ struct pci_match_conf match = {
+ .pc_sel = {
+ .pc_domain = addr->domain,
+ .pc_bus = addr->bus,
+ .pc_dev = addr->devid,
+ .pc_func = addr->function,
+ },
+ };
+ struct pci_conf_io conf_io = {
+ .pat_buf_len = 0,
+ .num_patterns = 1,
+ .patterns = { &match },
+ .match_buf_len = sizeof(matches),
+ .matches = &matches[0],
+ };
+
+ fd = open("/dev/pci", O_RDONLY);
+ if (fd < 0) {
+ RTE_LOG(ERR, EAL, "%s(): error opening /dev/pci\n", __func__);
+ goto error;
+ }
+
+ if (ioctl(fd, PCIOCGETCONF, &conf_io) < 0) {
+ RTE_LOG(ERR, EAL, "%s(): error with ioctl on /dev/pci: %s\n",
+ __func__, strerror(errno));
+ goto error;
+ }
+
+ if (conf_io.num_matches != 1)
+ goto error;
+
+ if (pci_scan_one(fd, &matches[0]) < 0)
+ goto error;
+
+ close(fd);
+
+ return 0;
+
+error:
+ if (fd >= 0)
+ close(fd);
+ return -1;
+}
+
/* Read PCI config space. */
int rte_eal_pci_read_config(const struct rte_pci_device *dev,
void *buf, size_t len, off_t offset)
@@ -155,6 +155,19 @@ struct rte_pci_driver;
struct rte_pci_device;
/**
+ * Refresh a pci device object by asking the kernel for the latest information.
+ *
+ * This function is private to EAL.
+ *
+ * @param addr
+ * The PCI Bus-Device-Function address to look for
+ * @return
+ * - 0 on success.
+ * - negative on error.
+ */
+int pci_refresh_device(const struct rte_pci_addr *addr);
+
+/**
* Unbind kernel driver for this device
*
* This function is private to EAL.
@@ -393,6 +393,19 @@ pci_scan_one(const char *dirname, uint16_t domain, uint8_t bus,
return 0;
}
+int
+pci_refresh_device(const struct rte_pci_addr *addr)
+{
+ char filename[PATH_MAX];
+
+ snprintf(filename, sizeof(filename), "%s/" PCI_PRI_FMT,
+ SYSFS_PCI_DEVICES, addr->domain, addr->bus, addr->devid,
+ addr->function);
+
+ return pci_scan_one(filename, addr->domain, addr->bus, addr->devid,
+ addr->function);
+}
+
/*
* split up a pci address into its constituent parts.
*/