| Message ID | 1433516792-16397-4-git-send-email-eric.auger@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, 2015-06-05 at 17:06 +0200, Eric Auger wrote: > The reset function lookup happens on vfio-platform probe. The reset > module load is requested and a reference to the function symbol is > hold. The reference is released on vfio-platform remove. > > Signed-off-by: Eric Auger <eric.auger@linaro.org> > > --- > > v1 -> v2: > - [get,put]_reset now is called once on probe/remove > - use request_module to automatically load the reset module that > matches the compatibility string > - lookup table is used instead of list > - remove registration mechanism: reset function name is stored in the > lookup table. > - use device_property_read_string instead of > device_property_read_string_array > --- > drivers/vfio/platform/vfio_platform_common.c | 48 +++++++++++++++++++++++++++- > 1 file changed, 47 insertions(+), 1 deletion(-) > > diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c > index 995929b..d474d6a 100644 > --- a/drivers/vfio/platform/vfio_platform_common.c > +++ b/drivers/vfio/platform/vfio_platform_common.c > @@ -31,6 +31,47 @@ static const struct vfio_platform_reset_combo reset_lookup_table[] = { > }, > }; > > +static int vfio_platform_get_reset(struct vfio_platform_device *vdev, > + struct device *dev) > +{ > + const char *compat; > + const struct vfio_platform_reset_combo *iter = reset_lookup_table; > + int (*reset)(struct vfio_platform_device *); > + int ret; > + > + vdev->type = VFIO_PLATFORM_RESET_TYPE_MAX; > + ret = device_property_read_string(dev, "compatible", &compat); > + if (ret) > + return ret; > + > + while (iter->type < VFIO_PLATFORM_RESET_TYPE_MAX) { > + if (!strcmp(iter->compat, compat)) { > + request_module(iter->module_name); > + reset = __symbol_get(iter->reset_function_name); symbol_get() appears to be the more robust and dominant interface for this, why use __symbol_get()? > + if (reset) { > + vdev->type = iter->type; > + vdev->reset = reset; > + return 0; > + } > + } > + iter++; > + } > + return -1; -ENODEV seems preferable to -1, but shouldn't this really be a void function? > +} > + > +static void vfio_platform_put_reset(struct vfio_platform_device *vdev) > +{ > + const struct vfio_platform_reset_combo *iter = reset_lookup_table; > + > + while (iter->type < VFIO_PLATFORM_RESET_TYPE_MAX) { > + if (iter->type == vdev->type) { Again, I don't see the value in storing the enum, since the table is static, it could just as easily be the array index and avoid this loop, but we can avoid it anyway with symbol_put_addr(). > + __symbol_put(iter->reset_function_name); > + return; > + } > + iter++; > + } > +} > + > static int vfio_platform_regions_init(struct vfio_platform_device *vdev) > { > int cnt = 0, i; > @@ -519,6 +560,8 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev, > return ret; > } > > + vfio_platform_get_reset(vdev, dev); > + > mutex_init(&vdev->igate); > > return 0; > @@ -530,8 +573,11 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev) > struct vfio_platform_device *vdev; > > vdev = vfio_del_group_dev(dev); > - if (vdev) > + > + if (vdev) { > + vfio_platform_put_reset(vdev); > iommu_group_put(dev->iommu_group); > + } > > return vdev; > }
On 06/09/2015 08:26 PM, Alex Williamson wrote: > On Fri, 2015-06-05 at 17:06 +0200, Eric Auger wrote: >> The reset function lookup happens on vfio-platform probe. The reset >> module load is requested and a reference to the function symbol is >> hold. The reference is released on vfio-platform remove. >> >> Signed-off-by: Eric Auger <eric.auger@linaro.org> >> >> --- >> >> v1 -> v2: >> - [get,put]_reset now is called once on probe/remove >> - use request_module to automatically load the reset module that >> matches the compatibility string >> - lookup table is used instead of list >> - remove registration mechanism: reset function name is stored in the >> lookup table. >> - use device_property_read_string instead of >> device_property_read_string_array >> --- >> drivers/vfio/platform/vfio_platform_common.c | 48 +++++++++++++++++++++++++++- >> 1 file changed, 47 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c >> index 995929b..d474d6a 100644 >> --- a/drivers/vfio/platform/vfio_platform_common.c >> +++ b/drivers/vfio/platform/vfio_platform_common.c >> @@ -31,6 +31,47 @@ static const struct vfio_platform_reset_combo reset_lookup_table[] = { >> }, >> }; >> >> +static int vfio_platform_get_reset(struct vfio_platform_device *vdev, >> + struct device *dev) >> +{ >> + const char *compat; >> + const struct vfio_platform_reset_combo *iter = reset_lookup_table; >> + int (*reset)(struct vfio_platform_device *); >> + int ret; >> + >> + vdev->type = VFIO_PLATFORM_RESET_TYPE_MAX; >> + ret = device_property_read_string(dev, "compatible", &compat); >> + if (ret) >> + return ret; >> + >> + while (iter->type < VFIO_PLATFORM_RESET_TYPE_MAX) { >> + if (!strcmp(iter->compat, compat)) { >> + request_module(iter->module_name); >> + reset = __symbol_get(iter->reset_function_name); > > symbol_get() appears to be the more robust and dominant interface for > this, why use __symbol_get()? I used this because it takes a const char * as an argument and this is what I use as a datatype for storing the reset function name. Symbol_get is provided with the symbol directly? It is also used drivers/mtd/chips/gen_probe.c. > >> + if (reset) { >> + vdev->type = iter->type; >> + vdev->reset = reset; >> + return 0; >> + } >> + } >> + iter++; >> + } >> + return -1; > > -ENODEV seems preferable to -1, but shouldn't this really be a void > function? yes indeed > >> +} >> + >> +static void vfio_platform_put_reset(struct vfio_platform_device *vdev) >> +{ >> + const struct vfio_platform_reset_combo *iter = reset_lookup_table; >> + >> + while (iter->type < VFIO_PLATFORM_RESET_TYPE_MAX) { >> + if (iter->type == vdev->type) { > > Again, I don't see the value in storing the enum, since the table is > static, it could just as easily be the array index and avoid this loop, > but we can avoid it anyway with symbol_put_addr(). yes you're definitively right! Thanks Eric > >> + __symbol_put(iter->reset_function_name); >> + return; >> + } >> + iter++; >> + } >> +} >> + >> static int vfio_platform_regions_init(struct vfio_platform_device *vdev) >> { >> int cnt = 0, i; >> @@ -519,6 +560,8 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev, >> return ret; >> } >> >> + vfio_platform_get_reset(vdev, dev); >> + >> mutex_init(&vdev->igate); >> >> return 0; >> @@ -530,8 +573,11 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev) >> struct vfio_platform_device *vdev; >> >> vdev = vfio_del_group_dev(dev); >> - if (vdev) >> + >> + if (vdev) { >> + vfio_platform_put_reset(vdev); >> iommu_group_put(dev->iommu_group); >> + } >> >> return vdev; >> } > > > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >
On Wed, 2015-06-10 at 13:44 +0200, Eric Auger wrote: > On 06/09/2015 08:26 PM, Alex Williamson wrote: > > On Fri, 2015-06-05 at 17:06 +0200, Eric Auger wrote: > >> The reset function lookup happens on vfio-platform probe. The reset > >> module load is requested and a reference to the function symbol is > >> hold. The reference is released on vfio-platform remove. > >> > >> Signed-off-by: Eric Auger <eric.auger@linaro.org> > >> > >> --- > >> > >> v1 -> v2: > >> - [get,put]_reset now is called once on probe/remove > >> - use request_module to automatically load the reset module that > >> matches the compatibility string > >> - lookup table is used instead of list > >> - remove registration mechanism: reset function name is stored in the > >> lookup table. > >> - use device_property_read_string instead of > >> device_property_read_string_array > >> --- > >> drivers/vfio/platform/vfio_platform_common.c | 48 +++++++++++++++++++++++++++- > >> 1 file changed, 47 insertions(+), 1 deletion(-) > >> > >> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c > >> index 995929b..d474d6a 100644 > >> --- a/drivers/vfio/platform/vfio_platform_common.c > >> +++ b/drivers/vfio/platform/vfio_platform_common.c > >> @@ -31,6 +31,47 @@ static const struct vfio_platform_reset_combo reset_lookup_table[] = { > >> }, > >> }; > >> > >> +static int vfio_platform_get_reset(struct vfio_platform_device *vdev, > >> + struct device *dev) > >> +{ > >> + const char *compat; > >> + const struct vfio_platform_reset_combo *iter = reset_lookup_table; > >> + int (*reset)(struct vfio_platform_device *); > >> + int ret; > >> + > >> + vdev->type = VFIO_PLATFORM_RESET_TYPE_MAX; > >> + ret = device_property_read_string(dev, "compatible", &compat); > >> + if (ret) > >> + return ret; > >> + > >> + while (iter->type < VFIO_PLATFORM_RESET_TYPE_MAX) { > >> + if (!strcmp(iter->compat, compat)) { > >> + request_module(iter->module_name); > >> + reset = __symbol_get(iter->reset_function_name); > > > > symbol_get() appears to be the more robust and dominant interface for > > this, why use __symbol_get()? > I used this because it takes a const char * as an argument and this is > what I use as a datatype for storing the reset function name. Symbol_get > is provided with the symbol directly? It is also used > drivers/mtd/chips/gen_probe.c. But symbol_get() is just some macro wrappers around __symbol_get() that handles tool chains that precede symbols with underscores. I don't really know if that's still a concern, but are you sure it doesn't work? > > > >> + if (reset) { > >> + vdev->type = iter->type; > >> + vdev->reset = reset; > >> + return 0; > >> + } > >> + } > >> + iter++; > >> + } > >> + return -1; > > > > -ENODEV seems preferable to -1, but shouldn't this really be a void > > function? > yes indeed > > > >> +} > >> + > >> +static void vfio_platform_put_reset(struct vfio_platform_device *vdev) > >> +{ > >> + const struct vfio_platform_reset_combo *iter = reset_lookup_table; > >> + > >> + while (iter->type < VFIO_PLATFORM_RESET_TYPE_MAX) { > >> + if (iter->type == vdev->type) { > > > > Again, I don't see the value in storing the enum, since the table is > > static, it could just as easily be the array index and avoid this loop, > > but we can avoid it anyway with symbol_put_addr(). > yes you're definitively right! > > Thanks > > Eric > > > >> + __symbol_put(iter->reset_function_name); > >> + return; > >> + } > >> + iter++; > >> + } > >> +} > >> + > >> static int vfio_platform_regions_init(struct vfio_platform_device *vdev) > >> { > >> int cnt = 0, i; > >> @@ -519,6 +560,8 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev, > >> return ret; > >> } > >> > >> + vfio_platform_get_reset(vdev, dev); > >> + > >> mutex_init(&vdev->igate); > >> > >> return 0; > >> @@ -530,8 +573,11 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev) > >> struct vfio_platform_device *vdev; > >> > >> vdev = vfio_del_group_dev(dev); > >> - if (vdev) > >> + > >> + if (vdev) { > >> + vfio_platform_put_reset(vdev); > >> iommu_group_put(dev->iommu_group); > >> + } > >> > >> return vdev; > >> } > > > > > > > > > > _______________________________________________ > > linux-arm-kernel mailing list > > linux-arm-kernel@lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > > >
On 06/10/2015 05:10 PM, Alex Williamson wrote: > On Wed, 2015-06-10 at 13:44 +0200, Eric Auger wrote: >> On 06/09/2015 08:26 PM, Alex Williamson wrote: >>> On Fri, 2015-06-05 at 17:06 +0200, Eric Auger wrote: >>>> The reset function lookup happens on vfio-platform probe. The reset >>>> module load is requested and a reference to the function symbol is >>>> hold. The reference is released on vfio-platform remove. >>>> >>>> Signed-off-by: Eric Auger <eric.auger@linaro.org> >>>> >>>> --- >>>> >>>> v1 -> v2: >>>> - [get,put]_reset now is called once on probe/remove >>>> - use request_module to automatically load the reset module that >>>> matches the compatibility string >>>> - lookup table is used instead of list >>>> - remove registration mechanism: reset function name is stored in the >>>> lookup table. >>>> - use device_property_read_string instead of >>>> device_property_read_string_array >>>> --- >>>> drivers/vfio/platform/vfio_platform_common.c | 48 +++++++++++++++++++++++++++- >>>> 1 file changed, 47 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c >>>> index 995929b..d474d6a 100644 >>>> --- a/drivers/vfio/platform/vfio_platform_common.c >>>> +++ b/drivers/vfio/platform/vfio_platform_common.c >>>> @@ -31,6 +31,47 @@ static const struct vfio_platform_reset_combo reset_lookup_table[] = { >>>> }, >>>> }; >>>> >>>> +static int vfio_platform_get_reset(struct vfio_platform_device *vdev, >>>> + struct device *dev) >>>> +{ >>>> + const char *compat; >>>> + const struct vfio_platform_reset_combo *iter = reset_lookup_table; >>>> + int (*reset)(struct vfio_platform_device *); >>>> + int ret; >>>> + >>>> + vdev->type = VFIO_PLATFORM_RESET_TYPE_MAX; >>>> + ret = device_property_read_string(dev, "compatible", &compat); >>>> + if (ret) >>>> + return ret; >>>> + >>>> + while (iter->type < VFIO_PLATFORM_RESET_TYPE_MAX) { >>>> + if (!strcmp(iter->compat, compat)) { >>>> + request_module(iter->module_name); >>>> + reset = __symbol_get(iter->reset_function_name); >>> >>> symbol_get() appears to be the more robust and dominant interface for >>> this, why use __symbol_get()? >> I used this because it takes a const char * as an argument and this is >> what I use as a datatype for storing the reset function name. Symbol_get >> is provided with the symbol directly? It is also used >> drivers/mtd/chips/gen_probe.c. > > But symbol_get() is just some macro wrappers around __symbol_get() that > handles tool chains that precede symbols with underscores. I don't > really know if that's still a concern, but are you sure it doesn't work? > >>> >>>> + if (reset) { >>>> + vdev->type = iter->type; >>>> + vdev->reset = reset; >>>> + return 0; >>>> + } >>>> + } >>>> + iter++; >>>> + } >>>> + return -1; >>> >>> -ENODEV seems preferable to -1, but shouldn't this really be a void >>> function? >> yes indeed >>> >>>> +} >>>> + >>>> +static void vfio_platform_put_reset(struct vfio_platform_device *vdev) >>>> +{ >>>> + const struct vfio_platform_reset_combo *iter = reset_lookup_table; >>>> + >>>> + while (iter->type < VFIO_PLATFORM_RESET_TYPE_MAX) { >>>> + if (iter->type == vdev->type) { >>> >>> Again, I don't see the value in storing the enum, since the table is >>> static, it could just as easily be the array index and avoid this loop, >>> but we can avoid it anyway with symbol_put_addr(). >> yes you're definitively right! to be honest I don't remember. I Will try anyway ;-) Eric >> >> Thanks >> >> Eric >>> >>>> + __symbol_put(iter->reset_function_name); >>>> + return; >>>> + } >>>> + iter++; >>>> + } >>>> +} >>>> + >>>> static int vfio_platform_regions_init(struct vfio_platform_device *vdev) >>>> { >>>> int cnt = 0, i; >>>> @@ -519,6 +560,8 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev, >>>> return ret; >>>> } >>>> >>>> + vfio_platform_get_reset(vdev, dev); >>>> + >>>> mutex_init(&vdev->igate); >>>> >>>> return 0; >>>> @@ -530,8 +573,11 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev) >>>> struct vfio_platform_device *vdev; >>>> >>>> vdev = vfio_del_group_dev(dev); >>>> - if (vdev) >>>> + >>>> + if (vdev) { >>>> + vfio_platform_put_reset(vdev); >>>> iommu_group_put(dev->iommu_group); >>>> + } >>>> >>>> return vdev; >>>> } >>> >>> >>> >>> >>> _______________________________________________ >>> linux-arm-kernel mailing list >>> linux-arm-kernel@lists.infradead.org >>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >>> >> > > >
Hi Alex, On 06/10/2015 05:10 PM, Alex Williamson wrote: > On Wed, 2015-06-10 at 13:44 +0200, Eric Auger wrote: >> On 06/09/2015 08:26 PM, Alex Williamson wrote: >>> On Fri, 2015-06-05 at 17:06 +0200, Eric Auger wrote: >>>> The reset function lookup happens on vfio-platform probe. The reset >>>> module load is requested and a reference to the function symbol is >>>> hold. The reference is released on vfio-platform remove. >>>> >>>> Signed-off-by: Eric Auger <eric.auger@linaro.org> >>>> >>>> --- >>>> >>>> v1 -> v2: >>>> - [get,put]_reset now is called once on probe/remove >>>> - use request_module to automatically load the reset module that >>>> matches the compatibility string >>>> - lookup table is used instead of list >>>> - remove registration mechanism: reset function name is stored in the >>>> lookup table. >>>> - use device_property_read_string instead of >>>> device_property_read_string_array >>>> --- >>>> drivers/vfio/platform/vfio_platform_common.c | 48 +++++++++++++++++++++++++++- >>>> 1 file changed, 47 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c >>>> index 995929b..d474d6a 100644 >>>> --- a/drivers/vfio/platform/vfio_platform_common.c >>>> +++ b/drivers/vfio/platform/vfio_platform_common.c >>>> @@ -31,6 +31,47 @@ static const struct vfio_platform_reset_combo reset_lookup_table[] = { >>>> }, >>>> }; >>>> >>>> +static int vfio_platform_get_reset(struct vfio_platform_device *vdev, >>>> + struct device *dev) >>>> +{ >>>> + const char *compat; >>>> + const struct vfio_platform_reset_combo *iter = reset_lookup_table; >>>> + int (*reset)(struct vfio_platform_device *); >>>> + int ret; >>>> + >>>> + vdev->type = VFIO_PLATFORM_RESET_TYPE_MAX; >>>> + ret = device_property_read_string(dev, "compatible", &compat); >>>> + if (ret) >>>> + return ret; >>>> + >>>> + while (iter->type < VFIO_PLATFORM_RESET_TYPE_MAX) { >>>> + if (!strcmp(iter->compat, compat)) { >>>> + request_module(iter->module_name); >>>> + reset = __symbol_get(iter->reset_function_name); >>> >>> symbol_get() appears to be the more robust and dominant interface for >>> this, why use __symbol_get()? >> I used this because it takes a const char * as an argument and this is >> what I use as a datatype for storing the reset function name. Symbol_get >> is provided with the symbol directly? It is also used >> drivers/mtd/chips/gen_probe.c. > > But symbol_get() is just some macro wrappers around __symbol_get() that > handles tool chains that precede symbols with underscores. I don't > really know if that's still a concern, but are you sure it doesn't work? I confirm it doesn't work due the (typeof(&x)) which in my case matches a const char *. drivers/vfio/platform/vfio_platform_common.c:45:10: warning: assignment from incompatible pointer type [enabled by default] reset = symbol_get( #define symbol_get(x) ((typeof(&x))(__symbol_get(VMLINUX_SYMBOL_STR(x)))) Best Regards Eric > >>> >>>> + if (reset) { >>>> + vdev->type = iter->type; >>>> + vdev->reset = reset; >>>> + return 0; >>>> + } >>>> + } >>>> + iter++; >>>> + } >>>> + return -1; >>> >>> -ENODEV seems preferable to -1, but shouldn't this really be a void >>> function? >> yes indeed >>> >>>> +} >>>> + >>>> +static void vfio_platform_put_reset(struct vfio_platform_device *vdev) >>>> +{ >>>> + const struct vfio_platform_reset_combo *iter = reset_lookup_table; >>>> + >>>> + while (iter->type < VFIO_PLATFORM_RESET_TYPE_MAX) { >>>> + if (iter->type == vdev->type) { >>> >>> Again, I don't see the value in storing the enum, since the table is >>> static, it could just as easily be the array index and avoid this loop, >>> but we can avoid it anyway with symbol_put_addr(). >> yes you're definitively right! >> >> Thanks >> >> Eric >>> >>>> + __symbol_put(iter->reset_function_name); >>>> + return; >>>> + } >>>> + iter++; >>>> + } >>>> +} >>>> + >>>> static int vfio_platform_regions_init(struct vfio_platform_device *vdev) >>>> { >>>> int cnt = 0, i; >>>> @@ -519,6 +560,8 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev, >>>> return ret; >>>> } >>>> >>>> + vfio_platform_get_reset(vdev, dev); >>>> + >>>> mutex_init(&vdev->igate); >>>> >>>> return 0; >>>> @@ -530,8 +573,11 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev) >>>> struct vfio_platform_device *vdev; >>>> >>>> vdev = vfio_del_group_dev(dev); >>>> - if (vdev) >>>> + >>>> + if (vdev) { >>>> + vfio_platform_put_reset(vdev); >>>> iommu_group_put(dev->iommu_group); >>>> + } >>>> >>>> return vdev; >>>> } >>> >>> >>> >>> >>> _______________________________________________ >>> linux-arm-kernel mailing list >>> linux-arm-kernel@lists.infradead.org >>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >>> >> > > >
diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c index 995929b..d474d6a 100644 --- a/drivers/vfio/platform/vfio_platform_common.c +++ b/drivers/vfio/platform/vfio_platform_common.c @@ -31,6 +31,47 @@ static const struct vfio_platform_reset_combo reset_lookup_table[] = { }, }; +static int vfio_platform_get_reset(struct vfio_platform_device *vdev, + struct device *dev) +{ + const char *compat; + const struct vfio_platform_reset_combo *iter = reset_lookup_table; + int (*reset)(struct vfio_platform_device *); + int ret; + + vdev->type = VFIO_PLATFORM_RESET_TYPE_MAX; + ret = device_property_read_string(dev, "compatible", &compat); + if (ret) + return ret; + + while (iter->type < VFIO_PLATFORM_RESET_TYPE_MAX) { + if (!strcmp(iter->compat, compat)) { + request_module(iter->module_name); + reset = __symbol_get(iter->reset_function_name); + if (reset) { + vdev->type = iter->type; + vdev->reset = reset; + return 0; + } + } + iter++; + } + return -1; +} + +static void vfio_platform_put_reset(struct vfio_platform_device *vdev) +{ + const struct vfio_platform_reset_combo *iter = reset_lookup_table; + + while (iter->type < VFIO_PLATFORM_RESET_TYPE_MAX) { + if (iter->type == vdev->type) { + __symbol_put(iter->reset_function_name); + return; + } + iter++; + } +} + static int vfio_platform_regions_init(struct vfio_platform_device *vdev) { int cnt = 0, i; @@ -519,6 +560,8 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev, return ret; } + vfio_platform_get_reset(vdev, dev); + mutex_init(&vdev->igate); return 0; @@ -530,8 +573,11 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev) struct vfio_platform_device *vdev; vdev = vfio_del_group_dev(dev); - if (vdev) + + if (vdev) { + vfio_platform_put_reset(vdev); iommu_group_put(dev->iommu_group); + } return vdev; }
The reset function lookup happens on vfio-platform probe. The reset module load is requested and a reference to the function symbol is hold. The reference is released on vfio-platform remove. Signed-off-by: Eric Auger <eric.auger@linaro.org> --- v1 -> v2: - [get,put]_reset now is called once on probe/remove - use request_module to automatically load the reset module that matches the compatibility string - lookup table is used instead of list - remove registration mechanism: reset function name is stored in the lookup table. - use device_property_read_string instead of device_property_read_string_array --- drivers/vfio/platform/vfio_platform_common.c | 48 +++++++++++++++++++++++++++- 1 file changed, 47 insertions(+), 1 deletion(-)