Hi Tomasz,
On Fri, Jun 10, 2016 at 09:55:19PM +0200, Tomasz Nowicki wrote:
> Implement pci_acpi_scan_root and other arch-specific call so that ARM64
> can start using ACPI to setup and enumerate PCI buses.
>
> Prior to buses enumeration the pci_acpi_scan_root() implementation looks
> for configuration space start address (obtained through ACPI _CBA method or
> MCFG interface). If succeed, it uses ECAM library to create new mapping.
> Then it attaches generic ECAM ops (pci_generic_ecam_ops) which are used
> for accessing configuration space later on.
> ...
> +static struct acpi_pci_root_ops acpi_pci_root_ops = {
> + .release_info = pci_acpi_generic_release_info,
> +};
> +
> +/* Interface called from ACPI code to setup PCI host controller */
> struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
> {
> - /* TODO: Should be revisited when implementing PCI on ACPI */
> - return NULL;
> + int node = acpi_get_node(root->device->handle);
> + struct acpi_pci_generic_root_info *ri;
> + struct pci_bus *bus, *child;
> +
> + ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
> + if (!ri)
> + return NULL;
> +
> + ri->cfg = pci_acpi_setup_ecam_mapping(root);
> + if (!ri->cfg) {
> + kfree(ri);
> + return NULL;
> + }
> +
> + acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops;
This has already been merged, but this isn't right, is it? We're
writing a host controller-specific pointer into the single system-wide
acpi_pci_root_ops, then passing it on to acpi_pci_root_create().
Today, I think ri->cfg->ops->pci_ops is always &pci_generic_ecam_ops,
from this path:
ri->cfg = pci_acpi_setup_ecam_mapping
cfg = pci_ecam_create(..., &pci_generic_ecam_ops)
cfg = kzalloc(...)
cfg->ops = ops # &pci_generic_ecam_ops
But we're about to merge the ECAM quirks series, which will mean it
may not be &pci_generic_ecam_ops. Even apart from the ECAM quirks, we
should avoid this pattern of putting device-specific info in a single
shared structure because it's too difficult to verify that it's
correct.
> + bus = acpi_pci_root_create(root, &acpi_pci_root_ops, &ri->common,
> + ri->cfg);
Bjorn
Hi Bjorn,
On 23.11.2016 00:13, Bjorn Helgaas wrote:
> Hi Tomasz,
>
> On Fri, Jun 10, 2016 at 09:55:19PM +0200, Tomasz Nowicki wrote:
>> Implement pci_acpi_scan_root and other arch-specific call so that ARM64
>> can start using ACPI to setup and enumerate PCI buses.
>>
>> Prior to buses enumeration the pci_acpi_scan_root() implementation looks
>> for configuration space start address (obtained through ACPI _CBA method or
>> MCFG interface). If succeed, it uses ECAM library to create new mapping.
>> Then it attaches generic ECAM ops (pci_generic_ecam_ops) which are used
>> for accessing configuration space later on.
>> ...
>
>> +static struct acpi_pci_root_ops acpi_pci_root_ops = {
>> + .release_info = pci_acpi_generic_release_info,
>> +};
>> +
>> +/* Interface called from ACPI code to setup PCI host controller */
>> struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
>> {
>> - /* TODO: Should be revisited when implementing PCI on ACPI */
>> - return NULL;
>> + int node = acpi_get_node(root->device->handle);
>> + struct acpi_pci_generic_root_info *ri;
>> + struct pci_bus *bus, *child;
>> +
>> + ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
>> + if (!ri)
>> + return NULL;
>> +
>> + ri->cfg = pci_acpi_setup_ecam_mapping(root);
>> + if (!ri->cfg) {
>> + kfree(ri);
>> + return NULL;
>> + }
>> +
>> + acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops;
>
> This has already been merged, but this isn't right, is it? We're
> writing a host controller-specific pointer into the single system-wide
> acpi_pci_root_ops, then passing it on to acpi_pci_root_create().
>
> Today, I think ri->cfg->ops->pci_ops is always &pci_generic_ecam_ops,
> from this path:
>
> ri->cfg = pci_acpi_setup_ecam_mapping
> cfg = pci_ecam_create(..., &pci_generic_ecam_ops)
> cfg = kzalloc(...)
> cfg->ops = ops # &pci_generic_ecam_ops
>
> But we're about to merge the ECAM quirks series, which will mean it
> may not be &pci_generic_ecam_ops. Even apart from the ECAM quirks, we
> should avoid this pattern of putting device-specific info in a single
> shared structure because it's too difficult to verify that it's
> correct.
>
Well spotted. I agree, we need to fix this. How about this:
diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
index fb439c7..31c0e1c 100644
--- a/arch/arm64/kernel/pci.c
+++ b/arch/arm64/kernel/pci.c
@@ -152,33 +152,35 @@ static void pci_acpi_generic_release_info(struct
acpi_pci_root_info *ci)
ri = container_of(ci, struct acpi_pci_generic_root_info, common);
pci_ecam_free(ri->cfg);
+ kfree(ci->ops);
kfree(ri);
}
-static struct acpi_pci_root_ops acpi_pci_root_ops = {
- .release_info = pci_acpi_generic_release_info,
-};
-
/* Interface called from ACPI code to setup PCI host controller */
struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
{
int node = acpi_get_node(root->device->handle);
struct acpi_pci_generic_root_info *ri;
struct pci_bus *bus, *child;
+ struct acpi_pci_root_ops *root_ops;
ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
if (!ri)
return NULL;
+ root_ops = kzalloc_node(sizeof(*root_ops), GFP_KERNEL, node);
+ if (!root_ops)
+ return NULL;
+
ri->cfg = pci_acpi_setup_ecam_mapping(root);
if (!ri->cfg) {
kfree(ri);
+ kfree(root_ops);
return NULL;
}
- acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops;
- bus = acpi_pci_root_create(root, &acpi_pci_root_ops, &ri->common,
- ri->cfg);
+ root_ops->release_info = pci_acpi_generic_release_info;
+ root_ops->pci_ops = &ri->cfg->ops->pci_ops;
+ bus = acpi_pci_root_create(root, root_ops, &ri->common, ri->cfg);
if (!bus)
return NULL;
Of course, this should be the part of ECAM quirks core patches.
The other option we have is to remove "struct pci_ops *pci_ops;" from
acpi_pci_root_ops structure and pass struct pci_ops as an extra argument
to acpi_pci_root_create(). What do you think?
Thanks,
Tomasz
On Wed, Nov 23, 2016 at 12:21:03PM +0100, Tomasz Nowicki wrote:
> Hi Bjorn,
>
> On 23.11.2016 00:13, Bjorn Helgaas wrote:
> >Hi Tomasz,
> >
> >On Fri, Jun 10, 2016 at 09:55:19PM +0200, Tomasz Nowicki wrote:
> >>Implement pci_acpi_scan_root and other arch-specific call so that ARM64
> >>can start using ACPI to setup and enumerate PCI buses.
> >>
> >>Prior to buses enumeration the pci_acpi_scan_root() implementation looks
> >>for configuration space start address (obtained through ACPI _CBA method or
> >>MCFG interface). If succeed, it uses ECAM library to create new mapping.
> >>Then it attaches generic ECAM ops (pci_generic_ecam_ops) which are used
> >>for accessing configuration space later on.
> >>...
> >
> >>+static struct acpi_pci_root_ops acpi_pci_root_ops = {
> >>+ .release_info = pci_acpi_generic_release_info,
> >>+};
> >>+
> >>+/* Interface called from ACPI code to setup PCI host controller */
> >> struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
> >> {
> >>- /* TODO: Should be revisited when implementing PCI on ACPI */
> >>- return NULL;
> >>+ int node = acpi_get_node(root->device->handle);
> >>+ struct acpi_pci_generic_root_info *ri;
> >>+ struct pci_bus *bus, *child;
> >>+
> >>+ ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
> >>+ if (!ri)
> >>+ return NULL;
> >>+
> >>+ ri->cfg = pci_acpi_setup_ecam_mapping(root);
> >>+ if (!ri->cfg) {
> >>+ kfree(ri);
> >>+ return NULL;
> >>+ }
> >>+
> >>+ acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops;
> >
> >This has already been merged, but this isn't right, is it? We're
> >writing a host controller-specific pointer into the single system-wide
> >acpi_pci_root_ops, then passing it on to acpi_pci_root_create().
> >
> >Today, I think ri->cfg->ops->pci_ops is always &pci_generic_ecam_ops,
> >from this path:
> >
> > ri->cfg = pci_acpi_setup_ecam_mapping
> > cfg = pci_ecam_create(..., &pci_generic_ecam_ops)
> > cfg = kzalloc(...)
> > cfg->ops = ops # &pci_generic_ecam_ops
> >
> >But we're about to merge the ECAM quirks series, which will mean it
> >may not be &pci_generic_ecam_ops. Even apart from the ECAM quirks, we
> >should avoid this pattern of putting device-specific info in a single
> >shared structure because it's too difficult to verify that it's
> >correct.
> >
>
> Well spotted. I agree, we need to fix this. How about this:
> diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
> index fb439c7..31c0e1c 100644
> --- a/arch/arm64/kernel/pci.c
> +++ b/arch/arm64/kernel/pci.c
> @@ -152,33 +152,35 @@ static void
> pci_acpi_generic_release_info(struct acpi_pci_root_info *ci)
>
> ri = container_of(ci, struct acpi_pci_generic_root_info, common);
> pci_ecam_free(ri->cfg);
> + kfree(ci->ops);
> kfree(ri);
> }
>
> -static struct acpi_pci_root_ops acpi_pci_root_ops = {
> - .release_info = pci_acpi_generic_release_info,
> -};
> -
> /* Interface called from ACPI code to setup PCI host controller */
> struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
> {
> int node = acpi_get_node(root->device->handle);
> struct acpi_pci_generic_root_info *ri;
> struct pci_bus *bus, *child;
> + struct acpi_pci_root_ops *root_ops;
>
> ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
> if (!ri)
> return NULL;
>
> + root_ops = kzalloc_node(sizeof(*root_ops), GFP_KERNEL, node);
> + if (!root_ops)
> + return NULL;
> +
> ri->cfg = pci_acpi_setup_ecam_mapping(root);
> if (!ri->cfg) {
> kfree(ri);
> + kfree(root_ops);
> return NULL;
> }
>
> - acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops;
> - bus = acpi_pci_root_create(root, &acpi_pci_root_ops, &ri->common,
> - ri->cfg);
> + root_ops->release_info = pci_acpi_generic_release_info;
> + root_ops->pci_ops = &ri->cfg->ops->pci_ops;
> + bus = acpi_pci_root_create(root, root_ops, &ri->common, ri->cfg);
> if (!bus)
> return NULL;
>
> Of course, this should be the part of ECAM quirks core patches.
>
> The other option we have is to remove "struct pci_ops *pci_ops;"
> from acpi_pci_root_ops structure and pass struct pci_ops as an extra
> argument to acpi_pci_root_create(). What do you think?
I think your patch above is fine and avoids the need to change the x86 and
ia64 code. Would you mind packaging this up with a changelog and
signed-off-by? I can take care of putting it in the ECAM series.
Thanks,
Bjorn
On 23.11.2016 19:22, Bjorn Helgaas wrote:
> On Wed, Nov 23, 2016 at 12:21:03PM +0100, Tomasz Nowicki wrote:
>> Hi Bjorn,
>>
>> On 23.11.2016 00:13, Bjorn Helgaas wrote:
>>> Hi Tomasz,
>>>
>>> On Fri, Jun 10, 2016 at 09:55:19PM +0200, Tomasz Nowicki wrote:
>>>> Implement pci_acpi_scan_root and other arch-specific call so that ARM64
>>>> can start using ACPI to setup and enumerate PCI buses.
>>>>
>>>> Prior to buses enumeration the pci_acpi_scan_root() implementation looks
>>>> for configuration space start address (obtained through ACPI _CBA method or
>>>> MCFG interface). If succeed, it uses ECAM library to create new mapping.
>>>> Then it attaches generic ECAM ops (pci_generic_ecam_ops) which are used
>>>> for accessing configuration space later on.
>>>> ...
>>>
>>>> +static struct acpi_pci_root_ops acpi_pci_root_ops = {
>>>> + .release_info = pci_acpi_generic_release_info,
>>>> +};
>>>> +
>>>> +/* Interface called from ACPI code to setup PCI host controller */
>>>> struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
>>>> {
>>>> - /* TODO: Should be revisited when implementing PCI on ACPI */
>>>> - return NULL;
>>>> + int node = acpi_get_node(root->device->handle);
>>>> + struct acpi_pci_generic_root_info *ri;
>>>> + struct pci_bus *bus, *child;
>>>> +
>>>> + ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
>>>> + if (!ri)
>>>> + return NULL;
>>>> +
>>>> + ri->cfg = pci_acpi_setup_ecam_mapping(root);
>>>> + if (!ri->cfg) {
>>>> + kfree(ri);
>>>> + return NULL;
>>>> + }
>>>> +
>>>> + acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops;
>>>
>>> This has already been merged, but this isn't right, is it? We're
>>> writing a host controller-specific pointer into the single system-wide
>>> acpi_pci_root_ops, then passing it on to acpi_pci_root_create().
>>>
>>> Today, I think ri->cfg->ops->pci_ops is always &pci_generic_ecam_ops,
>> >from this path:
>>>
>>> ri->cfg = pci_acpi_setup_ecam_mapping
>>> cfg = pci_ecam_create(..., &pci_generic_ecam_ops)
>>> cfg = kzalloc(...)
>>> cfg->ops = ops # &pci_generic_ecam_ops
>>>
>>> But we're about to merge the ECAM quirks series, which will mean it
>>> may not be &pci_generic_ecam_ops. Even apart from the ECAM quirks, we
>>> should avoid this pattern of putting device-specific info in a single
>>> shared structure because it's too difficult to verify that it's
>>> correct.
>>>
>>
>> Well spotted. I agree, we need to fix this. How about this:
>> diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
>> index fb439c7..31c0e1c 100644
>> --- a/arch/arm64/kernel/pci.c
>> +++ b/arch/arm64/kernel/pci.c
>> @@ -152,33 +152,35 @@ static void
>> pci_acpi_generic_release_info(struct acpi_pci_root_info *ci)
>>
>> ri = container_of(ci, struct acpi_pci_generic_root_info, common);
>> pci_ecam_free(ri->cfg);
>> + kfree(ci->ops);
>> kfree(ri);
>> }
>>
>> -static struct acpi_pci_root_ops acpi_pci_root_ops = {
>> - .release_info = pci_acpi_generic_release_info,
>> -};
>> -
>> /* Interface called from ACPI code to setup PCI host controller */
>> struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
>> {
>> int node = acpi_get_node(root->device->handle);
>> struct acpi_pci_generic_root_info *ri;
>> struct pci_bus *bus, *child;
>> + struct acpi_pci_root_ops *root_ops;
>>
>> ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
>> if (!ri)
>> return NULL;
>>
>> + root_ops = kzalloc_node(sizeof(*root_ops), GFP_KERNEL, node);
>> + if (!root_ops)
>> + return NULL;
>> +
>> ri->cfg = pci_acpi_setup_ecam_mapping(root);
>> if (!ri->cfg) {
>> kfree(ri);
>> + kfree(root_ops);
>> return NULL;
>> }
>>
>> - acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops;
>> - bus = acpi_pci_root_create(root, &acpi_pci_root_ops, &ri->common,
>> - ri->cfg);
>> + root_ops->release_info = pci_acpi_generic_release_info;
>> + root_ops->pci_ops = &ri->cfg->ops->pci_ops;
>> + bus = acpi_pci_root_create(root, root_ops, &ri->common, ri->cfg);
>> if (!bus)
>> return NULL;
>>
>> Of course, this should be the part of ECAM quirks core patches.
>>
>> The other option we have is to remove "struct pci_ops *pci_ops;"
>> from acpi_pci_root_ops structure and pass struct pci_ops as an extra
>> argument to acpi_pci_root_create(). What do you think?
>
> I think your patch above is fine and avoids the need to change the x86 and
> ia64 code. Would you mind packaging this up with a changelog and
> signed-off-by? I can take care of putting it in the ECAM series.
>
Sure, I have just sent the patch in replay to ECAM quirks V6 patch set.
Let us know when you update your branch so we base our quirks on it.
Thanks,
Tomasz