2020-02-21 03:28:47

by Alastair D'Silva

[permalink] [raw]
Subject: [PATCH v3 06/27] ocxl: Tally up the LPC memory on a link & allow it to be mapped

From: Alastair D'Silva <[email protected]>

Tally up the LPC memory on an OpenCAPI link & allow it to be mapped

Signed-off-by: Alastair D'Silva <[email protected]>
---
drivers/misc/ocxl/core.c | 10 ++++++
drivers/misc/ocxl/link.c | 53 +++++++++++++++++++++++++++++++
drivers/misc/ocxl/ocxl_internal.h | 33 +++++++++++++++++++
3 files changed, 96 insertions(+)

diff --git a/drivers/misc/ocxl/core.c b/drivers/misc/ocxl/core.c
index b7a09b21ab36..2531c6cf19a0 100644
--- a/drivers/misc/ocxl/core.c
+++ b/drivers/misc/ocxl/core.c
@@ -230,8 +230,18 @@ static int configure_afu(struct ocxl_afu *afu, u8 afu_idx, struct pci_dev *dev)
if (rc)
goto err_free_pasid;

+ if (afu->config.lpc_mem_size || afu->config.special_purpose_mem_size) {
+ rc = ocxl_link_add_lpc_mem(afu->fn->link, afu->config.lpc_mem_offset,
+ afu->config.lpc_mem_size +
+ afu->config.special_purpose_mem_size);
+ if (rc)
+ goto err_free_mmio;
+ }
+
return 0;

+err_free_mmio:
+ unmap_mmio_areas(afu);
err_free_pasid:
reclaim_afu_pasid(afu);
err_free_actag:
diff --git a/drivers/misc/ocxl/link.c b/drivers/misc/ocxl/link.c
index 58d111afd9f6..1e039cc5ebe5 100644
--- a/drivers/misc/ocxl/link.c
+++ b/drivers/misc/ocxl/link.c
@@ -84,6 +84,11 @@ struct ocxl_link {
int dev;
atomic_t irq_available;
struct spa *spa;
+ struct mutex lpc_mem_lock; /* protects lpc_mem & lpc_mem_sz */
+ u64 lpc_mem_sz; /* Total amount of LPC memory presented on the link */
+ u64 lpc_mem;
+ int lpc_consumers;
+
void *platform_data;
};
static struct list_head links_list = LIST_HEAD_INIT(links_list);
@@ -396,6 +401,8 @@ static int alloc_link(struct pci_dev *dev, int PE_mask, struct ocxl_link **out_l
if (rc)
goto err_spa;

+ mutex_init(&link->lpc_mem_lock);
+
/* platform specific hook */
rc = pnv_ocxl_spa_setup(dev, link->spa->spa_mem, PE_mask,
&link->platform_data);
@@ -711,3 +718,49 @@ void ocxl_link_free_irq(void *link_handle, int hw_irq)
atomic_inc(&link->irq_available);
}
EXPORT_SYMBOL_GPL(ocxl_link_free_irq);
+
+int ocxl_link_add_lpc_mem(void *link_handle, u64 offset, u64 size)
+{
+ struct ocxl_link *link = (struct ocxl_link *) link_handle;
+
+ // Check for overflow
+ if (offset > (offset + size))
+ return -EINVAL;
+
+ mutex_lock(&link->lpc_mem_lock);
+ link->lpc_mem_sz = max(link->lpc_mem_sz, offset + size);
+
+ mutex_unlock(&link->lpc_mem_lock);
+
+ return 0;
+}
+
+u64 ocxl_link_lpc_map(void *link_handle, struct pci_dev *pdev)
+{
+ struct ocxl_link *link = (struct ocxl_link *) link_handle;
+
+ mutex_lock(&link->lpc_mem_lock);
+
+ if(!link->lpc_mem)
+ link->lpc_mem = pnv_ocxl_platform_lpc_setup(pdev, link->lpc_mem_sz);
+
+ if(link->lpc_mem)
+ link->lpc_consumers++;
+ mutex_unlock(&link->lpc_mem_lock);
+
+ return link->lpc_mem;
+}
+
+void ocxl_link_lpc_release(void *link_handle, struct pci_dev *pdev)
+{
+ struct ocxl_link *link = (struct ocxl_link *) link_handle;
+
+ mutex_lock(&link->lpc_mem_lock);
+ WARN_ON(--link->lpc_consumers < 0);
+ if (link->lpc_consumers == 0) {
+ pnv_ocxl_platform_lpc_release(pdev);
+ link->lpc_mem = 0;
+ }
+
+ mutex_unlock(&link->lpc_mem_lock);
+}
diff --git a/drivers/misc/ocxl/ocxl_internal.h b/drivers/misc/ocxl/ocxl_internal.h
index 198e4e4bc51d..d0c8c4838f42 100644
--- a/drivers/misc/ocxl/ocxl_internal.h
+++ b/drivers/misc/ocxl/ocxl_internal.h
@@ -142,4 +142,37 @@ int ocxl_irq_offset_to_id(struct ocxl_context *ctx, u64 offset);
u64 ocxl_irq_id_to_offset(struct ocxl_context *ctx, int irq_id);
void ocxl_afu_irq_free_all(struct ocxl_context *ctx);

+/**
+ * ocxl_link_add_lpc_mem() - Increment the amount of memory required by an OpenCAPI link
+ *
+ * @link_handle: The OpenCAPI link handle
+ * @offset: The offset of the memory to add
+ * @size: The amount of memory to increment by
+ *
+ * Returns 0 on success, negative on overflow
+ */
+int ocxl_link_add_lpc_mem(void *link_handle, u64 offset, u64 size);
+
+/**
+ * ocxl_link_lpc_map() - Map the LPC memory for an OpenCAPI device
+ * Since LPC memory belongs to a link, the whole LPC memory available
+ * on the link must be mapped in order to make it accessible to a device.
+ * @link_handle: The OpenCAPI link handle
+ * @pdev: A device that is on the link
+ *
+ * Returns the address of the mapped LPC memory, or 0 on error
+ */
+u64 ocxl_link_lpc_map(void *link_handle, struct pci_dev *pdev);
+
+/**
+ * ocxl_link_lpc_release() - Release the LPC memory device for an OpenCAPI device
+ *
+ * Offlines LPC memory on an OpenCAPI link for a device. If this is the
+ * last device on the link to release the memory, unmap it from the link.
+ *
+ * @link_handle: The OpenCAPI link handle
+ * @pdev: A device that is on the link
+ */
+void ocxl_link_lpc_release(void *link_handle, struct pci_dev *pdev);
+
#endif /* _OCXL_INTERNAL_H_ */
--
2.24.1


2020-02-24 05:25:54

by Andrew Donnellan

[permalink] [raw]
Subject: Re: [PATCH v3 06/27] ocxl: Tally up the LPC memory on a link & allow it to be mapped

On 21/2/20 2:26 pm, Alastair D'Silva wrote:
> From: Alastair D'Silva <[email protected]>
>
> Tally up the LPC memory on an OpenCAPI link & allow it to be mapped
>
> Signed-off-by: Alastair D'Silva <[email protected]>

This commit message is a bit short and could do with some further
explanation.

In particular - it's worth explaining why the tracking of available LPC
memory needs to be done at a link level, because a single OpenCAPI card
can have multiple PCI functions, each with multiple AFUs which define an
amount of LPC memory they have, even if the common case is expected to
be a single function with a single AFU and thus one LPC area per link.

Snowpatch has a few checkpatch issues to report:

https://openpower.xyz/job/snowpatch/job/snowpatch-linux-checkpatch/11800//artifact/linux/checkpatch.log

The code generally looks okay to me.

> diff --git a/drivers/misc/ocxl/ocxl_internal.h b/drivers/misc/ocxl/ocxl_internal.h
> index 198e4e4bc51d..d0c8c4838f42 100644
> --- a/drivers/misc/ocxl/ocxl_internal.h
> +++ b/drivers/misc/ocxl/ocxl_internal.h
> @@ -142,4 +142,37 @@ int ocxl_irq_offset_to_id(struct ocxl_context *ctx, u64 offset);
> u64 ocxl_irq_id_to_offset(struct ocxl_context *ctx, int irq_id);
> void ocxl_afu_irq_free_all(struct ocxl_context *ctx);
>
> +/**
> + * ocxl_link_add_lpc_mem() - Increment the amount of memory required by an OpenCAPI link
> + *
> + * @link_handle: The OpenCAPI link handle
> + * @offset: The offset of the memory to add
> + * @size: The amount of memory to increment by
> + *
> + * Returns 0 on success, negative on overflow
> + */

I think "amount of memory required" isn't the best way to express this.

Might as well explicitly say -EINVAL on overflow.

--
Andrew Donnellan OzLabs, ADL Canberra
[email protected] IBM Australia Limited

2020-02-24 05:37:26

by Alastair D'Silva

[permalink] [raw]
Subject: Re: [PATCH v3 06/27] ocxl: Tally up the LPC memory on a link & allow it to be mapped

On Mon, 2020-02-24 at 16:25 +1100, Andrew Donnellan wrote:
> On 21/2/20 2:26 pm, Alastair D'Silva wrote:
> > From: Alastair D'Silva <[email protected]>
> >
> > Tally up the LPC memory on an OpenCAPI link & allow it to be mapped
> >
> > Signed-off-by: Alastair D'Silva <[email protected]>
>
> This commit message is a bit short and could do with some further
> explanation.
>
> In particular - it's worth explaining why the tracking of available
> LPC
> memory needs to be done at a link level, because a single OpenCAPI
> card
> can have multiple PCI functions, each with multiple AFUs which define
> an
> amount of LPC memory they have, even if the common case is expected
> to
> be a single function with a single AFU and thus one LPC area per
> link.

Ok

>
> Snowpatch has a few checkpatch issues to report:
>
> https://openpower.xyz/job/snowpatch/job/snowpatch-linux-checkpatch/11800//artifact/linux/checkpatch.log
>

Gah, I could have sworn I ran checkpatch against this :/

> The code generally looks okay to me.
>
> > diff --git a/drivers/misc/ocxl/ocxl_internal.h
> > b/drivers/misc/ocxl/ocxl_internal.h
> > index 198e4e4bc51d..d0c8c4838f42 100644
> > --- a/drivers/misc/ocxl/ocxl_internal.h
> > +++ b/drivers/misc/ocxl/ocxl_internal.h
> > @@ -142,4 +142,37 @@ int ocxl_irq_offset_to_id(struct ocxl_context
> > *ctx, u64 offset);
> > u64 ocxl_irq_id_to_offset(struct ocxl_context *ctx, int irq_id);
> > void ocxl_afu_irq_free_all(struct ocxl_context *ctx);
> >
> > +/**
> > + * ocxl_link_add_lpc_mem() - Increment the amount of memory
> > required by an OpenCAPI link
> > + *
> > + * @link_handle: The OpenCAPI link handle
> > + * @offset: The offset of the memory to add
> > + * @size: The amount of memory to increment by
> > + *
> > + * Returns 0 on success, negative on overflow
> > + */
>
> I think "amount of memory required" isn't the best way to express
> this.
>
> Might as well explicitly say -EINVAL on overflow.
>

Ok

--
Alastair D'Silva
Open Source Developer
Linux Technology Centre, IBM Australia
mob: 0423 762 819

2020-02-25 16:31:41

by Frederic Barrat

[permalink] [raw]
Subject: Re: [PATCH v3 06/27] ocxl: Tally up the LPC memory on a link & allow it to be mapped



Le 21/02/2020 à 04:26, Alastair D'Silva a écrit :
> From: Alastair D'Silva <[email protected]>
>
> Tally up the LPC memory on an OpenCAPI link & allow it to be mapped
>
> Signed-off-by: Alastair D'Silva <[email protected]>
> ---
> drivers/misc/ocxl/core.c | 10 ++++++
> drivers/misc/ocxl/link.c | 53 +++++++++++++++++++++++++++++++
> drivers/misc/ocxl/ocxl_internal.h | 33 +++++++++++++++++++
> 3 files changed, 96 insertions(+)
>
> diff --git a/drivers/misc/ocxl/core.c b/drivers/misc/ocxl/core.c
> index b7a09b21ab36..2531c6cf19a0 100644
> --- a/drivers/misc/ocxl/core.c
> +++ b/drivers/misc/ocxl/core.c
> @@ -230,8 +230,18 @@ static int configure_afu(struct ocxl_afu *afu, u8 afu_idx, struct pci_dev *dev)
> if (rc)
> goto err_free_pasid;
>
> + if (afu->config.lpc_mem_size || afu->config.special_purpose_mem_size) {
> + rc = ocxl_link_add_lpc_mem(afu->fn->link, afu->config.lpc_mem_offset,
> + afu->config.lpc_mem_size +
> + afu->config.special_purpose_mem_size);
> + if (rc)
> + goto err_free_mmio;
> + }
> +
> return 0;
>
> +err_free_mmio:
> + unmap_mmio_areas(afu);
> err_free_pasid:
> reclaim_afu_pasid(afu);
> err_free_actag:
> diff --git a/drivers/misc/ocxl/link.c b/drivers/misc/ocxl/link.c
> index 58d111afd9f6..1e039cc5ebe5 100644
> --- a/drivers/misc/ocxl/link.c
> +++ b/drivers/misc/ocxl/link.c
> @@ -84,6 +84,11 @@ struct ocxl_link {
> int dev;
> atomic_t irq_available;
> struct spa *spa;
> + struct mutex lpc_mem_lock; /* protects lpc_mem & lpc_mem_sz */
> + u64 lpc_mem_sz; /* Total amount of LPC memory presented on the link */
> + u64 lpc_mem;
> + int lpc_consumers;
> +
> void *platform_data;
> };
> static struct list_head links_list = LIST_HEAD_INIT(links_list);
> @@ -396,6 +401,8 @@ static int alloc_link(struct pci_dev *dev, int PE_mask, struct ocxl_link **out_l
> if (rc)
> goto err_spa;
>
> + mutex_init(&link->lpc_mem_lock);
> +
> /* platform specific hook */
> rc = pnv_ocxl_spa_setup(dev, link->spa->spa_mem, PE_mask,
> &link->platform_data);
> @@ -711,3 +718,49 @@ void ocxl_link_free_irq(void *link_handle, int hw_irq)
> atomic_inc(&link->irq_available);
> }
> EXPORT_SYMBOL_GPL(ocxl_link_free_irq);
> +
> +int ocxl_link_add_lpc_mem(void *link_handle, u64 offset, u64 size)
> +{
> + struct ocxl_link *link = (struct ocxl_link *) link_handle;
> +
> + // Check for overflow
> + if (offset > (offset + size))
> + return -EINVAL;
> +
> + mutex_lock(&link->lpc_mem_lock);
> + link->lpc_mem_sz = max(link->lpc_mem_sz, offset + size);
> +
> + mutex_unlock(&link->lpc_mem_lock);
> +
> + return 0;
> +}
> +
> +u64 ocxl_link_lpc_map(void *link_handle, struct pci_dev *pdev)
> +{
> + struct ocxl_link *link = (struct ocxl_link *) link_handle;
> +
> + mutex_lock(&link->lpc_mem_lock);
> +
> + if(!link->lpc_mem)
> + link->lpc_mem = pnv_ocxl_platform_lpc_setup(pdev, link->lpc_mem_sz);
> +
> + if(link->lpc_mem)
> + link->lpc_consumers++;
> + mutex_unlock(&link->lpc_mem_lock);
> +
> + return link->lpc_mem;
> +}
> +
> +void ocxl_link_lpc_release(void *link_handle, struct pci_dev *pdev)
> +{
> + struct ocxl_link *link = (struct ocxl_link *) link_handle;
> +
> + mutex_lock(&link->lpc_mem_lock);
> + WARN_ON(--link->lpc_consumers < 0);


Here, we always decrement the lpc_consumers count. However, it was only
incremented if the mapping was setup correctly in opal.

We could arguably claim that ocxl_link_lpc_release() should only be
called if ocxl_link_lpc_map() succeeded, but it would make error path
handling easier if we only decrement the lpc_consumers count if
link->lpc_mem is set. So that we can just call ocxl_link_lpc_release()
in error paths without having to worry about triggering the WARN_ON message.

Fred



> + if (link->lpc_consumers == 0) {
> + pnv_ocxl_platform_lpc_release(pdev);
> + link->lpc_mem = 0;
> + }
> +
> + mutex_unlock(&link->lpc_mem_lock);
> +}
> diff --git a/drivers/misc/ocxl/ocxl_internal.h b/drivers/misc/ocxl/ocxl_internal.h
> index 198e4e4bc51d..d0c8c4838f42 100644
> --- a/drivers/misc/ocxl/ocxl_internal.h
> +++ b/drivers/misc/ocxl/ocxl_internal.h
> @@ -142,4 +142,37 @@ int ocxl_irq_offset_to_id(struct ocxl_context *ctx, u64 offset);
> u64 ocxl_irq_id_to_offset(struct ocxl_context *ctx, int irq_id);
> void ocxl_afu_irq_free_all(struct ocxl_context *ctx);
>
> +/**
> + * ocxl_link_add_lpc_mem() - Increment the amount of memory required by an OpenCAPI link
> + *
> + * @link_handle: The OpenCAPI link handle
> + * @offset: The offset of the memory to add
> + * @size: The amount of memory to increment by
> + *
> + * Returns 0 on success, negative on overflow
> + */
> +int ocxl_link_add_lpc_mem(void *link_handle, u64 offset, u64 size);
> +
> +/**
> + * ocxl_link_lpc_map() - Map the LPC memory for an OpenCAPI device
> + * Since LPC memory belongs to a link, the whole LPC memory available
> + * on the link must be mapped in order to make it accessible to a device.
> + * @link_handle: The OpenCAPI link handle
> + * @pdev: A device that is on the link
> + *
> + * Returns the address of the mapped LPC memory, or 0 on error
> + */
> +u64 ocxl_link_lpc_map(void *link_handle, struct pci_dev *pdev);
> +
> +/**
> + * ocxl_link_lpc_release() - Release the LPC memory device for an OpenCAPI device
> + *
> + * Offlines LPC memory on an OpenCAPI link for a device. If this is the
> + * last device on the link to release the memory, unmap it from the link.
> + *
> + * @link_handle: The OpenCAPI link handle
> + * @pdev: A device that is on the link
> + */
> +void ocxl_link_lpc_release(void *link_handle, struct pci_dev *pdev);
> +
> #endif /* _OCXL_INTERNAL_H_ */
>

2020-02-26 00:31:09

by Alastair D'Silva

[permalink] [raw]
Subject: Re: [PATCH v3 06/27] ocxl: Tally up the LPC memory on a link & allow it to be mapped

On Tue, 2020-02-25 at 17:30 +0100, Frederic Barrat wrote:
>
> Le 21/02/2020 à 04:26, Alastair D'Silva a écrit :
> > From: Alastair D'Silva <[email protected]>
> >
> > Tally up the LPC memory on an OpenCAPI link & allow it to be mapped
> >
> > Signed-off-by: Alastair D'Silva <[email protected]>
> > ---
> > drivers/misc/ocxl/core.c | 10 ++++++
> > drivers/misc/ocxl/link.c | 53
> > +++++++++++++++++++++++++++++++
> > drivers/misc/ocxl/ocxl_internal.h | 33 +++++++++++++++++++
> > 3 files changed, 96 insertions(+)
> >
> > diff --git a/drivers/misc/ocxl/core.c b/drivers/misc/ocxl/core.c
> > index b7a09b21ab36..2531c6cf19a0 100644
> > --- a/drivers/misc/ocxl/core.c
> > +++ b/drivers/misc/ocxl/core.c
> > @@ -230,8 +230,18 @@ static int configure_afu(struct ocxl_afu *afu,
> > u8 afu_idx, struct pci_dev *dev)
> > if (rc)
> > goto err_free_pasid;
> >
> > + if (afu->config.lpc_mem_size || afu-
> > >config.special_purpose_mem_size) {
> > + rc = ocxl_link_add_lpc_mem(afu->fn->link, afu-
> > >config.lpc_mem_offset,
> > + afu->config.lpc_mem_size +
> > + afu-
> > >config.special_purpose_mem_size);
> > + if (rc)
> > + goto err_free_mmio;
> > + }
> > +
> > return 0;
> >
> > +err_free_mmio:
> > + unmap_mmio_areas(afu);
> > err_free_pasid:
> > reclaim_afu_pasid(afu);
> > err_free_actag:
> > diff --git a/drivers/misc/ocxl/link.c b/drivers/misc/ocxl/link.c
> > index 58d111afd9f6..1e039cc5ebe5 100644
> > --- a/drivers/misc/ocxl/link.c
> > +++ b/drivers/misc/ocxl/link.c
> > @@ -84,6 +84,11 @@ struct ocxl_link {
> > int dev;
> > atomic_t irq_available;
> > struct spa *spa;
> > + struct mutex lpc_mem_lock; /* protects lpc_mem & lpc_mem_sz */
> > + u64 lpc_mem_sz; /* Total amount of LPC memory presented on the
> > link */
> > + u64 lpc_mem;
> > + int lpc_consumers;
> > +
> > void *platform_data;
> > };
> > static struct list_head links_list = LIST_HEAD_INIT(links_list);
> > @@ -396,6 +401,8 @@ static int alloc_link(struct pci_dev *dev, int
> > PE_mask, struct ocxl_link **out_l
> > if (rc)
> > goto err_spa;
> >
> > + mutex_init(&link->lpc_mem_lock);
> > +
> > /* platform specific hook */
> > rc = pnv_ocxl_spa_setup(dev, link->spa->spa_mem, PE_mask,
> > &link->platform_data);
> > @@ -711,3 +718,49 @@ void ocxl_link_free_irq(void *link_handle, int
> > hw_irq)
> > atomic_inc(&link->irq_available);
> > }
> > EXPORT_SYMBOL_GPL(ocxl_link_free_irq);
> > +
> > +int ocxl_link_add_lpc_mem(void *link_handle, u64 offset, u64 size)
> > +{
> > + struct ocxl_link *link = (struct ocxl_link *) link_handle;
> > +
> > + // Check for overflow
> > + if (offset > (offset + size))
> > + return -EINVAL;
> > +
> > + mutex_lock(&link->lpc_mem_lock);
> > + link->lpc_mem_sz = max(link->lpc_mem_sz, offset + size);
> > +
> > + mutex_unlock(&link->lpc_mem_lock);
> > +
> > + return 0;
> > +}
> > +
> > +u64 ocxl_link_lpc_map(void *link_handle, struct pci_dev *pdev)
> > +{
> > + struct ocxl_link *link = (struct ocxl_link *) link_handle;
> > +
> > + mutex_lock(&link->lpc_mem_lock);
> > +
> > + if(!link->lpc_mem)
> > + link->lpc_mem = pnv_ocxl_platform_lpc_setup(pdev, link-
> > >lpc_mem_sz);
> > +
> > + if(link->lpc_mem)
> > + link->lpc_consumers++;
> > + mutex_unlock(&link->lpc_mem_lock);
> > +
> > + return link->lpc_mem;
> > +}
> > +
> > +void ocxl_link_lpc_release(void *link_handle, struct pci_dev
> > *pdev)
> > +{
> > + struct ocxl_link *link = (struct ocxl_link *) link_handle;
> > +
> > + mutex_lock(&link->lpc_mem_lock);
> > + WARN_ON(--link->lpc_consumers < 0);
>
> Here, we always decrement the lpc_consumers count. However, it was
> only
> incremented if the mapping was setup correctly in opal.
>
> We could arguably claim that ocxl_link_lpc_release() should only be
> called if ocxl_link_lpc_map() succeeded, but it would make error
> path
> handling easier if we only decrement the lpc_consumers count if
> link->lpc_mem is set. So that we can just call
> ocxl_link_lpc_release()
> in error paths without having to worry about triggering the WARN_ON
> message.
>
> Fred
>
>

Ok, this makes sense.

>
> > + if (link->lpc_consumers == 0) {
> > + pnv_ocxl_platform_lpc_release(pdev);
> > + link->lpc_mem = 0;
> > + }
> > +
> > + mutex_unlock(&link->lpc_mem_lock);
> > +}
> > diff --git a/drivers/misc/ocxl/ocxl_internal.h
> > b/drivers/misc/ocxl/ocxl_internal.h
> > index 198e4e4bc51d..d0c8c4838f42 100644
> > --- a/drivers/misc/ocxl/ocxl_internal.h
> > +++ b/drivers/misc/ocxl/ocxl_internal.h
> > @@ -142,4 +142,37 @@ int ocxl_irq_offset_to_id(struct ocxl_context
> > *ctx, u64 offset);
> > u64 ocxl_irq_id_to_offset(struct ocxl_context *ctx, int irq_id);
> > void ocxl_afu_irq_free_all(struct ocxl_context *ctx);
> >
> > +/**
> > + * ocxl_link_add_lpc_mem() - Increment the amount of memory
> > required by an OpenCAPI link
> > + *
> > + * @link_handle: The OpenCAPI link handle
> > + * @offset: The offset of the memory to add
> > + * @size: The amount of memory to increment by
> > + *
> > + * Returns 0 on success, negative on overflow
> > + */
> > +int ocxl_link_add_lpc_mem(void *link_handle, u64 offset, u64
> > size);
> > +
> > +/**
> > + * ocxl_link_lpc_map() - Map the LPC memory for an OpenCAPI device
> > + * Since LPC memory belongs to a link, the whole LPC memory
> > available
> > + * on the link must be mapped in order to make it accessible to a
> > device.
> > + * @link_handle: The OpenCAPI link handle
> > + * @pdev: A device that is on the link
> > + *
> > + * Returns the address of the mapped LPC memory, or 0 on error
> > + */
> > +u64 ocxl_link_lpc_map(void *link_handle, struct pci_dev *pdev);
> > +
> > +/**
> > + * ocxl_link_lpc_release() - Release the LPC memory device for an
> > OpenCAPI device
> > + *
> > + * Offlines LPC memory on an OpenCAPI link for a device. If this
> > is the
> > + * last device on the link to release the memory, unmap it from
> > the link.
> > + *
> > + * @link_handle: The OpenCAPI link handle
> > + * @pdev: A device that is on the link
> > + */
> > +void ocxl_link_lpc_release(void *link_handle, struct pci_dev
> > *pdev);
> > +
> > #endif /* _OCXL_INTERNAL_H_ */
> >
--
Alastair D'Silva
Open Source Developer
Linux Technology Centre, IBM Australia
mob: 0423 762 819