[PATCH v2 06/27] ocxl: Tally up the LPC memory on a link & allow it to be mapped

Alastair D'Silva
2019-12-03T03:49:59Z

From: Alastair D'Silva <alastair@d-silva.org>

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

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
---
drivers/misc/ocxl/core.c | 10 ++++++
drivers/misc/ocxl/link.c | 60 +++++++++++++++++++++++++++++++
drivers/misc/ocxl/ocxl_internal.h | 33 +++++++++++++++++
3 files changed, 103 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..d8503f0dc6ec 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;
+ 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 +718,56 @@ 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;
+ u64 lpc_mem;
+
+ mutex_lock(&link->lpc_mem_lock);
+ if (link->lpc_mem) {
+ lpc_mem = link->lpc_mem;
+
+ link->lpc_consumers++;
+ mutex_unlock(&link->lpc_mem_lock);
+ return lpc_mem;
+ }
+
+ link->lpc_mem = pnv_ocxl_platform_lpc_setup(pdev, link->lpc_mem_sz);
+ if (link->lpc_mem)
+ link->lpc_consumers++;
+ lpc_mem = link->lpc_mem;
+ mutex_unlock(&link->lpc_mem_lock);
+
+ return 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 97415afd79f3..20b417e00949 100644
--- a/drivers/misc/ocxl/ocxl_internal.h
+++ b/drivers/misc/ocxl/ocxl_internal.h
@@ -141,4 +141,37 @@ 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
+ *
+ * Return 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 bust 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
+ */
+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_ */
--
2.23.0