[PATCH v4 07/25] ocxl: Add functions to map/unmap LPC memory

From: Alastair D'Silva
Date: Fri Mar 27 2020 - 03:12:25 EST


Add functions to map/unmap LPC memory

Signed-off-by: Alastair D'Silva <alastair@xxxxxxxxxxx>
Acked-by: Frederic Barrat <fbarrat@xxxxxxxxxxxxx>
---
drivers/misc/ocxl/core.c | 51 +++++++++++++++++++++++++++++++
drivers/misc/ocxl/ocxl_internal.h | 3 ++
include/misc/ocxl.h | 21 +++++++++++++
3 files changed, 75 insertions(+)

diff --git a/drivers/misc/ocxl/core.c b/drivers/misc/ocxl/core.c
index 2531c6cf19a0..75ff14e3882a 100644
--- a/drivers/misc/ocxl/core.c
+++ b/drivers/misc/ocxl/core.c
@@ -210,6 +210,56 @@ static void unmap_mmio_areas(struct ocxl_afu *afu)
release_fn_bar(afu->fn, afu->config.global_mmio_bar);
}

+int ocxl_afu_map_lpc_mem(struct ocxl_afu *afu)
+{
+ struct pci_dev *dev = to_pci_dev(afu->fn->dev.parent);
+
+ if ((afu->config.lpc_mem_size + afu->config.special_purpose_mem_size) == 0)
+ return 0;
+
+ afu->lpc_base_addr = ocxl_link_lpc_map(afu->fn->link, dev);
+ if (afu->lpc_base_addr == 0)
+ return -EINVAL;
+
+ if (afu->config.lpc_mem_size > 0) {
+ afu->lpc_res.start = afu->lpc_base_addr + afu->config.lpc_mem_offset;
+ afu->lpc_res.end = afu->lpc_res.start + afu->config.lpc_mem_size - 1;
+ }
+
+ if (afu->config.special_purpose_mem_size > 0) {
+ afu->special_purpose_res.start = afu->lpc_base_addr +
+ afu->config.special_purpose_mem_offset;
+ afu->special_purpose_res.end = afu->special_purpose_res.start +
+ afu->config.special_purpose_mem_size - 1;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(ocxl_afu_map_lpc_mem);
+
+struct resource *ocxl_afu_lpc_mem(struct ocxl_afu *afu)
+{
+ return &afu->lpc_res;
+}
+EXPORT_SYMBOL_GPL(ocxl_afu_lpc_mem);
+
+static void unmap_lpc_mem(struct ocxl_afu *afu)
+{
+ struct pci_dev *dev = to_pci_dev(afu->fn->dev.parent);
+
+ if (afu->lpc_res.start || afu->special_purpose_res.start) {
+ void *link = afu->fn->link;
+
+ // only release the link when the the last consumer calls release
+ ocxl_link_lpc_release(link, dev);
+
+ afu->lpc_res.start = 0;
+ afu->lpc_res.end = 0;
+ afu->special_purpose_res.start = 0;
+ afu->special_purpose_res.end = 0;
+ }
+}
+
static int configure_afu(struct ocxl_afu *afu, u8 afu_idx, struct pci_dev *dev)
{
int rc;
@@ -251,6 +301,7 @@ static int configure_afu(struct ocxl_afu *afu, u8 afu_idx, struct pci_dev *dev)

static void deconfigure_afu(struct ocxl_afu *afu)
{
+ unmap_lpc_mem(afu);
unmap_mmio_areas(afu);
reclaim_afu_pasid(afu);
reclaim_afu_actag(afu);
diff --git a/drivers/misc/ocxl/ocxl_internal.h b/drivers/misc/ocxl/ocxl_internal.h
index 2d7575225bd7..7b975a89db7b 100644
--- a/drivers/misc/ocxl/ocxl_internal.h
+++ b/drivers/misc/ocxl/ocxl_internal.h
@@ -52,6 +52,9 @@ struct ocxl_afu {
void __iomem *global_mmio_ptr;
u64 pp_mmio_start;
void *private;
+ u64 lpc_base_addr; /* Covers both LPC & special purpose memory */
+ struct resource lpc_res;
+ struct resource special_purpose_res;
};

enum ocxl_context_status {
diff --git a/include/misc/ocxl.h b/include/misc/ocxl.h
index 357ef1aadbc0..d8b0b4d46bfb 100644
--- a/include/misc/ocxl.h
+++ b/include/misc/ocxl.h
@@ -203,6 +203,27 @@ int ocxl_irq_set_handler(struct ocxl_context *ctx, int irq_id,

// AFU Metadata

+/**
+ * ocxl_afu_map_lpc_mem() - Map the LPC system & special purpose memory for an AFU
+ * Do not call this during device discovery, as there may me multiple
+ * devices on a link, and the memory is mapped for the whole link, not
+ * just one device. It should only be called after all devices have
+ * registered their memory on the link.
+ *
+ * @afu: The AFU that has the LPC memory to map
+ *
+ * Returns 0 on success, negative on failure
+ */
+int ocxl_afu_map_lpc_mem(struct ocxl_afu *afu);
+
+/**
+ * ocxl_afu_lpc_mem() - Get the physical address range of LPC memory for an AFU
+ * @afu: The AFU associated with the LPC memory
+ *
+ * Returns a pointer to the resource struct for the physical address range
+ */
+struct resource *ocxl_afu_lpc_mem(struct ocxl_afu *afu);
+
/**
* ocxl_afu_config() - Get a pointer to the config for an AFU
* @afu: a pointer to the AFU to get the config for
--
2.24.1