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From:   "Alastair D'Silva" <alastair@au1.ibm.com>
To:     alastair@d-silva.org
Cc:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Frederic Barrat <fbarrat@linux.ibm.com>,
        Andrew Donnellan <ajd@linux.ibm.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= <clg@kaod.org>,
        Allison Randal <allison@lohutok.net>,
        Vaibhav Jain <vaibhav@linux.ibm.com>,
        Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>,
        Anju T Sudhakar <anju@linux.vnet.ibm.com>,
        David Gibson <david@gibson.dropbear.id.au>,
        Nicholas Piggin <npiggin@gmail.com>,
        Masahiro Yamada <yamada.masahiro@socionext.com>,
        linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: [PATCH 4/5] ocxl: Add functions to map/unmap LPC memory
Date:   Tue, 17 Sep 2019 11:43:00 +1000
In-Reply-To: <20190917014307.30485-1-alastair@au1.ibm.com>
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Message-Id: <20190917014307.30485-5-alastair@au1.ibm.com>
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From: Alastair D'Silva <alastair@d-silva.org>

Add functions to map/unmap LPC memory

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
---
 drivers/misc/ocxl/config.c        |  4 +++
 drivers/misc/ocxl/core.c          | 50 +++++++++++++++++++++++++++++++
 drivers/misc/ocxl/link.c          |  4 +--
 drivers/misc/ocxl/ocxl_internal.h | 10 +++++--
 include/misc/ocxl.h               | 18 +++++++++++
 5 files changed, 82 insertions(+), 4 deletions(-)

diff --git a/drivers/misc/ocxl/config.c b/drivers/misc/ocxl/config.c
index c8e19bfb5ef9..fb0c3b6f8312 100644
--- a/drivers/misc/ocxl/config.c
+++ b/drivers/misc/ocxl/config.c
@@ -568,6 +568,10 @@ static int read_afu_lpc_memory_info(struct pci_dev *dev,
 		afu->special_purpose_mem_size =
 			total_mem_size - lpc_mem_size;
 	}
+
+	dev_info(&dev->dev, "Probed LPC memory of %#llx bytes and special purpose memory of %#llx bytes\n",
+		afu->lpc_mem_size, afu->special_purpose_mem_size);
+
 	return 0;
 }
 
diff --git a/drivers/misc/ocxl/core.c b/drivers/misc/ocxl/core.c
index fdfe4e0a34e1..eb24bb9d655f 100644
--- a/drivers/misc/ocxl/core.c
+++ b/drivers/misc/ocxl/core.c
@@ -210,6 +210,55 @@ static void unmap_mmio_areas(struct ocxl_afu *afu)
 	release_fn_bar(afu->fn, afu->config.global_mmio_bar);
 }
 
+int ocxl_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_online(afu->fn->link, dev);
+	if (afu->lpc_base_addr == 0)
+		return -EINVAL;
+
+	if (afu->config.lpc_mem_size) {
+		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) {
+		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(ocxl_map_lpc_mem);
+
+struct resource *ocxl_afu_lpc_mem(struct ocxl_afu *afu)
+{
+	return &afu->lpc_res;
+}
+EXPORT_SYMBOL(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;
+
+		ocxl_link_lpc_offline(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;
@@ -250,6 +299,7 @@ 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/link.c b/drivers/misc/ocxl/link.c
index 2874811a4398..9e303a5f4d85 100644
--- a/drivers/misc/ocxl/link.c
+++ b/drivers/misc/ocxl/link.c
@@ -738,7 +738,7 @@ int ocxl_link_add_lpc_mem(void *link_handle, u64 size)
 }
 EXPORT_SYMBOL_GPL(ocxl_link_add_lpc_mem);
 
-u64 ocxl_link_lpc_map(void *link_handle, struct pci_dev *pdev)
+u64 ocxl_link_lpc_online(void *link_handle, struct pci_dev *pdev)
 {
 	struct ocxl_link *link = (struct ocxl_link *) link_handle;
 
@@ -759,7 +759,7 @@ u64 ocxl_link_lpc_map(void *link_handle, struct pci_dev *pdev)
 	return link->lpc_mem;
 }
 
-void ocxl_link_lpc_release(void *link_handle, struct pci_dev *pdev)
+void ocxl_link_lpc_offline(void *link_handle, struct pci_dev *pdev)
 {
 	struct ocxl_link *link = (struct ocxl_link *) link_handle;
 
diff --git a/drivers/misc/ocxl/ocxl_internal.h b/drivers/misc/ocxl/ocxl_internal.h
index db2647a90fc8..5656a4aab5b7 100644
--- a/drivers/misc/ocxl/ocxl_internal.h
+++ b/drivers/misc/ocxl/ocxl_internal.h
@@ -52,6 +52,12 @@ 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 bin_attribute attr_global_mmio;
+	struct bin_attribute attr_lpc_mem;
+	struct resource lpc_res;
+	struct bin_attribute attr_special_purpose_mem;
+	struct resource special_purpose_res;
 };
 
 enum ocxl_context_status {
@@ -170,7 +176,7 @@ extern u64 ocxl_link_get_lpc_mem_sz(void *link_handle);
  * @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);
+u64 ocxl_link_lpc_online(void *link_handle, struct pci_dev *pdev);
 
 /**
  * Release the LPC memory device for an OpenCAPI device
@@ -181,6 +187,6 @@ u64 ocxl_link_lpc_map(void *link_handle, struct pci_dev *pdev);
  * @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);
+void ocxl_link_lpc_offline(void *link_handle, struct pci_dev *pdev);
 
 #endif /* _OCXL_INTERNAL_H_ */
diff --git a/include/misc/ocxl.h b/include/misc/ocxl.h
index 06dd5839e438..a1897737908d 100644
--- a/include/misc/ocxl.h
+++ b/include/misc/ocxl.h
@@ -212,6 +212,24 @@ int ocxl_irq_set_handler(struct ocxl_context *ctx, int irq_id,
 
 // AFU Metadata
 
+/**
+ * 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
+ */
+extern int ocxl_map_lpc_mem(struct ocxl_afu *afu);
+
+/**
+ * Get the physical address range of LPC memory for an AFU
+ * afu: The AFU associated with the LPC memory
+ */
+extern struct resource *ocxl_afu_lpc_mem(struct ocxl_afu *afu);
+
 /**
  * Get a pointer to the config for an AFU
  *
-- 
2.21.0