[PATCH 2/6] thunderbolt: Split common NVM functionality into a separate file

[Mika Westerberg <mika.westerberg@linux.intel.com>]

We are going to reuse some of this functionality to implement retimer
NVM upgrade so move common NVM functionality into its own file. We also
rename the structure from tb_switch_nvm to tb_nvm to make it clear that
it is not just for switches.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/thunderbolt/Makefile |   1 +
 drivers/thunderbolt/domain.c |   2 +-
 drivers/thunderbolt/nvm.c    | 169 +++++++++++++++++++++++++++++++++++
 drivers/thunderbolt/switch.c | 116 +++++-------------------
 drivers/thunderbolt/tb.h     |  31 +++++--
 5 files changed, 220 insertions(+), 99 deletions(-)
 create mode 100644 drivers/thunderbolt/nvm.c

diff --git a/drivers/thunderbolt/Makefile b/drivers/thunderbolt/Makefile
index 68f7a19690d8..7ee257cee7ff 100644
--- a/drivers/thunderbolt/Makefile
+++ b/drivers/thunderbolt/Makefile
@@ -2,5 +2,6 @@
 obj-${CONFIG_USB4} := thunderbolt.o
 thunderbolt-objs := nhi.o nhi_ops.o ctl.o tb.o switch.o cap.o path.o tunnel.o eeprom.o
 thunderbolt-objs += domain.o dma_port.o icm.o property.o xdomain.o lc.o tmu.o usb4.o
+thunderbolt-objs += nvm.o
 
 obj-${CONFIG_USB4_KUNIT_TEST} += test.o
diff --git a/drivers/thunderbolt/domain.c b/drivers/thunderbolt/domain.c
index 68c1b93ac5d9..bba4cbfa9759 100644
--- a/drivers/thunderbolt/domain.c
+++ b/drivers/thunderbolt/domain.c
@@ -812,6 +812,6 @@ void tb_domain_exit(void)
 {
 	bus_unregister(&tb_bus_type);
 	ida_destroy(&tb_domain_ida);
-	tb_switch_exit();
+	tb_nvm_exit();
 	tb_xdomain_exit();
 }
diff --git a/drivers/thunderbolt/nvm.c b/drivers/thunderbolt/nvm.c
new file mode 100644
index 000000000000..4c6aa06ab3d5
--- /dev/null
+++ b/drivers/thunderbolt/nvm.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NVM helpers
+ *
+ * Copyright (C) 2020, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
+ */
+
+#include <linux/idr.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#include "tb.h"
+
+static DEFINE_IDA(nvm_ida);
+
+/**
+ * tb_nvm_alloc() - Allocate new NVM structure
+ * @dev: Device owning the NVM
+ *
+ * Allocates new NVM structure with unique @id and returns it. In case
+ * of error returns ERR_PTR().
+ */
+struct tb_nvm *tb_nvm_alloc(struct device *dev)
+{
+	struct tb_nvm *nvm;
+	int ret;
+
+	nvm = kzalloc(sizeof(*nvm), GFP_KERNEL);
+	if (!nvm)
+		return ERR_PTR(-ENOMEM);
+
+	ret = ida_simple_get(&nvm_ida, 0, 0, GFP_KERNEL);
+	if (ret < 0) {
+		kfree(nvm);
+		return ERR_PTR(ret);
+	}
+
+	nvm->id = ret;
+	nvm->dev = dev;
+
+	return nvm;
+}
+
+/**
+ * tb_nvm_add_active() - Adds active NVMem device to NVM
+ * @nvm: NVM structure
+ * @size: Size of the active NVM in bytes
+ * @reg_read: Pointer to the function to read the NVM (passed directly to the
+ *	      NVMem device)
+ *
+ * Registers new active NVmem device for @nvm. The @reg_read is called
+ * directly from NVMem so it must handle possible concurrent access if
+ * needed. The first parameter passed to @reg_read is @nvm structure.
+ * Returns %0 in success and negative errno otherwise.
+ */
+int tb_nvm_add_active(struct tb_nvm *nvm, size_t size, nvmem_reg_read_t reg_read)
+{
+	struct nvmem_config config;
+	struct nvmem_device *nvmem;
+
+	memset(&config, 0, sizeof(config));
+
+	config.name = "nvm_active";
+	config.reg_read = reg_read;
+	config.read_only = true;
+	config.id = nvm->id;
+	config.stride = 4;
+	config.word_size = 4;
+	config.size = size;
+	config.dev = nvm->dev;
+	config.owner = THIS_MODULE;
+	config.priv = nvm;
+
+	nvmem = nvmem_register(&config);
+	if (IS_ERR(nvmem))
+		return PTR_ERR(nvmem);
+
+	nvm->active = nvmem;
+	return 0;
+}
+
+/**
+ * tb_nvm_write_buf() - Write data to @nvm buffer
+ * @nvm: NVM structure
+ * @offset: Offset where to write the data
+ * @val: Data buffer to write
+ * @bytes: Number of bytes to write
+ *
+ * Helper function to cache the new NVM image before it is actually
+ * written to the flash. Copies @bytes from @val to @nvm->buf starting
+ * from @offset.
+ */
+int tb_nvm_write_buf(struct tb_nvm *nvm, unsigned int offset, void *val,
+		     size_t bytes)
+{
+	if (!nvm->buf) {
+		nvm->buf = vmalloc(NVM_MAX_SIZE);
+		if (!nvm->buf)
+			return -ENOMEM;
+	}
+
+	nvm->buf_data_size = offset + bytes;
+	memcpy(nvm->buf + offset, val, bytes);
+	return 0;
+}
+
+/**
+ * tb_nvm_add_non_active() - Adds non-active NVMem device to NVM
+ * @nvm: NVM structure
+ * @size: Size of the non-active NVM in bytes
+ * @reg_write: Pointer to the function to write the NVM (passed directly
+ *	       to the NVMem device)
+ *
+ * Registers new non-active NVmem device for @nvm. The @reg_write is called
+ * directly from NVMem so it must handle possible concurrent access if
+ * needed. The first parameter passed to @reg_write is @nvm structure.
+ * Returns %0 in success and negative errno otherwise.
+ */
+int tb_nvm_add_non_active(struct tb_nvm *nvm, size_t size,
+			  nvmem_reg_write_t reg_write)
+{
+	struct nvmem_config config;
+	struct nvmem_device *nvmem;
+
+	memset(&config, 0, sizeof(config));
+
+	config.name = "nvm_non_active";
+	config.reg_write = reg_write;
+	config.root_only = true;
+	config.id = nvm->id;
+	config.stride = 4;
+	config.word_size = 4;
+	config.size = size;
+	config.dev = nvm->dev;
+	config.owner = THIS_MODULE;
+	config.priv = nvm;
+
+	nvmem = nvmem_register(&config);
+	if (IS_ERR(nvmem))
+		return PTR_ERR(nvmem);
+
+	nvm->non_active = nvmem;
+	return 0;
+}
+
+/**
+ * tb_nvm_free() - Release NVM and its resources
+ * @nvm: NVM structure to release
+ *
+ * Releases NVM and the NVMem devices if they were registered.
+ */
+void tb_nvm_free(struct tb_nvm *nvm)
+{
+	if (nvm) {
+		if (nvm->non_active)
+			nvmem_unregister(nvm->non_active);
+		if (nvm->active)
+			nvmem_unregister(nvm->active);
+		vfree(nvm->buf);
+		ida_simple_remove(&nvm_ida, nvm->id);
+	}
+	kfree(nvm);
+}
+
+void tb_nvm_exit(void)
+{
+	ida_destroy(&nvm_ida);
+}
diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index 6659b2b0663d..c8ed614f14e6 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -13,21 +13,12 @@
 #include <linux/sched/signal.h>
 #include <linux/sizes.h>
 #include <linux/slab.h>
-#include <linux/vmalloc.h>
 
 #include "tb.h"
 
 /* Switch NVM support */
 
-#define NVM_DEVID		0x05
-#define NVM_VERSION		0x08
 #define NVM_CSS			0x10
-#define NVM_FLASH_SIZE		0x45
-
-#define NVM_MIN_SIZE		SZ_32K
-#define NVM_MAX_SIZE		SZ_512K
-
-static DEFINE_IDA(nvm_ida);
 
 struct nvm_auth_status {
 	struct list_head list;
@@ -328,7 +319,8 @@ static int nvm_authenticate(struct tb_switch *sw)
 static int tb_switch_nvm_read(void *priv, unsigned int offset, void *val,
 			      size_t bytes)
 {
-	struct tb_switch *sw = priv;
+	struct tb_nvm *nvm = priv;
+	struct tb_switch *sw = tb_to_switch(nvm->dev);
 	int ret;
 
 	pm_runtime_get_sync(&sw->dev);
@@ -351,8 +343,9 @@ static int tb_switch_nvm_read(void *priv, unsigned int offset, void *val,
 static int tb_switch_nvm_write(void *priv, unsigned int offset, void *val,
 			       size_t bytes)
 {
-	struct tb_switch *sw = priv;
-	int ret = 0;
+	struct tb_nvm *nvm = priv;
+	struct tb_switch *sw = tb_to_switch(nvm->dev);
+	int ret;
 
 	if (!mutex_trylock(&sw->tb->lock))
 		return restart_syscall();
@@ -363,55 +356,15 @@ static int tb_switch_nvm_write(void *priv, unsigned int offset, void *val,
 	 * locally here and handle the special cases when the user asks
 	 * us to authenticate the image.
 	 */
-	if (!sw->nvm->buf) {
-		sw->nvm->buf = vmalloc(NVM_MAX_SIZE);
-		if (!sw->nvm->buf) {
-			ret = -ENOMEM;
-			goto unlock;
-		}
-	}
-
-	sw->nvm->buf_data_size = offset + bytes;
-	memcpy(sw->nvm->buf + offset, val, bytes);
-
-unlock:
+	ret = tb_nvm_write_buf(nvm, offset, val, bytes);
 	mutex_unlock(&sw->tb->lock);
 
 	return ret;
 }
 
-static struct nvmem_device *register_nvmem(struct tb_switch *sw, int id,
-					   size_t size, bool active)
-{
-	struct nvmem_config config;
-
-	memset(&config, 0, sizeof(config));
-
-	if (active) {
-		config.name = "nvm_active";
-		config.reg_read = tb_switch_nvm_read;
-		config.read_only = true;
-	} else {
-		config.name = "nvm_non_active";
-		config.reg_write = tb_switch_nvm_write;
-		config.root_only = true;
-	}
-
-	config.id = id;
-	config.stride = 4;
-	config.word_size = 4;
-	config.size = size;
-	config.dev = &sw->dev;
-	config.owner = THIS_MODULE;
-	config.priv = sw;
-
-	return nvmem_register(&config);
-}
-
 static int tb_switch_nvm_add(struct tb_switch *sw)
 {
-	struct nvmem_device *nvm_dev;
-	struct tb_switch_nvm *nvm;
+	struct tb_nvm *nvm;
 	u32 val;
 	int ret;
 
@@ -431,11 +384,9 @@ static int tb_switch_nvm_add(struct tb_switch *sw)
 		return 0;
 	}
 
-	nvm = kzalloc(sizeof(*nvm), GFP_KERNEL);
-	if (!nvm)
-		return -ENOMEM;
-
-	nvm->id = ida_simple_get(&nvm_ida, 0, 0, GFP_KERNEL);
+	nvm = tb_nvm_alloc(&sw->dev);
+	if (IS_ERR(nvm))
+		return PTR_ERR(nvm);
 
 	/*
 	 * If the switch is in safe-mode the only accessible portion of
@@ -447,7 +398,7 @@ static int tb_switch_nvm_add(struct tb_switch *sw)
 
 		ret = nvm_read(sw, NVM_FLASH_SIZE, &val, sizeof(val));
 		if (ret)
-			goto err_ida;
+			goto err_nvm;
 
 		hdr_size = sw->generation < 3 ? SZ_8K : SZ_16K;
 		nvm_size = (SZ_1M << (val & 7)) / 8;
@@ -455,44 +406,34 @@ static int tb_switch_nvm_add(struct tb_switch *sw)
 
 		ret = nvm_read(sw, NVM_VERSION, &val, sizeof(val));
 		if (ret)
-			goto err_ida;
+			goto err_nvm;
 
 		nvm->major = val >> 16;
 		nvm->minor = val >> 8;
 
-		nvm_dev = register_nvmem(sw, nvm->id, nvm_size, true);
-		if (IS_ERR(nvm_dev)) {
-			ret = PTR_ERR(nvm_dev);
-			goto err_ida;
-		}
-		nvm->active = nvm_dev;
+		ret = tb_nvm_add_active(nvm, nvm_size, tb_switch_nvm_read);
+		if (ret)
+			goto err_nvm;
 	}
 
 	if (!sw->no_nvm_upgrade) {
-		nvm_dev = register_nvmem(sw, nvm->id, NVM_MAX_SIZE, false);
-		if (IS_ERR(nvm_dev)) {
-			ret = PTR_ERR(nvm_dev);
-			goto err_nvm_active;
-		}
-		nvm->non_active = nvm_dev;
+		ret = tb_nvm_add_non_active(nvm, NVM_MAX_SIZE,
+					    tb_switch_nvm_write);
+		if (ret)
+			goto err_nvm;
 	}
 
 	sw->nvm = nvm;
 	return 0;
 
-err_nvm_active:
-	if (nvm->active)
-		nvmem_unregister(nvm->active);
-err_ida:
-	ida_simple_remove(&nvm_ida, nvm->id);
-	kfree(nvm);
-
+err_nvm:
+	tb_nvm_free(nvm);
 	return ret;
 }
 
 static void tb_switch_nvm_remove(struct tb_switch *sw)
 {
-	struct tb_switch_nvm *nvm;
+	struct tb_nvm *nvm;
 
 	nvm = sw->nvm;
 	sw->nvm = NULL;
@@ -504,13 +445,7 @@ static void tb_switch_nvm_remove(struct tb_switch *sw)
 	if (!nvm->authenticating)
 		nvm_clear_auth_status(sw);
 
-	if (nvm->non_active)
-		nvmem_unregister(nvm->non_active);
-	if (nvm->active)
-		nvmem_unregister(nvm->active);
-	ida_simple_remove(&nvm_ida, nvm->id);
-	vfree(nvm->buf);
-	kfree(nvm);
+	tb_nvm_free(nvm);
 }
 
 /* port utility functions */
@@ -2772,8 +2707,3 @@ struct tb_port *tb_switch_find_port(struct tb_switch *sw,
 
 	return NULL;
 }
-
-void tb_switch_exit(void)
-{
-	ida_destroy(&nvm_ida);
-}
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index a62db231f07b..3d54f36f8805 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -18,8 +18,17 @@
 #include "ctl.h"
 #include "dma_port.h"
 
+#define NVM_MIN_SIZE		SZ_32K
+#define NVM_MAX_SIZE		SZ_512K
+
+/* Intel specific NVM offsets */
+#define NVM_DEVID		0x05
+#define NVM_VERSION		0x08
+#define NVM_FLASH_SIZE		0x45
+
 /**
- * struct tb_switch_nvm - Structure holding switch NVM information
+ * struct tb_nvm - Structure holding NVM information
+ * @dev: Owner of the NVM
  * @major: Major version number of the active NVM portion
  * @minor: Minor version number of the active NVM portion
  * @id: Identifier used with both NVM portions
@@ -29,9 +38,13 @@
  *	 the actual NVM flash device
  * @buf_data_size: Number of bytes actually consumed by the new NVM
  *		   image
- * @authenticating: The switch is authenticating the new NVM
+ * @authenticating: The device is authenticating the new NVM
+ *
+ * The user of this structure needs to handle serialization of possible
+ * concurrent access.
  */
-struct tb_switch_nvm {
+struct tb_nvm {
+	struct device *dev;
 	u8 major;
 	u8 minor;
 	int id;
@@ -143,7 +156,7 @@ struct tb_switch {
 	int cap_lc;
 	bool is_unplugged;
 	u8 *drom;
-	struct tb_switch_nvm *nvm;
+	struct tb_nvm *nvm;
 	bool no_nvm_upgrade;
 	bool safe_mode;
 	bool boot;
@@ -544,7 +557,6 @@ extern struct device_type tb_switch_type;
 
 int tb_domain_init(void);
 void tb_domain_exit(void);
-void tb_switch_exit(void);
 int tb_xdomain_init(void);
 void tb_xdomain_exit(void);
 
@@ -577,6 +589,15 @@ static inline void tb_domain_put(struct tb *tb)
 	put_device(&tb->dev);
 }
 
+struct tb_nvm *tb_nvm_alloc(struct device *dev);
+int tb_nvm_add_active(struct tb_nvm *nvm, size_t size, nvmem_reg_read_t reg_read);
+int tb_nvm_write_buf(struct tb_nvm *nvm, unsigned int offset, void *val,
+		     size_t bytes);
+int tb_nvm_add_non_active(struct tb_nvm *nvm, size_t size,
+			  nvmem_reg_write_t reg_write);
+void tb_nvm_free(struct tb_nvm *nvm);
+void tb_nvm_exit(void);
+
 struct tb_switch *tb_switch_alloc(struct tb *tb, struct device *parent,
 				  u64 route);
 struct tb_switch *tb_switch_alloc_safe_mode(struct tb *tb,
-- 
2.27.0.rc2