This is a note to let you know that I've just added the patch titled
cxl/mbox: Introduce the mbox_send operation
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cxl-mbox-introduce-the-mbox_send-operation.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 95450736c43196f26156fd19c4304c558fc7cc04
Author: Dan Williams <dan.j.williams@xxxxxxxxx>
Date: Wed Sep 8 22:12:21 2021 -0700
cxl/mbox: Introduce the mbox_send operation
[ Upstream commit b64955a92929346f16df058ad2bb53630eb80466 ]
In preparation for implementing a unit test backend transport for ioctl
operations, and making the mailbox available to the cxl/pmem
infrastructure, move the existing PCI specific portion of mailbox handling
to an "mbox_send" operation.
With this split all the PCI-specific transport details are comprehended
by a single operation and the rest of the mailbox infrastructure is
'struct cxl_mem' and 'struct cxl_memdev' generic.
Acked-by: Ben Widawsky <ben.widawsky@xxxxxxxxx>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Reviewed-by: Ben Widawsky <ben.widawsky@xxxxxxxxx>
Link: https://lore.kernel.org/r/163116434098.2460985.9004760022659400540.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Stable-dep-of: 88d3917f82ed ("cxl/mem: Fix shutdown order")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index e14bcd7a1ba14..c142532db8cb6 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -66,6 +66,45 @@ struct cxl_memdev *
devm_cxl_add_memdev(struct cxl_mem *cxlm,
const struct cdevm_file_operations *cdevm_fops);
+/**
+ * struct cxl_mbox_cmd - A command to be submitted to hardware.
+ * @opcode: (input) The command set and command submitted to hardware.
+ * @payload_in: (input) Pointer to the input payload.
+ * @payload_out: (output) Pointer to the output payload. Must be allocated by
+ * the caller.
+ * @size_in: (input) Number of bytes to load from @payload_in.
+ * @size_out: (input) Max number of bytes loaded into @payload_out.
+ * (output) Number of bytes generated by the device. For fixed size
+ * outputs commands this is always expected to be deterministic. For
+ * variable sized output commands, it tells the exact number of bytes
+ * written.
+ * @return_code: (output) Error code returned from hardware.
+ *
+ * This is the primary mechanism used to send commands to the hardware.
+ * All the fields except @payload_* correspond exactly to the fields described in
+ * Command Register section of the CXL 2.0 8.2.8.4.5. @payload_in and
+ * @payload_out are written to, and read from the Command Payload Registers
+ * defined in CXL 2.0 8.2.8.4.8.
+ */
+struct cxl_mbox_cmd {
+ u16 opcode;
+ void *payload_in;
+ void *payload_out;
+ size_t size_in;
+ size_t size_out;
+ u16 return_code;
+#define CXL_MBOX_SUCCESS 0
+};
+
+/*
+ * CXL 2.0 - Memory capacity multiplier
+ * See Section 8.2.9.5
+ *
+ * Volatile, Persistent, and Partition capacities are specified to be in
+ * multiples of 256MB - define a multiplier to convert to/from bytes.
+ */
+#define CXL_CAPACITY_MULTIPLIER SZ_256M
+
/**
* struct cxl_mem - A CXL memory device
* @dev: The device associated with this CXL device.
@@ -88,6 +127,7 @@ devm_cxl_add_memdev(struct cxl_mem *cxlm,
* @active_persistent_bytes: sum of hard + soft persistent
* @next_volatile_bytes: volatile capacity change pending device reset
* @next_persistent_bytes: persistent capacity change pending device reset
+ * @mbox_send: @dev specific transport for transmitting mailbox commands
*
* See section 8.2.9.5.2 Capacity Configuration and Label Storage for
* details on capacity parameters.
@@ -115,5 +155,7 @@ struct cxl_mem {
u64 active_persistent_bytes;
u64 next_volatile_bytes;
u64 next_persistent_bytes;
+
+ int (*mbox_send)(struct cxl_mem *cxlm, struct cxl_mbox_cmd *cmd);
};
#endif /* __CXL_MEM_H__ */
diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index a242bcd950800..e6cf607448bfe 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -64,45 +64,6 @@ enum opcode {
CXL_MBOX_OP_MAX = 0x10000
};
-/*
- * CXL 2.0 - Memory capacity multiplier
- * See Section 8.2.9.5
- *
- * Volatile, Persistent, and Partition capacities are specified to be in
- * multiples of 256MB - define a multiplier to convert to/from bytes.
- */
-#define CXL_CAPACITY_MULTIPLIER SZ_256M
-
-/**
- * struct mbox_cmd - A command to be submitted to hardware.
- * @opcode: (input) The command set and command submitted to hardware.
- * @payload_in: (input) Pointer to the input payload.
- * @payload_out: (output) Pointer to the output payload. Must be allocated by
- * the caller.
- * @size_in: (input) Number of bytes to load from @payload_in.
- * @size_out: (input) Max number of bytes loaded into @payload_out.
- * (output) Number of bytes generated by the device. For fixed size
- * outputs commands this is always expected to be deterministic. For
- * variable sized output commands, it tells the exact number of bytes
- * written.
- * @return_code: (output) Error code returned from hardware.
- *
- * This is the primary mechanism used to send commands to the hardware.
- * All the fields except @payload_* correspond exactly to the fields described in
- * Command Register section of the CXL 2.0 8.2.8.4.5. @payload_in and
- * @payload_out are written to, and read from the Command Payload Registers
- * defined in CXL 2.0 8.2.8.4.8.
- */
-struct mbox_cmd {
- u16 opcode;
- void *payload_in;
- void *payload_out;
- size_t size_in;
- size_t size_out;
- u16 return_code;
-#define CXL_MBOX_SUCCESS 0
-};
-
static DECLARE_RWSEM(cxl_memdev_rwsem);
static struct dentry *cxl_debugfs;
static bool cxl_raw_allow_all;
@@ -266,7 +227,7 @@ static bool cxl_is_security_command(u16 opcode)
}
static void cxl_mem_mbox_timeout(struct cxl_mem *cxlm,
- struct mbox_cmd *mbox_cmd)
+ struct cxl_mbox_cmd *mbox_cmd)
{
struct device *dev = cxlm->dev;
@@ -297,7 +258,7 @@ static void cxl_mem_mbox_timeout(struct cxl_mem *cxlm,
* mailbox.
*/
static int __cxl_mem_mbox_send_cmd(struct cxl_mem *cxlm,
- struct mbox_cmd *mbox_cmd)
+ struct cxl_mbox_cmd *mbox_cmd)
{
void __iomem *payload = cxlm->regs.mbox + CXLDEV_MBOX_PAYLOAD_OFFSET;
struct device *dev = cxlm->dev;
@@ -472,6 +433,20 @@ static void cxl_mem_mbox_put(struct cxl_mem *cxlm)
mutex_unlock(&cxlm->mbox_mutex);
}
+static int cxl_pci_mbox_send(struct cxl_mem *cxlm, struct cxl_mbox_cmd *cmd)
+{
+ int rc;
+
+ rc = cxl_mem_mbox_get(cxlm);
+ if (rc)
+ return rc;
+
+ rc = __cxl_mem_mbox_send_cmd(cxlm, cmd);
+ cxl_mem_mbox_put(cxlm);
+
+ return rc;
+}
+
/**
* handle_mailbox_cmd_from_user() - Dispatch a mailbox command for userspace.
* @cxlm: The CXL memory device to communicate with.
@@ -503,7 +478,7 @@ static int handle_mailbox_cmd_from_user(struct cxl_mem *cxlm,
s32 *size_out, u32 *retval)
{
struct device *dev = cxlm->dev;
- struct mbox_cmd mbox_cmd = {
+ struct cxl_mbox_cmd mbox_cmd = {
.opcode = cmd->opcode,
.size_in = cmd->info.size_in,
.size_out = cmd->info.size_out,
@@ -525,10 +500,6 @@ static int handle_mailbox_cmd_from_user(struct cxl_mem *cxlm,
}
}
- rc = cxl_mem_mbox_get(cxlm);
- if (rc)
- goto out;
-
dev_dbg(dev,
"Submitting %s command for user\n"
"\topcode: %x\n"
@@ -539,8 +510,7 @@ static int handle_mailbox_cmd_from_user(struct cxl_mem *cxlm,
dev_WARN_ONCE(dev, cmd->info.id == CXL_MEM_COMMAND_ID_RAW,
"raw command path used\n");
- rc = __cxl_mem_mbox_send_cmd(cxlm, &mbox_cmd);
- cxl_mem_mbox_put(cxlm);
+ rc = cxlm->mbox_send(cxlm, &mbox_cmd);
if (rc)
goto out;
@@ -874,7 +844,7 @@ static int cxl_mem_mbox_send_cmd(struct cxl_mem *cxlm, u16 opcode,
void *out, size_t out_size)
{
const struct cxl_mem_command *cmd = cxl_mem_find_command(opcode);
- struct mbox_cmd mbox_cmd = {
+ struct cxl_mbox_cmd mbox_cmd = {
.opcode = opcode,
.payload_in = in,
.size_in = in_size,
@@ -886,12 +856,7 @@ static int cxl_mem_mbox_send_cmd(struct cxl_mem *cxlm, u16 opcode,
if (out_size > cxlm->payload_size)
return -E2BIG;
- rc = cxl_mem_mbox_get(cxlm);
- if (rc)
- return rc;
-
- rc = __cxl_mem_mbox_send_cmd(cxlm, &mbox_cmd);
- cxl_mem_mbox_put(cxlm);
+ rc = cxlm->mbox_send(cxlm, &mbox_cmd);
if (rc)
return rc;
@@ -913,6 +878,7 @@ static int cxl_mem_setup_mailbox(struct cxl_mem *cxlm)
{
const int cap = readl(cxlm->regs.mbox + CXLDEV_MBOX_CAPS_OFFSET);
+ cxlm->mbox_send = cxl_pci_mbox_send;
cxlm->payload_size =
1 << FIELD_GET(CXLDEV_MBOX_CAP_PAYLOAD_SIZE_MASK, cap);
