[PATCH v2 13/27] nvdimm/ocxl: Add support for Admin commands

Alastair D'Silva
2019-12-03T03:48:41Z

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

This patch requests the metadata required to issue admin commands, as well
as some helper functions to construct and check the completion of the
commands.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
---
drivers/nvdimm/ocxl/scm.c | 67 +++++++++++++
drivers/nvdimm/ocxl/scm_internal.c | 152 +++++++++++++++++++++++++++++
drivers/nvdimm/ocxl/scm_internal.h | 62 ++++++++++++
3 files changed, 281 insertions(+)

diff --git a/drivers/nvdimm/ocxl/scm.c b/drivers/nvdimm/ocxl/scm.c
index 8088f65c289e..1e175f3c3cf2 100644
--- a/drivers/nvdimm/ocxl/scm.c
+++ b/drivers/nvdimm/ocxl/scm.c
@@ -267,6 +267,58 @@ static int scm_register_lpc_mem(struct scm_data *scm_data)
return 0;
}

+/**
+ * scm_extract_command_metadata() - Extract command data from MMIO & save it for further use
+ * @scm_data: a pointer to the SCM device data
+ * @offset: The base address of the command data structures (address of CREQO)
+ * @command_metadata: A pointer to the command metadata to populate
+ * Return: 0 on success, negative on failure
+ */
+static int scm_extract_command_metadata(struct scm_data *scm_data, u32 offset,
+ struct command_metadata *command_metadata)
+{
+ int rc;
+ u64 tmp;
+
+ rc = ocxl_global_mmio_read64(scm_data->ocxl_afu, offset, OCXL_LITTLE_ENDIAN,
+ &tmp);
+ if (rc)
+ return rc;
+
+ command_metadata->request_offset = tmp >> 32;
+ command_metadata->response_offset = tmp & 0xFFFFFFFF;
+
+ rc = ocxl_global_mmio_read64(scm_data->ocxl_afu, offset + 8, OCXL_LITTLE_ENDIAN,
+ &tmp);
+ if (rc)
+ return rc;
+
+ command_metadata->data_offset = tmp >> 32;
+ command_metadata->data_size = tmp & 0xFFFFFFFF;
+
+ command_metadata->id = 0;
+
+ return 0;
+}
+
+/**
+ * scm_setup_command_metadata() - Set up the command metadata
+ * @scm_data: a pointer to the SCM device data
+ */
+static int scm_setup_command_metadata(struct scm_data *scm_data)
+{
+ int rc;
+
+ mutex_init(&scm_data->admin_command.lock);
+
+ rc = scm_extract_command_metadata(scm_data, GLOBAL_MMIO_ACMA_CREQO,
+ &scm_data->admin_command);
+ if (rc)
+ return rc;
+
+ return 0;
+}
+
/**
* scm_is_usable() - Is a controller usable?
* @scm_data: a pointer to the SCM device data
@@ -276,6 +328,8 @@ static bool scm_is_usable(const struct scm_data *scm_data)
{
u64 chi = 0;
int rc = scm_chi(scm_data, &chi);
+ if (rc)
+ return false;

if (!(chi & GLOBAL_MMIO_CHI_CRDY)) {
dev_err(&scm_data->dev, "SCM controller is not ready.\n");
@@ -502,6 +556,14 @@ static int scm_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
}
scm_data->pdev = pdev;

+ scm_data->timeouts[ADMIN_COMMAND_ERRLOG] = 2000; // ms
+ scm_data->timeouts[ADMIN_COMMAND_HEARTBEAT] = 100; // ms
+ scm_data->timeouts[ADMIN_COMMAND_SMART] = 100; // ms
+ scm_data->timeouts[ADMIN_COMMAND_CONTROLLER_DUMP] = 1000; // ms
+ scm_data->timeouts[ADMIN_COMMAND_CONTROLLER_STATS] = 100; // ms
+ scm_data->timeouts[ADMIN_COMMAND_SHUTDOWN] = 1000; // ms
+ scm_data->timeouts[ADMIN_COMMAND_FW_UPDATE] = 16000; // ms
+
pci_set_drvdata(pdev, scm_data);

scm_data->ocxl_fn = ocxl_function_open(pdev);
@@ -543,6 +605,11 @@ static int scm_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
goto err;
}

+ if (scm_setup_command_metadata(scm_data)) {
+ dev_err(&pdev->dev, "Could not read OCXL command matada\n");
+ goto err;
+ }
+
elapsed = 0;
timeout = scm_data->readiness_timeout + scm_data->memory_available_timeout;
while (!scm_is_usable(scm_data)) {
diff --git a/drivers/nvdimm/ocxl/scm_internal.c b/drivers/nvdimm/ocxl/scm_internal.c
index 72d3c0e7d846..7b11b56863fb 100644
--- a/drivers/nvdimm/ocxl/scm_internal.c
+++ b/drivers/nvdimm/ocxl/scm_internal.c
@@ -17,3 +17,155 @@ int scm_chi(const struct scm_data *scm_data, u64 *chi)

return 0;
}
+
+static int scm_command_request(const struct scm_data *scm_data,
+ struct command_metadata *cmd, u8 op_code)
+{
+ u64 val = op_code;
+ int rc;
+ u8 i;
+
+ cmd->op_code = op_code;
+ cmd->id++;
+
+ val |= ((u64)cmd->id) << 16;
+
+ rc = ocxl_global_mmio_write64(scm_data->ocxl_afu, cmd->request_offset,
+ OCXL_LITTLE_ENDIAN, val);
+ if (rc)
+ return rc;
+
+ for (i = 0x08; i <= 0x38; i += 0x08) {
+ rc = ocxl_global_mmio_write64(scm_data->ocxl_afu,
+ cmd->request_offset + i,
+ OCXL_LITTLE_ENDIAN, 0);
+ if (rc)
+ return rc;
+ }
+
+ return 0;
+}
+
+int scm_admin_command_request(struct scm_data *scm_data, u8 op_code)
+{
+ u64 val;
+ int rc = ocxl_global_mmio_read64(scm_data->ocxl_afu, GLOBAL_MMIO_CHI,
+ OCXL_LITTLE_ENDIAN, &val);
+ if (rc)
+ return rc;
+
+ return scm_command_request(scm_data, &scm_data->admin_command, op_code);
+}
+
+static int scm_command_response(const struct scm_data *scm_data,
+ const struct command_metadata *cmd)
+{
+ u64 val;
+ u16 id;
+ u8 status;
+ int rc = ocxl_global_mmio_read64(scm_data->ocxl_afu,
+ cmd->response_offset,
+ OCXL_LITTLE_ENDIAN, &val);
+ if (rc)
+ return rc;
+
+ status = val & 0xff;
+ id = (val >> 16) & 0xffff;
+
+ if (id != cmd->id) {
+ dev_warn(&scm_data->dev,
+ "Expected response for command %d, but received response for command %d instead.\n",
+ cmd->id, id);
+ }
+
+ return status;
+}
+
+int scm_admin_response(const struct scm_data *scm_data)
+{
+ return scm_command_response(scm_data, &scm_data->admin_command);
+}
+
+
+int scm_admin_command_execute(const struct scm_data *scm_data)
+{
+ return ocxl_global_mmio_set64(scm_data->ocxl_afu, GLOBAL_MMIO_HCI,
+ OCXL_LITTLE_ENDIAN, GLOBAL_MMIO_HCI_ACRW);
+}
+
+static bool scm_admin_command_complete(const struct scm_data *scm_data)
+{
+ u64 val = 0;
+
+ int rc = scm_chi(scm_data, &val);
+
+ WARN_ON(rc);
+
+ return (val & GLOBAL_MMIO_CHI_ACRA) != 0;
+}
+
+int scm_admin_command_complete_timeout(const struct scm_data *scm_data,
+ int command)
+{
+ u32 timeout = scm_data->timeouts[command];
+ // 32 is the next power of 2 greater than the 20ms minimum for msleep
+#define TIMEOUT_SLEEP_MILLIS 32
+ timeout /= TIMEOUT_SLEEP_MILLIS;
+ if (!timeout)
+ timeout = SCM_DEFAULT_TIMEOUT / TIMEOUT_SLEEP_MILLIS;
+
+ while (timeout-- > 0) {
+ if (scm_admin_command_complete(scm_data))
+ return 0;
+ msleep(TIMEOUT_SLEEP_MILLIS);
+ }
+
+ if (scm_admin_command_complete(scm_data))
+ return 0;
+
+ return -EBUSY;
+}
+
+int scm_admin_response_handled(const struct scm_data *scm_data)
+{
+ return ocxl_global_mmio_set64(scm_data->ocxl_afu, GLOBAL_MMIO_CHIC,
+ OCXL_LITTLE_ENDIAN, GLOBAL_MMIO_CHI_ACRA);
+}
+
+void scm_warn_status(const struct scm_data *scm_data, const char *message,
+ u8 status)
+{
+ const char *text = "Unknown";
+
+ switch (status) {
+ case STATUS_SUCCESS:
+ text = "Success";
+ break;
+
+ case STATUS_MEM_UNAVAILABLE:
+ text = "Persistent memory unavailable";
+ break;
+
+ case STATUS_BAD_OPCODE:
+ text = "Bad opcode";
+ break;
+
+ case STATUS_BAD_REQUEST_PARM:
+ text = "Bad request parameter";
+ break;
+
+ case STATUS_BAD_DATA_PARM:
+ text = "Bad data parameter";
+ break;
+
+ case STATUS_DEBUG_BLOCKED:
+ text = "Debug action blocked";
+ break;
+
+ case STATUS_FAIL:
+ text = "Failed";
+ break;
+ }
+
+ dev_warn(&scm_data->dev, "%s: %s (%x)\n", message, text, status);
+}
diff --git a/drivers/nvdimm/ocxl/scm_internal.h b/drivers/nvdimm/ocxl/scm_internal.h
index 584450f55e30..9bff684cd069 100644
--- a/drivers/nvdimm/ocxl/scm_internal.h
+++ b/drivers/nvdimm/ocxl/scm_internal.h
@@ -6,6 +6,8 @@
#include <linux/libnvdimm.h>
#include <linux/mm.h>

+#define SCM_DEFAULT_TIMEOUT 100
+
#define GLOBAL_MMIO_CHI 0x000
#define GLOBAL_MMIO_CHIC 0x008
#define GLOBAL_MMIO_CHIE 0x010
@@ -80,6 +82,16 @@

#define SCM_LABEL_AREA_SIZE (1UL << PA_SECTION_SHIFT)

+struct command_metadata {
+ u32 request_offset;
+ u32 response_offset;
+ u32 data_offset;
+ u32 data_size;
+ struct mutex lock;
+ u16 id;
+ u8 op_code;
+};
+
struct scm_function_0 {
struct pci_dev *pdev;
struct ocxl_fn *ocxl_fn;
@@ -95,9 +107,11 @@ struct scm_data {
struct ocxl_afu *ocxl_afu;
struct ocxl_context *ocxl_context;
void *metadata_addr;
+ struct command_metadata admin_command;
struct resource scm_res;
struct nd_region *nd_region;
char fw_version[8+1];
+ u32 timeouts[ADMIN_COMMAND_MAX+1];

u32 max_controller_dump_size;
u16 scm_revision; // major/minor
@@ -122,3 +136,51 @@ struct scm_data {
* Returns 0 on success, negative on error
*/
int scm_chi(const struct scm_data *scm_data, u64 *chi);
+
+/**
+ * scm_admin_command_request() - Issue an admin command request
+ * @scm_data: a pointer to the SCM device data
+ * @op_code: The op-code for the command
+ *
+ * Returns an identifier for the command, or negative on error
+ */
+int scm_admin_command_request(struct scm_data *scm_data, u8 op_code);
+
+/**
+ * scm_admin_response() - Validate an admin response
+ * @scm_data: a pointer to the SCM device data
+ * Returns the status code of the command, or negative on error
+ */
+int scm_admin_response(const struct scm_data *scm_data);
+
+/**
+ * scm_admin_command_execute() - Notify the controller to start processing a pending admin command
+ * @scm_data: a pointer to the SCM device data
+ * Returns 0 on success, negative on error
+ */
+int scm_admin_command_execute(const struct scm_data *scm_data);
+
+/**
+ * scm_admin_command_complete_timeout() - Wait for an admin command to finish executing
+ * @scm_data: a pointer to the SCM device data
+ * @command: the admin command to wait for completion (determines the timeout)
+ * Returns 0 on success, -EBUSY on timeout
+ */
+int scm_admin_command_complete_timeout(const struct scm_data *scm_data,
+ int command);
+
+/**
+ * scm_admin_response_handled() - Notify the controller that the admin response has been handled
+ * @scm_data: a pointer to the SCM device data
+ * Returns 0 on success, negative on failure
+ */
+int scm_admin_response_handled(const struct scm_data *scm_data);
+
+/**
+ * scm_warn_status() - Emit a kernel warning showing a command status.
+ * @scm_data: a pointer to the SCM device data
+ * @message: A message to accompany the warning
+ * @status: The command status
+ */
+void scm_warn_status(const struct scm_data *scm_data, const char *message,
+ u8 status);
--
2.23.0