On 21/2/20 2:27 pm, Alastair D'Silva wrote:
From: Alastair D'Silva <alast...@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 <alast...@d-silva.org>
---
arch/powerpc/platforms/powernv/pmem/ocxl.c | 65 ++++++++
.../platforms/powernv/pmem/ocxl_internal.c | 153 ++++++++++++++++++
.../platforms/powernv/pmem/ocxl_internal.h | 61 +++++++
3 files changed, 279 insertions(+)
diff --git a/arch/powerpc/platforms/powernv/pmem/ocxl.c
b/arch/powerpc/platforms/powernv/pmem/ocxl.c
index 431212c9f0cc..4e782d22605b 100644
--- a/arch/powerpc/platforms/powernv/pmem/ocxl.c
+++ b/arch/powerpc/platforms/powernv/pmem/ocxl.c
@@ -216,6 +216,58 @@ static int register_lpc_mem(struct ocxlpmem *ocxlpmem)
return 0;
}
+/**
+ * extract_command_metadata() - Extract command data from MMIO & save it for
further use
+ * @ocxlpmem: the device metadata
+ * @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 extract_command_metadata(struct ocxlpmem *ocxlpmem, u32 offset,
+ struct command_metadata
*command_metadata)
+{
+ int rc;
+ u64 tmp;
+
+ rc = ocxl_global_mmio_read64(ocxlpmem->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(ocxlpmem->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;
+}
+
+/**
+ * setup_command_metadata() - Set up the command metadata
+ * @ocxlpmem: the device metadata
+ */
+static int setup_command_metadata(struct ocxlpmem *ocxlpmem)
+{
+ int rc;
+
+ mutex_init(&ocxlpmem->admin_command.lock);
+
+ rc = extract_command_metadata(ocxlpmem, GLOBAL_MMIO_ACMA_CREQO,
+ &ocxlpmem->admin_command);
+ if (rc)
+ return rc;
+
+ return 0;
+}
+
/**
* is_usable() - Is a controller usable?
* @ocxlpmem: the device metadata
@@ -456,6 +508,14 @@ static int probe(struct pci_dev *pdev, const struct
pci_device_id *ent)
}
ocxlpmem->pdev = pdev;
+ ocxlpmem->timeouts[ADMIN_COMMAND_ERRLOG] = 2000; // ms
+ ocxlpmem->timeouts[ADMIN_COMMAND_HEARTBEAT] = 100; // ms
+ ocxlpmem->timeouts[ADMIN_COMMAND_SMART] = 100; // ms
+ ocxlpmem->timeouts[ADMIN_COMMAND_CONTROLLER_DUMP] = 1000; // ms
+ ocxlpmem->timeouts[ADMIN_COMMAND_CONTROLLER_STATS] = 100; // ms
+ ocxlpmem->timeouts[ADMIN_COMMAND_SHUTDOWN] = 1000; // ms
+ ocxlpmem->timeouts[ADMIN_COMMAND_FW_UPDATE] = 16000; // ms
Why are we keeping these timeouts in a per device struct? I can't see
anywhere where we change these values.
+
pci_set_drvdata(pdev, ocxlpmem);
ocxlpmem->ocxl_fn = ocxl_function_open(pdev);
@@ -501,6 +561,11 @@ static int probe(struct pci_dev *pdev, const struct
pci_device_id *ent)
goto err;
}
+ if (setup_command_metadata(ocxlpmem)) {
+ dev_err(&pdev->dev, "Could not read OCXL command matada\n");
metadata
Also, "OCXL command metadata" is misleading, this is a pmem specific
thing, not an OpenCAPI thing, I would prefer just "command metadata".
+ goto err;
+ }
+
elapsed = 0;
timeout = ocxlpmem->readiness_timeout +
ocxlpmem->memory_available_timeout;
while (!is_usable(ocxlpmem, false)) {
diff --git a/arch/powerpc/platforms/powernv/pmem/ocxl_internal.c
b/arch/powerpc/platforms/powernv/pmem/ocxl_internal.c
index 617ca943b1b8..583f48023025 100644
--- a/arch/powerpc/platforms/powernv/pmem/ocxl_internal.c
+++ b/arch/powerpc/platforms/powernv/pmem/ocxl_internal.c
@@ -17,3 +17,156 @@ int ocxlpmem_chi(const struct ocxlpmem *ocxlpmem, u64 *chi)
return 0;
}
+
+#define COMMAND_REQUEST_SIZE (8 * sizeof(u64))
+static int scm_command_request(const struct ocxlpmem *ocxlpmem,
+ 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(ocxlpmem->ocxl_afu, cmd->request_offset,
+ OCXL_LITTLE_ENDIAN, val);
+ if (rc)
+ return rc;
+
+ for (i = sizeof(u64); i < COMMAND_REQUEST_SIZE; i += sizeof(u64)) {
+ rc = ocxl_global_mmio_write64(ocxlpmem->ocxl_afu,
+ cmd->request_offset + i,
+ OCXL_LITTLE_ENDIAN, 0);
+ if (rc)
+ return rc;
+ }
+
+ return 0;
+}
+
+int admin_command_request(struct ocxlpmem *ocxlpmem, u8 op_code)
+{
+ u64 val;
+ int rc = ocxl_global_mmio_read64(ocxlpmem->ocxl_afu, GLOBAL_MMIO_CHI,
+ OCXL_LITTLE_ENDIAN, &val);
+ if (rc)
+ return rc;
Ignoring the value here expected, you're just trying to verify that you
don't see an error on the read?
+
+ return scm_command_request(ocxlpmem, &ocxlpmem->admin_command, op_code);
+}
+
+static int command_response(const struct ocxlpmem *ocxlpmem,
+ const struct command_metadata *cmd)
+{
+ u64 val;
+ u16 id;
+ u8 status;
+ int rc = ocxl_global_mmio_read64(ocxlpmem->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(&ocxlpmem->dev,
+ "Expected response for command %d, but received response
for command %d instead.\n",
+ cmd->id, id);
If this happens I imagine something's gone pretty wrong - this should
probably be a dev_err()? And perhaps we want to make sure we return an
error code rather than whatever status code we get from the MMIO?
+ }
+
+ return status;
+}
+
+int admin_response(const struct ocxlpmem *ocxlpmem)
+{
+ return command_response(ocxlpmem, &ocxlpmem->admin_command);
+}
+
+
+int admin_command_execute(const struct ocxlpmem *ocxlpmem)
+{
+ return ocxl_global_mmio_set64(ocxlpmem->ocxl_afu, GLOBAL_MMIO_HCI,
+ OCXL_LITTLE_ENDIAN, GLOBAL_MMIO_HCI_ACRW);
+}
+
+static bool admin_command_complete(const struct ocxlpmem *ocxlpmem)
+{
+ u64 val = 0;
+
+ int rc = ocxlpmem_chi(ocxlpmem, &val);
+
+ WARN_ON(rc);
+
+ return (val & GLOBAL_MMIO_CHI_ACRA) != 0;
+}
+
+int admin_command_complete_timeout(const struct ocxlpmem *ocxlpmem,
+ int command)
+{
+ u32 timeout = ocxlpmem->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 = DEFAULT_TIMEOUT / TIMEOUT_SLEEP_MILLIS;
+
+ while (timeout-- > 0) {
+ if (admin_command_complete(ocxlpmem))
+ return 0;
+ msleep(TIMEOUT_SLEEP_MILLIS);
+ }
I think the more traditional way to implement timeouts is something more
like:
unsigned long timeout = jiffies + msecs_to_jiffies(<timeout period>);
do {
<check>
<sleep>
} while (time_before(jiffies, timeout));
+
+ if (admin_command_complete(ocxlpmem))
+ return 0;
+
+ return -EBUSY;
+}
+
+int admin_response_handled(const struct ocxlpmem *ocxlpmem)
+{
+ return ocxl_global_mmio_set64(ocxlpmem->ocxl_afu, GLOBAL_MMIO_CHIC,
+ OCXL_LITTLE_ENDIAN, GLOBAL_MMIO_CHI_ACRA);
+}
This looks wrong? My reading of the spec is that you're meant to *clear*
ACRA upon completion of handing, this looks like it's setting ACRA to 1.
+
+void warn_status(const struct ocxlpmem *ocxlpmem, 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(&ocxlpmem->dev, "%s: %s (%x)\n", message, text, status);
+}
diff --git a/arch/powerpc/platforms/powernv/pmem/ocxl_internal.h
b/arch/powerpc/platforms/powernv/pmem/ocxl_internal.h
index ba0301533d00..2fef68c71271 100644
--- a/arch/powerpc/platforms/powernv/pmem/ocxl_internal.h
+++ b/arch/powerpc/platforms/powernv/pmem/ocxl_internal.h
@@ -7,6 +7,7 @@
#include <linux/mm.h>
#define LABEL_AREA_SIZE (1UL << PA_SECTION_SHIFT)
+#define DEFAULT_TIMEOUT 100
#define GLOBAL_MMIO_CHI 0x000
#define GLOBAL_MMIO_CHIC 0x008
@@ -80,6 +81,16 @@
#define STATUS_FW_ARG_INVALID 0x51
#define STATUS_FW_INVALID 0x52
+struct command_metadata {
+ u32 request_offset;
+ u32 response_offset;
+ u32 data_offset;
+ u32 data_size;
+ struct mutex lock;
+ u16 id;
+ u8 op_code;
+};
+
struct ocxlpmem_function0 {
struct pci_dev *pdev;
struct ocxl_fn *ocxl_fn;
@@ -95,9 +106,11 @@ struct ocxlpmem {
struct ocxl_afu *ocxl_afu;
struct ocxl_context *ocxl_context;
void *metadata_addr;
+ struct command_metadata admin_command;
struct resource pmem_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 +135,51 @@ struct ocxlpmem {
* Returns 0 on success, negative on error
*/
int ocxlpmem_chi(const struct ocxlpmem *ocxlpmem, u64 *chi);
+
+/**
+ * admin_command_request() - Issue an admin command request
+ * @ocxlpmem: the device metadata
+ * @op_code: The op-code for the command
+ *
+ * Returns an identifier for the command, or negative on error
+ */
+int admin_command_request(struct ocxlpmem *ocxlpmem, u8 op_code);
+
+/**
+ * admin_response() - Validate an admin response
+ * @ocxlpmem: the device metadata
+ * Returns the status code of the command, or negative on error
+ */
+int admin_response(const struct ocxlpmem *ocxlpmem);
+
+/**
+ * admin_command_execute() - Notify the controller to start processing a
pending admin command
+ * @ocxlpmem: the device metadata
+ * Returns 0 on success, negative on error
+ */
+int admin_command_execute(const struct ocxlpmem *ocxlpmem);
+
+/**
+ * admin_command_complete_timeout() - Wait for an admin command to finish
executing
+ * @ocxlpmem: the device metadata
+ * @command: the admin command to wait for completion (determines the timeout)
+ * Returns 0 on success, -EBUSY on timeout
+ */
+int admin_command_complete_timeout(const struct ocxlpmem *ocxlpmem,
+ int command);
+
+/**
+ * admin_response_handled() - Notify the controller that the admin response
has been handled
+ * @ocxlpmem: the device metadata
+ * Returns 0 on success, negative on failure
+ */
+int admin_response_handled(const struct ocxlpmem *ocxlpmem);
+
+/**
+ * warn_status() - Emit a kernel warning showing a command status.
+ * @ocxlpmem: the device metadata
+ * @message: A message to accompany the warning
+ * @status: The command status
+ */
+void warn_status(const struct ocxlpmem *ocxlpmem, const char *message,
+ u8 status);
--
Andrew Donnellan OzLabs, ADL Canberra
a...@linux.ibm.com IBM Australia Limited
