[PATCH V2 2/2] powerpc/powernv : Add support for OPAL-OCC command/response interface
Shilpasri G Bhat
shilpa.bhat at linux.vnet.ibm.com
Wed Jun 14 03:56:41 AEST 2017
In P9, OCC (On-Chip-Controller) supports shared memory based
commad-response interface. Within the shared memory there is an OPAL
command buffer and OCC response buffer that can be used to send
inband commands to OCC. This patch adds a platform driver to support
the command/response interface between OCC and the host.
Signed-off-by: Shilpasri G Bhat <shilpa.bhat at linux.vnet.ibm.com>
---
Changes from V2:
- Remove spinlock and use atomic_t for setting and clearing flags
- Fix endian swapping
- Use pa() and va() before and after opal call for accessing buffer
data
- Replace (u8 *) with __be64 for buffer pointers
- User reads the previous OCC response if the user does a read()
before a write(). Is this wrong?
- Add WARN_ON check for nr_occs > 254
arch/powerpc/include/asm/opal-api.h | 41 +++-
arch/powerpc/include/asm/opal.h | 3 +
arch/powerpc/platforms/powernv/Makefile | 2 +-
arch/powerpc/platforms/powernv/opal-occ.c | 314 +++++++++++++++++++++++++
arch/powerpc/platforms/powernv/opal-wrappers.S | 1 +
arch/powerpc/platforms/powernv/opal.c | 8 +
6 files changed, 367 insertions(+), 2 deletions(-)
create mode 100644 arch/powerpc/platforms/powernv/opal-occ.c
diff --git a/arch/powerpc/include/asm/opal-api.h b/arch/powerpc/include/asm/opal-api.h
index cb3e624..011d86c 100644
--- a/arch/powerpc/include/asm/opal-api.h
+++ b/arch/powerpc/include/asm/opal-api.h
@@ -42,6 +42,10 @@
#define OPAL_I2C_STOP_ERR -24
#define OPAL_XIVE_PROVISIONING -31
#define OPAL_XIVE_FREE_ACTIVE -32
+#define OPAL_OCC_INVALID_STATE -33
+#define OPAL_OCC_BUSY -34
+#define OPAL_OCC_CMD_TIMEOUT -35
+#define OPAL_OCC_RSP_MISMATCH -36
/* API Tokens (in r0) */
#define OPAL_INVALID_CALL -1
@@ -190,7 +194,8 @@
#define OPAL_NPU_INIT_CONTEXT 146
#define OPAL_NPU_DESTROY_CONTEXT 147
#define OPAL_NPU_MAP_LPAR 148
-#define OPAL_LAST 148
+#define OPAL_OCC_COMMAND 149
+#define OPAL_LAST 149
/* Device tree flags */
@@ -829,6 +834,40 @@ struct opal_prd_msg_header {
struct opal_prd_msg;
+enum occ_cmd {
+ OCC_CMD_AMESTER_PASS_THRU = 0,
+ OCC_CMD_CLEAR_SENSOR_DATA,
+ OCC_CMD_SET_POWER_CAP,
+ OCC_CMD_SET_POWER_SHIFTING_RATIO,
+ OCC_CMD_SELECT_SENSOR_GROUPS,
+ OCC_CMD_LAST
+};
+
+struct opal_occ_cmd_rsp_msg {
+ __be64 cdata;
+ __be64 rdata;
+ __be16 cdata_size;
+ __be16 rdata_size;
+ u8 cmd;
+ u8 request_id;
+ u8 status;
+};
+
+struct opal_occ_cmd_data {
+ __be16 size;
+ u8 cmd;
+ u8 data[];
+};
+
+struct opal_occ_rsp_data {
+ __be16 size;
+ u8 status;
+ u8 data[];
+};
+
+#define MAX_OPAL_CMD_DATA_LENGTH 4090
+#define MAX_OCC_RSP_DATA_LENGTH 8698
+
#define OCC_RESET 0
#define OCC_LOAD 1
#define OCC_THROTTLE 2
diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index 03ed493..e55ed79 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -346,6 +346,9 @@ static inline int opal_get_async_rc(struct opal_msg msg)
void opal_wake_poller(void);
+int64_t opal_occ_command(int chip_id, struct opal_occ_cmd_rsp_msg *msg,
+ bool retry);
+
#endif /* __ASSEMBLY__ */
#endif /* _ASM_POWERPC_OPAL_H */
diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
index b5d98cb..f5f0902 100644
--- a/arch/powerpc/platforms/powernv/Makefile
+++ b/arch/powerpc/platforms/powernv/Makefile
@@ -2,7 +2,7 @@ obj-y += setup.o opal-wrappers.o opal.o opal-async.o idle.o
obj-y += opal-rtc.o opal-nvram.o opal-lpc.o opal-flash.o
obj-y += rng.o opal-elog.o opal-dump.o opal-sysparam.o opal-sensor.o
obj-y += opal-msglog.o opal-hmi.o opal-power.o opal-irqchip.o
-obj-y += opal-kmsg.o
+obj-y += opal-kmsg.o opal-occ.o
obj-$(CONFIG_SMP) += smp.o subcore.o subcore-asm.o
obj-$(CONFIG_PCI) += pci.o pci-ioda.o npu-dma.o
diff --git a/arch/powerpc/platforms/powernv/opal-occ.c b/arch/powerpc/platforms/powernv/opal-occ.c
new file mode 100644
index 0000000..912cdc4
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-occ.c
@@ -0,0 +1,314 @@
+/*
+ * Copyright IBM Corporation 2017
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt) "opal-occ: " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/miscdevice.h>
+#include <linux/highmem.h>
+#include <linux/slab.h>
+#include <asm/opal.h>
+
+struct occ {
+ struct miscdevice dev;
+ struct opal_occ_rsp_data *rsp;
+ atomic_t session;
+ atomic_t cmd_in_progress;
+ int id;
+ u8 last_token;
+} *occs;
+static int nr_occs;
+
+static int __send_occ_command(struct opal_occ_cmd_rsp_msg *msg,
+ int chip_id, bool retry)
+{
+ struct opal_msg async_msg;
+ int rc;
+
+ if (!retry) {
+ msg->cdata = cpu_to_be64(__pa(msg->cdata));
+ msg->cdata_size = cpu_to_be16(msg->cdata_size);
+ msg->rdata = cpu_to_be64(__pa(msg->rdata));
+ }
+
+ rc = opal_occ_command(chip_id, msg, retry);
+ if (rc == OPAL_ASYNC_COMPLETION) {
+ rc = opal_async_wait_response(msg->request_id, &async_msg);
+ if (rc) {
+ pr_info("Failed to wait for async response %d\n", rc);
+ return rc;
+ }
+ } else if (rc) {
+ pr_info("Failed to send opal_occ_command %d\n", rc);
+ return rc;
+ }
+
+ rc = opal_get_async_rc(async_msg);
+ if (rc) {
+ pr_info("opal_occ_command failed with %d\n", rc);
+ return rc;
+ }
+
+ msg->rdata_size = be16_to_cpu(msg->rdata_size);
+ msg->rdata = be64_to_cpu(__va(msg->rdata));
+ msg->cdata_size = be16_to_cpu(msg->cdata_size);
+ msg->cdata = be64_to_cpu(__va(msg->cdata));
+
+ if (msg->rdata_size > MAX_OCC_RSP_DATA_LENGTH) {
+ pr_info("Opal sent bigger data, clipping to the max response size\n");
+ msg->rdata_size = MAX_OCC_RSP_DATA_LENGTH;
+ }
+
+ return rc;
+}
+
+static int send_occ_command(struct opal_occ_cmd_rsp_msg *msg, struct occ *occ)
+{
+ int token, rc;
+
+ token = opal_async_get_unique_token_interruptible(occ->last_token);
+ if (token < 0) {
+ pr_info("Failed to get the request_id/token for command %d (%d)\n",
+ msg->cmd, token);
+ return token;
+ }
+
+ msg->request_id = token;
+ rc = __send_occ_command(msg, occ->id, false);
+
+ switch (rc) {
+ case OPAL_OCC_CMD_TIMEOUT:
+ case OPAL_OCC_RSP_MISMATCH:
+ occ->last_token = token;
+ opal_async_release_token(token);
+ token = opal_async_get_unique_token_interruptible(token);
+ if (token < 0) {
+ pr_info("Failed to get the request_id/token for retry command %d (%d)\n",
+ msg->cmd, token);
+
+ return opal_error_code(rc);
+ }
+
+ msg->request_id = token;
+ rc = __send_occ_command(msg, occ->id, true);
+ break;
+ default:
+ break;
+ }
+
+ occ->last_token = token;
+ opal_async_release_token(token);
+ return opal_error_code(rc);
+}
+
+static int opal_occ_cmd_prepare(struct opal_occ_cmd_data *cmd, struct occ *occ)
+{
+ struct opal_occ_cmd_rsp_msg msg;
+ int rc;
+
+ msg.cmd = cmd->cmd;
+ msg.cdata_size = cmd->size;
+ msg.rdata = (u64)occ->rsp->data;
+ msg.cdata = (u64)cmd->data;
+ rc = send_occ_command(&msg, occ);
+ if (rc)
+ return rc;
+
+ occ->rsp->size = msg.rdata_size;
+ occ->rsp->status = msg.status;
+
+ return rc;
+}
+
+static ssize_t opal_occ_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct miscdevice *dev = file->private_data;
+ struct occ *occ = container_of(dev, struct occ, dev);
+ struct opal_occ_cmd_data *cmd;
+ int rc;
+
+ if (count < sizeof(*cmd))
+ return -EINVAL;
+
+ if (atomic_xchg(&occ->cmd_in_progress, 1) == 1)
+ return -EBUSY;
+
+ cmd = kmalloc(count, GFP_KERNEL);
+ if (!cmd) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ rc = copy_from_user(cmd, buf, count);
+ if (rc) {
+ pr_err("Failed to copy OCC command request message\n");
+ rc = -EFAULT;
+ goto free_cmd;
+ }
+
+ if (cmd->size > MAX_OPAL_CMD_DATA_LENGTH) {
+ rc = -EINVAL;
+ goto free_cmd;
+ }
+
+ rc = opal_occ_cmd_prepare(cmd, occ);
+ if (!rc)
+ rc = count;
+
+free_cmd:
+ kfree(cmd);
+out:
+ atomic_xchg(&occ->cmd_in_progress, 0);
+ return rc;
+}
+
+static ssize_t opal_occ_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct miscdevice *dev = file->private_data;
+ struct occ *occ = container_of(dev, struct occ, dev);
+ int rc;
+
+ if (count < sizeof(*occ->rsp) + occ->rsp->size)
+ return -EINVAL;
+
+ rc = copy_to_user((void __user *)buf, occ->rsp,
+ sizeof(occ->rsp) + occ->rsp->size);
+ if (rc) {
+ pr_err("Failed to copy OCC response data to user\n");
+ return rc;
+ }
+
+ return sizeof(*occ->rsp) + occ->rsp->size;
+}
+
+static int opal_occ_open(struct inode *inode, struct file *file)
+{
+ struct miscdevice *dev = file->private_data;
+ struct occ *occ = container_of(dev, struct occ, dev);
+
+ if (atomic_xchg(&occ->session, 1) == 1)
+ return -EBUSY;
+
+ return 0;
+}
+
+static int opal_occ_release(struct inode *inode, struct file *file)
+{
+ struct miscdevice *dev = file->private_data;
+ struct occ *occ = container_of(dev, struct occ, dev);
+
+ atomic_xchg(&occ->session, 0);
+
+ return 0;
+}
+
+static const struct file_operations opal_occ_fops = {
+ .open = opal_occ_open,
+ .read = opal_occ_read,
+ .write = opal_occ_write,
+ .release = opal_occ_release,
+ .owner = THIS_MODULE,
+};
+
+static int opal_occ_probe(struct platform_device *pdev)
+{
+ unsigned int chip[256];
+ unsigned int cpu;
+ unsigned int prev_chip_id = UINT_MAX;
+ int i, rc;
+
+ for_each_possible_cpu(cpu) {
+ unsigned int id = cpu_to_chip_id(cpu);
+
+ if (prev_chip_id != id) {
+ prev_chip_id = id;
+ chip[nr_occs++] = id;
+ WARN_ON(nr_occs > 254);
+ }
+ }
+
+ occs = kcalloc(nr_occs, sizeof(*occs), GFP_KERNEL);
+ if (!occs)
+ return -ENOMEM;
+
+ for (i = 0; i < nr_occs; i++) {
+ char name[10];
+
+ occs[i].id = chip[i];
+ occs[i].dev.minor = MISC_DYNAMIC_MINOR;
+ snprintf(name, 10, "occ%d", chip[i]);
+ occs[i].dev.name = name;
+ occs[i].dev.fops = &opal_occ_fops;
+ occs[i].last_token = -1;
+ occs[i].rsp = kmalloc(sizeof(occs[i].rsp) +
+ MAX_OCC_RSP_DATA_LENGTH,
+ GFP_KERNEL);
+ if (!occs[i].rsp) {
+ rc = -ENOMEM;
+ goto free_occs;
+ }
+
+ rc = misc_register(&occs[i].dev);
+ if (rc)
+ goto free_occ_rsp_data;
+ }
+
+ return 0;
+
+free_occ_rsp_data:
+ kfree(occs[i].rsp);
+free_occs:
+ while (--i >= 0) {
+ kfree(occs[i].rsp);
+ misc_deregister(&occs[i].dev);
+ }
+ kfree(occs);
+
+ return rc;
+}
+
+static int opal_occ_remove(struct platform_device *pdev)
+{
+ int i;
+
+ for (i = 0; i < nr_occs; i++) {
+ kfree(occs[i].rsp);
+ misc_deregister(&occs[i].dev);
+ }
+
+ kfree(occs);
+ return 0;
+}
+
+static const struct of_device_id opal_occ_match[] = {
+ { .compatible = "ibm,opal-occ-cmd-rsp-interface" },
+ { },
+};
+
+static struct platform_driver opal_occ_driver = {
+ .driver = {
+ .name = "opal-occ",
+ .of_match_table = opal_occ_match,
+ },
+ .probe = opal_occ_probe,
+ .remove = opal_occ_remove,
+};
+
+module_platform_driver(opal_occ_driver);
+
+MODULE_DESCRIPTION("PowerNV OPAL-OCC driver");
+MODULE_LICENSE("GPL");
diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S
index f620572..e6bf18d 100644
--- a/arch/powerpc/platforms/powernv/opal-wrappers.S
+++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
@@ -310,3 +310,4 @@ OPAL_CALL(opal_xive_dump, OPAL_XIVE_DUMP);
OPAL_CALL(opal_npu_init_context, OPAL_NPU_INIT_CONTEXT);
OPAL_CALL(opal_npu_destroy_context, OPAL_NPU_DESTROY_CONTEXT);
OPAL_CALL(opal_npu_map_lpar, OPAL_NPU_MAP_LPAR);
+OPAL_CALL(opal_occ_command, OPAL_OCC_COMMAND);
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index 59684b4..d87c61b 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -815,6 +815,9 @@ static int __init opal_init(void)
opal_pdev_init("ibm,opal-flash");
opal_pdev_init("ibm,opal-prd");
+ /* Initialize platform device: OCC_OPAL command-response interface */
+ opal_pdev_init("ibm,opal-occ-cmd-rsp-interface");
+
/* Initialise platform device: oppanel interface */
opal_pdev_init("ibm,opal-oppanel");
@@ -859,6 +862,7 @@ void opal_shutdown(void)
EXPORT_SYMBOL_GPL(opal_flash_write);
EXPORT_SYMBOL_GPL(opal_flash_erase);
EXPORT_SYMBOL_GPL(opal_prd_msg);
+EXPORT_SYMBOL_GPL(opal_occ_command);
/* Convert a region of vmalloc memory to an opal sg list */
struct opal_sg_list *opal_vmalloc_to_sg_list(void *vmalloc_addr,
@@ -937,6 +941,10 @@ int opal_error_code(int rc)
case OPAL_UNSUPPORTED: return -EIO;
case OPAL_HARDWARE: return -EIO;
case OPAL_INTERNAL_ERROR: return -EIO;
+ case OPAL_OCC_BUSY: return -EBUSY;
+ case OPAL_OCC_INVALID_STATE:
+ case OPAL_OCC_CMD_TIMEOUT:
+ case OPAL_OCC_RSP_MISMATCH: return -EIO;
default:
pr_err("%s: unexpected OPAL error %d\n", __func__, rc);
return -EIO;
--
1.8.3.1
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