[Skiboot] [RFC PATCH v2 3/4] libflash: blocklevel backend for MBOX flash access
Cyril Bur
cyril.bur at au1.ibm.com
Tue Jan 24 11:54:16 AEDT 2017
The use MBOX protocol to request flash access from the BMC. Then
read/write to the 'flash' through the LPC bus.
Signed-off-by: Cyril Bur <cyril.bur at au1.ibm.com>
---
libflash/Makefile.inc | 2 +-
libflash/mbox-flash.c | 562 ++++++++++++++++++++++++++++++++++++++++++++++++++
libflash/mbox-flash.h | 24 +++
3 files changed, 587 insertions(+), 1 deletion(-)
create mode 100644 libflash/mbox-flash.c
create mode 100644 libflash/mbox-flash.h
diff --git a/libflash/Makefile.inc b/libflash/Makefile.inc
index 4db02a1f..ea64eb46 100644
--- a/libflash/Makefile.inc
+++ b/libflash/Makefile.inc
@@ -1,4 +1,4 @@
-LIBFLASH_SRCS = libflash.c libffs.c ecc.c blocklevel.c
+LIBFLASH_SRCS = libflash.c libffs.c ecc.c blocklevel.c mbox-flash.c
LIBFLASH_OBJS = $(LIBFLASH_SRCS:%.c=%.o)
SUBDIRS += libflash
diff --git a/libflash/mbox-flash.c b/libflash/mbox-flash.c
new file mode 100644
index 00000000..fe94da99
--- /dev/null
+++ b/libflash/mbox-flash.c
@@ -0,0 +1,562 @@
+/* Copyright 2017 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define pr_fmt(fmt) "MBOX-FLASH: " fmt
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <skiboot.h>
+#include <timebase.h>
+#include <timer.h>
+#include <libflash/libflash.h>
+#include <libflash/mbox-flash.h>
+#include <lpc.h>
+#include <lpc-mbox.h>
+
+#include <ccan/container_of/container_of.h>
+
+#ifndef __SKIBOOT__
+#error "This libflash backend must be compiled with skiboot"
+#endif
+
+#define MBOX_DEFAULT_TIMEOUT 30
+
+struct lpc_window {
+ uint32_t lpc;
+ uint32_t pos;
+ uint32_t size;
+ bool open;
+};
+
+struct mbox_flash_data {
+ uint32_t shift;
+ struct lpc_window read;
+ struct lpc_window write;
+ struct blocklevel_device bl;
+ uint32_t total_size;
+ uint32_t erase_granule;
+ int rc;
+ bool busy;
+ struct bmc_mbox_msg msg_mem;
+};
+
+static uint16_t get_u16(uint8_t *ptr)
+{
+ return le16_to_cpu(*(uint16_t *)ptr);
+}
+
+static void put_u16(uint8_t *ptr, uint16_t val)
+{
+ uint16_t valt = cpu_to_le16(val);
+ memcpy(ptr, &valt, sizeof(val));
+}
+
+static uint32_t get_u32(uint8_t *ptr)
+{
+ return le32_to_cpu(*(uint32_t *)ptr);
+}
+
+static void put_u32(uint8_t *ptr, uint32_t val)
+{
+ uint32_t valt = cpu_to_le32(val);
+ memcpy(ptr, &valt, sizeof(val));
+}
+
+static struct bmc_mbox_msg *get_msg_memory(struct mbox_flash_data *lpc)
+{
+ /*
+ * Yes this causes *slow*.
+ * This file and lpc-mbox have far greater slow points, zeroed
+ * data regs are VERY useful for debugging. Think twice if this is
+ * really the performance optimisation you want to make.
+ */
+ memset(&lpc->msg_mem, 0, sizeof(lpc->msg_mem));
+ return &lpc->msg_mem;
+}
+
+static void free_msg_memory(struct bmc_mbox_msg *mem __unused)
+{
+ /* Allocation is so simple this isn't required */
+}
+
+static bool wait_for_bmc(struct mbox_flash_data *lpc, unsigned int timeout_sec)
+{
+ unsigned long last = 1, start = tb_to_secs(mftb());
+ prlog(PR_DEBUG, "Waiting for BMC\n");
+ while (lpc->busy && timeout_sec) {
+ long now = tb_to_secs(mftb());
+ if (now - start > last) {
+ timeout_sec--;
+ last = now - start;
+ if (last < timeout_sec / 2)
+ prlog(PR_TRACE, "Been waiting for the BMC for %lu secs\n", last);
+ else
+ prlog(PR_ERR, "BMC NOT RESPONDING %lu second wait\n", last);
+ }
+ /*
+ * Both functions are important.
+ * Well time_wait_ms() relaxes the spin... so... its nice
+ */
+ time_wait_ms(MBOX_DEFAULT_POLL_MS);
+ check_timers(false);
+ asm volatile ("" ::: "memory");
+ }
+
+ return lpc->busy;
+}
+
+static int lpc_window_read(struct mbox_flash_data *lpc, uint32_t pos, void *buf, uint32_t len)
+{
+ int rc;
+ uint32_t off = lpc->read.lpc + (pos - lpc->read.pos);
+
+ prlog(PR_TRACE, "Reading at 0x%08x for 0x%08x offset: 0x%08x\n",
+ pos, len, off);
+
+ while(len) {
+ uint32_t chunk;
+ uint32_t dat;
+
+ /* Choose access size */
+ if (len > 3 && !(off & 3)) {
+ rc = lpc_read(OPAL_LPC_FW, off, &dat, 4);
+ if (!rc)
+ *(uint32_t *)buf = dat;
+ chunk = 4;
+ } else {
+ rc = lpc_read(OPAL_LPC_FW, off, &dat, 1);
+ if (!rc)
+ *(uint8_t *)buf = dat;
+ chunk = 1;
+ }
+ if (rc) {
+ prlog(PR_ERR, "lpc_read failure %d to FW 0x%08x\n", rc, off);
+ return rc;
+ }
+ len -= chunk;
+ off += chunk;
+ buf += chunk;
+ }
+
+ return 0;
+}
+
+static int lpc_window_write(struct mbox_flash_data *lpc, uint32_t pos, const void *buf, uint32_t len)
+{
+ uint32_t off = lpc->write.lpc + (pos - lpc->write.pos);
+ int rc;
+
+
+ prlog(PR_TRACE, "Writing at 0x%08x for 0x%08x offset: 0x%08x\n",
+ pos, len, off);
+
+ while(len) {
+ uint32_t chunk;
+
+ if (len > 3 && !(off & 3)) {
+ rc = lpc_write(OPAL_LPC_FW, off,
+ *(uint32_t *)buf, 4);
+ chunk = 4;
+ } else {
+ rc = lpc_write(OPAL_LPC_FW, off,
+ *(uint8_t *)buf, 1);
+ chunk = 1;
+ }
+ if (rc) {
+ prlog(PR_ERR, "lpc_write failure %d to FW 0x%08x\n", rc, off);
+ return rc;
+ }
+ len -= chunk;
+ off += chunk;
+ buf += chunk;
+ }
+
+ return 0;
+}
+
+static void write_dirty_cb(struct bmc_mbox_msg *msg)
+{
+ struct mbox_flash_data *lpc;
+
+ lpc = msg->priv;
+
+ prlog(PR_DEBUG, "WRITE_DRITY CB, BMC OK\n");
+
+ if (msg->response != MBOX_R_SUCCESS) {
+ prlog(PR_ERR, "Bad response code from BMC %d\n", msg->response);
+ lpc->rc = msg->response;
+ goto out;
+ }
+
+ lpc->rc = 0;
+
+out:
+ lpc->busy = false;
+}
+
+static void write_cb(struct bmc_mbox_msg *msg)
+{
+ struct mbox_flash_data *lpc;
+
+ lpc = msg->priv;
+
+ prlog(PR_DEBUG, "WRITE_WINDOW CB, BMC OK\n");
+
+ if (msg->response != MBOX_R_SUCCESS) {
+ prlog(PR_ERR, "Bad response code from BMC %d\n", msg->response);
+ lpc->rc = msg->response;
+ goto out;
+ }
+
+ lpc->write.lpc = get_u16(&msg->data[0]) << lpc->shift;
+ lpc->write.open = true;
+ lpc->read.open = false;
+
+ lpc->rc = 0;
+
+out:
+ lpc->busy = false;
+}
+
+static int mbox_flash_write(struct blocklevel_device *bl, uint64_t pos,
+ const void *buf, uint64_t len)
+{
+ struct mbox_flash_data *lpc;
+ struct bmc_mbox_msg *msg;
+ int rc;
+
+ /* LPC is only 32bit */
+ if (pos > UINT_MAX || len > UINT_MAX)
+ return FLASH_ERR_PARM_ERROR;
+
+ lpc = container_of(bl, struct mbox_flash_data, bl);
+ msg = get_msg_memory(lpc);
+ if (!msg)
+ return FLASH_ERR_MALLOC_FAILED;
+
+ prlog(PR_TRACE, "Flash write at 0x%08llx for 0x%08llx\n", pos, len);
+ if (!lpc->write.open || pos < lpc->write.pos || pos + len > lpc->write.pos + lpc->write.size) {
+ prlog(PR_INFO, "Adjusting the write window\n");
+
+ lpc->write.pos = pos & ~(lpc->shift - 1);
+ msg->priv = lpc;
+ msg->command = MBOX_C_WRITE_WINDOW;
+ msg->callback = &write_cb;
+ put_u16(&msg->data[0], pos >> lpc->shift);
+
+ lpc->busy = true;
+ rc = bmc_mbox_enqueue(msg);
+ if (rc) {
+ prlog(PR_ERR, "Failed to enqueue/send BMC MBOX message\n");
+ rc = FLASH_ERR_MALLOC_FAILED; /* Not necessarily the reason... */
+ goto out;
+ }
+
+ if (wait_for_bmc(lpc, MBOX_DEFAULT_TIMEOUT)) {
+ prlog(PR_ERR, "Timeout waiting for BMC\n");
+ rc = FLASH_ERR_CTRL_TIMEOUT;
+ return rc;
+ }
+
+ if (lpc->rc) {
+ rc = lpc->rc;
+ goto out;
+ }
+ }
+
+ rc = lpc_window_write(lpc, pos, buf, len);
+ if (rc)
+ return rc;
+
+ msg->priv = lpc;
+ msg->command = MBOX_C_WRITE_DIRTY;
+ msg->callback = &write_dirty_cb;
+ put_u16(&msg->data[0], pos >> lpc->shift);
+ put_u32(&msg->data[2], len);
+
+ lpc->busy = true;
+ rc = bmc_mbox_enqueue(msg);
+ if (rc) {
+ prlog(PR_ERR, "Failed to enqueue/send BMC MBOX message\n");
+ rc = FLASH_ERR_MALLOC_FAILED; /* Not necessarily the reason... */
+ goto out;
+ }
+
+ if (wait_for_bmc(lpc, MBOX_DEFAULT_TIMEOUT)) {
+ prlog(PR_ERR, "Timeout waiting for BMC\n");
+ rc = FLASH_ERR_CTRL_TIMEOUT;
+ goto out;
+ }
+
+ rc = lpc->rc;
+
+out:
+ free_msg_memory(msg);
+ return rc;
+}
+
+static void read_cb(struct bmc_mbox_msg *msg)
+{
+ struct mbox_flash_data *lpc;
+
+ lpc = msg->priv;
+
+ prlog(PR_DEBUG, "READ_WINDOW CB, BMC OK\n");
+
+ if (msg->response != MBOX_R_SUCCESS) {
+ prlog(PR_ERR, "Bad response code from BMC %d\n", msg->response);
+ lpc->rc = msg->response;
+ goto out;
+ }
+
+ lpc->read.lpc = get_u16(&msg->data[0]) << lpc->shift;
+ lpc->read.open = true;
+ lpc->write.open = false;
+
+ lpc->rc = 0;
+out:
+ lpc->busy = false;
+}
+
+static int mbox_flash_read(struct blocklevel_device *bl, uint64_t pos, void *buf, uint64_t len)
+{
+ struct mbox_flash_data *lpc;
+ int rc = 0;
+
+ /* LPC is only 32bit */
+ if (pos > UINT_MAX || len > UINT_MAX)
+ return FLASH_ERR_PARM_ERROR;
+
+ lpc = container_of(bl, struct mbox_flash_data, bl);
+
+ prlog(PR_TRACE, "Flash read at 0x%08llx for 0x%08llx\n", pos, len);
+ if (!lpc->read.open || pos < lpc->read.pos || pos + len > lpc->read.pos + lpc->read.size) {
+ struct bmc_mbox_msg *msg = get_msg_memory(lpc);
+ if (!msg)
+ return FLASH_ERR_MALLOC_FAILED;
+
+ prlog(PR_INFO, "Adjusting the read window\n");
+
+ lpc->read.pos = pos & ~(lpc->shift - 1);
+ msg->priv = lpc;
+ msg->command = MBOX_C_READ_WINDOW;
+ msg->callback = &read_cb;
+ put_u16(&msg->data[0], pos >> lpc->shift);
+
+ lpc->busy = true;
+ rc = bmc_mbox_enqueue(msg);
+ if (rc) {
+ prlog(PR_ERR, "Failed to enqueue/send BMC MBOX message\n");
+ goto out;
+ }
+
+ if (wait_for_bmc(lpc, MBOX_DEFAULT_TIMEOUT)) {
+ prlog(PR_ERR, "Timeout waiting for BMC\n");
+ rc = FLASH_ERR_CTRL_TIMEOUT;
+ goto out;
+ }
+
+ rc = lpc->rc;
+out:
+ free_msg_memory(msg);
+ }
+
+ return rc ? rc : lpc_window_read(lpc, pos, buf, len);
+}
+
+static void get_info_cb(struct bmc_mbox_msg *msg)
+{
+ struct mbox_flash_data *lpc;
+
+ prlog(PR_DEBUG, "FLASH_INFO CB, BMC OK\n");
+
+ lpc = msg->priv;
+
+ if (msg->response != MBOX_R_SUCCESS) {
+ prlog(PR_ERR, "Bad response code from BMC %d\n", msg->response);
+ lpc->rc = msg->response;
+ goto out;
+ }
+
+ lpc->total_size = get_u32(&msg->data[0]);
+ lpc->erase_granule = get_u32(&msg->data[4]);
+
+ lpc->rc = 0;
+out:
+ lpc->busy = false;
+}
+
+static int mbox_flash_get_info(struct blocklevel_device *bl, const char **name,
+ uint64_t *total_size, uint32_t *erase_granule)
+{
+ struct mbox_flash_data *lpc;
+ struct bmc_mbox_msg *msg;
+ int rc;
+
+ lpc = container_of(bl, struct mbox_flash_data, bl);
+ msg = get_msg_memory(lpc);
+ if (!msg)
+ return FLASH_ERR_MALLOC_FAILED;
+
+ msg->command = MBOX_C_GET_FLASH_INFO;
+ msg->callback = &get_info_cb;
+ msg->priv = lpc;
+ msg->data[0] = 1; /* V1, do better */
+
+ /*
+ * We want to avoid runtime mallocs in skiboot. The expected
+ * behavour to uses of libflash is that one can free() the memory
+ * returned.
+ * NULL will do for now.
+ */
+ if (name)
+ *name = NULL;
+
+ lpc->busy = true;
+ rc = bmc_mbox_enqueue(msg);
+ if (rc) {
+ prlog(PR_ERR, "Failed to enqueue/send BMC MBOX message\n");
+ goto out;
+ }
+
+ if (wait_for_bmc(lpc, MBOX_DEFAULT_TIMEOUT)) {
+ prlog(PR_ERR, "Timeout waiting for BMC\n");
+ rc = FLASH_ERR_CTRL_TIMEOUT;
+ goto out;
+ }
+
+ rc = lpc->rc;
+ if (rc)
+ goto out;
+
+ lpc->bl.erase_mask = lpc->erase_granule - 1;
+
+ if (total_size)
+ *total_size = lpc->total_size;
+ if (erase_granule)
+ *erase_granule = lpc->erase_granule;
+
+out:
+ free_msg_memory(msg);
+ return rc;
+}
+
+static int mbox_flash_erase(struct blocklevel_device *bl __unused, uint64_t pos __unused, uint64_t len __unused)
+{
+ /*
+ * We can probably get away with doing nothing.
+ * TODO: Rethink this, causes interesting behaviour in pflash.
+ * Users do expect pflash -{e,E} to do something
+ */
+ return 0;
+}
+
+static void init_cb(struct bmc_mbox_msg *msg)
+{
+ struct mbox_flash_data *lpc;
+
+ prlog(PR_DEBUG, "INIT CB, BMC OK\n");
+
+ lpc = msg->priv;
+
+ if (msg->response != MBOX_R_SUCCESS) {
+ prlog(PR_ERR, "Bad response code from BMC %d\n", msg->response);
+ lpc->rc = msg->response;
+ goto out;
+ }
+
+ lpc->read.size = get_u16(&msg->data[1]) << lpc->shift;
+ lpc->write.size = get_u16(&msg->data[3]) << lpc->shift;
+
+ lpc->rc = 0;
+out:
+ lpc->busy = false;
+}
+
+int mbox_flash_init(struct blocklevel_device **bl)
+{
+ struct mbox_flash_data *lpc;
+ struct bmc_mbox_msg *msg;
+ int rc;
+
+ if (!bl)
+ return FLASH_ERR_PARM_ERROR;
+
+ *bl = NULL;
+
+ lpc = zalloc(sizeof(struct mbox_flash_data));
+ if (!lpc)
+ return FLASH_ERR_MALLOC_FAILED;
+
+ /* For V1 of the protocol this is fixed. This could change */
+ lpc->shift = 12;
+
+ msg = get_msg_memory(lpc);
+ if (!msg) {
+ rc = FLASH_ERR_MALLOC_FAILED;
+ goto out;
+ }
+
+ msg->command = MBOX_C_GET_MBOX_INFO;
+ msg->callback = &init_cb;
+ msg->priv = lpc;
+ msg->data[0] = 1; /* V1, do better */
+
+ lpc->busy = true;
+ rc = bmc_mbox_enqueue(msg);
+ if (rc) {
+ prlog(PR_ERR, "Failed to enqueue/send BMC MBOX message\n");
+ goto out_msg;
+ }
+
+ if (wait_for_bmc(lpc, MBOX_DEFAULT_TIMEOUT)) {
+ prlog(PR_ERR, "Timeout waiting for BMC\n");
+ rc = FLASH_ERR_CTRL_TIMEOUT;
+ goto out_msg;
+ }
+
+ rc = lpc->rc;
+ if (rc)
+ goto out_msg;
+
+ lpc->bl.keep_alive = 0;
+ lpc->bl.read = &mbox_flash_read;
+ lpc->bl.write = &mbox_flash_write;
+ lpc->bl.erase = &mbox_flash_erase;
+ lpc->bl.get_info = &mbox_flash_get_info;
+
+ *bl = &(lpc->bl);
+ return 0;
+
+out_msg:
+ free_msg_memory(msg);
+out:
+ free(lpc);
+ return rc;
+}
+
+void mbox_flash_exit(struct blocklevel_device *bl)
+{
+ struct mbox_flash_data *lpc;
+ if (bl) {
+ lpc = container_of(bl, struct mbox_flash_data, bl);
+ free(lpc);
+ }
+}
diff --git a/libflash/mbox-flash.h b/libflash/mbox-flash.h
new file mode 100644
index 00000000..cd587d4c
--- /dev/null
+++ b/libflash/mbox-flash.h
@@ -0,0 +1,24 @@
+/* Copyright 2017 IBM Corp.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __LIBFLASH_MBOX_FLASH_H
+#define __LIBFLASH_MBOX_FLASH_H
+
+int mbox_flash_init(struct blocklevel_device **bl);
+void mbox_flash_exit(struct blocklevel_device *bl);
+#endif /* __LIBFLASH_MBOX_FLASH_H */
+
+
--
2.11.0
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