--- /dev/null
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2026 Intel Corporation
+ */
+
+#include <linux/bitfield.h>
+#include <linux/cleanup.h>
+#include <linux/minmax.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include "regs/xe_sysctrl_regs.h"
+#include "xe_device.h"
+#include "xe_mmio.h"
+#include "xe_pm.h"
+#include "xe_printk.h"
+#include "xe_sysctrl.h"
+#include "xe_sysctrl_mailbox.h"
+#include "xe_sysctrl_mailbox_types.h"
+
+struct xe_sysctrl_mailbox_msg_hdr {
+ __le32 data;
+} __packed;
+
+#define XE_SYSCTRL_HDR_GROUP_ID(hdr) \
+ FIELD_GET(SYSCTRL_HDR_GROUP_ID_MASK, le32_to_cpu((hdr)->data))
+
+#define XE_SYSCTRL_HDR_COMMAND(hdr) \
+ FIELD_GET(SYSCTRL_HDR_COMMAND_MASK, le32_to_cpu((hdr)->data))
+
+#define XE_SYSCTRL_HDR_IS_RESPONSE(hdr) \
+ FIELD_GET(SYSCTRL_HDR_IS_RESPONSE, le32_to_cpu((hdr)->data))
+
+#define XE_SYSCTRL_HDR_RESULT(hdr) \
+ FIELD_GET(SYSCTRL_HDR_RESULT_MASK, le32_to_cpu((hdr)->data))
+
+static bool sysctrl_wait_bit_clear(struct xe_sysctrl *sc, u32 bit_mask,
+ unsigned int timeout_ms)
+{
+ int ret;
+
+ ret = xe_mmio_wait32_not(sc->mmio, SYSCTRL_MB_CTRL, bit_mask, bit_mask,
+ timeout_ms * 1000, NULL, false);
+
+ return ret == 0;
+}
+
+static bool sysctrl_wait_bit_set(struct xe_sysctrl *sc, u32 bit_mask,
+ unsigned int timeout_ms)
+{
+ int ret;
+
+ ret = xe_mmio_wait32(sc->mmio, SYSCTRL_MB_CTRL, bit_mask, bit_mask,
+ timeout_ms * 1000, NULL, false);
+
+ return ret == 0;
+}
+
+static int sysctrl_write_frame(struct xe_sysctrl *sc, const void *frame,
+ size_t len)
+{
+ static const struct xe_reg regs[] = {
+ SYSCTRL_MB_DATA0, SYSCTRL_MB_DATA1, SYSCTRL_MB_DATA2, SYSCTRL_MB_DATA3
+ };
+ struct xe_device *xe = sc_to_xe(sc);
+ u32 val[XE_SYSCTRL_MB_FRAME_SIZE / sizeof(u32)] = {0};
+ u32 dw = DIV_ROUND_UP(len, sizeof(u32));
+ u32 i;
+
+ xe_assert(xe, len > 0 && len <= XE_SYSCTRL_MB_FRAME_SIZE);
+
+ memcpy(val, frame, len);
+
+ for (i = 0; i < dw; i++)
+ xe_mmio_write32(sc->mmio, regs[i], val[i]);
+
+ return 0;
+}
+
+static int sysctrl_read_frame(struct xe_sysctrl *sc, void *frame,
+ size_t len)
+{
+ static const struct xe_reg regs[] = {
+ SYSCTRL_MB_DATA0, SYSCTRL_MB_DATA1, SYSCTRL_MB_DATA2, SYSCTRL_MB_DATA3
+ };
+ struct xe_device *xe = sc_to_xe(sc);
+ u32 val[XE_SYSCTRL_MB_FRAME_SIZE / sizeof(u32)] = {0};
+ u32 dw = DIV_ROUND_UP(len, sizeof(u32));
+ u32 i;
+
+ xe_assert(xe, len > 0 && len <= XE_SYSCTRL_MB_FRAME_SIZE);
+
+ for (i = 0; i < dw; i++)
+ val[i] = xe_mmio_read32(sc->mmio, regs[i]);
+
+ memcpy(frame, val, len);
+
+ return 0;
+}
+
+static void sysctrl_clear_response(struct xe_sysctrl *sc)
+{
+ xe_mmio_rmw32(sc->mmio, SYSCTRL_MB_CTRL, SYSCTRL_MB_CTRL_RUN_BUSY_OUT, 0);
+}
+
+static int sysctrl_prepare_command(struct xe_device *xe,
+ u8 group_id, u8 command,
+ const void *data_in, size_t data_in_len,
+ u8 **mbox_cmd, size_t *cmd_size)
+{
+ struct xe_sysctrl_mailbox_msg_hdr *hdr;
+ size_t size;
+ u8 *buffer;
+
+ xe_assert(xe, command <= SYSCTRL_HDR_COMMAND_MAX);
+
+ if (data_in_len > XE_SYSCTRL_MB_MAX_MESSAGE_SIZE - sizeof(*hdr)) {
+ xe_err(xe, "sysctrl: Input data too large: %zu bytes\n", data_in_len);
+ return -EINVAL;
+ }
+
+ size = sizeof(*hdr) + data_in_len;
+
+ buffer = kmalloc(size, GFP_KERNEL);
+ if (!buffer)
+ return -ENOMEM;
+
+ hdr = (struct xe_sysctrl_mailbox_msg_hdr *)buffer;
+ hdr->data = cpu_to_le32(FIELD_PREP(SYSCTRL_HDR_GROUP_ID_MASK, group_id) |
+ FIELD_PREP(SYSCTRL_HDR_COMMAND_MASK, command));
+
+ if (data_in && data_in_len)
+ memcpy(buffer + sizeof(*hdr), data_in, data_in_len);
+
+ *mbox_cmd = buffer;
+ *cmd_size = size;
+
+ return 0;
+}
+
+static int sysctrl_send_frames(struct xe_sysctrl *sc,
+ const u8 *mbox_cmd,
+ size_t cmd_size, unsigned int timeout_ms)
+{
+ struct xe_device *xe = sc_to_xe(sc);
+ u32 ctrl_reg, total_frames, frame;
+ size_t bytes_sent, frame_size;
+
+ total_frames = DIV_ROUND_UP(cmd_size, XE_SYSCTRL_MB_FRAME_SIZE);
+
+ if (!sysctrl_wait_bit_clear(sc, SYSCTRL_MB_CTRL_RUN_BUSY, timeout_ms)) {
+ xe_err(xe, "sysctrl: Mailbox busy\n");
+ return -EBUSY;
+ }
+
+ sc->phase_bit ^= 1;
+ bytes_sent = 0;
+
+ for (frame = 0; frame < total_frames; frame++) {
+ frame_size = min_t(size_t, cmd_size - bytes_sent, XE_SYSCTRL_MB_FRAME_SIZE);
+
+ if (sysctrl_write_frame(sc, mbox_cmd + bytes_sent, frame_size)) {
+ xe_err(xe, "sysctrl: Failed to write frame %u\n", frame);
+ sc->phase_bit = 0;
+ return -EIO;
+ }
+
+ ctrl_reg = SYSCTRL_MB_CTRL_RUN_BUSY |
+ REG_FIELD_PREP(SYSCTRL_FRAME_CURRENT_MASK, frame) |
+ REG_FIELD_PREP(SYSCTRL_FRAME_TOTAL_MASK, total_frames - 1) |
+ SYSCTRL_MB_CTRL_CMD |
+ (sc->phase_bit ? SYSCTRL_FRAME_PHASE : 0);
+
+ xe_mmio_write32(sc->mmio, SYSCTRL_MB_CTRL, ctrl_reg);
+
+ if (!sysctrl_wait_bit_clear(sc, SYSCTRL_MB_CTRL_RUN_BUSY, timeout_ms)) {
+ xe_err(xe, "sysctrl: Frame %u acknowledgment timeout\n", frame);
+ sc->phase_bit = 0;
+ return -ETIMEDOUT;
+ }
+
+ bytes_sent += frame_size;
+ }
+
+ return 0;
+}
+
+static int sysctrl_process_frame(struct xe_sysctrl *sc, void *out,
+ size_t frame_size, unsigned int timeout_ms,
+ bool *done)
+{
+ u32 curr_frame, total_frames, ctrl_reg;
+ struct xe_device *xe = sc_to_xe(sc);
+ int ret;
+
+ if (!sysctrl_wait_bit_set(sc, SYSCTRL_MB_CTRL_RUN_BUSY_OUT, timeout_ms)) {
+ xe_err(xe, "sysctrl: Response frame timeout\n");
+ return -ETIMEDOUT;
+ }
+
+ ctrl_reg = xe_mmio_read32(sc->mmio, SYSCTRL_MB_CTRL);
+ total_frames = FIELD_GET(SYSCTRL_FRAME_TOTAL_MASK, ctrl_reg);
+ curr_frame = FIELD_GET(SYSCTRL_FRAME_CURRENT_MASK, ctrl_reg);
+
+ ret = sysctrl_read_frame(sc, out, frame_size);
+ if (ret)
+ return ret;
+
+ sysctrl_clear_response(sc);
+
+ if (curr_frame == total_frames)
+ *done = true;
+
+ return 0;
+}
+
+static int sysctrl_receive_frames(struct xe_sysctrl *sc,
+ const struct xe_sysctrl_mailbox_msg_hdr *req,
+ void *data_out, size_t data_out_len,
+ size_t *rdata_len, unsigned int timeout_ms)
+{
+ struct xe_sysctrl_mailbox_msg_hdr *hdr;
+ struct xe_device *xe = sc_to_xe(sc);
+ size_t remain = sizeof(*hdr) + data_out_len;
+ u8 *buffer __free(kfree) = kzalloc(remain, GFP_KERNEL);
+ size_t frame_size;
+ bool done = false;
+ int ret = 0;
+ u8 *out;
+
+ if (!buffer)
+ return -ENOMEM;
+
+ out = buffer;
+ while (!done && remain) {
+ frame_size = min_t(size_t, remain, XE_SYSCTRL_MB_FRAME_SIZE);
+
+ ret = sysctrl_process_frame(sc, out, frame_size, timeout_ms,
+ &done);
+ if (ret)
+ return ret;
+
+ remain -= frame_size;
+ out += frame_size;
+ }
+
+ hdr = (struct xe_sysctrl_mailbox_msg_hdr *)buffer;
+
+ if (!XE_SYSCTRL_HDR_IS_RESPONSE(hdr) ||
+ XE_SYSCTRL_HDR_GROUP_ID(hdr) != XE_SYSCTRL_HDR_GROUP_ID(req) ||
+ XE_SYSCTRL_HDR_COMMAND(hdr) != XE_SYSCTRL_HDR_COMMAND(req)) {
+ xe_err(xe, "sysctrl: Response header mismatch\n");
+ return -EPROTO;
+ }
+
+ if (XE_SYSCTRL_HDR_RESULT(hdr) != 0) {
+ xe_err(xe, "sysctrl: Firmware error: 0x%02lx\n",
+ XE_SYSCTRL_HDR_RESULT(hdr));
+ return -EIO;
+ }
+
+ memcpy(data_out, hdr + 1, data_out_len);
+ *rdata_len = out - buffer - sizeof(*hdr);
+
+ return 0;
+}
+
+static int sysctrl_send_command(struct xe_sysctrl *sc,
+ const u8 *mbox_cmd, size_t cmd_size,
+ void *data_out, size_t data_out_len,
+ size_t *rdata_len, unsigned int timeout_ms)
+{
+ const struct xe_sysctrl_mailbox_msg_hdr *hdr;
+ size_t received;
+ int ret;
+
+ ret = sysctrl_send_frames(sc, mbox_cmd, cmd_size, timeout_ms);
+ if (ret)
+ return ret;
+
+ if (!data_out || !rdata_len)
+ return 0;
+
+ hdr = (const struct xe_sysctrl_mailbox_msg_hdr *)mbox_cmd;
+
+ ret = sysctrl_receive_frames(sc, hdr, data_out, data_out_len,
+ &received, timeout_ms);
+ if (ret)
+ return ret;
+
+ *rdata_len = received;
+
+ return 0;
+}
+
+/**
+ * xe_sysctrl_mailbox_init - Initialize System Controller mailbox interface
+ * @sc: System controller structure
+ *
+ * Initialize system controller mailbox interface for communication.
+ */
+void xe_sysctrl_mailbox_init(struct xe_sysctrl *sc)
+{
+ u32 ctrl_reg;
+
+ ctrl_reg = xe_mmio_read32(sc->mmio, SYSCTRL_MB_CTRL);
+ sc->phase_bit = (ctrl_reg & SYSCTRL_FRAME_PHASE) ? 1 : 0;
+}
+
+/**
+ * xe_sysctrl_send_command() - Send mailbox command to System Controller
+ * @sc: System Controller instance
+ * @cmd: Command descriptor containing request header and payload buffers
+ * @rdata_len: Pointer to store actual response data length
+ *
+ * Sends a mailbox command to System Controller firmware using
+ * System Controller mailbox and waits for a response.
+ *
+ * Request payload is provided via @cmd->data_in and @cmd->data_in_len.
+ * If a response is expected, @cmd->data_out must point to a buffer of
+ * size @cmd->data_out_len supplied by caller.
+ *
+ * On success, @rdata_len is updated with number of valid response bytes
+ * returned by firmware, bounded by @cmd->data_out_len.
+ *
+ * Return: 0 on success, or negative errno on failure.
+ */
+int xe_sysctrl_send_command(struct xe_sysctrl *sc,
+ struct xe_sysctrl_mailbox_command *cmd,
+ size_t *rdata_len)
+{
+ struct xe_device *xe = sc_to_xe(sc);
+ u8 group_id, command_code;
+ u8 *mbox_cmd = NULL;
+ size_t cmd_size = 0;
+ int ret;
+
+ guard(xe_pm_runtime_noresume)(xe);
+
+ if (!xe->info.has_sysctrl)
+ return -ENODEV;
+
+ xe_assert(xe, cmd->data_in || cmd->data_out);
+ xe_assert(xe, !cmd->data_in || cmd->data_in_len);
+ xe_assert(xe, !cmd->data_out || cmd->data_out_len);
+
+ group_id = XE_SYSCTRL_APP_HDR_GROUP_ID(&cmd->header);
+ command_code = XE_SYSCTRL_APP_HDR_COMMAND(&cmd->header);
+
+ might_sleep();
+
+ ret = sysctrl_prepare_command(xe, group_id, command_code,
+ cmd->data_in, cmd->data_in_len,
+ &mbox_cmd, &cmd_size);
+ if (ret) {
+ xe_err(xe, "sysctrl: Failed to prepare command: %pe\n", ERR_PTR(ret));
+ return ret;
+ }
+
+ guard(mutex)(&sc->cmd_lock);
+
+ ret = sysctrl_send_command(sc, mbox_cmd, cmd_size,
+ cmd->data_out, cmd->data_out_len, rdata_len,
+ XE_SYSCTRL_MB_DEFAULT_TIMEOUT_MS);
+ if (ret)
+ xe_err(xe, "sysctrl: Mailbox command failed: %pe\n", ERR_PTR(ret));
+
+ kfree(mbox_cmd);
+
+ return ret;
+}
projects / thirdparty / kernel / linux.git / commitdiff
