drm/i915: Move sandybride pcode access to intel_sideband.c

sandybride_pcode is another sideband, so move it to their new home.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190426081725.31217-8-chris@chris-wilson.co.uk

1 files changed, 196 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_sideband.c b/drivers/gpu/drm/i915/intel_sideband.c
index 7113fb8850d6..87b5a14c7ca8 100644
--- a/drivers/gpu/drm/i915/intel_sideband.c
+++ b/drivers/gpu/drm/i915/intel_sideband.c
@@ -333,3 +333,199 @@ void intel_sbi_write(struct drm_i915_private *i915, u16 reg, u32 value,
 {
 	intel_sbi_rw(i915, reg, destination, &value, false);
 }
+
+static inline int gen6_check_mailbox_status(u32 mbox)
+{
+	switch (mbox & GEN6_PCODE_ERROR_MASK) {
+	case GEN6_PCODE_SUCCESS:
+		return 0;
+	case GEN6_PCODE_UNIMPLEMENTED_CMD:
+		return -ENODEV;
+	case GEN6_PCODE_ILLEGAL_CMD:
+		return -ENXIO;
+	case GEN6_PCODE_MIN_FREQ_TABLE_GT_RATIO_OUT_OF_RANGE:
+	case GEN7_PCODE_MIN_FREQ_TABLE_GT_RATIO_OUT_OF_RANGE:
+		return -EOVERFLOW;
+	case GEN6_PCODE_TIMEOUT:
+		return -ETIMEDOUT;
+	default:
+		MISSING_CASE(mbox & GEN6_PCODE_ERROR_MASK);
+		return 0;
+	}
+}
+
+static inline int gen7_check_mailbox_status(u32 mbox)
+{
+	switch (mbox & GEN6_PCODE_ERROR_MASK) {
+	case GEN6_PCODE_SUCCESS:
+		return 0;
+	case GEN6_PCODE_ILLEGAL_CMD:
+		return -ENXIO;
+	case GEN7_PCODE_TIMEOUT:
+		return -ETIMEDOUT;
+	case GEN7_PCODE_ILLEGAL_DATA:
+		return -EINVAL;
+	case GEN7_PCODE_MIN_FREQ_TABLE_GT_RATIO_OUT_OF_RANGE:
+		return -EOVERFLOW;
+	default:
+		MISSING_CASE(mbox & GEN6_PCODE_ERROR_MASK);
+		return 0;
+	}
+}
+
+static int __sandybridge_pcode_rw(struct drm_i915_private *i915,
+				  u32 mbox, u32 *val,
+				  int fast_timeout_us,
+				  int slow_timeout_ms,
+				  bool is_read)
+{
+	struct intel_uncore *uncore = &i915->uncore;
+
+	lockdep_assert_held(&i915->sb_lock);
+
+	/*
+	 * GEN6_PCODE_* are outside of the forcewake domain, we can
+	 * use te fw I915_READ variants to reduce the amount of work
+	 * required when reading/writing.
+	 */
+
+	if (intel_uncore_read_fw(uncore, GEN6_PCODE_MAILBOX) & GEN6_PCODE_READY)
+		return -EAGAIN;
+
+	intel_uncore_write_fw(uncore, GEN6_PCODE_DATA, *val);
+	intel_uncore_write_fw(uncore, GEN6_PCODE_DATA1, 0);
+	intel_uncore_write_fw(uncore,
+			      GEN6_PCODE_MAILBOX, GEN6_PCODE_READY | mbox);
+
+	if (__intel_wait_for_register_fw(uncore,
+					 GEN6_PCODE_MAILBOX,
+					 GEN6_PCODE_READY, 0,
+					 fast_timeout_us,
+					 slow_timeout_ms,
+					 &mbox))
+		return -ETIMEDOUT;
+
+	if (is_read)
+		*val = intel_uncore_read_fw(uncore, GEN6_PCODE_DATA);
+
+	if (INTEL_GEN(i915) > 6)
+		return gen7_check_mailbox_status(mbox);
+	else
+		return gen6_check_mailbox_status(mbox);
+}
+
+int sandybridge_pcode_read(struct drm_i915_private *i915, u32 mbox, u32 *val)
+{
+	int err;
+
+	mutex_lock(&i915->sb_lock);
+	err = __sandybridge_pcode_rw(i915, mbox, val,
+				     500, 0,
+				     true);
+	mutex_unlock(&i915->sb_lock);
+
+	if (err) {
+		DRM_DEBUG_DRIVER("warning: pcode (read from mbox %x) mailbox access failed for %ps: %d\n",
+				 mbox, __builtin_return_address(0), err);
+	}
+
+	return err;
+}
+
+int sandybridge_pcode_write_timeout(struct drm_i915_private *i915,
+				    u32 mbox, u32 val,
+				    int fast_timeout_us,
+				    int slow_timeout_ms)
+{
+	int err;
+
+	mutex_lock(&i915->sb_lock);
+	err = __sandybridge_pcode_rw(i915, mbox, &val,
+				     fast_timeout_us, slow_timeout_ms,
+				     false);
+	mutex_unlock(&i915->sb_lock);
+
+	if (err) {
+		DRM_DEBUG_DRIVER("warning: pcode (write of 0x%08x to mbox %x) mailbox access failed for %ps: %d\n",
+				 val, mbox, __builtin_return_address(0), err);
+	}
+
+	return err;
+}
+
+static bool skl_pcode_try_request(struct drm_i915_private *i915, u32 mbox,
+				  u32 request, u32 reply_mask, u32 reply,
+				  u32 *status)
+{
+	*status = __sandybridge_pcode_rw(i915, mbox, &request,
+					 500, 0,
+					 true);
+
+	return *status || ((request & reply_mask) == reply);
+}
+
+/**
+ * skl_pcode_request - send PCODE request until acknowledgment
+ * @i915: device private
+ * @mbox: PCODE mailbox ID the request is targeted for
+ * @request: request ID
+ * @reply_mask: mask used to check for request acknowledgment
+ * @reply: value used to check for request acknowledgment
+ * @timeout_base_ms: timeout for polling with preemption enabled
+ *
+ * Keep resending the @request to @mbox until PCODE acknowledges it, PCODE
+ * reports an error or an overall timeout of @timeout_base_ms+50 ms expires.
+ * The request is acknowledged once the PCODE reply dword equals @reply after
+ * applying @reply_mask. Polling is first attempted with preemption enabled
+ * for @timeout_base_ms and if this times out for another 50 ms with
+ * preemption disabled.
+ *
+ * Returns 0 on success, %-ETIMEDOUT in case of a timeout, <0 in case of some
+ * other error as reported by PCODE.
+ */
+int skl_pcode_request(struct drm_i915_private *i915, u32 mbox, u32 request,
+		      u32 reply_mask, u32 reply, int timeout_base_ms)
+{
+	u32 status;
+	int ret;
+
+	mutex_lock(&i915->sb_lock);
+
+#define COND \
+	skl_pcode_try_request(i915, mbox, request, reply_mask, reply, &status)
+
+	/*
+	 * Prime the PCODE by doing a request first. Normally it guarantees
+	 * that a subsequent request, at most @timeout_base_ms later, succeeds.
+	 * _wait_for() doesn't guarantee when its passed condition is evaluated
+	 * first, so send the first request explicitly.
+	 */
+	if (COND) {
+		ret = 0;
+		goto out;
+	}
+	ret = _wait_for(COND, timeout_base_ms * 1000, 10, 10);
+	if (!ret)
+		goto out;
+
+	/*
+	 * The above can time out if the number of requests was low (2 in the
+	 * worst case) _and_ PCODE was busy for some reason even after a
+	 * (queued) request and @timeout_base_ms delay. As a workaround retry
+	 * the poll with preemption disabled to maximize the number of
+	 * requests. Increase the timeout from @timeout_base_ms to 50ms to
+	 * account for interrupts that could reduce the number of these
+	 * requests, and for any quirks of the PCODE firmware that delays
+	 * the request completion.
+	 */
+	DRM_DEBUG_KMS("PCODE timeout, retrying with preemption disabled\n");
+	WARN_ON_ONCE(timeout_base_ms > 3);
+	preempt_disable();
+	ret = wait_for_atomic(COND, 50);
+	preempt_enable();
+
+out:
+	mutex_unlock(&i915->sb_lock);
+	return ret ? ret : status;
+#undef COND
+}