[PATCH 4/5] ASoC: SOF: Intel: hda-loader: add IMR restore support

[Pierre-Louis Bossart]

From: Keyon Jie <yang.jie at linux.intel.com>

If the firmware declares the IMR restore feature, we only need to do a
simple powering up to resume from D3, no firmware re-downloading
needed - the context is saved/restored to/from IMR without needing
driver support.

Add a hda_dsp_boot_imr() helper for this simple DSP reboot, and use it
when it is available.

Reviewed-by: Ranjani Sridharan <ranjani.sridharan at linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi at linux.intel.com>
Signed-off-by: Keyon Jie <yang.jie at linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
---
 sound/soc/sof/intel/hda-loader.c | 38 ++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/sound/soc/sof/intel/hda-loader.c b/sound/soc/sof/intel/hda-loader.c
index 7f1b1d0f2422..baf2ff146f50 100644
--- a/sound/soc/sof/intel/hda-loader.c
+++ b/sound/soc/sof/intel/hda-loader.c
@@ -353,6 +353,38 @@ int hda_dsp_cl_boot_firmware_iccmax(struct snd_sof_dev *sdev)
 	return ret;
 }
 
+static int hda_dsp_boot_imr(struct snd_sof_dev *sdev)
+{
+	struct sof_intel_hda_dev *hda = sdev->pdata->hw_pdata;
+	const struct sof_intel_dsp_desc *chip = hda->desc;
+	unsigned long mask;
+	u32 j;
+	int ret;
+
+	/* power up & unstall/run the cores to run the firmware */
+	ret = hda_dsp_enable_core(sdev, chip->init_core_mask);
+	if (ret < 0) {
+		dev_err(sdev->dev, "dsp core start failed %d\n", ret);
+		return -EIO;
+	}
+
+	/* set enabled cores mask and increment ref count for cores in init_core_mask */
+	sdev->enabled_cores_mask |= chip->init_core_mask;
+	mask = sdev->enabled_cores_mask;
+	for_each_set_bit(j, &mask, SOF_MAX_DSP_NUM_CORES)
+		sdev->dsp_core_ref_count[j]++;
+
+	hda_ssp_set_cbp_cfp(sdev);
+
+	/* enable IPC interrupts */
+	hda_dsp_ipc_int_enable(sdev);
+
+	/* process wakes */
+	hda_sdw_process_wakeen(sdev);
+
+	return ret;
+}
+
 int hda_dsp_cl_boot_firmware(struct snd_sof_dev *sdev)
 {
 	struct sof_intel_hda_dev *hda = sdev->pdata->hw_pdata;
@@ -363,6 +395,12 @@ int hda_dsp_cl_boot_firmware(struct snd_sof_dev *sdev)
 	struct firmware stripped_firmware;
 	int ret, ret1, i;
 
+	if ((sdev->fw_ready.flags & SOF_IPC_INFO_D3_PERSISTENT) &&
+	    !sdev->first_boot) {
+		dev_dbg(sdev->dev, "IMR restore supported, booting from IMR directly\n");
+		return hda_dsp_boot_imr(sdev);
+	}
+
 	chip_info = desc->chip_info;
 
 	if (plat_data->fw->size <= plat_data->fw_offset) {
-- 
2.25.1