iwlwifi: trans: Take ownership on secure machine before FW load

When we load the firmware for the 8000 B step device, it'll
verify its signature. In the current version of the
hardware, there can be a race between the WiFi firmware
being loaded and the Bluetooth firmware being loaded.

Check that WiFi is authenticated, if not, take ownership
on the authentication machine to make sure that the WiFi
firmware will be authenticated.

Signed-off-by: Eran Harary <eran.harary@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/pcie/trans.c b/drivers/net/wireless/iwlwifi/pcie/trans.c
index 421ef6b5fae2..9ce5e614c324 100644
--- a/drivers/net/wireless/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/iwlwifi/pcie/trans.c
@@ -682,6 +682,43 @@ static int iwl_pcie_load_section(struct iwl_trans *trans, u8 section_num,
 	return ret;
 }
 
+/*
+ * Driver Takes the ownership on secure machine before FW load
+ * and prevent race with the BT load.
+ * W/A for ROM bug. (should be remove in the next Si step)
+ */
+static int iwl_pcie_rsa_race_bug_wa(struct iwl_trans *trans)
+{
+	u32 val, loop = 1000;
+
+	/* Check the RSA semaphore is accessible - if not, we are in trouble */
+	val = iwl_read_prph(trans, PREG_AUX_BUS_WPROT_0);
+	if (val & (BIT(1) | BIT(17))) {
+		IWL_ERR(trans,
+			"can't access the RSA semaphore it is write protected\n");
+		return 0;
+	}
+
+	/* take ownership on the AUX IF */
+	iwl_write_prph(trans, WFPM_CTRL_REG, WFPM_AUX_CTL_AUX_IF_MAC_OWNER_MSK);
+	iwl_write_prph(trans, AUX_MISC_MASTER1_EN, AUX_MISC_MASTER1_EN_SBE_MSK);
+
+	do {
+		iwl_write_prph(trans, AUX_MISC_MASTER1_SMPHR_STATUS, 0x1);
+		val = iwl_read_prph(trans, AUX_MISC_MASTER1_SMPHR_STATUS);
+		if (val == 0x1) {
+			iwl_write_prph(trans, RSA_ENABLE, 0);
+			return 0;
+		}
+
+		udelay(10);
+		loop--;
+	} while (loop > 0);
+
+	IWL_ERR(trans, "Failed to take ownership on secure machine\n");
+	return -EIO;
+}
+
 static int iwl_pcie_load_cpu_sections_8000b(struct iwl_trans *trans,
 					    const struct fw_img *image,
 					    int cpu,
@@ -901,6 +938,11 @@ static int iwl_pcie_load_given_ucode_8000b(struct iwl_trans *trans,
 	if (trans->dbg_dest_tlv)
 		iwl_pcie_apply_destination(trans);
 
+	/* TODO: remove in the next Si step */
+	ret = iwl_pcie_rsa_race_bug_wa(trans);
+	if (ret)
+		return ret;
+
 	/* configure the ucode to be ready to get the secured image */
 	/* release CPU reset */
 	iwl_write_prph(trans, RELEASE_CPU_RESET, RELEASE_CPU_RESET_BIT);