wifi: rtw89: fw: shrink download size of security section for RTL8852B

For RTL8852B, when current firmware is secure boot, the security section
needs a special treatment that shrink its size to 960.

As figure below, not only shrink the amount of download size of security
section (2), but also need to modify the section size in firmware header
(1) that is also downloaded to chip.

   +---------------------------+
   |      firmware header      |
   |                           |
   | +-----------------------+ |
   | | section type, size N -|-|-------+
   | | ...               (1) | |       |
   | +-----------------------+ |       |
   +---------------------------+       | 2048 shrink to 960
   :                           :       |
   +---------------------------+ -\    |
   |  security section type 9  |  |    |
   |           (2)             |  | <--+
   |                           |  |
   +---------------------------+ -/

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20241030022135.11688-5-pkshih@realtek.com

2 files changed, 34 insertions, 3 deletions

diff --git a/drivers/net/wireless/realtek/rtw89/fw.c b/drivers/net/wireless/realtek/rtw89/fw.c
index 2435e6d285c3..3d36e17b2ff8 100644
--- a/drivers/net/wireless/realtek/rtw89/fw.c
+++ b/drivers/net/wireless/realtek/rtw89/fw.c
@@ -124,7 +124,9 @@ static int rtw89_fw_hdr_parser_v0(struct rtw89_dev *rtwdev, const u8 *fw, u32 le
 				  struct rtw89_fw_bin_info *info)
 {
 	const struct rtw89_fw_hdr *fw_hdr = (const struct rtw89_fw_hdr *)fw;
+	const struct rtw89_chip_info *chip = rtwdev->chip;
 	struct rtw89_fw_hdr_section_info *section_info;
+	struct rtw89_fw_secure *sec = &rtwdev->fw.sec;
 	const struct rtw89_fw_dynhdr_hdr *fwdynhdr;
 	const struct rtw89_fw_hdr_section *section;
 	const u8 *fw_end = fw + len;
@@ -165,6 +167,9 @@ static int rtw89_fw_hdr_parser_v0(struct rtw89_dev *rtwdev, const u8 *fw, u32 le
 			section_info->mssc =
 				le32_get_bits(section->w2, FWSECTION_HDR_W2_MSSC);
 			mssc_len += section_info->mssc * FWDL_SECURITY_SIGLEN;
+
+			if (sec->secure_boot && chip->chip_id == RTL8852B)
+				section_info->len_override = 960;
 		} else {
 			section_info->mssc = 0;
 		}
@@ -1155,9 +1160,24 @@ static u32 __rtw89_fw_download_tweak_hdr_v0(struct rtw89_dev *rtwdev,
 					    struct rtw89_fw_bin_info *info,
 					    struct rtw89_fw_hdr *fw_hdr)
 {
+	struct rtw89_fw_hdr_section_info *section_info;
+	struct rtw89_fw_hdr_section *section;
+	int i;
+
 	le32p_replace_bits(&fw_hdr->w7, FWDL_SECTION_PER_PKT_LEN,
 			   FW_HDR_W7_PART_SIZE);
 
+	for (i = 0; i < info->section_num; i++) {
+		section_info = &info->section_info[i];
+
+		if (!section_info->len_override)
+			continue;
+
+		section = &fw_hdr->sections[i];
+		le32p_replace_bits(&section->w1, section_info->len_override,
+				   FWSECTION_HDR_W1_SEC_SIZE);
+	}
+
 	return 0;
 }
 
@@ -1286,10 +1306,20 @@ static int __rtw89_fw_download_main(struct rtw89_dev *rtwdev,
 	if (info->ignore)
 		return 0;
 
+	if (info->len_override) {
+		if (info->len_override > info->len)
+			rtw89_warn(rtwdev, "override length %u larger than original %u\n",
+				   info->len_override, info->len);
+		else
+			residue_len = info->len_override;
+	}
+
 	if (info->key_addr && info->key_len) {
-		if (info->len > FWDL_SECTION_PER_PKT_LEN || info->len < info->key_len)
-			rtw89_warn(rtwdev, "ignore to copy key data because of len %d, %d, %d\n",
-				   info->len, FWDL_SECTION_PER_PKT_LEN, info->key_len);
+		if (residue_len > FWDL_SECTION_PER_PKT_LEN || info->len < info->key_len)
+			rtw89_warn(rtwdev,
+				   "ignore to copy key data because of len %d, %d, %d, %d\n",
+				   info->len, FWDL_SECTION_PER_PKT_LEN,
+				   info->key_len, residue_len);
 		else
 			copy_key = true;
 	}
diff --git a/drivers/net/wireless/realtek/rtw89/fw.h b/drivers/net/wireless/realtek/rtw89/fw.h
index 2e2035705881..83fcd5edc057 100644
--- a/drivers/net/wireless/realtek/rtw89/fw.h
+++ b/drivers/net/wireless/realtek/rtw89/fw.h
@@ -261,6 +261,7 @@ struct rtw89_fw_hdr_section_info {
 	u8 redl;
 	const u8 *addr;
 	u32 len;
+	u32 len_override;
 	u32 dladdr;
 	u32 mssc;
 	u8 type;