bus: mhi: host: Fix endianness of BHI vector table

JIRA: https://issues.redhat.com/browse/RHEL-122857

commit f471578
Author: Alexander Wilhelm <alexander.wilhelm@westermo.com>
Date:   Mon May 19 16:58:37 2025 +0200

    bus: mhi: host: Fix endianness of BHI vector table
    
    On big endian platform like PowerPC, the MHI bus (which is little endian)
    does not start properly. The following example shows the error messages by
    using QCN9274 WLAN device with ath12k driver:
    
        ath12k_pci 0001:01:00.0: BAR 0: assigned [mem 0xc00000000-0xc001fffff 64bit]
        ath12k_pci 0001:01:00.0: MSI vectors: 1
        ath12k_pci 0001:01:00.0: Hardware name: qcn9274 hw2.0
        ath12k_pci 0001:01:00.0: failed to set mhi state: POWER_ON(2)
        ath12k_pci 0001:01:00.0: failed to start mhi: -110
        ath12k_pci 0001:01:00.0: failed to power up :-110
        ath12k_pci 0001:01:00.0: failed to create soc core: -110
        ath12k_pci 0001:01:00.0: failed to init core: -110
        ath12k_pci: probe of 0001:01:00.0 failed with error -110
    
    The issue seems to be with the incorrect DMA address/size used for
    transferring the firmware image over BHI. So fix it by converting the DMA
    address and size of the BHI vector table to little endian format before
    sending them to the device.
    
    Fixes: 6cd330a ("bus: mhi: core: Add support for ringing channel/event ring doorbells")
    Signed-off-by: Alexander Wilhelm <alexander.wilhelm@westermo.com>
    [mani: added stable tag and reworded commit message]
    Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
    Reviewed-by: Jeff Hugo <jeff.hugo@oss.qualcomm.com>
    Reviewed-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
    Cc: stable@vger.kernel.org
    Link: https://patch.msgid.link/20250519145837.958153-1-alexander.wilhelm@westermo.com

Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>

Author: jtornosm

drivers/bus/mhi/host/boot.c

@@ -31,8 +31,8 @@ int mhi_rddm_prepare(struct mhi_controller *mhi_cntrl,
 	int ret;
 
 	for (i = 0; i < img_info->entries - 1; i++, mhi_buf++, bhi_vec++) {
-		bhi_vec->dma_addr = mhi_buf->dma_addr;
-		bhi_vec->size = mhi_buf->len;
+		bhi_vec->dma_addr = cpu_to_le64(mhi_buf->dma_addr);
+		bhi_vec->size = cpu_to_le64(mhi_buf->len);
 	}
 
 	dev_dbg(dev, "BHIe programming for RDDM\n");
@@ -431,8 +431,8 @@ static void mhi_firmware_copy_bhie(struct mhi_controller *mhi_cntrl,
 	while (remainder) {
 		to_cpy = min(remainder, mhi_buf->len);
 		memcpy(mhi_buf->buf, buf, to_cpy);
-		bhi_vec->dma_addr = mhi_buf->dma_addr;
-		bhi_vec->size = to_cpy;
+		bhi_vec->dma_addr = cpu_to_le64(mhi_buf->dma_addr);
+		bhi_vec->size = cpu_to_le64(to_cpy);
 
 		buf += to_cpy;
 		remainder -= to_cpy;

drivers/bus/mhi/host/internal.h

@@ -25,8 +25,8 @@ struct mhi_ctxt {
 };
 
 struct bhi_vec_entry {
-	u64 dma_addr;
-	u64 size;
+	__le64 dma_addr;
+	__le64 size;
 };
 
 enum mhi_fw_load_type {