bus: mhi: Fix MHI DMA structure endianness

The MHI driver does not work on big endian architectures.  The
controller never transitions into mission mode.  This appears to be due
to the modem device expecting the various contexts and transfer rings to
have fields in little endian order in memory, but the driver constructs
them in native endianness.

Fix MHI event, channel and command contexts and TRE handling macros to
use explicit conversion to little endian.  Mark fields in relevant
structures as little endian to document this requirement.

Fixes: a6e2e3522f29 ("bus: mhi: core: Add support for PM state transitions")
Fixes: 6cd330ae76ff ("bus: mhi: core: Add support for ringing channel/event ring doorbells")
Cc: stable@vger.kernel.org
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paul Davey <paul.davey@alliedtelesis.co.nz>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20220301160308.107452-4-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 18 insertions, 18 deletions

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 09394a1c29ec..d8787aaa176b 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -293,17 +293,17 @@ int mhi_init_dev_ctxt(struct mhi_controller *mhi_cntrl)
 		if (mhi_chan->offload_ch)
 			continue;
 
-		tmp = chan_ctxt->chcfg;
+		tmp = le32_to_cpu(chan_ctxt->chcfg);
 		tmp &= ~CHAN_CTX_CHSTATE_MASK;
 		tmp |= (MHI_CH_STATE_DISABLED << CHAN_CTX_CHSTATE_SHIFT);
 		tmp &= ~CHAN_CTX_BRSTMODE_MASK;
 		tmp |= (mhi_chan->db_cfg.brstmode << CHAN_CTX_BRSTMODE_SHIFT);
 		tmp &= ~CHAN_CTX_POLLCFG_MASK;
 		tmp |= (mhi_chan->db_cfg.pollcfg << CHAN_CTX_POLLCFG_SHIFT);
-		chan_ctxt->chcfg = tmp;
+		chan_ctxt->chcfg = cpu_to_le32(tmp);
 
-		chan_ctxt->chtype = mhi_chan->type;
-		chan_ctxt->erindex = mhi_chan->er_index;
+		chan_ctxt->chtype = cpu_to_le32(mhi_chan->type);
+		chan_ctxt->erindex = cpu_to_le32(mhi_chan->er_index);
 
 		mhi_chan->ch_state = MHI_CH_STATE_DISABLED;
 		mhi_chan->tre_ring.db_addr = (void __iomem *)&chan_ctxt->wp;
@@ -328,14 +328,14 @@ int mhi_init_dev_ctxt(struct mhi_controller *mhi_cntrl)
 		if (mhi_event->offload_ev)
 			continue;
 
-		tmp = er_ctxt->intmod;
+		tmp = le32_to_cpu(er_ctxt->intmod);
 		tmp &= ~EV_CTX_INTMODC_MASK;
 		tmp &= ~EV_CTX_INTMODT_MASK;
 		tmp |= (mhi_event->intmod << EV_CTX_INTMODT_SHIFT);
-		er_ctxt->intmod = tmp;
+		er_ctxt->intmod = cpu_to_le32(tmp);
 
-		er_ctxt->ertype = MHI_ER_TYPE_VALID;
-		er_ctxt->msivec = mhi_event->irq;
+		er_ctxt->ertype = cpu_to_le32(MHI_ER_TYPE_VALID);
+		er_ctxt->msivec = cpu_to_le32(mhi_event->irq);
 		mhi_event->db_cfg.db_mode = true;
 
 		ring->el_size = sizeof(struct mhi_tre);
@@ -349,9 +349,9 @@ int mhi_init_dev_ctxt(struct mhi_controller *mhi_cntrl)
 		 * ring is empty
 		 */
 		ring->rp = ring->wp = ring->base;
-		er_ctxt->rbase = ring->iommu_base;
+		er_ctxt->rbase = cpu_to_le64(ring->iommu_base);
 		er_ctxt->rp = er_ctxt->wp = er_ctxt->rbase;
-		er_ctxt->rlen = ring->len;
+		er_ctxt->rlen = cpu_to_le64(ring->len);
 		ring->ctxt_wp = &er_ctxt->wp;
 	}
 
@@ -378,9 +378,9 @@ int mhi_init_dev_ctxt(struct mhi_controller *mhi_cntrl)
 			goto error_alloc_cmd;
 
 		ring->rp = ring->wp = ring->base;
-		cmd_ctxt->rbase = ring->iommu_base;
+		cmd_ctxt->rbase = cpu_to_le64(ring->iommu_base);
 		cmd_ctxt->rp = cmd_ctxt->wp = cmd_ctxt->rbase;
-		cmd_ctxt->rlen = ring->len;
+		cmd_ctxt->rlen = cpu_to_le64(ring->len);
 		ring->ctxt_wp = &cmd_ctxt->wp;
 	}
 
@@ -581,10 +581,10 @@ void mhi_deinit_chan_ctxt(struct mhi_controller *mhi_cntrl,
 	chan_ctxt->rp = 0;
 	chan_ctxt->wp = 0;
 
-	tmp = chan_ctxt->chcfg;
+	tmp = le32_to_cpu(chan_ctxt->chcfg);
 	tmp &= ~CHAN_CTX_CHSTATE_MASK;
 	tmp |= (MHI_CH_STATE_DISABLED << CHAN_CTX_CHSTATE_SHIFT);
-	chan_ctxt->chcfg = tmp;
+	chan_ctxt->chcfg = cpu_to_le32(tmp);
 
 	/* Update to all cores */
 	smp_wmb();
@@ -618,14 +618,14 @@ int mhi_init_chan_ctxt(struct mhi_controller *mhi_cntrl,
 		return -ENOMEM;
 	}
 
-	tmp = chan_ctxt->chcfg;
+	tmp = le32_to_cpu(chan_ctxt->chcfg);
 	tmp &= ~CHAN_CTX_CHSTATE_MASK;
 	tmp |= (MHI_CH_STATE_ENABLED << CHAN_CTX_CHSTATE_SHIFT);
-	chan_ctxt->chcfg = tmp;
+	chan_ctxt->chcfg = cpu_to_le32(tmp);
 
-	chan_ctxt->rbase = tre_ring->iommu_base;
+	chan_ctxt->rbase = cpu_to_le64(tre_ring->iommu_base);
 	chan_ctxt->rp = chan_ctxt->wp = chan_ctxt->rbase;
-	chan_ctxt->rlen = tre_ring->len;
+	chan_ctxt->rlen = cpu_to_le64(tre_ring->len);
 	tre_ring->ctxt_wp = &chan_ctxt->wp;
 
 	tre_ring->rp = tre_ring->wp = tre_ring->base;