Commit 0ab9fcd0 authored by Bhaumik Bhatt's avatar Bhaumik Bhatt Committed by Greg Kroah-Hartman
Browse files

bus: mhi: core: Ensure non-zero session or sequence ID values are used 



While writing any sequence or session identifiers, it is possible that
the host could write a zero value, whereas only non-zero values should
be supported writes to those registers. Ensure that the host does not
write a non-zero value for them and also log them in debug messages. A
macro is introduced to simplify this check and the existing checks are
also converted to use this macro.

Signed-off-by: default avatarBhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: default avatarJeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: default avatarManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: default avatarManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20200521170249.21795-9-manivannan.sadhasivam@linaro.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 0a895f09

drivers/bus/mhi/core/boot.c

+7 −8
Original line number Diff line number Diff line
@@ -43,10 +43,7 @@ void mhi_rddm_prepare(struct mhi_controller *mhi_cntrl, 
		      lower_32_bits(mhi_buf->dma_addr));



	mhi_write_reg(mhi_cntrl, base, BHIE_RXVECSIZE_OFFS, mhi_buf->len);

	sequence_id = prandom_u32() & BHIE_RXVECSTATUS_SEQNUM_BMSK;



	if (unlikely(!sequence_id))

		sequence_id = 1;

	sequence_id = MHI_RANDOM_U32_NONZERO(BHIE_RXVECSTATUS_SEQNUM_BMSK);



	mhi_write_reg_field(mhi_cntrl, base, BHIE_RXVECDB_OFFS,

			    BHIE_RXVECDB_SEQNUM_BMSK, BHIE_RXVECDB_SEQNUM_SHFT,
@@ -189,7 +186,9 @@ static int mhi_fw_load_amss(struct mhi_controller *mhi_cntrl, 
		return -EIO;

	}



	dev_dbg(dev, "Starting AMSS download via BHIe\n");

	sequence_id = MHI_RANDOM_U32_NONZERO(BHIE_TXVECSTATUS_SEQNUM_BMSK);

	dev_dbg(dev, "Starting AMSS download via BHIe. Sequence ID:%u\n",

		sequence_id);

	mhi_write_reg(mhi_cntrl, base, BHIE_TXVECADDR_HIGH_OFFS,

		      upper_32_bits(mhi_buf->dma_addr));
@@ -198,7 +197,6 @@ static int mhi_fw_load_amss(struct mhi_controller *mhi_cntrl, 


	mhi_write_reg(mhi_cntrl, base, BHIE_TXVECSIZE_OFFS, mhi_buf->len);



	sequence_id = prandom_u32() & BHIE_TXVECSTATUS_SEQNUM_BMSK;

	mhi_write_reg_field(mhi_cntrl, base, BHIE_TXVECDB_OFFS,

			    BHIE_TXVECDB_SEQNUM_BMSK, BHIE_TXVECDB_SEQNUM_SHFT,

			    sequence_id);
@@ -246,14 +244,15 @@ static int mhi_fw_load_sbl(struct mhi_controller *mhi_cntrl, 
		goto invalid_pm_state;

	}



	dev_dbg(dev, "Starting SBL download via BHI\n");

	session_id = MHI_RANDOM_U32_NONZERO(BHI_TXDB_SEQNUM_BMSK);

	dev_dbg(dev, "Starting SBL download via BHI. Session ID:%u\n",

		session_id);

	mhi_write_reg(mhi_cntrl, base, BHI_STATUS, 0);

	mhi_write_reg(mhi_cntrl, base, BHI_IMGADDR_HIGH,

		      upper_32_bits(dma_addr));

	mhi_write_reg(mhi_cntrl, base, BHI_IMGADDR_LOW,

		      lower_32_bits(dma_addr));

	mhi_write_reg(mhi_cntrl, base, BHI_IMGSIZE, size);

	session_id = prandom_u32() & BHI_TXDB_SEQNUM_BMSK;

	mhi_write_reg(mhi_cntrl, base, BHI_IMGTXDB, session_id);

	read_unlock_bh(pm_lock);

drivers/bus/mhi/core/internal.h

+1 −0
Original line number Diff line number Diff line
@@ -452,6 +452,7 @@ enum mhi_pm_state { 
#define PRIMARY_CMD_RING		0

#define MHI_DEV_WAKE_DB			127

#define MHI_MAX_MTU			0xffff

#define MHI_RANDOM_U32_NONZERO(bmsk)	(prandom_u32_max(bmsk) + 1)



enum mhi_er_type {

	MHI_ER_TYPE_INVALID = 0x0,

CRA Git | Maintained and supported by SUSTech CRA and CCSE