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| author | Bhaumik Bhatt <bbhatt@codeaurora.org> | 2020-05-21 22:32:43 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-05-22 09:35:43 +0200 |
| commit | 0ab9fcd0e7b2b45dd407e145f50fd55091405d3c (patch) | |
| tree | 0d980982c2a46c9a2eb12caa5949f2874f00faaf /drivers/bus | |
| parent | 0a895f091ebd943555efce3d7b0e96d667208fdc (diff) | |
| download | linux-0ab9fcd0e7b2b45dd407e145f50fd55091405d3c.tar.gz linux-0ab9fcd0e7b2b45dd407e145f50fd55091405d3c.tar.bz2 linux-0ab9fcd0e7b2b45dd407e145f50fd55091405d3c.zip | |
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: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20200521170249.21795-9-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/bus')
| -rw-r--r-- | drivers/bus/mhi/core/boot.c | 15 | ||||
| -rw-r--r-- | drivers/bus/mhi/core/internal.h | 1 |
2 files changed, 8 insertions, 8 deletions
diff --git a/drivers/bus/mhi/core/boot.c b/drivers/bus/mhi/core/boot.c index 80e4d7609aaa..0b38014d040e 100644 --- a/drivers/bus/mhi/core/boot.c +++ b/drivers/bus/mhi/core/boot.c @@ -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); diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h index 0965ca3c9632..80b32c20149c 100644 --- a/drivers/bus/mhi/core/internal.h +++ b/drivers/bus/mhi/core/internal.h @@ -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, |