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authorBhaumik Bhatt2020-05-21 22:32:43 +0530
committerGreg Kroah-Hartman2020-05-22 09:35:43 +0200
commit0ab9fcd0e7b2b45dd407e145f50fd55091405d3c (patch)
tree0d980982c2a46c9a2eb12caa5949f2874f00faaf /drivers/bus
parent0a895f091ebd943555efce3d7b0e96d667208fdc (diff)
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.c15
-rw-r--r--drivers/bus/mhi/core/internal.h1
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,