| Message ID | 20240105174253.863388-1-quic_jhugo@quicinc.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | [v2] bus: mhi: host: Read PK HASH dynamically | expand |
On Fri, Jan 05, 2024 at 10:42:53AM -0700, Jeffrey Hugo wrote: > The OEM PK HASH registers in the BHI region are read once during firmware > load (boot), cached, and displayed on demand via sysfs. This has a few > problems - if firmware load is skipped, the registers will not be read and > if the register values change over the life of the device the local cache > will be out of sync. > > Qualcomm Cloud AI 100 can expose both these problems. It is possible for > mhi_async_power_up() to be invoked while the device is in AMSS EE, which > would bypass firmware loading. Also, Qualcomm Cloud AI 100 has 5 PK HASH > slots which can be dynamically provisioned while the device is active, > which would result in the values changing and users may want to know what > keys are active. > > Address these concerns by reading the PK HASH registers on-demand during > the sysfs read. This will result in showing the most current information. > > Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> - Mani > Reviewed-by: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy@quicinc.com> > --- > > v2: > -Return ret instead of cnt on error in show() > > drivers/bus/mhi/host/boot.c | 11 +---------- > drivers/bus/mhi/host/init.c | 16 ++++++++++++---- > include/linux/mhi.h | 2 -- > 3 files changed, 13 insertions(+), 16 deletions(-) > > diff --git a/drivers/bus/mhi/host/boot.c b/drivers/bus/mhi/host/boot.c > index edc0ec5a0933..dedd29ca8db3 100644 > --- a/drivers/bus/mhi/host/boot.c > +++ b/drivers/bus/mhi/host/boot.c > @@ -395,7 +395,7 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl) > void *buf; > dma_addr_t dma_addr; > size_t size, fw_sz; > - int i, ret; > + int ret; > > if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) { > dev_err(dev, "Device MHI is not in valid state\n"); > @@ -408,15 +408,6 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl) > if (ret) > dev_err(dev, "Could not capture serial number via BHI\n"); > > - for (i = 0; i < ARRAY_SIZE(mhi_cntrl->oem_pk_hash); i++) { > - ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_OEMPKHASH(i), > - &mhi_cntrl->oem_pk_hash[i]); > - if (ret) { > - dev_err(dev, "Could not capture OEM PK HASH via BHI\n"); > - break; > - } > - } > - > /* wait for ready on pass through or any other execution environment */ > if (!MHI_FW_LOAD_CAPABLE(mhi_cntrl->ee)) > goto fw_load_ready_state; > diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c > index f78aefd2d7a3..15c1740a2c88 100644 > --- a/drivers/bus/mhi/host/init.c > +++ b/drivers/bus/mhi/host/init.c > @@ -97,11 +97,19 @@ static ssize_t oem_pk_hash_show(struct device *dev, > { > struct mhi_device *mhi_dev = to_mhi_device(dev); > struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl; > - int i, cnt = 0; > + u32 hash_segment[MHI_MAX_OEM_PK_HASH_SEGMENTS]; > + int i, cnt = 0, ret; > > - for (i = 0; i < ARRAY_SIZE(mhi_cntrl->oem_pk_hash); i++) > - cnt += sysfs_emit_at(buf, cnt, "OEMPKHASH[%d]: 0x%x\n", > - i, mhi_cntrl->oem_pk_hash[i]); > + for (i = 0; i < MHI_MAX_OEM_PK_HASH_SEGMENTS; i++) { > + ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_OEMPKHASH(i), &hash_segment[i]); > + if (ret) { > + dev_err(dev, "Could not capture OEM PK HASH\n"); > + return ret; > + } > + } > + > + for (i = 0; i < MHI_MAX_OEM_PK_HASH_SEGMENTS; i++) > + cnt += sysfs_emit_at(buf, cnt, "OEMPKHASH[%d]: 0x%x\n", i, hash_segment[i]); > > return cnt; > } > diff --git a/include/linux/mhi.h b/include/linux/mhi.h > index 039943ec4d4e..e46c68218fe4 100644 > --- a/include/linux/mhi.h > +++ b/include/linux/mhi.h > @@ -323,7 +323,6 @@ struct mhi_controller_config { > * @major_version: MHI controller major revision number > * @minor_version: MHI controller minor revision number > * @serial_number: MHI controller serial number obtained from BHI > - * @oem_pk_hash: MHI controller OEM PK Hash obtained from BHI > * @mhi_event: MHI event ring configurations table > * @mhi_cmd: MHI command ring configurations table > * @mhi_ctxt: MHI device context, shared memory between host and device > @@ -410,7 +409,6 @@ struct mhi_controller { > u32 major_version; > u32 minor_version; > u32 serial_number; > - u32 oem_pk_hash[MHI_MAX_OEM_PK_HASH_SEGMENTS]; > > struct mhi_event *mhi_event; > struct mhi_cmd *mhi_cmd; > -- > 2.34.1 >
On Fri, Jan 05, 2024 at 10:42:53AM -0700, Jeffrey Hugo wrote: > The OEM PK HASH registers in the BHI region are read once during firmware > load (boot), cached, and displayed on demand via sysfs. This has a few > problems - if firmware load is skipped, the registers will not be read and > if the register values change over the life of the device the local cache > will be out of sync. > > Qualcomm Cloud AI 100 can expose both these problems. It is possible for > mhi_async_power_up() to be invoked while the device is in AMSS EE, which > would bypass firmware loading. Also, Qualcomm Cloud AI 100 has 5 PK HASH > slots which can be dynamically provisioned while the device is active, > which would result in the values changing and users may want to know what > keys are active. > > Address these concerns by reading the PK HASH registers on-demand during > the sysfs read. This will result in showing the most current information. > > Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> - Mani > Reviewed-by: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy@quicinc.com> > --- > > v2: > -Return ret instead of cnt on error in show() > > drivers/bus/mhi/host/boot.c | 11 +---------- > drivers/bus/mhi/host/init.c | 16 ++++++++++++---- > include/linux/mhi.h | 2 -- > 3 files changed, 13 insertions(+), 16 deletions(-) > > diff --git a/drivers/bus/mhi/host/boot.c b/drivers/bus/mhi/host/boot.c > index edc0ec5a0933..dedd29ca8db3 100644 > --- a/drivers/bus/mhi/host/boot.c > +++ b/drivers/bus/mhi/host/boot.c > @@ -395,7 +395,7 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl) > void *buf; > dma_addr_t dma_addr; > size_t size, fw_sz; > - int i, ret; > + int ret; > > if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) { > dev_err(dev, "Device MHI is not in valid state\n"); > @@ -408,15 +408,6 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl) > if (ret) > dev_err(dev, "Could not capture serial number via BHI\n"); > > - for (i = 0; i < ARRAY_SIZE(mhi_cntrl->oem_pk_hash); i++) { > - ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_OEMPKHASH(i), > - &mhi_cntrl->oem_pk_hash[i]); > - if (ret) { > - dev_err(dev, "Could not capture OEM PK HASH via BHI\n"); > - break; > - } > - } > - > /* wait for ready on pass through or any other execution environment */ > if (!MHI_FW_LOAD_CAPABLE(mhi_cntrl->ee)) > goto fw_load_ready_state; > diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c > index f78aefd2d7a3..15c1740a2c88 100644 > --- a/drivers/bus/mhi/host/init.c > +++ b/drivers/bus/mhi/host/init.c > @@ -97,11 +97,19 @@ static ssize_t oem_pk_hash_show(struct device *dev, > { > struct mhi_device *mhi_dev = to_mhi_device(dev); > struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl; > - int i, cnt = 0; > + u32 hash_segment[MHI_MAX_OEM_PK_HASH_SEGMENTS]; > + int i, cnt = 0, ret; > > - for (i = 0; i < ARRAY_SIZE(mhi_cntrl->oem_pk_hash); i++) > - cnt += sysfs_emit_at(buf, cnt, "OEMPKHASH[%d]: 0x%x\n", > - i, mhi_cntrl->oem_pk_hash[i]); > + for (i = 0; i < MHI_MAX_OEM_PK_HASH_SEGMENTS; i++) { > + ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_OEMPKHASH(i), &hash_segment[i]); > + if (ret) { > + dev_err(dev, "Could not capture OEM PK HASH\n"); > + return ret; > + } > + } > + > + for (i = 0; i < MHI_MAX_OEM_PK_HASH_SEGMENTS; i++) > + cnt += sysfs_emit_at(buf, cnt, "OEMPKHASH[%d]: 0x%x\n", i, hash_segment[i]); > > return cnt; > } > diff --git a/include/linux/mhi.h b/include/linux/mhi.h > index 039943ec4d4e..e46c68218fe4 100644 > --- a/include/linux/mhi.h > +++ b/include/linux/mhi.h > @@ -323,7 +323,6 @@ struct mhi_controller_config { > * @major_version: MHI controller major revision number > * @minor_version: MHI controller minor revision number > * @serial_number: MHI controller serial number obtained from BHI > - * @oem_pk_hash: MHI controller OEM PK Hash obtained from BHI > * @mhi_event: MHI event ring configurations table > * @mhi_cmd: MHI command ring configurations table > * @mhi_ctxt: MHI device context, shared memory between host and device > @@ -410,7 +409,6 @@ struct mhi_controller { > u32 major_version; > u32 minor_version; > u32 serial_number; > - u32 oem_pk_hash[MHI_MAX_OEM_PK_HASH_SEGMENTS]; > > struct mhi_event *mhi_event; > struct mhi_cmd *mhi_cmd; > -- > 2.34.1 > >
diff --git a/drivers/bus/mhi/host/boot.c b/drivers/bus/mhi/host/boot.c index edc0ec5a0933..dedd29ca8db3 100644 --- a/drivers/bus/mhi/host/boot.c +++ b/drivers/bus/mhi/host/boot.c @@ -395,7 +395,7 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl) void *buf; dma_addr_t dma_addr; size_t size, fw_sz; - int i, ret; + int ret; if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) { dev_err(dev, "Device MHI is not in valid state\n"); @@ -408,15 +408,6 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl) if (ret) dev_err(dev, "Could not capture serial number via BHI\n"); - for (i = 0; i < ARRAY_SIZE(mhi_cntrl->oem_pk_hash); i++) { - ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_OEMPKHASH(i), - &mhi_cntrl->oem_pk_hash[i]); - if (ret) { - dev_err(dev, "Could not capture OEM PK HASH via BHI\n"); - break; - } - } - /* wait for ready on pass through or any other execution environment */ if (!MHI_FW_LOAD_CAPABLE(mhi_cntrl->ee)) goto fw_load_ready_state; diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c index f78aefd2d7a3..15c1740a2c88 100644 --- a/drivers/bus/mhi/host/init.c +++ b/drivers/bus/mhi/host/init.c @@ -97,11 +97,19 @@ static ssize_t oem_pk_hash_show(struct device *dev, { struct mhi_device *mhi_dev = to_mhi_device(dev); struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl; - int i, cnt = 0; + u32 hash_segment[MHI_MAX_OEM_PK_HASH_SEGMENTS]; + int i, cnt = 0, ret; - for (i = 0; i < ARRAY_SIZE(mhi_cntrl->oem_pk_hash); i++) - cnt += sysfs_emit_at(buf, cnt, "OEMPKHASH[%d]: 0x%x\n", - i, mhi_cntrl->oem_pk_hash[i]); + for (i = 0; i < MHI_MAX_OEM_PK_HASH_SEGMENTS; i++) { + ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_OEMPKHASH(i), &hash_segment[i]); + if (ret) { + dev_err(dev, "Could not capture OEM PK HASH\n"); + return ret; + } + } + + for (i = 0; i < MHI_MAX_OEM_PK_HASH_SEGMENTS; i++) + cnt += sysfs_emit_at(buf, cnt, "OEMPKHASH[%d]: 0x%x\n", i, hash_segment[i]); return cnt; } diff --git a/include/linux/mhi.h b/include/linux/mhi.h index 039943ec4d4e..e46c68218fe4 100644 --- a/include/linux/mhi.h +++ b/include/linux/mhi.h @@ -323,7 +323,6 @@ struct mhi_controller_config { * @major_version: MHI controller major revision number * @minor_version: MHI controller minor revision number * @serial_number: MHI controller serial number obtained from BHI - * @oem_pk_hash: MHI controller OEM PK Hash obtained from BHI * @mhi_event: MHI event ring configurations table * @mhi_cmd: MHI command ring configurations table * @mhi_ctxt: MHI device context, shared memory between host and device @@ -410,7 +409,6 @@ struct mhi_controller { u32 major_version; u32 minor_version; u32 serial_number; - u32 oem_pk_hash[MHI_MAX_OEM_PK_HASH_SEGMENTS]; struct mhi_event *mhi_event; struct mhi_cmd *mhi_cmd;