[Public] > -----Original Message----- > From: Lendacky, Thomas <Thomas.Lendacky@xxxxxxx> > Sent: Thursday, March 2, 2023 15:52 > To: Limonciello, Mario <Mario.Limonciello@xxxxxxx>; Jan Dąbroś > <jsd@xxxxxxxxxxxx>; Grzegorz Bernacki <gjb@xxxxxxxxxxxx>; Thomas, Rijo- > john <Rijo-john.Thomas@xxxxxxx>; herbert@xxxxxxxxxxxxxxxxxxx; Allen, > John <John.Allen@xxxxxxx> > Cc: David S. Miller <davem@xxxxxxxxxxxxx>; linux-crypto@xxxxxxxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx > Subject: Re: [PATCH v2 7/9] crypto: ccp: Add support for ringing a platform > doorbell > > On 3/2/23 13:42, Mario Limonciello wrote: > > Some platforms support using a doorbell to communicate. Export > > this feature for other drivers to utilize as well. > > > > Link: https://lore.kernel.org/linux-i2c/20220916131854.687371-3- > jsd@xxxxxxxxxxxx/ > > Suggested-by: Jan Dabros <jsd@xxxxxxxxxxxx> > > Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx> > > --- > > v1->v2: > > * New patch > > --- > > drivers/crypto/ccp/platform-access.c | 47 > ++++++++++++++++++++++++++++ > > drivers/crypto/ccp/sp-dev.h | 1 + > > include/linux/psp-platform-access.h | 15 +++++++++ > > include/linux/psp.h | 3 ++ > > 4 files changed, 66 insertions(+) > > > > diff --git a/drivers/crypto/ccp/platform-access.c > b/drivers/crypto/ccp/platform-access.c > > index af3a1e97abfe..0763389a2814 100644 > > --- a/drivers/crypto/ccp/platform-access.c > > +++ b/drivers/crypto/ccp/platform-access.c > > @@ -135,6 +135,53 @@ int psp_send_platform_access_msg(enum > psp_platform_access_msg msg, > > } > > EXPORT_SYMBOL_GPL(psp_send_platform_access_msg); > > > > +int psp_ring_platform_doorbell(enum psp_platform_access_msg msg) > > +{ > > + struct psp_device *psp = psp_get_master_device(); > > + struct psp_platform_access_device *pa_dev; > > + u32 __iomem *drbl; > > + u32 drbl_reg; > > Lets spell out doorbell for these two variable names. Ack. Given drbl_reg is only used one place, I might just drop it too. > > > + int ret; > > + > > + if (!psp || !psp->platform_access_data) > > + return -ENODEV; > > + > > + pa_dev = psp->platform_access_data; > > + drbl = psp->io_regs + pa_dev->vdata->doorbell_reg; > > + > > + if (!drbl) > > + return -ENODEV; > > This will be non-zero because psp->io_regs will always be non-zero. Maybe > you meant to check the actual pa_dev->vdata->doorbell_reg value? > > I think you should squash this and patch #9 together so that patch #8 just > works right away. Ack, I'll squash them together. > > > + > > + mutex_lock(&pa_dev->mutex); > > Does the doorbell register operate independently from the other registers > (C2PMSG_28 - C2PMSG_30)? If it does, you could probably just introduce a > doorbell mutex. It does work independently. I'll add a second mutex. > > > + > > + if (check_recovery(drbl)) { > > + dev_dbg(psp->dev, "in recovery\n"); > > Maybe a bit more info as to what is "in recovery" (that goes for patch #4, > too) or just prefix it with "doorbell" (and "platform" in #4) since you > now have duplicated messages. Will add prefixes to make unique messages. > > > + ret = -EBUSY; > > + goto unlock; > > + } > > + > > + if (wait_cmd(drbl)) { > > + dev_dbg(psp->dev, "not done processing command\n"); > > Ditto. > > Thanks, > Tom Thanks for the new comments. I'll wait on Jan and Grzegorz to confirm whether the new doorbell stuff works on Skyrim or not to spin a v3. > > > + ret = -EBUSY; > > + goto unlock; > > + } > > + > > + drbl_reg = FIELD_PREP(PSP_DRBL_MSG, msg) | PSP_DRBL_RING; > > + iowrite32(drbl_reg, drbl); > > + > > + if (wait_cmd(drbl)) { > > + ret = -ETIMEDOUT; > > + goto unlock; > > + } > > + > > + ret = 0; > > +unlock: > > + mutex_unlock(&pa_dev->mutex); > > + > > + return ret; > > +} > > +EXPORT_SYMBOL_GPL(psp_ring_platform_doorbell); > > + > > void platform_access_dev_destroy(struct psp_device *psp) > > { > > struct psp_platform_access_device *pa_dev = psp- > >platform_access_data; > > diff --git a/drivers/crypto/ccp/sp-dev.h b/drivers/crypto/ccp/sp-dev.h > > index 5ec6c219a731..87c0b9350bc2 100644 > > --- a/drivers/crypto/ccp/sp-dev.h > > +++ b/drivers/crypto/ccp/sp-dev.h > > @@ -54,6 +54,7 @@ struct tee_vdata { > > }; > > > > struct platform_access_vdata { > > + const unsigned int doorbell_reg; > > const unsigned int cmdresp_reg; > > const unsigned int cmdbuff_addr_lo_reg; > > const unsigned int cmdbuff_addr_hi_reg; > > diff --git a/include/linux/psp-platform-access.h b/include/linux/psp- > platform-access.h > > index f5a03cd11f10..1e1d0e077cec 100644 > > --- a/include/linux/psp-platform-access.h > > +++ b/include/linux/psp-platform-access.h > > @@ -35,6 +35,21 @@ struct psp_request { > > */ > > int psp_send_platform_access_msg(enum psp_platform_access_msg, > struct psp_request *req); > > > > +/** > > + * psp_ring_platform_doorbell() - Ring platform doorbell > > + * > > + * This function is intended to be used by drivers outside of ccp to ring the > > + * platform doorbell with a message. > > + * > > + * Returns: > > + * 0: success > > + * -%EBUSY: mailbox in recovery or in use > > + * -%ENODEV: driver not bound with PSP device > > + * -%ETIMEDOUT: request timed out > > + * -%EIO: unknown error (see kernel log) > > + */ > > +int psp_ring_platform_doorbell(enum psp_platform_access_msg); > > + > > /** > > * psp_check_platform_access_status() - Checks whether platform > features is ready > > * > > diff --git a/include/linux/psp.h b/include/linux/psp.h > > index d3424790a70e..92e60aeef21e 100644 > > --- a/include/linux/psp.h > > +++ b/include/linux/psp.h > > @@ -23,4 +23,7 @@ > > #define PSP_CMDRESP_RECOVERY BIT(30) > > #define PSP_CMDRESP_RESP BIT(31) > > > > +#define PSP_DRBL_MSG PSP_CMDRESP_CMD > > +#define PSP_DRBL_RING BIT(0) > > + > > #endif /* __PSP_H */
