linux-kernel - RE: [char-misc-next 2/2] mei: send OS type to the FW

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Date:   Thu, 10 Nov 2016 12:13:50 +0000
From:   "Winkler, Tomas" <tomas.winkler@...el.com>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
CC:     "Usyskin, Alexander" <alexander.usyskin@...el.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "Jarkko Sakkinen" <jarkko.sakkinen@...ux.intel.com>
Subject: RE: [char-misc-next 2/2] mei: send OS type to the FW



> -----Original Message-----
> From: Greg Kroah-Hartman [mailto:gregkh@...uxfoundation.org]
> Sent: Thursday, November 10, 2016 09:25
> To: Winkler, Tomas <tomas.winkler@...el.com>
> Cc: Usyskin, Alexander <alexander.usyskin@...el.com>; linux-
> kernel@...r.kernel.org; Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
> Subject: Re: [char-misc-next 2/2] mei: send OS type to the FW
> 
> On Tue, Nov 08, 2016 at 06:26:09PM +0200, Tomas Winkler wrote:
> > From: Alexander Usyskin <alexander.usyskin@...el.com>
> >
> > Tell the FW that we are running a sane OS and TPM2_ChangeEPS() is
> > supported. This workaround was added to support other broken OS and we
> > need to follow here. The command is sent just once at the boot time.
> >
> > Cc: Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
> > Signed-off-by: Tomas Winkler <tomas.winkler@...el.com>
> > Signed-off-by: Alexander Usyskin <alexander.usyskin@...el.com>
> > ---
> >  drivers/misc/mei/bus-fixup.c | 98
> > ++++++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 98 insertions(+)
> >
> > diff --git a/drivers/misc/mei/bus-fixup.c
> > b/drivers/misc/mei/bus-fixup.c index 9e10d86e3887..344a0c99ee44 100644
> > --- a/drivers/misc/mei/bus-fixup.c
> > +++ b/drivers/misc/mei/bus-fixup.c
> > @@ -38,6 +38,9 @@ static const uuid_le mei_nfc_info_guid =
> > MEI_UUID_NFC_INFO;  #define MEI_UUID_WD UUID_LE(0x05B79A6F,
> 0x4628, 0x4D7F, \
> >  			    0x89, 0x9D, 0xA9, 0x15, 0x14, 0xCB, 0x32, 0xAB)
> >
> > +#define MEI_UUID_MKHIF_FIX UUID_LE(0x55213584, 0x9a29, 0x4916, \
> > +			0xba, 0xdf, 0xf, 0xb7, 0xed, 0x68, 0x2a, 0xeb)
> > +
> >  #define MEI_UUID_ANY NULL_UUID_LE
> >
> >  /**
> > @@ -69,6 +72,100 @@ static void blacklist(struct mei_cl_device *cldev)
> >  	cldev->do_match = 0;
> >  }
> >
> > +#define OSTYPE_LINUX    2
> > +struct mei_os_ver {
> > +	u16 build;
> > +	u16 reserved1;
> > +	u8  os_type;
> > +	u8  major;
> > +	u8  minor;
> > +	u8  reserved2;
> > +} __packed;
> > +
> > +#define MKHI_FEATURE_PTT 0x10
> > +
> > +struct mkhi_rule_id {
> > +	u16 rule_type;
> 
> Endian?

Device is x86 only burned to PCH/SoC. 

> > +	u8 feature_id;
> > +	u8 reserved;
> > +} __packed;
> > +
> > +struct mkhi_fwcaps {
> > +	struct mkhi_rule_id id;
> > +	u8 len;
> > +	u8 data[0];
> > +} __packed;
> > +
> > +#define MKHI_FWCAPS_GROUP_ID 0x3
> > +#define MKHI_FWCAPS_SET_OS_VER_APP_RULE_CMD 6 struct
> mkhi_msg_hdr {
> > +	u32  group_id    :8;
> > +	u32  command     :7;
> > +	u32  is_response :1;
> > +	u32  reserved    :8;
> > +	u32  result      :8;
> 
> Oh that's scary, does this really work?  It's usually better to use bitmasks to get
> the values out properly.

Yes, it works, but yes I may fix it with bit mask. 

> > +};
> > +
> > +struct mkhi_msg {
> > +	struct mkhi_msg_hdr hdr;
> > +	u8 data[0];
> > +} __packed;
> > +
> > +static int mei_osver(struct mei_cl_device *cldev) {
> > +	int ret;
> > +	const size_t size = sizeof(struct mkhi_msg_hdr) +
> > +			    sizeof(struct mkhi_fwcaps) +
> > +			    sizeof(struct mei_os_ver);
> > +	size_t length = 8;
> > +	char buf[size];
> > +	struct mkhi_msg *req;
> > +	struct mkhi_fwcaps *fwcaps;
> > +	struct mei_os_ver *os_ver;
> > +	unsigned int mode = MEI_CL_IO_TX_BLOCKING |
> MEI_CL_IO_TX_INTERNAL;
> > +
> > +	memset(buf, 0, size);
> > +
> > +	req = (struct mkhi_msg *)buf;
> > +	req->hdr.group_id = MKHI_FWCAPS_GROUP_ID;
> > +	req->hdr.command = MKHI_FWCAPS_SET_OS_VER_APP_RULE_CMD;
> > +
> > +	fwcaps = (struct mkhi_fwcaps *)req->data;
> > +
> > +	fwcaps->id.rule_type = 0x0;
> > +	fwcaps->id.feature_id = MKHI_FEATURE_PTT;
> > +	fwcaps->len = sizeof(*os_ver);
> > +	os_ver = (struct mei_os_ver *)fwcaps->data;
> > +	os_ver->os_type = OSTYPE_LINUX;
> > +
> > +	ret = __mei_cl_send(cldev->cl, buf, size, mode);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	ret = __mei_cl_recv(cldev->cl, buf, length);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	return 0;
> > +}
> > +
> > +static void mei_mkhi_fix(struct mei_cl_device *cldev) {
> > +	int ret;
> > +
> > +	dev_dbg(&cldev->dev, "running hook %s\n", __func__);
> 
> ftrace can provide you this, right?

Sure it can, I'm just old chap working with printks. Will remove. 
 
> > +
> > +	ret = mei_cldev_enable(cldev);
> > +	if (ret)
> > +		return;
> > +
> > +	ret = mei_osver(cldev);
> > +	if (ret)
> > +		dev_info(&cldev->dev, "OS version command failed\n");
> 
> dev_err()?

It's not really fata value 
> And what about the error value?

Will add 

Thanks
Tomas