On Wed, Sep 16, 2015 at 10:19:17AM +0300, Jarkko Sakkinen wrote: > On Tue, Sep 15, 2015 at 11:22:27AM -0600, Jason Gunthorpe wrote: > > On Tue, Sep 15, 2015 at 08:05:40PM +0300, Jarkko Sakkinen wrote: > > > The command buffer address must be read with exactly two 32-bit reads. > > > Otherwise, on some HW platforms, it seems that HW will abort the read > > > operation, which causes CPU to fill the read bytes with 1's. Therefore, > > > we cannot rely on memcpy_fromio() but must call ioread32() two times > > > instead. > > > > > > Also, this matches the PC Client Platform TPM Profile specification, > > > which defines command buffer address with two 32-bit fields. > > > > > > Signed-off-by: Jarkko Sakkinen <[email protected]> > > > drivers/char/tpm/tpm_crb.c | 7 ++++--- > > > 1 file changed, 4 insertions(+), 3 deletions(-) > > > > > > diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c > > > index b4564b6..c09b370 100644 > > > +++ b/drivers/char/tpm/tpm_crb.c > > > @@ -68,7 +68,8 @@ struct crb_control_area { > > > u32 int_enable; > > > u32 int_sts; > > > u32 cmd_size; > > > - u64 cmd_pa; > > > + u32 cmd_pa_low; > > > + u32 cmd_pa_high; > > > u32 rsp_size; > > > u64 rsp_pa; > > > > What about rsp_pa? > > It's naturally aligned and defined as 64-bit field in: > > http://www.trustedcomputinggroup.org/developers/pc_client/specifications > > Also in a platform (not available in public yet) it gets read correctly.
memcpy_64.S uses rep movsq and rep movsb for the remainder. That's why the read failed in the case of cmd address but it does not fail with rsp address. See http://lxr.free-electrons.com/source/arch/x86/lib/memcpy_64.S > > > } __packed; > > > > As I mentioned, drop the __packed. > > I didn't do that because it is not mandatory for the bug fix. > > I would rather submit it as a separate commit later on. > > > Otherwise: > > > > Reviewed-By: Jason Gunthorpe <[email protected]> > > > > Jason > > /Jarkko /Jarkko -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
