lkml.org 
[lkml]   [2015]   [Oct]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v3] tpm, tpm_crb: fix unaligned read of the command buffer address
Hi

This would desperately neeed Tested-by's (with Haswell PTT).

/Jarkko

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 <jarkko.sakkinen@linux.intel.com>
> ---
> 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
> --- a/drivers/char/tpm/tpm_crb.c
> +++ 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;
> } __packed;
> @@ -263,8 +264,8 @@ static int crb_acpi_add(struct acpi_device *device)
> return -ENOMEM;
> }
>
> - memcpy_fromio(&pa, &priv->cca->cmd_pa, 8);
> - pa = le64_to_cpu(pa);
> + pa = ((u64) le32_to_cpu(ioread32(&priv->cca->cmd_pa_high)) << 32) +
> + (u64) le32_to_cpu(ioread32(&priv->cca->cmd_pa_low));
> priv->cmd = devm_ioremap_nocache(dev, pa,
> ioread32(&priv->cca->cmd_size));
> if (!priv->cmd) {
> --
> 2.5.0
>


\
 
 \ /
  Last update: 2015-10-09 13:01    [W:0.114 / U:0.676 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site