Messages in this thread Patch in this message | | | From | Jarkko Sakkinen <> | Subject | [PATCH] tpm, tpm_crb: fix unaligned read of the command buffer address | Date | Tue, 29 Sep 2015 09:02:33 +0300 |
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The command buffer address must be read with exactly two 32-bit reads. Otherwise, on Broxton platform HW will abort the read operation, which causes the CPU to fill the read 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.
Reported-by: Imran Desai <imran.desai@intel.com> 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
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