tpm, tpm_crb: fix unaligned read of the command buffer address

commit 149789ce9d472e6b4fd99336e779ab843754a96c upstream.

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>
Reviewed-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index 2b971b3e5c1cfc285ebde4aef3728a9b0a229098..4bb9727c1047172f70b77db1649729597da1ce52 100644 (file)
--- 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) {