The purpose of crb_fixup_cmd_size() function is to work around broken BIOSes and get the trustable size between the ACPI region and register. When the TPM has a command buffer and response buffer independently, the crb_map_io() function calls crb_fixup_cmd_size() twice to calculate each buffer size. However, the current implementation of it considers one of two buffers.
To support independent command and response buffers, I changed crb_check_resource() function for storing ACPI TPB regions to a list. I also changed crb_fixup_cmd_size() to use the list for calculating each buffer size. Signed-off-by: Seunghun Han <[email protected]> --- Changes in v2: same as v1. drivers/char/tpm/tpm_crb.c | 44 +++++++++++++++++++++++++++++++------- 1 file changed, 36 insertions(+), 8 deletions(-) diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c index e59f1f91d7f3..14f486c23af2 100644 --- a/drivers/char/tpm/tpm_crb.c +++ b/drivers/char/tpm/tpm_crb.c @@ -442,6 +442,9 @@ static int crb_check_resource(struct acpi_resource *ares, void *data) acpi_dev_resource_address_space(ares, &win)) { *io_res = *res; io_res->name = NULL; + + /* Add this TPM CRB resource to the list */ + return 0; } return 1; @@ -471,7 +474,7 @@ static void __iomem *crb_map_res(struct device *dev, struct crb_priv *priv, * region vs the registers. Trust the ACPI region. Such broken systems * probably cannot send large TPM commands since the buffer will be truncated. */ -static u64 crb_fixup_cmd_size(struct device *dev, struct resource *io_res, +static u64 __crb_fixup_cmd_size(struct device *dev, struct resource *io_res, u64 start, u64 size) { if (io_res->start > start || io_res->end < start) @@ -487,6 +490,26 @@ static u64 crb_fixup_cmd_size(struct device *dev, struct resource *io_res, return io_res->end - start + 1; } +static u64 crb_fixup_cmd_size(struct device *dev, struct list_head *resources, + u64 start, u64 size) +{ + struct resource_entry *pos; + struct resource *cur_res; + u64 ret = size; + + /* Check all TPM CRB resources with the start and size values */ + resource_list_for_each_entry(pos, resources) { + cur_res = pos->res; + + ret = __crb_fixup_cmd_size(dev, cur_res, start, size); + /* Broken BIOS is detected. Trust the ACPI region. */ + if (ret < size) + break; + } + + return ret; +} + static int crb_map_io(struct acpi_device *device, struct crb_priv *priv, struct acpi_table_tpm2 *buf) { @@ -506,16 +529,18 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv, &io_res); if (ret < 0) return ret; - acpi_dev_free_resource_list(&resources); if (resource_type(&io_res) != IORESOURCE_MEM) { dev_err(dev, FW_BUG "TPM2 ACPI table does not define a memory resource\n"); - return -EINVAL; + ret = -EINVAL; + goto out_early; } priv->iobase = devm_ioremap_resource(dev, &io_res); - if (IS_ERR(priv->iobase)) - return PTR_ERR(priv->iobase); + if (IS_ERR(priv->iobase)) { + ret = PTR_ERR(priv->iobase); + goto out_early; + } /* The ACPI IO region starts at the head area and continues to include * the control area, as one nice sane region except for some older @@ -532,7 +557,7 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv, ret = __crb_request_locality(dev, priv, 0); if (ret) - return ret; + goto out_early; priv->regs_t = crb_map_res(dev, priv, &io_res, buf->control_address, sizeof(struct crb_regs_tail)); @@ -552,7 +577,7 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv, pa_high = ioread32(&priv->regs_t->ctrl_cmd_pa_high); pa_low = ioread32(&priv->regs_t->ctrl_cmd_pa_low); cmd_pa = ((u64)pa_high << 32) | pa_low; - cmd_size = crb_fixup_cmd_size(dev, &io_res, cmd_pa, + cmd_size = crb_fixup_cmd_size(dev, &resources, cmd_pa, ioread32(&priv->regs_t->ctrl_cmd_size)); dev_dbg(dev, "cmd_hi = %X cmd_low = %X cmd_size %X\n", @@ -566,7 +591,7 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv, memcpy_fromio(&__rsp_pa, &priv->regs_t->ctrl_rsp_pa, 8); rsp_pa = le64_to_cpu(__rsp_pa); - rsp_size = crb_fixup_cmd_size(dev, &io_res, rsp_pa, + rsp_size = crb_fixup_cmd_size(dev, &resources, rsp_pa, ioread32(&priv->regs_t->ctrl_rsp_size)); if (cmd_pa != rsp_pa) { @@ -596,6 +621,9 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv, __crb_relinquish_locality(dev, priv, 0); +out_early: + acpi_dev_free_resource_list(&resources); + return ret; } -- 2.21.0
