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path: root/drivers/char/tpm/tpm_tis.c
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Diffstat (limited to 'drivers/char/tpm/tpm_tis.c')
-rw-r--r--drivers/char/tpm/tpm_tis.c148
1 files changed, 89 insertions, 59 deletions
diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index f08949a5f678..9aa230a63616 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2005, 2006 IBM Corporation
* Copyright (C) 2014, 2015 Intel Corporation
@@ -13,11 +14,6 @@
*
* This device driver implements the TPM interface as defined in
* the TCG TPM Interface Spec version 1.2, revision 1.0.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation, version 2 of the
- * License.
*/
#include <linux/init.h>
#include <linux/module.h>
@@ -29,7 +25,6 @@
#include <linux/acpi.h>
#include <linux/freezer.h>
#include <linux/of.h>
-#include <linux/of_device.h>
#include <linux/kernel.h>
#include "tpm.h"
#include "tpm_tis_core.h"
@@ -53,7 +48,46 @@ static inline struct tpm_tis_tcg_phy *to_tpm_tis_tcg_phy(struct tpm_tis_data *da
return container_of(data, struct tpm_tis_tcg_phy, priv);
}
-static bool interrupts = true;
+#ifdef CONFIG_PREEMPT_RT
+/*
+ * Flush previous write operations with a dummy read operation to the
+ * TPM MMIO base address.
+ */
+static inline void tpm_tis_flush(void __iomem *iobase)
+{
+ ioread8(iobase + TPM_ACCESS(0));
+}
+#else
+#define tpm_tis_flush(iobase) do { } while (0)
+#endif
+
+/*
+ * Write a byte word to the TPM MMIO address, and flush the write queue.
+ * The flush ensures that the data is sent immediately over the bus and not
+ * aggregated with further requests and transferred later in a batch. The large
+ * write requests can lead to unwanted latency spikes by blocking the CPU until
+ * the complete batch has been transferred.
+ */
+static inline void tpm_tis_iowrite8(u8 b, void __iomem *iobase, u32 addr)
+{
+ iowrite8(b, iobase + addr);
+ tpm_tis_flush(iobase);
+}
+
+/*
+ * Write a 32-bit word to the TPM MMIO address, and flush the write queue.
+ * The flush ensures that the data is sent immediately over the bus and not
+ * aggregated with further requests and transferred later in a batch. The large
+ * write requests can lead to unwanted latency spikes by blocking the CPU until
+ * the complete batch has been transferred.
+ */
+static inline void tpm_tis_iowrite32(u32 b, void __iomem *iobase, u32 addr)
+{
+ iowrite32(b, iobase + addr);
+ tpm_tis_flush(iobase);
+}
+
+static bool interrupts;
module_param(interrupts, bool, 0444);
MODULE_PARM_DESC(interrupts, "Enable interrupts");
@@ -106,6 +140,7 @@ static int check_acpi_tpm2(struct device *dev)
const struct acpi_device_id *aid = acpi_match_device(tpm_acpi_tbl, dev);
struct acpi_table_tpm2 *tbl;
acpi_status st;
+ int ret = 0;
if (!aid || aid->driver_data != DEVICE_IS_TPM2)
return 0;
@@ -113,8 +148,7 @@ static int check_acpi_tpm2(struct device *dev)
/* If the ACPI TPM2 signature is matched then a global ACPI_SIG_TPM2
* table is mandatory
*/
- st =
- acpi_get_table(ACPI_SIG_TPM2, 1, (struct acpi_table_header **)&tbl);
+ st = acpi_get_table(ACPI_SIG_TPM2, 1, (struct acpi_table_header **)&tbl);
if (ACPI_FAILURE(st) || tbl->header.length < sizeof(*tbl)) {
dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n");
return -EINVAL;
@@ -122,9 +156,10 @@ static int check_acpi_tpm2(struct device *dev)
/* The tpm2_crb driver handles this device */
if (tbl->start_method != ACPI_TPM2_MEMORY_MAPPED)
- return -ENODEV;
+ ret = -ENODEV;
- return 0;
+ acpi_put_table((struct acpi_table_header *)tbl);
+ return ret;
}
#else
static int check_acpi_tpm2(struct device *dev)
@@ -134,50 +169,46 @@ static int check_acpi_tpm2(struct device *dev)
#endif
static int tpm_tcg_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
- u8 *result)
+ u8 *result, enum tpm_tis_io_mode io_mode)
{
struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
-
- while (len--)
- *result++ = ioread8(phy->iobase + addr);
+ __le16 result_le16;
+ __le32 result_le32;
+
+ switch (io_mode) {
+ case TPM_TIS_PHYS_8:
+ while (len--)
+ *result++ = ioread8(phy->iobase + addr);
+ break;
+ case TPM_TIS_PHYS_16:
+ result_le16 = cpu_to_le16(ioread16(phy->iobase + addr));
+ memcpy(result, &result_le16, sizeof(u16));
+ break;
+ case TPM_TIS_PHYS_32:
+ result_le32 = cpu_to_le32(ioread32(phy->iobase + addr));
+ memcpy(result, &result_le32, sizeof(u32));
+ break;
+ }
return 0;
}
static int tpm_tcg_write_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
- const u8 *value)
-{
- struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
-
- while (len--)
- iowrite8(*value++, phy->iobase + addr);
-
- return 0;
-}
-
-static int tpm_tcg_read16(struct tpm_tis_data *data, u32 addr, u16 *result)
+ const u8 *value, enum tpm_tis_io_mode io_mode)
{
struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
- *result = ioread16(phy->iobase + addr);
-
- return 0;
-}
-
-static int tpm_tcg_read32(struct tpm_tis_data *data, u32 addr, u32 *result)
-{
- struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
-
- *result = ioread32(phy->iobase + addr);
-
- return 0;
-}
-
-static int tpm_tcg_write32(struct tpm_tis_data *data, u32 addr, u32 value)
-{
- struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
-
- iowrite32(value, phy->iobase + addr);
+ switch (io_mode) {
+ case TPM_TIS_PHYS_8:
+ while (len--)
+ tpm_tis_iowrite8(*value++, phy->iobase, addr);
+ break;
+ case TPM_TIS_PHYS_16:
+ return -EINVAL;
+ case TPM_TIS_PHYS_32:
+ tpm_tis_iowrite32(le32_to_cpu(*((__le32 *)value)), phy->iobase, addr);
+ break;
+ }
return 0;
}
@@ -185,9 +216,6 @@ static int tpm_tcg_write32(struct tpm_tis_data *data, u32 addr, u32 value)
static const struct tpm_tis_phy_ops tpm_tcg = {
.read_bytes = tpm_tcg_read_bytes,
.write_bytes = tpm_tcg_write_bytes,
- .read16 = tpm_tcg_read16,
- .read32 = tpm_tcg_read32,
- .write32 = tpm_tcg_write32,
};
static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info)
@@ -212,7 +240,7 @@ static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info)
irq = tpm_info->irq;
if (itpm || is_itpm(ACPI_COMPANION(dev)))
- phy->priv.flags |= TPM_TIS_ITPM_WORKAROUND;
+ set_bit(TPM_TIS_ITPM_WORKAROUND, &phy->priv.flags);
return tpm_tis_core_init(dev, &phy->priv, irq, &tpm_tcg,
ACPI_HANDLE(dev));
@@ -239,6 +267,13 @@ static int tpm_tis_pnp_init(struct pnp_dev *pnp_dev,
return tpm_tis_init(&pnp_dev->dev, &tpm_info);
}
+/*
+ * There is a known bug caused by 93e1b7d42e1e ("[PATCH] tpm: add HID module
+ * parameter"). This commit added IFX0102 device ID, which is also used by
+ * tpm_infineon but ignored to add quirks to probe which driver ought to be
+ * used.
+ */
+
static struct pnp_device_id tpm_pnp_tbl[] = {
{"PNP0C31", 0}, /* TPM */
{"ATM1200", 0}, /* Atmel */
@@ -290,7 +325,7 @@ static int tpm_tis_plat_probe(struct platform_device *pdev)
}
tpm_info.res = *res;
- tpm_info.irq = platform_get_irq(pdev, 0);
+ tpm_info.irq = platform_get_irq_optional(pdev, 0);
if (tpm_info.irq <= 0) {
if (pdev != force_pdev)
tpm_info.irq = -1;
@@ -302,18 +337,17 @@ static int tpm_tis_plat_probe(struct platform_device *pdev)
return tpm_tis_init(&pdev->dev, &tpm_info);
}
-static int tpm_tis_plat_remove(struct platform_device *pdev)
+static void tpm_tis_plat_remove(struct platform_device *pdev)
{
struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
tpm_chip_unregister(chip);
tpm_tis_remove(chip);
-
- return 0;
}
#ifdef CONFIG_OF
static const struct of_device_id tis_of_platform_match[] = {
+ {.compatible = "atmel,at97sc3204"},
{.compatible = "tcg,tpm-tis-mmio"},
{},
};
@@ -335,11 +369,7 @@ static int tpm_tis_force_device(void)
{
struct platform_device *pdev;
static const struct resource x86_resources[] = {
- {
- .start = 0xFED40000,
- .end = 0xFED40000 + TIS_MEM_LEN - 1,
- .flags = IORESOURCE_MEM,
- },
+ DEFINE_RES_MEM(0xFED40000, TIS_MEM_LEN)
};
if (!force)
@@ -399,7 +429,7 @@ static void __exit cleanup_tis(void)
module_init(init_tis);
module_exit(cleanup_tis);
-MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
+MODULE_AUTHOR("Leendert van Doorn <leendert@watson.ibm.com>");
MODULE_DESCRIPTION("TPM Driver");
MODULE_VERSION("2.0");
MODULE_LICENSE("GPL");