From: Ivan Lazeev <ivan.laz...@gmail.com>

Bug link: https://bugzilla.kernel.org/show_bug.cgi?id=195657

cmd/rsp buffers are expected to be in the same ACPI region.
For Zen+ CPUs BIOS's might report two different regions, some of
them also report region sizes inconsistent with values from TPM
registers.

Memory configuration on ASRock x470 ITX:

db0a0000-dc59efff : Reserved
        dc57e000-dc57efff : MSFT0101:00
        dc582000-dc582fff : MSFT0101:00

Work around the issue by storing ACPI regions declared for the
device in struct crb_resources. It contains fixed arrays of
copies of ACPI resourses (iores field) and pointers
to a possibly allocated with devm_ioremap_resource memory region
(iobase field), along with number of entries (num field).
This data was previously held for a single resource
in struct crb_priv (iobase field) and local variable io_res in
crb_map_io function. ACPI resources array is used to find index of
corresponding region for each buffer with crb_containing_res_idx,
make the buffer size consistent with region's length and map it at
most once, storing pointer to the allocated resource in iobase
array at the same index.

Signed-off-by: Ivan Lazeev <ivan.laz...@gmail.com>
---

Changes in v5:
        - prefix new symbols with tpm_crb_
        - get rid of dynamic allocation in ACPI walker

 drivers/char/tpm/tpm_crb.c | 129 +++++++++++++++++++++++++++----------
 1 file changed, 96 insertions(+), 33 deletions(-)

diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index e59f1f91d7f3..3c2485c71260 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -22,6 +22,7 @@
 #include "tpm.h"
 
 #define ACPI_SIG_TPM2 "TPM2"
+#define TPM_CRB_MAX_RESOURCES 3
 
 static const guid_t crb_acpi_start_guid =
        GUID_INIT(0x6BBF6CAB, 0x5463, 0x4714,
@@ -91,7 +92,6 @@ enum crb_status {
 struct crb_priv {
        u32 sm;
        const char *hid;
-       void __iomem *iobase;
        struct crb_regs_head __iomem *regs_h;
        struct crb_regs_tail __iomem *regs_t;
        u8 __iomem *cmd;
@@ -108,6 +108,12 @@ struct tpm2_crb_smc {
        u32 smc_func_id;
 };
 
+struct tpm_crb_resources {
+       struct resource iores[TPM_CRB_MAX_RESOURCES];
+       void __iomem *iobase[TPM_CRB_MAX_RESOURCES];
+       int num;
+};
+
 static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value,
                                unsigned long timeout)
 {
@@ -432,38 +438,75 @@ static const struct tpm_class_ops tpm_crb = {
        .req_complete_val = CRB_DRV_STS_COMPLETE,
 };
 
+static bool tpm_crb_resource_contains(struct resource *iores,
+                                     u64 address)
+{
+       return address >= iores->start && address <= iores->end;
+}
+
+static int tpm_crb_containing_res_idx(struct tpm_crb_resources *resources,
+                                     u64 address)
+{
+       int res_idx;
+
+       for (res_idx = 0; res_idx < resources->num; ++res_idx) {
+               if (tpm_crb_resource_contains(&resources->iores[res_idx],
+                                             address))
+                       return res_idx;
+       }
+
+       return -1;
+}
+
 static int crb_check_resource(struct acpi_resource *ares, void *data)
 {
-       struct resource *io_res = data;
+       struct tpm_crb_resources *resources = data;
        struct resource_win win;
        struct resource *res = &(win.res);
 
        if (acpi_dev_resource_memory(ares, res) ||
            acpi_dev_resource_address_space(ares, &win)) {
-               *io_res = *res;
-               io_res->name = NULL;
+               if (resources->num < TPM_CRB_MAX_RESOURCES) {
+                       resources->iores[resources->num] = *res;
+                       resources->iores[resources->num].name = NULL;
+               }
+               resources->num += 1;
        }
 
        return 1;
 }
 
-static void __iomem *crb_map_res(struct device *dev, struct crb_priv *priv,
-                                struct resource *io_res, u64 start, u32 size)
+static void __iomem *crb_map_res(struct device *dev,
+                                struct tpm_crb_resources *resources,
+                                int res_idx,
+                                u64 start, u32 size)
 {
        struct resource new_res = {
                .start  = start,
                .end    = start + size - 1,
                .flags  = IORESOURCE_MEM,
        };
+       struct resource *iores;
+       void __iomem *iobase;
 
        /* Detect a 64 bit address on a 32 bit system */
        if (start != new_res.start)
                return (void __iomem *) ERR_PTR(-EINVAL);
 
-       if (!resource_contains(io_res, &new_res))
+       if (res_idx < 0)
                return devm_ioremap_resource(dev, &new_res);
 
-       return priv->iobase + (new_res.start - io_res->start);
+       iores = &resources->iores[res_idx];
+       iobase = resources->iobase[res_idx];
+       if (!iobase) {
+               iobase = devm_ioremap_resource(dev, iores);
+               if (IS_ERR(iobase))
+                       return iobase;
+
+               resources->iobase[res_idx] = iobase;
+       }
+
+       return iobase + (new_res.start - iores->start);
 }
 
 /*
@@ -490,9 +533,10 @@ static u64 crb_fixup_cmd_size(struct device *dev, struct 
resource *io_res,
 static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
                      struct acpi_table_tpm2 *buf)
 {
-       struct list_head resources;
-       struct resource io_res;
+       struct list_head acpi_resources;
        struct device *dev = &device->dev;
+       struct tpm_crb_resources resources;
+       int res_idx;
        u32 pa_high, pa_low;
        u64 cmd_pa;
        u32 cmd_size;
@@ -501,21 +545,36 @@ static int crb_map_io(struct acpi_device *device, struct 
crb_priv *priv,
        u32 rsp_size;
        int ret;
 
-       INIT_LIST_HEAD(&resources);
-       ret = acpi_dev_get_resources(device, &resources, crb_check_resource,
-                                    &io_res);
+       INIT_LIST_HEAD(&acpi_resources);
+       memset(&resources, 0, sizeof(resources));
+       ret = acpi_dev_get_resources(device, &acpi_resources,
+                                    crb_check_resource, &resources);
        if (ret < 0)
                return ret;
-       acpi_dev_free_resource_list(&resources);
+       acpi_dev_free_resource_list(&acpi_resources);
 
-       if (resource_type(&io_res) != IORESOURCE_MEM) {
+       if (resources.num == 0) {
                dev_err(dev, FW_BUG "TPM2 ACPI table does not define a memory 
resource\n");
                return -EINVAL;
+       } else if (resources.num > TPM_CRB_MAX_RESOURCES) {
+               dev_warn(dev, FW_BUG "TPM2 ACPI table defines too many memory 
resources\n");
+               resources.num = TPM_CRB_MAX_RESOURCES;
        }
 
-       priv->iobase = devm_ioremap_resource(dev, &io_res);
-       if (IS_ERR(priv->iobase))
-               return PTR_ERR(priv->iobase);
+       res_idx = tpm_crb_containing_res_idx(&resources, buf->control_address);
+
+       if (res_idx >= 0 &&
+           !tpm_crb_resource_contains(&resources.iores[res_idx],
+                                      buf->control_address +
+                                      sizeof(struct crb_regs_tail) - 1))
+               res_idx = -1;
+
+       priv->regs_t = crb_map_res(dev, &resources, res_idx,
+                                  buf->control_address,
+                                  sizeof(struct crb_regs_tail));
+
+       if (IS_ERR(priv->regs_t))
+               return PTR_ERR(priv->regs_t);
 
        /* 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
@@ -523,9 +582,10 @@ static int crb_map_io(struct acpi_device *device, struct 
crb_priv *priv,
         */
        if ((priv->sm == ACPI_TPM2_COMMAND_BUFFER) ||
            (priv->sm == ACPI_TPM2_MEMORY_MAPPED)) {
-               if (buf->control_address == io_res.start +
+               if (res_idx >= 0 &&
+                   buf->control_address == resources.iores[res_idx].start +
                    sizeof(*priv->regs_h))
-                       priv->regs_h = priv->iobase;
+                       priv->regs_h = resources.iobase[res_idx];
                else
                        dev_warn(dev, FW_BUG "Bad ACPI memory layout");
        }
@@ -534,13 +594,6 @@ static int crb_map_io(struct acpi_device *device, struct 
crb_priv *priv,
        if (ret)
                return ret;
 
-       priv->regs_t = crb_map_res(dev, priv, &io_res, buf->control_address,
-                                  sizeof(struct crb_regs_tail));
-       if (IS_ERR(priv->regs_t)) {
-               ret = PTR_ERR(priv->regs_t);
-               goto out_relinquish_locality;
-       }
-
        /*
         * PTT HW bug w/a: wake up the device to access
         * possibly not retained registers.
@@ -552,13 +605,17 @@ 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,
-                                     ioread32(&priv->regs_t->ctrl_cmd_size));
+       cmd_size = ioread32(&priv->regs_t->ctrl_cmd_size);
+
+       res_idx = tpm_crb_containing_res_idx(&resources, cmd_pa);
+       if (res_idx >= 0)
+               cmd_size = crb_fixup_cmd_size(dev, &resources.iores[res_idx],
+                                             cmd_pa, cmd_size);
 
        dev_dbg(dev, "cmd_hi = %X cmd_low = %X cmd_size %X\n",
                pa_high, pa_low, cmd_size);
 
-       priv->cmd = crb_map_res(dev, priv, &io_res, cmd_pa, cmd_size);
+       priv->cmd = crb_map_res(dev, &resources, res_idx, cmd_pa, cmd_size);
        if (IS_ERR(priv->cmd)) {
                ret = PTR_ERR(priv->cmd);
                goto out;
@@ -566,11 +623,17 @@ 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,
-                                     ioread32(&priv->regs_t->ctrl_rsp_size));
+       rsp_size = ioread32(&priv->regs_t->ctrl_rsp_size);
+
+       res_idx = tpm_crb_containing_res_idx(&resources, rsp_pa);
+
+       if (res_idx >= 0)
+               rsp_size = crb_fixup_cmd_size(dev, &resources.iores[res_idx],
+                                             rsp_pa, rsp_size);
 
        if (cmd_pa != rsp_pa) {
-               priv->rsp = crb_map_res(dev, priv, &io_res, rsp_pa, rsp_size);
+               priv->rsp = crb_map_res(dev, &resources, res_idx,
+                                       rsp_pa, rsp_size);
                ret = PTR_ERR_OR_ZERO(priv->rsp);
                goto out;
        }
-- 
2.20.1

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