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SubjectRe: [PATCH v5] tpm_crb: fix fTPM on AMD Zen+ CPUs
On Thu, Sep 26, 2019 at 12:56:46AM +0300, ivan.lazeev@gmail.com wrote:
> +struct tpm_crb_resources {
> + struct resource iores[TPM_CRB_MAX_RESOURCES];
> + void __iomem *iobase[TPM_CRB_MAX_RESOURCES];
> + int num;
> +};

Do not add a new struct.

> +
> 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;
> +}

Open code this. Makes the code only more unreadable.

> +static int tpm_crb_containing_res_idx(struct tpm_crb_resources *resources,
> + u64 address)
> +{
> + int res_idx;

Use "int i;"

> +
> + 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;
> +}

Open code this. Two call sites do not make the function worth it.

> +
> 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;

Remove FW_BUG as this would not be a bug.

/Jarkko

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