The ASP table indicates the presence of a Platform Security Processor with a register window and registers to configure interrupt delivery. The helper checks for the presence of the table and returns a resource and struct with register offsets. Link: https://github.com/acpica/acpica/commit/15b939b034ab41a864b4e7647b8e2233780bb0c7 Link: https://www.amd.com/system/files/TechDocs/58028_1.00-PUB.pdf Acked-by: Tom Lendacky <thomas.lendacky@xxxxxxx> Signed-off-by: Jeremi Piotrowski <jpiotrowski@xxxxxxxxxxxxxxxxxxx> --- drivers/acpi/Makefile | 1 + drivers/acpi/aspt.c | 104 ++++++++++++++++++++++++++++++ include/linux/platform_data/psp.h | 32 +++++++++ 3 files changed, 137 insertions(+) create mode 100644 drivers/acpi/aspt.c create mode 100644 include/linux/platform_data/psp.h diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index feb36c0b9446..831d7a12b522 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -57,6 +57,7 @@ acpi-y += evged.o acpi-y += sysfs.o acpi-y += property.o acpi-$(CONFIG_X86) += acpi_cmos_rtc.o +acpi-$(CONFIG_X86) += aspt.o acpi-$(CONFIG_X86) += x86/apple.o acpi-$(CONFIG_X86) += x86/utils.o acpi-$(CONFIG_X86) += x86/s2idle.o diff --git a/drivers/acpi/aspt.c b/drivers/acpi/aspt.c new file mode 100644 index 000000000000..cf629db35036 --- /dev/null +++ b/drivers/acpi/aspt.c @@ -0,0 +1,104 @@ +// SPDX-License-Identifier: GPL-2.0-only +#define pr_fmt(fmt) "ACPI: ASPT: " fmt +#include <linux/acpi.h> +#include <linux/kernel.h> +#include <linux/platform_data/psp.h> + +static int __init psp_validate_regs(const struct acpi_aspt_global_regs *gregs, + const struct acpi_aspt_sev_mbox_regs *sevregs, + const struct acpi_aspt_acpi_mbox_regs *acpiregs) +{ + u64 pfn; + int idx; + u64 regs[] = { + gregs->feature_reg_addr, + gregs->irq_en_reg_addr, + gregs->irq_st_reg_addr, + sevregs->cmd_resp_reg_addr, + sevregs->cmd_buf_lo_reg_addr, + sevregs->cmd_buf_hi_reg_addr, + acpiregs->cmd_resp_reg_addr + }; + pfn = regs[0] >> PAGE_SHIFT; + for (idx = 1; idx < ARRAY_SIZE(regs); idx++) { + if (regs[idx] >> PAGE_SHIFT != pfn) + return -EINVAL; + } + return 0; +} + +/** + * acpi_parse_aspt - Parse ASPT table and return contained information + * @res: will be filled with the address and size of the ASP register window + * @pdata: will be filled with the register offsets parsed from the ASPT table + */ +int __init acpi_parse_aspt(struct resource *res, struct psp_platform_data *pdata) +{ + struct acpi_aspt_acpi_mbox_regs acpiregs = {}; + struct acpi_aspt_sev_mbox_regs sevregs = {}; + struct acpi_aspt_global_regs gregs = {}; + struct acpi_aspt_header *entry, *end; + struct acpi_table_aspt *aspt; + unsigned long base; + acpi_status status; + int err = 0; + + status = acpi_get_table(ACPI_SIG_ASPT, 0, (struct acpi_table_header **)&aspt); + if (ACPI_FAILURE(status)) + return -ENODEV; + if (aspt->header.revision != ASPT_REVISION_ID) { + pr_err("unsupported table revision: %d\n", (int)aspt->header.revision); + err = -ENODEV; + goto exit; + } + entry = (struct acpi_aspt_header *)(aspt + 1); + end = (struct acpi_aspt_header *)((void *)aspt + aspt->header.length); + while (entry < end) { + if (((void *)entry + entry->length) > (void *)end) { + pr_err("error during parsing\n"); + err = -EINVAL; + goto exit; + } + switch (entry->type) { + case ACPI_ASPT_TYPE_GLOBAL_REGS: + memcpy(&gregs, entry, entry->length); + break; + case ACPI_ASPT_TYPE_SEV_MBOX_REGS: + memcpy(&sevregs, entry, entry->length); + break; + case ACPI_ASPT_TYPE_ACPI_MBOX_REGS: + memcpy(&acpiregs, entry, entry->length); + break; + } + entry = (struct acpi_aspt_header *)((void *)entry + entry->length); + } + if (!gregs.header.length || !sevregs.header.length || !acpiregs.header.length) { + pr_err("missing ASPT table entry: %u %u %u\n", gregs.header.length, + sevregs.header.length, + acpiregs.header.length); + err = -EINVAL; + goto exit; + } + /* All registers are expected to be within the same page */ + err = psp_validate_regs(&gregs, &sevregs, &acpiregs); + if (err) { + pr_err("ASPT registers span multiple pages\n"); + goto exit; + } + + base = ALIGN_DOWN(gregs.feature_reg_addr, PAGE_SIZE); + *res = (struct resource)DEFINE_RES_MEM(base, PAGE_SIZE); + + pdata->sev_cmd_resp_reg = sevregs.cmd_resp_reg_addr & ~PAGE_MASK; + pdata->sev_cmd_buf_lo_reg = sevregs.cmd_buf_lo_reg_addr & ~PAGE_MASK; + pdata->sev_cmd_buf_hi_reg = sevregs.cmd_buf_hi_reg_addr & ~PAGE_MASK; + pdata->feature_reg = gregs.feature_reg_addr & ~PAGE_MASK; + pdata->irq_en_reg = gregs.irq_en_reg_addr & ~PAGE_MASK; + pdata->irq_st_reg = gregs.irq_st_reg_addr & ~PAGE_MASK; + pdata->mbox_irq_id = sevregs.mbox_irq_id; + pdata->acpi_cmd_resp_reg = acpiregs.cmd_resp_reg_addr & ~PAGE_MASK; + +exit: + acpi_put_table((struct acpi_table_header *)aspt); + return err; +} diff --git a/include/linux/platform_data/psp.h b/include/linux/platform_data/psp.h new file mode 100644 index 000000000000..b761f72168d6 --- /dev/null +++ b/include/linux/platform_data/psp.h @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * psp.h - PSP register offsets parsed from ASPT ACPI table + */ + +#ifndef __LINUX_PSP_H +#define __LINUX_PSP_H + +#include <linux/types.h> +#include <linux/ioport.h> + +struct psp_platform_data { + int sev_cmd_resp_reg; + int sev_cmd_buf_lo_reg; + int sev_cmd_buf_hi_reg; + int feature_reg; + int irq_en_reg; + int irq_st_reg; + int mbox_irq_id; + int acpi_cmd_resp_reg; +}; + +#if IS_ENABLED(CONFIG_ACPI) +int acpi_parse_aspt(struct resource *res, struct psp_platform_data *pdata); +#else +static inline acpi_parse_aspt(struct resource *res, struct psp_platform_data *pdata) +{ + return -ENODEV; +} +#endif + +#endif /* __LINUX_PSP_H */ -- 2.34.1
