@@ -29,6 +29,7 @@ obj-$(CONFIG_ARM_SMCCC) += smccc-call.o
ifndef CONFIG_SPL_BUILD
obj-$(CONFIG_ARMV8_SPIN_TABLE) += spin_table.o spin_table_v8.o
+obj-$(CONFIG_ACPI_PARKING_PROTOCOL) += acpi_park_v8.o
else
obj-$(CONFIG_ARCH_SUNXI) += fel_utils.o
endif
new file mode 100644
@@ -0,0 +1,113 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2024 9elements GmbH
+ * Author: Patrick Rudolph <patrick.rudolph@9elements.com>
+ *
+ * This file provides ARMv8 specific code for the generic part of the
+ * ACPI parking protocol implementation. It contains the spinning code
+ * that will be installed into the parking protocol and it points the
+ * secondary CPUs to their own parking protocol page once it has been
+ * set up by the generic part.
+ */
+
+#include <asm/acpi_table.h>
+#include <linux/linkage.h>
+
+/* Filled by C code */
+.global acpi_pp_tables
+acpi_pp_tables:
+ .quad 0
+
+.global acpi_pp_etables
+acpi_pp_etables:
+ .quad 0
+
+/* Read by C code */
+.global acpi_pp_code_size
+acpi_pp_code_size:
+ .word __secondary_pp_code_end - __secondary_pp_code_start
+
+.global acpi_pp_secondary_jump
+ENTRY(acpi_pp_secondary_jump)
+0:
+ /*
+ * Cannot use atomic operations since the MMU and D-cache
+ * might be off. Use the MPIDR instead to find the spintable.
+ */
+
+ /* Check if parking protocol table is ready */
+ ldr x1, =acpi_pp_tables
+ ldr x0, [x1]
+ cbnz x0, 0f
+ wfe
+ b 0b
+
+0: /* Get end of page tables in x3 */
+ ldr x1, =acpi_pp_etables
+ ldr x3, [x1]
+
+ /* Get own CPU ID in w2 */
+ mrs x2, mpidr_el1
+ lsr x9, x2, #32
+ bfi x2, x9, #24, #8 /* w2 is aff3:aff2:aff1:aff0 */
+
+0: /* Loop over all parking protocol pages */
+ cmp x0, x3
+ b.ge hlt
+
+ /* Fetch CPU_ID from current page */
+ ldr x1, [x0, #ACPI_PP_CPU_ID_OFFSET]
+ lsr x9, x1, #32
+ bfi x1, x9, #24, #8 /* w1 is aff3:aff2:aff1:aff0 */
+
+ /* Compare CPU_IDs */
+ cmp w1, w2
+ b.eq 0f
+
+ add x0, x0, #ACPI_PP_PAGE_SIZE
+ b 0b
+
+hlt: wfi
+ b hlt /* Should never happen. */
+
+0: /* x0 points to the 4K-aligned, parking protocol page */
+ add x2, x0, #ACPI_PP_CPU_CODE_OFFSET
+
+ /* Jump to spin code in own parking protocol page */
+ br x2
+ENDPROC(acpi_pp_secondary_jump)
+
+.align 8
+__secondary_pp_code_start:
+.global acpi_pp_code_start
+ENTRY(acpi_pp_code_start)
+ /* x0 points to the 4K-aligned, parking protocol page */
+
+ /* Prepare defines for spinning code */
+ mov w3, #ACPI_PP_CPU_ID_INVALID
+ mov x2, #ACPI_PP_JMP_ADR_INVALID
+
+ /* Mark parking protocol page as ready */
+ str w3, [x0, #ACPI_PP_CPU_ID_OFFSET]
+ dsb sy
+
+0: wfe
+ ldr w1, [x0, #ACPI_PP_CPU_ID_OFFSET]
+
+ /* Check CPU ID is valid */
+ cmp w1, w3
+ b.eq 0b
+
+ /* Check jump address valid */
+ ldr x1, [x0, #ACPI_PP_CPU_JMP_OFFSET]
+ cmp x1, x2
+ b.eq 0b
+
+ /* Clear jump address before jump */
+ str x2, [x0, #ACPI_PP_CPU_JMP_OFFSET]
+ dsb sy
+
+ br x1
+ENDPROC(acpi_pp_code_start)
+ /* Secondary Boot Code ends here */
+__secondary_pp_code_end:
@@ -4,6 +4,7 @@
#define __ASM_ACPI_TABLE_H__
#ifndef __ACPI__
+#ifndef __ASSEMBLY__
#include <acpi/acpi_table.h>
@@ -109,7 +110,38 @@ int acpi_pptt_add_cache(struct acpi_ctx *ctx, const u32 flags,
const u32 sets, const u8 assoc, const u8 attributes,
const u16 line_size);
+/* Multi-processor Startup for ARM Platforms */
+/**
+ * struct acpi_pp_page - MP startup handshake mailbox
+ *
+ * Defines a 4096 byte memory region that is used for starting secondary CPUs on
+ * an Arm system that follows the "Multi-processor Startup for ARM Platforms" spec.
+ *
+ * @cpu_id: MPIDR as returned by the Multiprocessor Affinity Register.
+ * On 32bit Arm systems the upper bits are unused.
+ * @jumping_address: On 32bit Arm systems the address must be below 4 GiB
+ * @os_reserved: Reserved for OS use. Firmware must not access this memory.
+ * @spinning_code: Reserved for firmware use. OS must not access this memory.
+ * The spinning code will be installed by firmware and the secondary
+ * CPUs will enter it before the control is handed over to the OS.
+ */
+struct acpi_pp_page {
+ u64 cpu_id;
+ u64 jumping_address;
+ u8 os_reserved[2032];
+ u8 spinning_code[2048];
+} __packed;
+
#endif /* !__ASSEMBLY__ */
#endif /* !__ACPI__ */
+/* Multi-processor Startup for ARM Platforms defines */
+#define ACPI_PP_CPU_ID_INVALID 0xffffffff
+#define ACPI_PP_JMP_ADR_INVALID 0
+#define ACPI_PP_PAGE_SIZE 4096
+#define ACPI_PP_CPU_ID_OFFSET 0
+#define ACPI_PP_CPU_JMP_OFFSET 8
+#define ACPI_PP_CPU_CODE_OFFSET 2048
+#define ACPI_PP_VERSION 1
+
#endif /* __ASM_ACPI_TABLE_H__ */
@@ -7,12 +7,48 @@
#define LOG_CATEGORY LOGC_ACPI
+#include <bloblist.h>
+#include <cpu_func.h>
+#include <efi_loader.h>
+#include <malloc.h>
#include <string.h>
+#include <tables_csum.h>
#include <acpi/acpigen.h>
#include <acpi/acpi_device.h>
#include <acpi/acpi_table.h>
+#include <asm-generic/io.h>
#include <dm/acpi.h>
#include <dm/uclass.h>
+#include <linux/log2.h>
+#include <linux/sizes.h>
+
+/* defined in assembly file */
+/**
+ * acpi_pp_code_size - Spinloop code size *
+ */
+extern u16 acpi_pp_code_size;
+
+/**
+ * acpi_pp_tables - Start of ACPI PP tables.
+ */
+extern ulong acpi_pp_tables;
+
+/**
+ * acpi_pp_etables - End of ACPI PP tables.
+ */
+extern ulong acpi_pp_etables;
+
+/**
+ * acpi_pp_code_start() - Spinloop code
+ *
+ * Architectural spinloop code to be installed in each parking protocol
+ * page. The spinloop code must be less than 2048 bytes.
+ *
+ * The spinloop code will be entered after calling
+ * acpi_parking_protocol_install().
+ *
+ */
+void acpi_pp_code_start(void);
void acpi_write_madt_gicc(struct acpi_madt_gicc *gicc, uint cpu_num,
uint perf_gsiv, ulong phys_base, ulong gicv,
@@ -125,3 +161,116 @@ void *acpi_fill_madt(struct acpi_madt *madt, struct acpi_ctx *ctx)
return ctx->current;
}
+
+/**
+ * acpi_write_pp_setup_one_page() - Fill out one page used by the PP
+ *
+ * Fill out the struct acpi_pp_page to contain the spin-loop
+ * code and the mailbox area. After this function the page is ready for
+ * the secondary core's to enter the spin-loop code.
+ *
+ * @page: Pointer to current parking protocol page
+ * @gicc: Pointer to corresponding GICC sub-table
+ */
+static void acpi_write_pp_setup_one_page(struct acpi_pp_page *page,
+ struct acpi_madt_gicc *gicc)
+{
+ void *reloc;
+
+ /* Update GICC. Mark parking protocol as available. */
+ gicc->parking_proto = ACPI_PP_VERSION;
+ gicc->parked_addr = virt_to_phys(page);
+
+ /* Prepare parking protocol page */
+ memset(page, '\0', sizeof(struct acpi_pp_page));
+
+ /* Init mailbox. Set MPIDR so core's will find their page. */
+ page->cpu_id = gicc->mpidr;
+ page->jumping_address = ACPI_PP_JMP_ADR_INVALID;
+
+ /* Relocate spinning code */
+ reloc = &page->spinning_code[0];
+
+ log_debug("Relocating spin table from %lx to %lx (size %x)\n",
+ (ulong)&acpi_pp_code_start, (ulong)reloc, acpi_pp_code_size);
+ memcpy(reloc, &acpi_pp_code_start, acpi_pp_code_size);
+
+ if (!CONFIG_IS_ENABLED(SYS_DCACHE_OFF))
+ flush_dcache_range((unsigned long)page,
+ (unsigned long)(page + 1));
+}
+
+void acpi_write_park(struct acpi_madt *madt)
+{
+ struct acpi_pp_page *start, *page;
+ struct acpi_madt_gicc *gicc;
+ int ret, i, ncpus = 0;
+
+ /*
+ * According to the "Multi-processor Startup for ARM Platforms":
+ * - Every CPU as specified by MADT GICC has it's own 4K page
+ * - Every page is divided into two sections: OS and FW reserved
+ * - Memory occupied by "Parking Protocol" must be marked 'Reserved'
+ * - Spinloop code should reside in FW reserved 2048 bytes
+ * - Spinloop code will check the mailbox in OS reserved area
+ */
+
+ if (acpi_pp_code_size > sizeof(page->spinning_code)) {
+ log_err("Spinning code too big to fit: %d\n",
+ acpi_pp_code_size);
+ return;
+ }
+
+ /* Count all MADT GICCs including BSP */
+ for (i = sizeof(struct acpi_madt); i < madt->header.length;
+ i += gicc->length) {
+ gicc = (struct acpi_madt_gicc *)((void *)madt + i);
+ if (gicc->type != ACPI_APIC_GICC)
+ continue;
+ ncpus++;
+ }
+ log_debug("Found %#x GICCs in MADT\n", ncpus);
+
+ /* Allocate pages linearly due to assembly code requirements */
+ start = bloblist_add(BLOBLISTT_ACPI_PP, ACPI_PP_PAGE_SIZE * ncpus,
+ ilog2(SZ_4K));
+ if (!start) {
+ log_err("Failed to allocate memory for ACPI-parking-protocol pages\n");
+ return;
+ }
+ log_debug("Allocated parking protocol at %p\n", start);
+ page = start;
+
+ if (IS_ENABLED(CONFIG_EFI_LOADER)) {
+ /* Default mapping is 'BOOT CODE'. Mark as reserved instead. */
+ ret = efi_add_memory_map((u64)(uintptr_t)start,
+ ncpus * ACPI_PP_PAGE_SIZE,
+ EFI_RESERVED_MEMORY_TYPE);
+
+ if (ret)
+ log_err("Reserved memory mapping failed addr %p size %x\n",
+ start, ncpus * ACPI_PP_PAGE_SIZE);
+ }
+
+ /* Prepare the parking protocol pages */
+ for (i = sizeof(struct acpi_madt); i < madt->header.length;
+ i += gicc->length) {
+ gicc = (struct acpi_madt_gicc *)((void *)madt + i);
+ if (gicc->type != ACPI_APIC_GICC)
+ continue;
+
+ acpi_write_pp_setup_one_page(page++, gicc);
+ }
+
+ acpi_pp_etables = virt_to_phys(start) +
+ ACPI_PP_PAGE_SIZE * ncpus;
+ acpi_pp_tables = virt_to_phys(start);
+
+ /* Make sure other cores see written value in memory */
+ if (!CONFIG_IS_ENABLED(SYS_DCACHE_OFF))
+ flush_dcache_all();
+
+ /* Send an event to wake up the secondary CPU. */
+ asm("dsb ishst\n"
+ "sev");
+}
@@ -1237,6 +1237,16 @@ int acpi_iort_add_smmu_v3(struct acpi_ctx *ctx,
*/
void *acpi_fill_madt(struct acpi_madt *madt, struct acpi_ctx *ctx);
+/**
+ * acpi_write_park() - Installs the ACPI parking protocol.
+ *
+ * Sets up the ACPI parking protocol and installs the spinning code for
+ * secondary CPUs.
+ *
+ * @madt: The MADT to update
+ */
+void acpi_write_park(struct acpi_madt *madt);
+
/**
* acpi_get_rsdp_addr() - get ACPI RSDP table address
*
@@ -110,6 +110,7 @@ enum bloblist_tag_t {
BLOBLISTT_ACPI_TABLES = 4,
BLOBLISTT_TPM_EVLOG = 5,
BLOBLISTT_TPM_CRB_BASE = 6,
+ BLOBLISTT_ACPI_PP = 7,
/* Standard area to allocate blobs used across firmware components */
BLOBLISTT_AREA_FIRMWARE = 0x10,
@@ -315,6 +315,22 @@ config GENERATE_ACPI_TABLE
by the operating system. It defines platform-independent interfaces
for configuration and power management monitoring.
+config ACPI_PARKING_PROTOCOL
+ bool "Support ACPI parking protocol method"
+ depends on GENERATE_ACPI_TABLE
+ depends on ARMV8_MULTIENTRY
+ depends on BLOBLIST_TABLES
+ default y if !SEC_FIRMWARE_ARMV8_PSCI && !ARMV8_PSCI
+ help
+ Say Y here to support "ACPI parking protocol" enable method
+ for booting Linux.
+
+ To use this feature, you must do:
+ - Bring secondary CPUs into U-Boot proper in a board-specific
+ manner. This must be done *after* relocation. Otherwise, the
+ secondary CPUs will spin in unprotected memory-area because the
+ master CPU protects the relocated spin code.
+
config SPL_TINY_MEMSET
bool "Use a very small memset() in SPL"
depends on SPL
@@ -297,6 +297,10 @@ int acpi_write_madt(struct acpi_ctx *ctx, const struct acpi_writer *entry)
/* (Re)calculate length and checksum */
header->length = (uintptr_t)current - (uintptr_t)madt;
+
+ if (IS_ENABLED(CONFIG_ACPI_PARKING_PROTOCOL))
+ acpi_write_park(madt);
+
header->checksum = table_compute_checksum((void *)madt, header->length);
acpi_add_table(ctx, madt);
ctx->current = (void *)madt + madt->header.length;