diff options
| author | Patrick Rudolph <[email protected]> | 2024-10-23 15:20:13 +0200 |
|---|---|---|
| committer | Tom Rini <[email protected]> | 2024-10-27 17:24:13 -0600 |
| commit | 34bfe8eff895b864247d923ce37110a9053592ee (patch) | |
| tree | 627a145bd5527c6693b6a326dcf3cfb6badeccb2 /include | |
| parent | 2f3b679298903c6ce5169953dfe7e08ffeadc3b9 (diff) | |
arm: cpu: Add ACPI parking protocol support
On Arm platforms that use ACPI they cannot rely on the "spin-table"
CPU bringup usually defined in the FDT. Thus implement the
'ACPI Multi-processor Startup for ARM Platforms', also referred to as
'ACPI parking protocol'.
The ACPI parking protocol works similar to the spin-table mechanism, but
the specification also covers lots of shortcomings of the spin-table
implementations.
Every CPU defined in the ACPI MADT table has it's own 4K page where the
spinloop code and the OS mailbox resides. When selected the U-Boot board
code must make sure that the secondary CPUs enter u-boot after relocation
as well, so that they can enter the spinloop code residing in the ACPI
parking protocol pages.
The OS will then write to the mailbox and generate an IPI to release the
CPUs from the spinloop code.
For now it's only implemented on ARMv8, but can easily be extended to
other platforms, like ARMv7.
TEST: Boots all CPUs on qemu-system-aarch64 -machine raspi4b
Signed-off-by: Patrick Rudolph <[email protected]>
Reviewed-by: Simon Glass <[email protected]>
Cc: Simon Glass <[email protected]>
Cc: Tom Rini <[email protected]>
Diffstat (limited to 'include')
| -rw-r--r-- | include/acpi/acpi_table.h | 10 | ||||
| -rw-r--r-- | include/bloblist.h | 1 |
2 files changed, 11 insertions, 0 deletions
diff --git a/include/acpi/acpi_table.h b/include/acpi/acpi_table.h index 07c5f65d753..b8b1f1338c6 100644 --- a/include/acpi/acpi_table.h +++ b/include/acpi/acpi_table.h @@ -1238,6 +1238,16 @@ 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 * * This routine returns the ACPI RSDP table address in the system memory. diff --git a/include/bloblist.h b/include/bloblist.h index b0706b5637d..ff32d3fecfd 100644 --- a/include/bloblist.h +++ b/include/bloblist.h @@ -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, |