On Thu, Mar 11, 2021 at 04:36:31PM +0100, Rafael J. Wysocki wrote: > On Wed, Mar 10, 2021 at 8:47 PM David Hildenbrand <david@xxxxxxxxxx> wrote: > > > > > > There is some care that should be taken to make sure we get the order > > > right, but I don't see a fundamental issue here. > > Me neither. > > > > If I understand correctly, Rafael's concern is about changing the parts of > > > ACPICA that should be OS agnostic, so I think we just need another place to > > > call memblock_reserve() rather than acpi_tb_install_table_with_override(). > > Something like this. > > There is also the problem that memblock_reserve() needs to be called > for all of the tables early enough, which will require some reordering > of the early init code. > > > > Since the reservation should be done early in x86::setup_arch() (and > > > probably in arm64::setup_arch()) we might just have a function that parses > > > table headers and reserves them, similarly to how we parse the tables > > > during KASLR setup. > > Right. I've looked at it a bit more and we do something like the patch below that nearly duplicates acpi_tb_parse_root_table() which is not very nice. Besides, reserving ACPI tables early and then calling acpi_table_init() (and acpi_tb_parse_root_table() again would mean doing the dance with early_memremap() twice for no good reason. I believe the most effective way to deal with this would be to have a function that does parsing, reservation and installs the tables supplied by the firmware which can be called really early and then another function that overrides tables if needed a some later point. -------------------------------------------------------------- diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index d883176ef2ce..48bcb1c355ad 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -910,6 +910,8 @@ void __init setup_arch(char **cmdline_p) parse_early_param(); + acpi_reserve_tables(); + if (efi_enabled(EFI_BOOT)) efi_memblock_x86_reserve_range(); #ifdef CONFIG_MEMORY_HOTPLUG diff --git a/drivers/acpi/acpica/actables.h b/drivers/acpi/acpica/actables.h index e2d0046799a2..6cb5bcf3fb49 100644 --- a/drivers/acpi/acpica/actables.h +++ b/drivers/acpi/acpica/actables.h @@ -133,6 +133,9 @@ void acpi_tb_install_table_with_override(struct acpi_table_desc *new_table_desc, u8 override, u32 *table_index); +acpi_physical_address +acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size); + acpi_status acpi_tb_parse_root_table(acpi_physical_address rsdp_address); acpi_status diff --git a/drivers/acpi/acpica/tbutils.c b/drivers/acpi/acpica/tbutils.c index 4b9b329a5a92..2ad3c08915d4 100644 --- a/drivers/acpi/acpica/tbutils.c +++ b/drivers/acpi/acpica/tbutils.c @@ -14,10 +14,6 @@ #define _COMPONENT ACPI_TABLES ACPI_MODULE_NAME("tbutils") -/* Local prototypes */ -static acpi_physical_address -acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size); - #if (!ACPI_REDUCED_HARDWARE) /******************************************************************************* * @@ -162,7 +158,7 @@ struct acpi_table_header *acpi_tb_copy_dsdt(u32 table_index) * ******************************************************************************/ -static acpi_physical_address +acpi_physical_address acpi_tb_get_root_table_entry(u8 *table_entry, u32 table_entry_size) { u64 address64; diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c index e48690a006a4..e4b721bada04 100644 --- a/drivers/acpi/tables.c +++ b/drivers/acpi/tables.c @@ -23,6 +23,9 @@ #include <linux/security.h> #include "internal.h" +#include "acpica/aclocal.h" +#include "acpica/actables.h" + #ifdef CONFIG_ACPI_CUSTOM_DSDT #include CONFIG_ACPI_CUSTOM_DSDT_FILE #endif @@ -809,6 +812,107 @@ int __init acpi_table_init(void) return 0; } +void __init acpi_reserve_tables(void) +{ + u32 i, table_count, table_entry_size, length; + acpi_physical_address rsdp_address, address; + struct acpi_table_header *table, *hdr; + struct acpi_table_rsdp *rsdp; + u8 *table_entry; + + rsdp_address = acpi_os_get_root_pointer(); + if (!rsdp_address) { + pr_debug("%s: no rsdp_address\n", __func__); + return; + } + + /* Map the entire RSDP and extract the address of the RSDT or XSDT */ + rsdp = acpi_os_map_memory(rsdp_address, sizeof(struct acpi_table_rsdp)); + if (!rsdp) { + pr_debug("%s: can't map rsdp\n", __func__); + return; + } + + memblock_reserve(rsdp_address, sizeof(struct acpi_table_rsdp)); + + /* Use XSDT if present and not overridden. Otherwise, use RSDT */ + if ((rsdp->revision > 1) && + rsdp->xsdt_physical_address && !acpi_gbl_do_not_use_xsdt) { + address = (acpi_physical_address)rsdp->xsdt_physical_address; + table_entry_size = ACPI_XSDT_ENTRY_SIZE; + } else { + address = (acpi_physical_address)rsdp->rsdt_physical_address; + table_entry_size = ACPI_RSDT_ENTRY_SIZE; + } + + /* + * It is not possible to map more than one entry in some environments, + * so unmap the RSDP here before mapping other tables + */ + acpi_os_unmap_memory(rsdp, sizeof(struct acpi_table_rsdp)); + + /* Map the RSDT/XSDT table header to get the full table length */ + + table = acpi_os_map_memory(address, sizeof(struct acpi_table_header)); + if (!table) { + pr_debug("%s: can't map [RX]SDT header\n", __func__); + return; + } + + /* + * Validate length of the table, and map entire table. + * Minimum length table must contain at least one entry. + */ + length = table->length; + acpi_os_unmap_memory(table, sizeof(struct acpi_table_header)); + + if (length < (sizeof(struct acpi_table_header) + table_entry_size)) { + pr_debug("Invalid table length 0x%X in RSDT/XSDT", length); + return; + } + + memblock_reserve(address, length); + + table = acpi_os_map_memory(address, length); + if (!table) { + pr_debug("%s: can't map [RX]SDT table\n", __func__); + return; + } + + /* Get the number of entries and pointer to first entry */ + table_count = (u32)((table->length - sizeof(struct acpi_table_header)) / + table_entry_size); + table_entry = ACPI_ADD_PTR(u8, table, sizeof(struct acpi_table_header)); + + /* reserve tables pointed from the RSDT/XSDT */ + for (i = 0; i < table_count; i++, table_entry += table_entry_size) { + + /* Get the table physical address (32-bit for RSDT, 64-bit for XSDT) */ + + address = + acpi_tb_get_root_table_entry(table_entry, table_entry_size); + + /* Skip NULL entries in RSDT/XSDT */ + + if (!address) + continue; + + hdr = acpi_os_map_memory(address, sizeof(struct acpi_table_header)); + if (!hdr) { + pr_debug("%s: can't map %d header\n", __func__, i); + continue; + } + + memblock_reserve(address, hdr->length); + + /* FIXME: parse FADT and reserve embedded there tables */ + + acpi_os_unmap_memory(hdr, sizeof(struct acpi_table_header)); + } + + acpi_os_unmap_memory(table, length); +} + static int __init acpi_parse_apic_instance(char *str) { if (!str) diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 9f432411e988..d8688e4b6726 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -226,6 +226,8 @@ void acpi_boot_table_init (void); int acpi_mps_check (void); int acpi_numa_init (void); +void acpi_reserve_tables(void); + int acpi_table_init (void); int acpi_table_parse(char *id, acpi_tbl_table_handler handler); int __init acpi_table_parse_entries(char *id, unsigned long table_size, -- Sincerely yours, Mike.