On 02.07.21 11:02, Cedric Hombourger wrote: > This driver parses ACPI tables and looks for a "WDAT entry. It > then programs the watchdog using the actions/instructions specified > by the BIOS (where register addresses and values are specified). > Unlike Linux, we not need to create (allocate) a dictionary of > actions as we may just parse the tables on the go to perform our > SET_COUNTDOWN and SET_RUNNING actions. This driver was tested > on SIMATIC IPC127E. > > Signed-off-by: Cedric Hombourger <[email protected]> > --- > Makefile.am | 1 + > drivers/watchdog/wdat.c | 425 ++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 426 insertions(+) > create mode 100644 drivers/watchdog/wdat.c > > diff --git a/Makefile.am b/Makefile.am > index 8fb8652..6d61cc4 100644 > --- a/Makefile.am > +++ b/Makefile.am > @@ -129,6 +129,7 @@ efi_sources = \ > drivers/watchdog/i6300esb.c \ > drivers/watchdog/atom-quark.c \ > drivers/watchdog/ipc4x7e_wdt.c \ > + drivers/watchdog/wdat.c \
You should leave a comment like for the ipc4x7e_wdt.c on the required ordering. And I would actually restore your original prioritization of WDAT over anything else, i.e. move this right after init_array_start.S. Or do you see any reason we should generally prefer the specific PCI drivers over WDAT? Quirks could still be encoded by adding some excludion to the WDAT driver - if that should ever be needed. > drivers/watchdog/itco.c \ > drivers/watchdog/init_array_end.S \ > env/syspart.c \ > diff --git a/drivers/watchdog/wdat.c b/drivers/watchdog/wdat.c > new file mode 100644 > index 0000000..8fda156 > --- /dev/null > +++ b/drivers/watchdog/wdat.c > @@ -0,0 +1,425 @@ > +/* > + * EFI Boot Guard > + * > + * Copyright (C) 2021 Mentor Graphics, A Siemens business > + * Again, you need to add copyright notices for the origin of these structs with their comments. Could be linux/include/acpi/actbl.h. > + * Authors: > + * Cedric Hombourger <[email protected]> > + * > + * This work is licensed under the terms of the GNU GPL, version 2. See > + * the COPYING file in the top-level directory. > + * > + * SPDX-License-Identifier: GPL-2.0 > + */ > + > +#include <efi.h> > +#include <efilib.h> > +#include <mmio.h> > +#include <sys/io.h> > +#include "utils.h" > + > +#define EFI_ACPI_TABLE_GUID \ > + { 0xeb9d2d30, 0x2d88, 0x11d3, {0x9a, 0x16, 0x0, 0x90, 0x27, 0x3f, 0xc1, > 0x4d }} > +#define EFI_ACPI_20_TABLE_GUID \ > + { 0x8868e871, 0xe4f1, 0x11d3, {0xbc, 0x22, 0x0, 0x80, 0xc7, 0x3c, 0x88, > 0x81 }} > + > +#define EFI_ACPI_ROOT_SDP_REVISION 0x02 > + > +#define ACPI_SIG_RSDP (CHAR8 *)"RSD PTR " > +#define ACPI_SIG_XSDT (CHAR8 *)"XSDT" > +#define ACPI_SIG_WDAT (CHAR8 *)"WDAT" > + > +#pragma pack(1) > + > +/* Root System Description Pointer */ > +typedef struct { > + CHAR8 signature[8]; > + UINT8 checksum; > + UINT8 oem_id[6]; > + UINT8 revision; > + UINT32 rsdt_address; > + UINT32 length; > + UINT64 xsdt_address; > + UINT8 extended_checksum; > + UINT8 reserved[3]; > +} EFI_ACPI_ROOT_SDP_HEADER; > + > +/* System Description Table */ > +typedef struct { > + CHAR8 signature[4]; > + UINT32 length; > + UINT8 revision; > + UINT8 checksum; > + CHAR8 oem_id[6]; > + CHAR8 oem_table_id[8]; > + UINT32 oem_revision; > + UINT32 creator_id; > + UINT32 creator_revision; > +} EFI_ACPI_SDT_HEADER; > + > +/* Generic Address Structure */ > +typedef struct { > + UINT8 space_id; /* Address space where struct or register > exists */ > + UINT8 bit_width; /* Size in bits of given register */ > + UINT8 bit_offset; /* Bit offset within the register */ > + UINT8 access_width; /* Minimum Access size (ACPI 3.0) */ > + UINT64 address; /* 64-bit address of struct or register */ > +} ACPI_ADDR; > + > +/* Values for space_id field above */ > +enum acpi_spaces { > + ACPI_ADRR_SPACE_SYSTEM_MEMORY = 0, > + ACPI_ADDR_SPACE_SYSTEM_IO = 1 > +}; > + > +/* WDAT Instruction Entries (actions) */ > +typedef struct { > + UINT8 action; > + UINT8 instruction; > + UINT16 reserved; > + ACPI_ADDR register_region; > + UINT32 value; /* Value used with Read/Write register */ > + UINT32 mask; /* Bitmask required for this register > instruction */ > +} ACPI_WDAT_ENTRY; > + > +/* Values for action field above */ > +enum acpi_wdat_actions { > + ACPI_WDAT_RESET = 1, > + ACPI_WDAT_SET_COUNTDOWN = 6, > + ACPI_WDAT_SET_RUNNING_STATE = 9, > + ACPI_WDAT_SET_REBOOT = 17, > + ACPI_WDAT_GET_STATUS = 32 > +}; > + > +/* Values for instruction field above */ > +enum acpi_wdat_instructions { > + ACPI_WDAT_READ_VALUE = 0, > + ACPI_WDAT_READ_COUNTDOWN = 1, > + ACPI_WDAT_WRITE_VALUE = 2, > + ACPI_WDAT_WRITE_COUNTDOWN = 3, > + ACPI_WDAT_PRESERVE_REGISTER = 0x80 > +}; > + > +/* Watchdog Action Table */ > +typedef struct { > + EFI_ACPI_SDT_HEADER header; /* Common ACPI table header */ > + UINT32 header_length; /* Watchdog Header Length */ > + UINT16 pci_segment; /* PCI Segment number */ > + UINT8 pci_bus; /* PCI Bus number */ > + UINT8 pci_device; /* PCI Device number */ > + UINT8 pci_function; /* PCI Function number */ > + UINT8 reserved[3]; > + UINT32 timer_period; /* Period of one timer count (msec) */ > + UINT32 max_count; /* Maximum counter value supported */ > + UINT32 min_count; /* Minimum counter value */ > + UINT8 flags; > + UINT8 reserved2[3]; > + UINT32 entries; /* Number of watchdog entries that follow */ > +} ACPI_TABLE_WDAT; > + > +#pragma pack() > + > +static EFI_STATUS > +parse_rsdp(EFI_ACPI_ROOT_SDP_HEADER *rsdp, ACPI_TABLE_WDAT **wdat_table_ptr) > { > + EFI_ACPI_SDT_HEADER *xsdt, *entry; > + UINT64 *entry_ptr; > + UINT64 n, count; > + > + *wdat_table_ptr = NULL; > + > + if (rsdp->revision < EFI_ACPI_ROOT_SDP_REVISION) { > + return EFI_NOT_FOUND; > + } > + > + xsdt = (EFI_ACPI_SDT_HEADER *)(rsdp->xsdt_address); > + if (strncmpa(ACPI_SIG_XSDT, (CHAR8 *)(VOID *)(xsdt->signature), 4)) { > + return EFI_INCOMPATIBLE_VERSION; > + } > + > + entry_ptr = (UINT64 *)(xsdt + 1); > + count = (xsdt->length - sizeof (EFI_ACPI_SDT_HEADER)) / sizeof(UINT64); > + for (n = 0; n < count; n++, entry_ptr++) { > + entry = (EFI_ACPI_SDT_HEADER *)((UINTN)(*entry_ptr)); > + if (!strncmpa(ACPI_SIG_WDAT, entry->signature, 4)) { > + *wdat_table_ptr = (ACPI_TABLE_WDAT *)entry; > + return EFI_SUCCESS; > + } > + } > + return EFI_NOT_FOUND; > +} > + > +static EFI_STATUS > +locate_and_parse_rsdp(ACPI_TABLE_WDAT **wdat_table_ptr) { > + EFI_CONFIGURATION_TABLE *ect = ST->ConfigurationTable; > + EFI_ACPI_ROOT_SDP_HEADER *rsdp; > + EFI_GUID acpi_table_guid = ACPI_TABLE_GUID; > + EFI_GUID acpi2_table_guid = ACPI_20_TABLE_GUID; > + UINTN n; > + > + for (n = 0; n < ST->NumberOfTableEntries; n++) { > + if ((CompareGuid (&ect->VendorGuid, &acpi_table_guid)) || > + (CompareGuid (&ect->VendorGuid, &acpi2_table_guid))) { > + if (!strncmpa(ACPI_SIG_RSDP, (CHAR8 > *)(ect->VendorTable), 8)) { You didn't incorporate my refactoring suggestion. > + rsdp = (EFI_ACPI_ROOT_SDP_HEADER > *)ect->VendorTable; > + return parse_rsdp(rsdp, wdat_table_ptr); > + } > + } > + ect++; > + } > + return EFI_NOT_FOUND; > +} > + > +static EFI_STATUS > +read_reg(ACPI_ADDR *addr, UINT32 *value_ptr) > +{ > + UINT32 value; > + > + if (addr->access_width < 1 || addr->access_width > 3) { > + ERROR(L"invalid width for WDAT read operation!\n"); > + return EFI_UNSUPPORTED; > + } > + > + if (addr->space_id == ACPI_ADDR_SPACE_SYSTEM_IO) { > + switch (addr->access_width) { > + case 1: > + value = inb(addr->address); > + break; > + case 2: > + value = inw(addr->address); > + break; > + case 3: > + value = inl(addr->address); > + break; > + } > + } > + else { > + switch (addr->access_width) { > + case 1: > + value = readb(addr->address); > + break; > + case 2: > + value = readw(addr->address); > + break; > + case 3: > + value = readl(addr->address); > + break; > + } > + } > + > + if (value_ptr) { > + *value_ptr = value; > + } > + return EFI_SUCCESS; > +} > + > +static EFI_STATUS > +write_reg(ACPI_ADDR *addr, UINT32 value) > +{ > + if ((addr->access_width < 1) || (addr->access_width > 3)) { > + ERROR(L"invalid width for WDAT write operation!\n"); > + return EFI_UNSUPPORTED; > + } > + > + if (addr->space_id == ACPI_ADDR_SPACE_SYSTEM_IO) { > + switch (addr->access_width) { > + case 1: > + outb(value, addr->address); > + break; > + case 2: > + outw(value, addr->address); > + break; > + case 3: > + outl(value, addr->address); > + break; > + } > + } > + else { > + switch (addr->access_width) { > + case 1: > + writeb(value, addr->address); > + break; > + case 2: > + writew(value, addr->address); > + break; > + case 3: > + writel(value, addr->address); > + break; > + } > + } > + return EFI_SUCCESS; > +} > + > +static EFI_STATUS > +read_value(ACPI_ADDR *addr, UINT32 value, UINT32 mask, UINT32 *retval) > +{ > + EFI_STATUS status; > + UINT32 x; > + > + status = read_reg(addr, &x); > + if (EFI_ERROR(status)) { > + return status; > + } > + x >>= addr->bit_offset; > + x &= mask; > + if (retval) { > + *retval = (x == value); > + } > + return status; > +} > + > +static EFI_STATUS > +read_countdown(ACPI_ADDR *addr, UINT32 value, UINT32 mask, UINT32 *retval) > +{ > + EFI_STATUS status; > + UINT32 x; > + > + value = value; /* unused */ > + status = read_reg(addr, &x); > + if (EFI_ERROR(status)) { > + return status; > + } > + x >>= addr->bit_offset; > + x &= mask; > + if (retval) { > + *retval = x; > + } > + return status; > +} > + > +static EFI_STATUS > +write_value(ACPI_ADDR *addr, UINT32 value, UINT32 mask, BOOLEAN preserve) > +{ > + EFI_STATUS status; > + UINT32 x, y; > + > + x = value & mask; > + x <<= addr->bit_offset; > + if (preserve) { > + status = read_reg(addr, &y); > + if (EFI_ERROR(status)) { > + return status; > + } > + y = y & ~(mask << addr->bit_offset); > + x |= y; > + } > + return write_reg(addr, x); > +} > + > +static EFI_STATUS > +run_action(ACPI_TABLE_WDAT *wdat_table, UINT8 action, UINT32 param, UINT32 > *retval) > +{ > + ACPI_WDAT_ENTRY *wdat_entry; > + ACPI_ADDR *addr; > + EFI_STATUS status = EFI_UNSUPPORTED; > + BOOLEAN preserve; > + UINT32 flags, value, mask; > + UINTN n; > + > + /* ACPI_TABLE_WDAT is immediately followed by multiple ACPI_WDAT_ENTRY > tables, > + * the former tells us how many (via ->entries). */ > + wdat_entry = (ACPI_WDAT_ENTRY *)(wdat_table + 1); > + for (n = 0; n < wdat_table->entries; n++, wdat_entry++) { > + /* Check if this is the action we have requested */ > + if (wdat_entry->action != action) { > + continue; > + } > + > + /* Decode the action */ > + preserve = (wdat_entry->instruction & > ACPI_WDAT_PRESERVE_REGISTER) != 0; > + flags = wdat_entry->instruction & ~ACPI_WDAT_PRESERVE_REGISTER; > + value = wdat_entry->value; > + mask = wdat_entry->mask; > + addr = &wdat_entry->register_region; > + > + /* Operation */ > + switch (flags) { > + case ACPI_WDAT_READ_VALUE: > + status = read_value(addr, value, mask, retval); > + break; > + case ACPI_WDAT_READ_COUNTDOWN: > + status = read_countdown(addr, value, mask, retval); > + break; > + case ACPI_WDAT_WRITE_VALUE: > + status = write_value(addr, value, mask, preserve); > + break; > + case ACPI_WDAT_WRITE_COUNTDOWN: > + status = write_value(addr, param, mask, preserve); > + break; > + default: > + ERROR(L"Unsupported WDAT instruction %x!\n", flags); > + return EFI_UNSUPPORTED; > + } > + /* Stop on first error */ > + if (EFI_ERROR(status)) { > + return status; > + } > + } > + return status; > +} > + > +static EFI_STATUS __attribute__((constructor)) > +init(EFI_PCI_IO *pci_io, UINT16 pci_vendor_id, UINT16 pci_device_id, > + UINTN timeout) > +{ > + ACPI_TABLE_WDAT *wdat_table; > + EFI_STATUS status; > + UINT32 boot_status; > + UINTN n; > + > + /* do not probe when scanning PCI devices */ > + if (pci_io || pci_vendor_id || pci_device_id) { > + return EFI_UNSUPPORTED; > + } > + > + /* Locate WDAT in ACPI tables */ > + status = locate_and_parse_rsdp(&wdat_table); > + if (EFI_ERROR(status)) { > + return status; > + } > + INFO(L"Detected WDAT watchdog\n"); > + > + /* Check if the boot was caused by the watchdog */ > + status = run_action(wdat_table, ACPI_WDAT_GET_STATUS, 0, &boot_status); > + if ((status == EFI_SUCCESS) && (boot_status != 0)) { > + INFO(L"Boot caused by watchdog\n"); > + } > + > + /* Enable reboot */ > + status = run_action(wdat_table, ACPI_WDAT_SET_REBOOT, 0, NULL); > + if (EFI_ERROR(status) && (status != EFI_UNSUPPORTED)) { > + ERROR(L"Could not enable REBOOT for WDAT!\n"); > + return status; > + } > + > + /* Check period */ > + if (wdat_table->timer_period == 0) { > + ERROR(L"Invalid WDAT period in ACPI tables!\n"); > + return EFI_INVALID_PARAMETER; > + } > + > + /* Compute timeout in periods */ > + n = (timeout * 1000) / wdat_table->timer_period; > + > + /* Program countdown */ > + status = run_action(wdat_table, ACPI_WDAT_SET_COUNTDOWN, n, NULL); > + if (EFI_ERROR(status)) { > + ERROR(L"Could not change WDAT timeout!\n"); > + return status; > + } > + > + /* Initial ping with specified timeout */ > + status = run_action(wdat_table, ACPI_WDAT_RESET, n, NULL); > + if (EFI_ERROR(status)) { > + ERROR(L"Could not reset WDAT!\n"); > + return status; > + } > + > + /* Enable watchdog */ > + status = run_action(wdat_table, ACPI_WDAT_SET_RUNNING_STATE, 0, NULL); > + if (EFI_ERROR(status)) { > + ERROR(L"Could not change WDAT to RUNNING state!\n"); > + return status; > + } > + > + return EFI_SUCCESS; > +} > Jan -- Siemens AG, T RDA IOT Corporate Competence Center Embedded Linux -- You received this message because you are subscribed to the Google Groups "EFI Boot Guard" group. 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