coreboot-kgpe-d16/src/lib/fw_config.c

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/* SPDX-License-Identifier: GPL-2.0-only */
#include <assert.h>
#include <bootstate.h>
#include <cbfs.h>
#include <console/console.h>
#include <device/device.h>
#include <ec/google/chromeec/ec.h>
#include <fw_config.h>
#include <inttypes.h>
#include <lib.h>
#include <stdbool.h>
#include <stdint.h>
#include <drivers/vpd/vpd.h>
uint64_t fw_config_get(void)
{
static uint64_t fw_config_value;
static bool fw_config_value_initialized;
/* Nothing to prepare if setup is already done. */
if (fw_config_value_initialized)
return fw_config_value;
fw_config_value_initialized = true;
fw_config_value = UNDEFINED_FW_CONFIG;
/* Read the value from EC CBI. */
if (CONFIG(FW_CONFIG_SOURCE_CHROMEEC_CBI)) {
if (google_chromeec_cbi_get_fw_config(&fw_config_value))
printk(BIOS_WARNING, "%s: Could not get fw_config from CBI\n",
__func__);
else
printk(BIOS_INFO, "FW_CONFIG value from CBI is 0x%" PRIx64 "\n",
fw_config_value);
}
/* Look in CBFS to allow override of value. */
if (CONFIG(FW_CONFIG_SOURCE_CBFS) && fw_config_value == UNDEFINED_FW_CONFIG) {
cbfs: Simplify load/map API names, remove type arguments This patch renames cbfs_boot_map_with_leak() and cbfs_boot_load_file() to cbfs_map() and cbfs_load() respectively. This is supposed to be the start of a new, better organized CBFS API where the most common operations have the most simple and straight-forward names. Less commonly used variants of these operations (e.g. cbfs_ro_load() or cbfs_region_load()) can be introduced later. It seems unnecessary to keep carrying around "boot" in the names of most CBFS APIs if the vast majority of accesses go to the boot CBFS (instead, more unusual operations should have longer names that describe how they diverge from the common ones). cbfs_map() is paired with a new cbfs_unmap() to allow callers to cleanly reap mappings when desired. A few new cbfs_unmap() calls are added to generic code where it makes sense, but it seems unnecessary to introduce this everywhere in platform or architecture specific code where the boot medium is known to be memory-mapped anyway. In fact, even for non-memory-mapped platforms, sometimes leaking a mapping to the CBFS cache is a much cleaner solution than jumping through hoops to provide some other storage for some long-lived file object, and it shouldn't be outright forbidden when it makes sense. Additionally, remove the type arguments from these function signatures. The goal is to eventually remove type arguments for lookup from the whole CBFS API. Filenames already uniquely identify CBFS files. The type field is just informational, and there should be APIs to allow callers to check it when desired, but it's not clear what we gain from forcing this as a parameter into every single CBFS access when the vast majority of the time it provides no additional value and is just clutter. Signed-off-by: Julius Werner <jwerner@chromium.org> Change-Id: Ib24325400815a9c3d25f66c61829a24a239bb88e Reviewed-on: https://review.coreboot.org/c/coreboot/+/39304 Reviewed-by: Hung-Te Lin <hungte@chromium.org> Reviewed-by: Wim Vervoorn <wvervoorn@eltan.com> Reviewed-by: Mariusz Szafrański <mariuszx.szafranski@intel.com> Reviewed-by: Patrick Georgi <pgeorgi@google.com> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
2020-03-05 01:52:08 +01:00
if (cbfs_load(CONFIG_CBFS_PREFIX "/fw_config", &fw_config_value,
sizeof(fw_config_value)) != sizeof(fw_config_value))
printk(BIOS_WARNING, "%s: Could not get fw_config from CBFS\n",
__func__);
else
printk(BIOS_INFO, "FW_CONFIG value from CBFS is 0x%" PRIx64 "\n",
fw_config_value);
}
if (CONFIG(FW_CONFIG_SOURCE_VPD) && fw_config_value == UNDEFINED_FW_CONFIG) {
int vpd_value;
if (vpd_get_int("fw_config", VPD_RW_THEN_RO, &vpd_value)) {
fw_config_value = vpd_value;
printk(BIOS_INFO, "FW_CONFIG value from VPD is 0x%" PRIx64 "\n",
fw_config_value);
} else
printk(BIOS_WARNING, "%s: Could not get fw_config from vpd\n",
__func__);
}
return fw_config_value;
}
bool fw_config_probe(const struct fw_config *match)
{
fw_config: Return false in `fw_config_probe` in unprovisioned case fw_config is unprovisioned in the factory for the first boot. This is the only case where fw_config is left unprovisioned. On first boot in factory, fw_config gets correctly provisioned by the factory toolkit. When fw_config is unprovisioned, it is not always possible to make a guess which device to enable/disable since there can be certain conflicting devices which can never be enabled at the same time. That is the reason the original implementation of fw_config library kept fw_config as 0 when it was unprovisioned. CB:47956 ("fw_config: Use UNDEFINED_FW_CONFIG to mean unprovisioned") added support for a special unprovisioned value to allow any callers to identify this factory boot condition and take any appropriate action required for this boot (Ideally, this would just involve configuring any boot devices essential to getting to OS. All other non-essential devices can be kept disabled until fw_config is properly provisioned). However, CB:47956 missed handling the `fw_config_probe()` function and resulted in silent change in behavior. This change fixes the regression introduced by CB:47956 and returns `false` in `fw_config_probe()` if fw_config is not provisioned yet. Change-Id: Ic22cd650d3eb3a6016fa2e2775ea8272405ee23b Signed-off-by: Furquan Shaikh <furquan@google.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/54750 Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org> Reviewed-by: Karthik Ramasubramanian <kramasub@google.com> Reviewed-by: EricR Lai <ericr_lai@compal.corp-partner.google.com> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
2021-05-21 07:08:57 +02:00
/* If fw_config is not provisioned, then there is nothing to match. */
if (!fw_config_is_provisioned())
return false;
/* Compare to system value. */
if ((fw_config_get() & match->mask) == match->value) {
if (match->field_name && match->option_name)
printk(BIOS_INFO, "fw_config match found: %s=%s\n", match->field_name,
match->option_name);
else
printk(BIOS_INFO, "fw_config match found: mask=0x%" PRIx64 " value=0x%"
PRIx64 "\n",
match->mask, match->value);
return true;
}
return false;
}
bool fw_config_is_provisioned(void)
{
return fw_config_get() != UNDEFINED_FW_CONFIG;
}
bool fw_config_probe_dev(const struct device *dev, const struct fw_config **matching_probe)
{
const struct fw_config *probe;
if (matching_probe)
*matching_probe = NULL;
/* If the device does not have a probe list, then probing is not required. */
if (!dev->probe_list)
return true;
for (probe = dev->probe_list; probe && probe->mask != 0; probe++) {
if (!fw_config_probe(probe))
continue;
if (matching_probe)
*matching_probe = probe;
return true;
}
return false;
}
#if ENV_RAMSTAGE
/*
* The maximum number of fw_config fields is limited by the 64-bit mask that is used to
* represent them.
*/
#define MAX_CACHE_ELEMENTS (8 * sizeof(uint64_t))
static const struct fw_config *cached_configs[MAX_CACHE_ELEMENTS];
static size_t probe_index(uint64_t mask)
{
assert(mask);
return __ffs64(mask);
}
const struct fw_config *fw_config_get_found(uint64_t field_mask)
{
const struct fw_config *config;
config = cached_configs[probe_index(field_mask)];
if (config && config->mask == field_mask)
return config;
return NULL;
}
void fw_config_for_each_found(void (*cb)(const struct fw_config *config, void *arg), void *arg)
{
size_t i;
for (i = 0; i < MAX_CACHE_ELEMENTS; ++i)
if (cached_configs[i])
cb(cached_configs[i], arg);
}
static void fw_config_init(void *unused)
{
struct device *dev;
for (dev = all_devices; dev; dev = dev->next) {
const struct fw_config *probe;
if (!fw_config_probe_dev(dev, &probe)) {
printk(BIOS_INFO, "%s disabled by fw_config\n", dev_path(dev));
dev->enabled = 0;
continue;
}
if (probe)
cached_configs[probe_index(probe->mask)] = probe;
}
}
BOOT_STATE_INIT_ENTRY(BS_DEV_INIT_CHIPS, BS_ON_ENTRY, fw_config_init, NULL);
#endif