From 28f71b5c3adf2bf82f55b359f26a58a78b0f172e Mon Sep 17 00:00:00 2001 From: Subrata Banik Date: Thu, 7 Nov 2024 17:54:10 +0000 Subject: soc/intel/cmn/pmc: Perform PM register init for CSE Before entering FSP-M, AP firmware must ensure the PM1_CNT register reflects the correct sleep state if a global reset occurred. This is crucial when Intel CSE has reset the system, as indicated by the global reset bit and wake status register. If PM1_CNT doesn't contain a valid sleep state after a CSE reset, AP firmware must enforce an S5 exit path before handing control to FSP-M for CSE initialization. This ensures proper system initialization and avoids potential issues caused by an inconsistent sleep state. Additionally, clears the PM1 status register (PM1_STS) after retrieving the power state. This prevents stale status information from persisting across power cycles, which could lead to confusion during subsequent boots. BUG=b:265939425 TEST=Verified that `prev_sleep_state` holds the correct value (5 for S5) after CSE performs a global reset. Fixes: Inconsistent sleep state after CSE reset. Change-Id: Iae9c026da86fef4a3571e06b1bb20504c3d8c9be Signed-off-by: Subrata Banik Reviewed-on: https://review.coreboot.org/c/coreboot/+/85025 Tested-by: build bot (Jenkins) Reviewed-by: Karthik Ramasubramanian Reviewed-by: Kapil Porwal --- src/soc/intel/common/block/pmc/pmclib.c | 46 +++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) (limited to 'src/soc') diff --git a/src/soc/intel/common/block/pmc/pmclib.c b/src/soc/intel/common/block/pmc/pmclib.c index 0b3863a0f0..c51a960854 100644 --- a/src/soc/intel/common/block/pmc/pmclib.c +++ b/src/soc/intel/common/block/pmc/pmclib.c @@ -430,6 +430,9 @@ static int pmc_prev_sleep_state(const struct chipset_power_state *ps) /* Clear SLP_TYP. */ pmc_write_pm1_control(ps->pm1_cnt & ~(SLP_TYP)); + + /* Clear PM1_STATUS */ + pmc_clear_pm1_status(); } prev_sleep_state = soc_prev_sleep_state(ps, prev_sleep_state); @@ -440,6 +443,34 @@ static int pmc_prev_sleep_state(const struct chipset_power_state *ps) return prev_sleep_state; } +static bool pmc_get_global_reset_sts_mmio(void) +{ + uint8_t *addr = pmc_mmio_regs(); + + return !!(read32p((uintptr_t)(addr + GEN_PMCON_A)) & GBL_RST_STS); +} + +static bool pmc_get_global_reset_sts_pci(void) +{ +#if defined(__SIMPLE_DEVICE__) + pci_devfn_t dev = PCI_DEV(0, PCI_SLOT(PCH_DEVFN_PMC), PCI_FUNC(PCH_DEVFN_PMC)); +#else + struct device *dev = pcidev_path_on_root(PCH_DEVFN_PMC); + if (!dev) + return false; +#endif + + return !!(pci_read_config32(dev, GEN_PMCON_A) & GBL_RST_STS); +} + +static bool pmc_get_global_reset_sts(void) +{ + if (CONFIG(SOC_INTEL_MEM_MAPPED_PM_CONFIGURATION)) + return pmc_get_global_reset_sts_mmio(); + else + return pmc_get_global_reset_sts_pci(); +} + void pmc_fill_pm_reg_info(struct chipset_power_state *ps) { int i; @@ -450,6 +481,21 @@ void pmc_fill_pm_reg_info(struct chipset_power_state *ps) ps->pm1_en = inw(ACPI_BASE_ADDRESS + PM1_EN); ps->pm1_cnt = pmc_read_pm1_control(); + /* + * Before system memory initialization, AP firmware should check the wake status + * to determine if Intel CSE has reset the system and system sleep state (PM1_CNT) + * holds a valid sleep entry? + * + * If not, then AP FW should force to take a S5 exit path (by programming the PM1_CNT) + * register as per PM register initialization requirement for CSE. + */ + if (pmc_get_global_reset_sts() && (ps->pm1_sts & WAK_STS) && !(ps->pm1_cnt & SLP_TYP)) { + printk(BIOS_DEBUG, "Enforcing the S5 exit path\n"); + uint32_t pm1_cnt_slp_type = SLP_TYP_S5 << SLP_TYP_SHIFT; + ps->pm1_cnt |= pm1_cnt_slp_type; + pmc_enable_pm1_control(pm1_cnt_slp_type); + } + printk(BIOS_DEBUG, "pm1_sts: %04x pm1_en: %04x pm1_cnt: %08x\n", ps->pm1_sts, ps->pm1_en, ps->pm1_cnt); -- cgit v1.2.3