From 9583f9d22991d2cfb5cc59a2552040c4ae98d998 Mon Sep 17 00:00:00 2001 From: Jim Quinlan Date: Fri, 3 Oct 2025 13:04:36 -0400 Subject: [PATCH 1/3] PCI: brcmstb: Fix disabling L0s capability caab002d5069 ("PCI: brcmstb: Disable L0s component of ASPM if requested") set PCI_EXP_LNKCAP_ASPM_L1 and (optionally) PCI_EXP_LNKCAP_ASPM_L0S in PCI_EXP_LNKCAP (aka PCIE_RC_CFG_PRIV1_LINK_CAPABILITY in brcmstb). But instead of using PCI_EXP_LNKCAP_ASPM_L1 and PCI_EXP_LNKCAP_ASPM_L0S directly, it used PCIE_LINK_STATE_L1 and PCIE_LINK_STATE_L0S, which are Linux-created values that only coincidentally matched the PCIe spec. b478e162f227 ("PCI/ASPM: Consolidate link state defines") later changed them so they no longer matched the PCIe spec, so the bits ended up in the wrong place in PCI_EXP_LNKCAP. Use PCI_EXP_LNKCAP_ASPM_L0S to clear L0s support when there's an 'aspm-no-l0s' property. Rely on brcmstb hardware to advertise L0s and/or L1 support otherwise. Fixes: caab002d5069 ("PCI: brcmstb: Disable L0s component of ASPM if requested") Reported-by: Bjorn Helgaas Closes: https://lore.kernel.org/linux-pci/20250925194424.GA2197200@bhelgaas Signed-off-by: Jim Quinlan [mani: reworded subject and description, added closes tag and CCed stable] Signed-off-by: Manivannan Sadhasivam [bhelgaas: commit log] Signed-off-by: Bjorn Helgaas Reviewed-by: Florian Fainelli Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20251003170436.1446030-1-james.quinlan@broadcom.com --- drivers/pci/controller/pcie-brcmstb.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c index 9afbd02ded35..7e9b2f6a604a 100644 --- a/drivers/pci/controller/pcie-brcmstb.c +++ b/drivers/pci/controller/pcie-brcmstb.c @@ -48,7 +48,6 @@ #define PCIE_RC_CFG_PRIV1_LINK_CAPABILITY 0x04dc #define PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_MAX_LINK_WIDTH_MASK 0x1f0 -#define PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK 0xc00 #define PCIE_RC_CFG_PRIV1_ROOT_CAP 0x4f8 #define PCIE_RC_CFG_PRIV1_ROOT_CAP_L1SS_MODE_MASK 0xf8 @@ -1075,7 +1074,7 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie) void __iomem *base = pcie->base; struct pci_host_bridge *bridge; struct resource_entry *entry; - u32 tmp, burst, aspm_support, num_lanes, num_lanes_cap; + u32 tmp, burst, num_lanes, num_lanes_cap; u8 num_out_wins = 0; int num_inbound_wins = 0; int memc, ret; @@ -1175,12 +1174,9 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie) /* Don't advertise L0s capability if 'aspm-no-l0s' */ - aspm_support = PCIE_LINK_STATE_L1; - if (!of_property_read_bool(pcie->np, "aspm-no-l0s")) - aspm_support |= PCIE_LINK_STATE_L0S; tmp = readl(base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); - u32p_replace_bits(&tmp, aspm_support, - PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK); + if (of_property_read_bool(pcie->np, "aspm-no-l0s")) + tmp &= ~PCI_EXP_LNKCAP_ASPM_L0S; writel(tmp, base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); /* 'tmp' still holds the contents of PRIV1_LINK_CAPABILITY */ From a3f00f24d67014721e4efed9238be77b5b67f6fe Mon Sep 17 00:00:00 2001 From: Jim Quinlan Date: Wed, 29 Oct 2025 15:36:14 -0400 Subject: [PATCH 2/3] PCI: brcmstb: Add a way to indicate if PCIe bridge is active In a future commit, a new handler will be introduced that in part does reads and writes to some of the PCIe registers. When this handler is invoked, it is paramount that it does not do these register accesses when the PCIe bridge is inactive, as this will cause CPU abort errors. To solve this we keep a spinlock that guards a variable which indicates whether the bridge is on or off. When the bridge is on, access of the PCIe HW registers may proceed. Since there are multiple ways to reset the bridge, we introduce a general function to obtain the spinlock, call the specific function that is used for the specific SoC, sets the bridge active indicator variable, and releases the spinlock. Signed-off-by: Jim Quinlan Signed-off-by: Bjorn Helgaas Reviewed-by: Florian Fainelli Link: https://patch.msgid.link/20251029193616.3670003-2-james.quinlan@broadcom.com --- drivers/pci/controller/pcie-brcmstb.c | 40 +++++++++++++++++++++++---- 1 file changed, 35 insertions(+), 5 deletions(-) diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c index 7e9b2f6a604a..53434f09ac3d 100644 --- a/drivers/pci/controller/pcie-brcmstb.c +++ b/drivers/pci/controller/pcie-brcmstb.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include @@ -258,6 +259,7 @@ struct pcie_cfg_data { int (*perst_set)(struct brcm_pcie *pcie, u32 val); int (*bridge_sw_init_set)(struct brcm_pcie *pcie, u32 val); int (*post_setup)(struct brcm_pcie *pcie); + bool has_err_report; }; struct subdev_regulators { @@ -302,6 +304,8 @@ struct brcm_pcie { struct subdev_regulators *sr; bool ep_wakeup_capable; const struct pcie_cfg_data *cfg; + bool bridge_in_reset; + spinlock_t bridge_lock; }; static inline bool is_bmips(const struct brcm_pcie *pcie) @@ -309,6 +313,24 @@ static inline bool is_bmips(const struct brcm_pcie *pcie) return pcie->cfg->soc_base == BCM7435 || pcie->cfg->soc_base == BCM7425; } +static int brcm_pcie_bridge_sw_init_set(struct brcm_pcie *pcie, u32 val) +{ + unsigned long flags; + int ret; + + if (pcie->cfg->has_err_report) + spin_lock_irqsave(&pcie->bridge_lock, flags); + + ret = pcie->cfg->bridge_sw_init_set(pcie, val); + /* If we fail, assume the bridge is in reset (off) */ + pcie->bridge_in_reset = ret ? true : val; + + if (pcie->cfg->has_err_report) + spin_unlock_irqrestore(&pcie->bridge_lock, flags); + + return ret; +} + /* * This is to convert the size of the inbound "BAR" region to the * non-linear values of PCIE_X_MISC_RC_BAR[123]_CONFIG_LO.SIZE @@ -1080,7 +1102,7 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie) int memc, ret; /* Reset the bridge */ - ret = pcie->cfg->bridge_sw_init_set(pcie, 1); + ret = brcm_pcie_bridge_sw_init_set(pcie, 1); if (ret) return ret; @@ -1096,7 +1118,7 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie) usleep_range(100, 200); /* Take the bridge out of reset */ - ret = pcie->cfg->bridge_sw_init_set(pcie, 0); + ret = brcm_pcie_bridge_sw_init_set(pcie, 0); if (ret) return ret; @@ -1561,7 +1583,7 @@ static int brcm_pcie_turn_off(struct brcm_pcie *pcie) if (!(pcie->cfg->quirks & CFG_QUIRK_AVOID_BRIDGE_SHUTDOWN)) /* Shutdown PCIe bridge */ - ret = pcie->cfg->bridge_sw_init_set(pcie, 1); + ret = brcm_pcie_bridge_sw_init_set(pcie, 1); return ret; } @@ -1649,7 +1671,9 @@ static int brcm_pcie_resume_noirq(struct device *dev) goto err_reset; /* Take bridge out of reset so we can access the SERDES reg */ - pcie->cfg->bridge_sw_init_set(pcie, 0); + ret = brcm_pcie_bridge_sw_init_set(pcie, 0); + if (ret) + goto err_reset; /* SERDES_IDDQ = 0 */ tmp = readl(base + HARD_DEBUG(pcie)); @@ -1917,7 +1941,10 @@ static int brcm_pcie_probe(struct platform_device *pdev) if (ret) return dev_err_probe(&pdev->dev, ret, "could not enable clock\n"); - pcie->cfg->bridge_sw_init_set(pcie, 0); + ret = brcm_pcie_bridge_sw_init_set(pcie, 0); + if (ret) + return dev_err_probe(&pdev->dev, ret, + "could not de-assert bridge reset\n"); if (pcie->swinit_reset) { ret = reset_control_assert(pcie->swinit_reset); @@ -1992,6 +2019,9 @@ static int brcm_pcie_probe(struct platform_device *pdev) return ret; } + if (pcie->cfg->has_err_report) + spin_lock_init(&pcie->bridge_lock); + return 0; fail: From 8d4ec3fbb15e97b58c395398c743453012bbb93f Mon Sep 17 00:00:00 2001 From: Jim Quinlan Date: Wed, 29 Oct 2025 15:36:15 -0400 Subject: [PATCH 3/3] PCI: brcmstb: Add panic/die handler to driver Most PCIe HW returns 0xffffffff for failed reads on PCIe, but by default Broadcom's STB PCIe controller effects an abort. Some SoCs -- 7216 and its descendants -- have new HW that identifies error details. Add a simple handler to print diagnostic info in case the PCIe controller was the cause of the abort. Unfortunately, an abort still occurs. Read the error registers only when the PCIe bridge is active and the PCIe registers are accessible. Otherwise, a "die" event caused by something other than PCIe could cause an abort if the PCIe "die" handler tried to access registers when the bridge is off. Example error output: brcm-pcie 8b20000.pcie: Error: Mem Acc: 32bit, read, @0x38000000 brcm-pcie 8b20000.pcie: Type: TO=0 Abt=0 UnspReq=1 AccDsble=0 BadAddr=0 Signed-off-by: Jim Quinlan Signed-off-by: Bjorn Helgaas Reviewed-by: Florian Fainelli Link: https://patch.msgid.link/20251029193616.3670003-3-james.quinlan@broadcom.com --- drivers/pci/controller/pcie-brcmstb.c | 161 +++++++++++++++++++++++++- 1 file changed, 159 insertions(+), 2 deletions(-) diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c index 53434f09ac3d..062f55690012 100644 --- a/drivers/pci/controller/pcie-brcmstb.c +++ b/drivers/pci/controller/pcie-brcmstb.c @@ -14,15 +14,18 @@ #include #include #include +#include #include #include #include #include #include +#include #include #include #include #include +#include #include #include #include @@ -32,6 +35,7 @@ #include #include #include +#include #include #include "../pci.h" @@ -155,8 +159,40 @@ #define MSI_INT_MASK_SET 0x10 #define MSI_INT_MASK_CLR 0x14 +/* Error report registers */ +#define PCIE_OUTB_ERR_TREAT 0x6000 +#define PCIE_OUTB_ERR_TREAT_CONFIG 0x1 +#define PCIE_OUTB_ERR_TREAT_MEM 0x2 +#define PCIE_OUTB_ERR_VALID 0x6004 +#define PCIE_OUTB_ERR_CLEAR 0x6008 +#define PCIE_OUTB_ERR_ACC_INFO 0x600c +#define PCIE_OUTB_ERR_ACC_INFO_CFG_ERR BIT(0) +#define PCIE_OUTB_ERR_ACC_INFO_MEM_ERR BIT(1) +#define PCIE_OUTB_ERR_ACC_INFO_TYPE_64 BIT(2) +#define PCIE_OUTB_ERR_ACC_INFO_DIR_WRITE BIT(4) +#define PCIE_OUTB_ERR_ACC_INFO_BYTE_LANES 0xff00 +#define PCIE_OUTB_ERR_ACC_ADDR 0x6010 +#define PCIE_OUTB_ERR_ACC_ADDR_BUS 0xff00000 +#define PCIE_OUTB_ERR_ACC_ADDR_DEV 0xf8000 +#define PCIE_OUTB_ERR_ACC_ADDR_FUNC 0x7000 +#define PCIE_OUTB_ERR_ACC_ADDR_REG 0xfff +#define PCIE_OUTB_ERR_CFG_CAUSE 0x6014 +#define PCIE_OUTB_ERR_CFG_CAUSE_TIMEOUT BIT(6) +#define PCIE_OUTB_ERR_CFG_CAUSE_ABORT BIT(5) +#define PCIE_OUTB_ERR_CFG_CAUSE_UNSUPP_REQ BIT(4) +#define PCIE_OUTB_ERR_CFG_CAUSE_ACC_TIMEOUT BIT(2) +#define PCIE_OUTB_ERR_CFG_CAUSE_ACC_DISABLED BIT(1) +#define PCIE_OUTB_ERR_CFG_CAUSE_ACC_64BIT BIT(0) +#define PCIE_OUTB_ERR_MEM_ADDR_LO 0x6018 +#define PCIE_OUTB_ERR_MEM_ADDR_HI 0x601c +#define PCIE_OUTB_ERR_MEM_CAUSE 0x6020 +#define PCIE_OUTB_ERR_MEM_CAUSE_TIMEOUT BIT(6) +#define PCIE_OUTB_ERR_MEM_CAUSE_ABORT BIT(5) +#define PCIE_OUTB_ERR_MEM_CAUSE_UNSUPP_REQ BIT(4) +#define PCIE_OUTB_ERR_MEM_CAUSE_ACC_DISABLED BIT(1) +#define PCIE_OUTB_ERR_MEM_CAUSE_BAD_ADDR BIT(0) + #define PCIE_RGR1_SW_INIT_1_PERST_MASK 0x1 -#define PCIE_RGR1_SW_INIT_1_PERST_SHIFT 0x0 #define RGR1_SW_INIT_1_INIT_GENERIC_MASK 0x2 #define RGR1_SW_INIT_1_INIT_GENERIC_SHIFT 0x1 @@ -305,6 +341,8 @@ struct brcm_pcie { bool ep_wakeup_capable; const struct pcie_cfg_data *cfg; bool bridge_in_reset; + struct notifier_block die_notifier; + struct notifier_block panic_notifier; spinlock_t bridge_lock; }; @@ -1727,6 +1765,119 @@ static int brcm_pcie_resume_noirq(struct device *dev) return ret; } +/* Dump out PCIe errors on die or panic */ +static int brcm_pcie_dump_err(struct brcm_pcie *pcie, + const char *type) +{ + void __iomem *base = pcie->base; + int i, is_cfg_err, is_mem_err, lanes; + const char *width_str, *direction_str; + u32 info, cfg_addr, cfg_cause, mem_cause, lo, hi; + struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie); + unsigned long flags; + char lanes_str[9]; + + spin_lock_irqsave(&pcie->bridge_lock, flags); + /* Don't access registers when the bridge is off */ + if (pcie->bridge_in_reset || readl(base + PCIE_OUTB_ERR_VALID) == 0) { + spin_unlock_irqrestore(&pcie->bridge_lock, flags); + return NOTIFY_DONE; + } + + /* Read all necessary registers so we can release the spinlock ASAP */ + info = readl(base + PCIE_OUTB_ERR_ACC_INFO); + is_cfg_err = !!(info & PCIE_OUTB_ERR_ACC_INFO_CFG_ERR); + is_mem_err = !!(info & PCIE_OUTB_ERR_ACC_INFO_MEM_ERR); + if (is_cfg_err) { + cfg_addr = readl(base + PCIE_OUTB_ERR_ACC_ADDR); + cfg_cause = readl(base + PCIE_OUTB_ERR_CFG_CAUSE); + } + if (is_mem_err) { + mem_cause = readl(base + PCIE_OUTB_ERR_MEM_CAUSE); + lo = readl(base + PCIE_OUTB_ERR_MEM_ADDR_LO); + hi = readl(base + PCIE_OUTB_ERR_MEM_ADDR_HI); + } + /* We've got all of the info, clear the error */ + writel(1, base + PCIE_OUTB_ERR_CLEAR); + spin_unlock_irqrestore(&pcie->bridge_lock, flags); + + dev_err(pcie->dev, "reporting PCIe info which may be related to %s error\n", + type); + width_str = (info & PCIE_OUTB_ERR_ACC_INFO_TYPE_64) ? "64bit" : "32bit"; + direction_str = str_read_write(!(info & PCIE_OUTB_ERR_ACC_INFO_DIR_WRITE)); + lanes = FIELD_GET(PCIE_OUTB_ERR_ACC_INFO_BYTE_LANES, info); + for (i = 0, lanes_str[8] = 0; i < 8; i++) + lanes_str[i] = (lanes & (1 << i)) ? '1' : '0'; + + if (is_cfg_err) { + int bus = FIELD_GET(PCIE_OUTB_ERR_ACC_ADDR_BUS, cfg_addr); + int dev = FIELD_GET(PCIE_OUTB_ERR_ACC_ADDR_DEV, cfg_addr); + int func = FIELD_GET(PCIE_OUTB_ERR_ACC_ADDR_FUNC, cfg_addr); + int reg = FIELD_GET(PCIE_OUTB_ERR_ACC_ADDR_REG, cfg_addr); + + dev_err(pcie->dev, "Error: CFG Acc, %s, %s (%04x:%02x:%02x.%d) reg=0x%x, lanes=%s\n", + width_str, direction_str, bridge->domain_nr, bus, dev, + func, reg, lanes_str); + dev_err(pcie->dev, " Type: TO=%d Abt=%d UnsupReq=%d AccTO=%d AccDsbld=%d Acc64bit=%d\n", + !!(cfg_cause & PCIE_OUTB_ERR_CFG_CAUSE_TIMEOUT), + !!(cfg_cause & PCIE_OUTB_ERR_CFG_CAUSE_ABORT), + !!(cfg_cause & PCIE_OUTB_ERR_CFG_CAUSE_UNSUPP_REQ), + !!(cfg_cause & PCIE_OUTB_ERR_CFG_CAUSE_ACC_TIMEOUT), + !!(cfg_cause & PCIE_OUTB_ERR_CFG_CAUSE_ACC_DISABLED), + !!(cfg_cause & PCIE_OUTB_ERR_CFG_CAUSE_ACC_64BIT)); + } + + if (is_mem_err) { + u64 addr = ((u64)hi << 32) | (u64)lo; + + dev_err(pcie->dev, "Error: Mem Acc, %s, %s, @0x%llx, lanes=%s\n", + width_str, direction_str, addr, lanes_str); + dev_err(pcie->dev, " Type: TO=%d Abt=%d UnsupReq=%d AccDsble=%d BadAddr=%d\n", + !!(mem_cause & PCIE_OUTB_ERR_MEM_CAUSE_TIMEOUT), + !!(mem_cause & PCIE_OUTB_ERR_MEM_CAUSE_ABORT), + !!(mem_cause & PCIE_OUTB_ERR_MEM_CAUSE_UNSUPP_REQ), + !!(mem_cause & PCIE_OUTB_ERR_MEM_CAUSE_ACC_DISABLED), + !!(mem_cause & PCIE_OUTB_ERR_MEM_CAUSE_BAD_ADDR)); + } + + return NOTIFY_DONE; +} + +static int brcm_pcie_die_notify_cb(struct notifier_block *self, + unsigned long v, void *p) +{ + struct brcm_pcie *pcie = + container_of(self, struct brcm_pcie, die_notifier); + + return brcm_pcie_dump_err(pcie, "Die"); +} + +static int brcm_pcie_panic_notify_cb(struct notifier_block *self, + unsigned long v, void *p) +{ + struct brcm_pcie *pcie = + container_of(self, struct brcm_pcie, panic_notifier); + + return brcm_pcie_dump_err(pcie, "Panic"); +} + +static void brcm_register_die_notifiers(struct brcm_pcie *pcie) +{ + pcie->panic_notifier.notifier_call = brcm_pcie_panic_notify_cb; + atomic_notifier_chain_register(&panic_notifier_list, + &pcie->panic_notifier); + + pcie->die_notifier.notifier_call = brcm_pcie_die_notify_cb; + register_die_notifier(&pcie->die_notifier); +} + +static void brcm_unregister_die_notifiers(struct brcm_pcie *pcie) +{ + unregister_die_notifier(&pcie->die_notifier); + atomic_notifier_chain_unregister(&panic_notifier_list, + &pcie->panic_notifier); +} + static void __brcm_pcie_remove(struct brcm_pcie *pcie) { brcm_msi_remove(pcie); @@ -1745,6 +1896,9 @@ static void brcm_pcie_remove(struct platform_device *pdev) pci_stop_root_bus(bridge->bus); pci_remove_root_bus(bridge->bus); + if (pcie->cfg->has_err_report) + brcm_unregister_die_notifiers(pcie); + __brcm_pcie_remove(pcie); } @@ -1845,6 +1999,7 @@ static const struct pcie_cfg_data bcm7216_cfg = { .bridge_sw_init_set = brcm_pcie_bridge_sw_init_set_7278, .has_phy = true, .num_inbound_wins = 3, + .has_err_report = true, }; static const struct pcie_cfg_data bcm7712_cfg = { @@ -2019,8 +2174,10 @@ static int brcm_pcie_probe(struct platform_device *pdev) return ret; } - if (pcie->cfg->has_err_report) + if (pcie->cfg->has_err_report) { spin_lock_init(&pcie->bridge_lock); + brcm_register_die_notifiers(pcie); + } return 0;