From bf7325882525b580c4e41cd36845bcf8113307fe Mon Sep 17 00:00:00 2001 From: Christophe JAILLET Date: Sun, 7 Nov 2021 09:32:58 +0100 Subject: [PATCH 1/9] PCI: brcmstb: Declare 'used' as bitmap, not unsigned long The 'used' field of 'struct brcm_msi' is used as a bitmap. Declare it with DECLARE_BITMAP() and adjust users accordingly. This fixes a harmless Coverity warning about array vs singleton usage. This bitmap can be used for either legacy or MSI interrupts, which require a size of BRCM_INT_PCI_MSI_LEGACY_NR or BRCM_INT_PCI_MSI_NR respectively. Add a BUILD_BUG_ON() to ensure it is large enough. Suggested-by: Krzysztof Wilczynski Addresses-Coverity: "Out-of-bounds access (ARRAY_VS_SINGLETON)" Link: https://lore.kernel.org/r/e6d9da2112aab2939d1507b90962d07bfd735b4c.1636273671.git.christophe.jaillet@wanadoo.fr Signed-off-by: Christophe JAILLET Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas Reviewed-by: Florian Fainelli --- drivers/pci/controller/pcie-brcmstb.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c index 1fc7bd49a7ad..b016e43628bb 100644 --- a/drivers/pci/controller/pcie-brcmstb.c +++ b/drivers/pci/controller/pcie-brcmstb.c @@ -266,8 +266,7 @@ struct brcm_msi { struct mutex lock; /* guards the alloc/free operations */ u64 target_addr; int irq; - /* used indicates which MSI interrupts have been alloc'd */ - unsigned long used; + DECLARE_BITMAP(used, BRCM_INT_PCI_MSI_NR); bool legacy; /* Some chips have MSIs in bits [31..24] of a shared register. */ int legacy_shift; @@ -534,7 +533,7 @@ static int brcm_msi_alloc(struct brcm_msi *msi) int hwirq; mutex_lock(&msi->lock); - hwirq = bitmap_find_free_region(&msi->used, msi->nr, 0); + hwirq = bitmap_find_free_region(msi->used, msi->nr, 0); mutex_unlock(&msi->lock); return hwirq; @@ -543,7 +542,7 @@ static int brcm_msi_alloc(struct brcm_msi *msi) static void brcm_msi_free(struct brcm_msi *msi, unsigned long hwirq) { mutex_lock(&msi->lock); - bitmap_release_region(&msi->used, hwirq, 0); + bitmap_release_region(msi->used, hwirq, 0); mutex_unlock(&msi->lock); } @@ -661,6 +660,12 @@ static int brcm_pcie_enable_msi(struct brcm_pcie *pcie) msi->irq = irq; msi->legacy = pcie->hw_rev < BRCM_PCIE_HW_REV_33; + /* + * Sanity check to make sure that the 'used' bitmap in struct brcm_msi + * is large enough. + */ + BUILD_BUG_ON(BRCM_INT_PCI_MSI_LEGACY_NR > BRCM_INT_PCI_MSI_NR); + if (msi->legacy) { msi->intr_base = msi->base + PCIE_INTR2_CPU_BASE; msi->nr = BRCM_INT_PCI_MSI_LEGACY_NR; From 09a710d952b985331ff0ffa2b648f2ae4da5507a Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Mon, 22 Nov 2021 11:04:58 -0800 Subject: [PATCH 2/9] PCI: brcmstb: Do not use __GENMASK Define the legacy MSI interrupt bitmask as well as the non-legacy interrupt bitmask using GENMASK and then use them in brcm_msi_set_regs() in place of __GENMASK(). Link: https://lore.kernel.org/r/20211122190459.3189616-1-f.fainelli@gmail.com Reported-by: Andy Shevchenko Signed-off-by: Florian Fainelli Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas Reviewed-by: Andy Shevchenko --- drivers/pci/controller/pcie-brcmstb.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c index b016e43628bb..5c0376869ad7 100644 --- a/drivers/pci/controller/pcie-brcmstb.c +++ b/drivers/pci/controller/pcie-brcmstb.c @@ -144,6 +144,9 @@ #define BRCM_INT_PCI_MSI_NR 32 #define BRCM_INT_PCI_MSI_LEGACY_NR 8 #define BRCM_INT_PCI_MSI_SHIFT 0 +#define BRCM_INT_PCI_MSI_MASK GENMASK(BRCM_INT_PCI_MSI_NR - 1, 0) +#define BRCM_INT_PCI_MSI_LEGACY_MASK GENMASK(31, \ + 32 - BRCM_INT_PCI_MSI_LEGACY_NR) /* MSI target addresses */ #define BRCM_MSI_TARGET_ADDR_LT_4GB 0x0fffffffcULL @@ -618,7 +621,8 @@ static void brcm_msi_remove(struct brcm_pcie *pcie) static void brcm_msi_set_regs(struct brcm_msi *msi) { - u32 val = __GENMASK(31, msi->legacy_shift); + u32 val = msi->legacy ? BRCM_INT_PCI_MSI_LEGACY_MASK : + BRCM_INT_PCI_MSI_MASK; writel(val, msi->intr_base + MSI_INT_MASK_CLR); writel(val, msi->intr_base + MSI_INT_CLR); From 41ac424ac188d9d04c9831fd0fe6bce73ae2ec03 Mon Sep 17 00:00:00 2001 From: Jim Quinlan Date: Thu, 6 Jan 2022 11:03:24 -0500 Subject: [PATCH 3/9] PCI: brcmstb: Fix function return value handling Do at least a dev_err() on some calls to reset_control_rearm() and brcm_phy_stop(). In some cases it may not make sense to return this error value "above" as doing so will cause more trouble than is warranted. Link: https://lore.kernel.org/r/20220106160332.2143-2-jim2101024@gmail.com Signed-off-by: Jim Quinlan Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas Acked-by: Florian Fainelli --- drivers/pci/controller/pcie-brcmstb.c | 28 +++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-) diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c index 5c0376869ad7..9775aab33cc3 100644 --- a/drivers/pci/controller/pcie-brcmstb.c +++ b/drivers/pci/controller/pcie-brcmstb.c @@ -1155,11 +1155,23 @@ static int brcm_pcie_suspend(struct device *dev) int ret; brcm_pcie_turn_off(pcie); - ret = brcm_phy_stop(pcie); - reset_control_rearm(pcie->rescal); + /* + * If brcm_phy_stop() returns an error, just dev_err(). If we + * return the error it will cause the suspend to fail and this is a + * forgivable offense that will probably be erased on resume. + */ + if (brcm_phy_stop(pcie)) + dev_err(dev, "Could not stop phy for suspend\n"); + + ret = reset_control_rearm(pcie->rescal); + if (ret) { + dev_err(dev, "Could not rearm rescal reset\n"); + return ret; + } + clk_disable_unprepare(pcie->clk); - return ret; + return 0; } static int brcm_pcie_resume(struct device *dev) @@ -1170,7 +1182,9 @@ static int brcm_pcie_resume(struct device *dev) int ret; base = pcie->base; - clk_prepare_enable(pcie->clk); + ret = clk_prepare_enable(pcie->clk); + if (ret) + return ret; ret = reset_control_reset(pcie->rescal); if (ret) @@ -1211,8 +1225,10 @@ static void __brcm_pcie_remove(struct brcm_pcie *pcie) { brcm_msi_remove(pcie); brcm_pcie_turn_off(pcie); - brcm_phy_stop(pcie); - reset_control_rearm(pcie->rescal); + if (brcm_phy_stop(pcie)) + dev_err(pcie->dev, "Could not stop phy\n"); + if (reset_control_rearm(pcie->rescal)) + dev_err(pcie->dev, "Could not rearm rescal reset\n"); clk_disable_unprepare(pcie->clk); } From 504253e44a9dc91e535f84273ebded324de4d2f6 Mon Sep 17 00:00:00 2001 From: Jim Quinlan Date: Thu, 6 Jan 2022 11:03:25 -0500 Subject: [PATCH 4/9] dt-bindings: PCI: Correct brcmstb interrupts, interrupt-map. The "pcie" and "msi" interrupts were given the same interrupt when they are actually different. Interrupt-map only had the INTA entry; add the INTB, INTC, and INTD entries. Link: https://lore.kernel.org/r/20220106160332.2143-3-jim2101024@gmail.com Signed-off-by: Jim Quinlan Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas Acked-by: Florian Fainelli Acked-by: Rob Herring --- Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml b/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml index 1fe102743f82..22f2ef446f18 100644 --- a/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml +++ b/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml @@ -143,11 +143,15 @@ examples: #address-cells = <3>; #size-cells = <2>; #interrupt-cells = <1>; - interrupts = , + interrupts = , ; interrupt-names = "pcie", "msi"; interrupt-map-mask = <0x0 0x0 0x0 0x7>; - interrupt-map = <0 0 0 1 &gicv2 GIC_SPI 143 IRQ_TYPE_LEVEL_HIGH>; + interrupt-map = <0 0 0 1 &gicv2 GIC_SPI 143 IRQ_TYPE_LEVEL_HIGH + 0 0 0 2 &gicv2 GIC_SPI 144 IRQ_TYPE_LEVEL_HIGH + 0 0 0 3 &gicv2 GIC_SPI 145 IRQ_TYPE_LEVEL_HIGH + 0 0 0 4 &gicv2 GIC_SPI 146 IRQ_TYPE_LEVEL_HIGH>; + msi-parent = <&pcie0>; msi-controller; ranges = <0x02000000 0x0 0xf8000000 0x6 0x00000000 0x0 0x04000000>; From ea372f45cfff7774c57f685b0c1a86951a15e18a Mon Sep 17 00:00:00 2001 From: Jim Quinlan Date: Thu, 6 Jan 2022 11:03:26 -0500 Subject: [PATCH 5/9] dt-bindings: PCI: Add bindings for Brcmstb EP voltage regulators Add bindings for Brcmstb EP voltage regulators. A new mechanism is to be added to the Linux PCI subsystem that will allocate and turn on/off regulators. These are standard regulators -- vpcie12v, vpcie3v3, and vpcie3v3aux -- placed in the DT in the bridge node under the host bridge device. The use of a regulator property in the PCIe EP subnode such as "vpcie12v-supply" depends on a pending pullreq to the pci-bus.yaml file at https://github.com/devicetree-org/dt-schema/pull/63 Link: https://lore.kernel.org/r/20220106160332.2143-4-jim2101024@gmail.com Signed-off-by: Jim Quinlan Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas Reviewed-by: Rob Herring Acked-by: Florian Fainelli --- .../bindings/pci/brcm,stb-pcie.yaml | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml b/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml index 22f2ef446f18..3e3c8929c97c 100644 --- a/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml +++ b/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml @@ -159,5 +159,24 @@ examples: <0x42000000 0x1 0x80000000 0x3 0x00000000 0x0 0x80000000>; brcm,enable-ssc; brcm,scb-sizes = <0x0000000080000000 0x0000000080000000>; + + /* PCIe bridge, Root Port */ + pci@0,0 { + #address-cells = <3>; + #size-cells = <2>; + reg = <0x0 0x0 0x0 0x0 0x0>; + compatible = "pciclass,0604"; + device_type = "pci"; + vpcie3v3-supply = <&vreg7>; + ranges; + + /* PCIe endpoint */ + pci-ep@0,0 { + assigned-addresses = + <0x82010000 0x0 0xf8000000 0x6 0x00000000 0x0 0x2000>; + reg = <0x0 0x0 0x0 0x0 0x0>; + compatible = "pci14e4,1688"; + }; + }; }; }; From 830aa6f29f07a4e2f1a947dfa72b3ccddb46dd21 Mon Sep 17 00:00:00 2001 From: Jim Quinlan Date: Thu, 6 Jan 2022 11:03:27 -0500 Subject: [PATCH 6/9] PCI: brcmstb: Split brcm_pcie_setup() into two funcs We need to take some code in brcm_pcie_setup() and put it in a new function brcm_pcie_linkup(). In future commits the brcm_pcie_linkup() function will be called indirectly by pci_host_probe() as opposed to the host driver invoking it directly. Some code that was executed after the PCIe linkup is now placed so that it executes prior to linkup, since this code has to run prior to the invocation of pci_host_probe(). Link: https://lore.kernel.org/r/20220106160332.2143-5-jim2101024@gmail.com Signed-off-by: Jim Quinlan Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas --- drivers/pci/controller/pcie-brcmstb.c | 65 ++++++++++++++++----------- 1 file changed, 39 insertions(+), 26 deletions(-) diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c index 9775aab33cc3..41bd1938840e 100644 --- a/drivers/pci/controller/pcie-brcmstb.c +++ b/drivers/pci/controller/pcie-brcmstb.c @@ -872,16 +872,9 @@ static inline int brcm_pcie_get_rc_bar2_size_and_offset(struct brcm_pcie *pcie, static int brcm_pcie_setup(struct brcm_pcie *pcie) { - struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie); u64 rc_bar2_offset, rc_bar2_size; void __iomem *base = pcie->base; - struct device *dev = pcie->dev; - struct resource_entry *entry; - bool ssc_good = false; - struct resource *res; - int num_out_wins = 0; - u16 nlw, cls, lnksta; - int i, ret, memc; + int ret, memc; u32 tmp, burst, aspm_support; /* Reset the bridge */ @@ -966,6 +959,40 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie) if (pcie->gen) brcm_pcie_set_gen(pcie, pcie->gen); + /* 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); + writel(tmp, base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); + + /* + * For config space accesses on the RC, show the right class for + * a PCIe-PCIe bridge (the default setting is to be EP mode). + */ + tmp = readl(base + PCIE_RC_CFG_PRIV1_ID_VAL3); + u32p_replace_bits(&tmp, 0x060400, + PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK); + writel(tmp, base + PCIE_RC_CFG_PRIV1_ID_VAL3); + + return 0; +} + +static int brcm_pcie_linkup(struct brcm_pcie *pcie) +{ + struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie); + struct device *dev = pcie->dev; + void __iomem *base = pcie->base; + struct resource_entry *entry; + struct resource *res; + int num_out_wins = 0; + u16 nlw, cls, lnksta; + bool ssc_good = false; + u32 tmp; + int ret, i; + /* Unassert the fundamental reset */ pcie->perst_set(pcie, 0); @@ -1003,24 +1030,6 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie) num_out_wins++; } - /* 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); - writel(tmp, base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); - - /* - * For config space accesses on the RC, show the right class for - * a PCIe-PCIe bridge (the default setting is to be EP mode). - */ - tmp = readl(base + PCIE_RC_CFG_PRIV1_ID_VAL3); - u32p_replace_bits(&tmp, 0x060400, - PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK); - writel(tmp, base + PCIE_RC_CFG_PRIV1_ID_VAL3); - if (pcie->ssc) { ret = brcm_pcie_set_ssc(pcie); if (ret == 0) @@ -1209,6 +1218,10 @@ static int brcm_pcie_resume(struct device *dev) if (ret) goto err_reset; + ret = brcm_pcie_linkup(pcie); + if (ret) + goto err_reset; + if (pcie->msi) brcm_msi_set_regs(pcie->msi); From 67211aadcb4b968d0fdc57bc27240fa71500c2d4 Mon Sep 17 00:00:00 2001 From: Jim Quinlan Date: Thu, 6 Jan 2022 11:03:28 -0500 Subject: [PATCH 7/9] PCI: brcmstb: Add mechanism to turn on subdev regulators Add a mechanism to identify standard PCIe regulators in the DT, allocate them, and turn them on before the rest of the bus is scanned during pci_host_probe(). The allocated structure that contains the regulators is stored in the port driver dev.driver_data field. Here is a point-by-point of how and when this mechanism is activated: If: -- PCIe RC driver sets pci_ops {add,remove)_bus to pci_subdev_regulators_{add,remove}_bus during its probe. -- There is a DT node "RB" under the host bridge DT node. -- During the RC driver's pci_host_probe() the add_bus callback is invoked where (bus->parent && pci_is_root_bus(bus->parent) is true Then: -- A struct subdev_regulators structure will be allocated and assigned to bus->dev.driver_data. -- regulator_bulk_{get,enable} will be invoked on &bus->dev and the former will search for and process any vpcie{12v,3v3,3v3aux}-supply properties that reside in node "RB". -- The regulators will be turned off/on for any unbind/bind operations. -- The regulators will be turned off/on for any suspend/resumes, but only if the RC driver handles this on its own. This will appear in a later commit for the pcie-brcmstb.c driver. The unabridged reason for doing this is as follows. We would like the Broadcom STB PCIe root complex driver (and others) to be able to turn off/on regulators[1] that provide power to endpoint[2] devices. Typically, the drivers of these endpoint devices are stock Linux drivers that are not aware that these regulator(s) exist and must be turned on for the driver to be probed. The simple solution of course is to turn these regulators on at boot and keep them on. However, this solution does not satisfy at least three of our usage modes: 1. For example, one customer uses multiple PCIe controllers, but wants the ability to, by script invoking and unbind, turn any or all of them and their subdevices off to save power, e.g. when in battery mode. 2. Another example is when a watchdog script discovers that an endpoint device is in an unresponsive state and would like to unbind, power toggle, and re-bind just the PCIe endpoint and controller. 3. Of course we also want power turned off during suspend mode. However, some endpoint devices may be able to "wake" during suspend and we need to recognise this case and veto the nominal act of turning off its regulator. Such is the case with Wake-on-LAN and Wake-on-WLAN support where the PCIe endpoint device needs to be kept powered on in order to receive network packets and wake the system. In all of these cases it is advantageous for the PCIe controller to govern the turning off/on the regulators needed by the endpoint device. The first two cases can be done by simply unbinding and binding the PCIe controller, if the controller has control of these regulators. [1] These regulators typically govern the actual power supply to the endpoint chip. Sometimes they may be the official PCIe socket power -- such as 3.3v or aux-3.3v. Sometimes they are truly the regulator(s) that supply power to the EP chip. [2] The 99% configuration of our boards is a single endpoint device attached to the PCIe controller. I use the term endpoint but it could possibly mean a switch as well. Link: https://lore.kernel.org/r/20220106160332.2143-6-jim2101024@gmail.com Signed-off-by: Jim Quinlan Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas --- drivers/pci/controller/pcie-brcmstb.c | 76 +++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c index 41bd1938840e..bf46f1605f9a 100644 --- a/drivers/pci/controller/pcie-brcmstb.c +++ b/drivers/pci/controller/pcie-brcmstb.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include #include @@ -260,6 +261,14 @@ static const struct pcie_cfg_data bcm2711_cfg = { .bridge_sw_init_set = brcm_pcie_bridge_sw_init_set_generic, }; +struct subdev_regulators { + unsigned int num_supplies; + struct regulator_bulk_data supplies[]; +}; + +static int pci_subdev_regulators_add_bus(struct pci_bus *bus); +static void pci_subdev_regulators_remove_bus(struct pci_bus *bus); + struct brcm_msi { struct device *dev; void __iomem *base; @@ -408,6 +417,71 @@ static int brcm_pcie_set_ssc(struct brcm_pcie *pcie) return ssc && pll ? 0 : -EIO; } +static void *alloc_subdev_regulators(struct device *dev) +{ + static const char * const supplies[] = { + "vpcie3v3", + "vpcie3v3aux", + "vpcie12v", + }; + const size_t size = sizeof(struct subdev_regulators) + + sizeof(struct regulator_bulk_data) * ARRAY_SIZE(supplies); + struct subdev_regulators *sr; + int i; + + sr = devm_kzalloc(dev, size, GFP_KERNEL); + if (sr) { + sr->num_supplies = ARRAY_SIZE(supplies); + for (i = 0; i < ARRAY_SIZE(supplies); i++) + sr->supplies[i].supply = supplies[i]; + } + + return sr; +} + +static int pci_subdev_regulators_add_bus(struct pci_bus *bus) +{ + struct device *dev = &bus->dev; + struct subdev_regulators *sr; + int ret; + + if (!dev->of_node || !bus->parent || !pci_is_root_bus(bus->parent)) + return 0; + + if (dev->driver_data) + dev_err(dev, "dev.driver_data unexpectedly non-NULL\n"); + + sr = alloc_subdev_regulators(dev); + if (!sr) + return -ENOMEM; + + dev->driver_data = sr; + ret = regulator_bulk_get(dev, sr->num_supplies, sr->supplies); + if (ret) + return ret; + + ret = regulator_bulk_enable(sr->num_supplies, sr->supplies); + if (ret) { + dev_err(dev, "failed to enable regulators for downstream device\n"); + return ret; + } + + return 0; +} + +static void pci_subdev_regulators_remove_bus(struct pci_bus *bus) +{ + struct device *dev = &bus->dev; + struct subdev_regulators *sr = dev->driver_data; + + if (!sr || !bus->parent || !pci_is_root_bus(bus->parent)) + return; + + if (regulator_bulk_disable(sr->num_supplies, sr->supplies)) + dev_err(dev, "failed to disable regulators for downstream device\n"); + dev->driver_data = NULL; +} + /* Limits operation to a specific generation (1, 2, or 3) */ static void brcm_pcie_set_gen(struct brcm_pcie *pcie, int gen) { @@ -731,6 +805,8 @@ static struct pci_ops brcm_pcie_ops = { .map_bus = brcm_pcie_map_conf, .read = pci_generic_config_read, .write = pci_generic_config_write, + .add_bus = pci_subdev_regulators_add_bus, + .remove_bus = pci_subdev_regulators_remove_bus, }; static inline void brcm_pcie_bridge_sw_init_set_generic(struct brcm_pcie *pcie, u32 val) From 93e41f3fca3d4a0f927b784012338c37f80a8a80 Mon Sep 17 00:00:00 2001 From: Jim Quinlan Date: Thu, 6 Jan 2022 11:03:29 -0500 Subject: [PATCH 8/9] PCI: brcmstb: Add control of subdevice voltage regulators This Broadcom STB PCIe RC driver has one port and connects directly to one device, be it a switch or an endpoint. We want to be able to leverage the recently added mechanism that allocates and turns on/off subdevice regulators. All that needs to be done is to put the regulator DT nodes in the bridge below host and to set the pci_ops methods add_bus and remove_bus. Note that the pci_subdev_regulators_add_bus() method is wrapped for two reasons: 1. To achieve link up after the voltage regulators are turned on. 2. If, in the case of an unsuccessful link up, to redirect any PCIe accesses to subdevices, e.g. the scan for DEV/ID. This redirection is needed because the Broadcom PCIe HW will issue a CPU abort if such an access is made when the link is down. [bhelgaas: fold in https://lore.kernel.org/r/20220112013100.48029-1-jim2101024@gmail.com] Link: https://lore.kernel.org/r/20220106160332.2143-7-jim2101024@gmail.com Signed-off-by: Jim Quinlan Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas --- drivers/pci/controller/pcie-brcmstb.c | 83 +++++++++++++++++++++++++-- 1 file changed, 78 insertions(+), 5 deletions(-) diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c index bf46f1605f9a..5a7ee482ab9a 100644 --- a/drivers/pci/controller/pcie-brcmstb.c +++ b/drivers/pci/controller/pcie-brcmstb.c @@ -195,6 +195,8 @@ static inline void brcm_pcie_bridge_sw_init_set_generic(struct brcm_pcie *pcie, static inline void brcm_pcie_perst_set_4908(struct brcm_pcie *pcie, u32 val); static inline void brcm_pcie_perst_set_7278(struct brcm_pcie *pcie, u32 val); static inline void brcm_pcie_perst_set_generic(struct brcm_pcie *pcie, u32 val); +static int brcm_pcie_linkup(struct brcm_pcie *pcie); +static int brcm_pcie_add_bus(struct pci_bus *bus); enum { RGR1_SW_INIT_1, @@ -306,6 +308,8 @@ struct brcm_pcie { u32 hw_rev; void (*perst_set)(struct brcm_pcie *pcie, u32 val); void (*bridge_sw_init_set)(struct brcm_pcie *pcie, u32 val); + bool refusal_mode; + struct subdev_regulators *sr; }; /* @@ -469,6 +473,34 @@ static int pci_subdev_regulators_add_bus(struct pci_bus *bus) return 0; } +static int brcm_pcie_add_bus(struct pci_bus *bus) +{ + struct device *dev = &bus->dev; + struct brcm_pcie *pcie = (struct brcm_pcie *) bus->sysdata; + int ret; + + if (!dev->of_node || !bus->parent || !pci_is_root_bus(bus->parent)) + return 0; + + ret = pci_subdev_regulators_add_bus(bus); + if (ret) + return ret; + + /* Grab the regulators for suspend/resume */ + pcie->sr = bus->dev.driver_data; + + /* + * If we have failed linkup there is no point to return an error as + * currently it will cause a WARNING() from pci_alloc_child_bus(). + * We return 0 and turn on the "refusal_mode" so that any further + * accesses to the pci_dev just get 0xffffffff + */ + if (brcm_pcie_linkup(pcie) != 0) + pcie->refusal_mode = true; + + return 0; +} + static void pci_subdev_regulators_remove_bus(struct pci_bus *bus) { struct device *dev = &bus->dev; @@ -794,6 +826,18 @@ static void __iomem *brcm_pcie_map_conf(struct pci_bus *bus, unsigned int devfn, /* Accesses to the RC go right to the RC registers if slot==0 */ if (pci_is_root_bus(bus)) return PCI_SLOT(devfn) ? NULL : base + where; + if (pcie->refusal_mode) { + /* + * At this point we do not have link. There will be a CPU + * abort -- a quirk with this controller --if Linux tries + * to read any config-space registers besides those + * targeting the host bridge. To prevent this we hijack + * the address to point to a safe access that will return + * 0xffffffff. + */ + writel(0xffffffff, base + PCIE_MISC_RC_BAR2_CONFIG_HI); + return base + PCIE_MISC_RC_BAR2_CONFIG_HI + (where & 0x3); + } /* For devices, write to the config space index register */ idx = PCIE_ECAM_OFFSET(bus->number, devfn, 0); @@ -805,7 +849,7 @@ static struct pci_ops brcm_pcie_ops = { .map_bus = brcm_pcie_map_conf, .read = pci_generic_config_read, .write = pci_generic_config_write, - .add_bus = pci_subdev_regulators_add_bus, + .add_bus = brcm_pcie_add_bus, .remove_bus = pci_subdev_regulators_remove_bus, }; @@ -1254,6 +1298,14 @@ static int brcm_pcie_suspend(struct device *dev) return ret; } + if (pcie->sr) { + ret = regulator_bulk_disable(pcie->sr->num_supplies, pcie->sr->supplies); + if (ret) { + dev_err(dev, "Could not turn off regulators\n"); + reset_control_reset(pcie->rescal); + return ret; + } + } clk_disable_unprepare(pcie->clk); return 0; @@ -1271,9 +1323,17 @@ static int brcm_pcie_resume(struct device *dev) if (ret) return ret; + if (pcie->sr) { + ret = regulator_bulk_enable(pcie->sr->num_supplies, pcie->sr->supplies); + if (ret) { + dev_err(dev, "Could not turn on regulators\n"); + goto err_disable_clk; + } + } + ret = reset_control_reset(pcie->rescal); if (ret) - goto err_disable_clk; + goto err_regulator; ret = brcm_phy_start(pcie); if (ret) @@ -1305,6 +1365,9 @@ static int brcm_pcie_resume(struct device *dev) err_reset: reset_control_rearm(pcie->rescal); +err_regulator: + if (pcie->sr) + regulator_bulk_disable(pcie->sr->num_supplies, pcie->sr->supplies); err_disable_clk: clk_disable_unprepare(pcie->clk); return ret; @@ -1434,7 +1497,17 @@ static int brcm_pcie_probe(struct platform_device *pdev) platform_set_drvdata(pdev, pcie); - return pci_host_probe(bridge); + ret = pci_host_probe(bridge); + if (!ret && !brcm_pcie_link_up(pcie)) + ret = -ENODEV; + + if (ret) { + brcm_pcie_remove(pdev); + return ret; + } + + return 0; + fail: __brcm_pcie_remove(pcie); return ret; @@ -1443,8 +1516,8 @@ static int brcm_pcie_probe(struct platform_device *pdev) MODULE_DEVICE_TABLE(of, brcm_pcie_match); static const struct dev_pm_ops brcm_pcie_pm_ops = { - .suspend = brcm_pcie_suspend, - .resume = brcm_pcie_resume, + .suspend_noirq = brcm_pcie_suspend, + .resume_noirq = brcm_pcie_resume, }; static struct platform_driver brcm_pcie_driver = { From 11ed8b8624b8085f706864b4addcd304b1e4fc38 Mon Sep 17 00:00:00 2001 From: Jim Quinlan Date: Thu, 6 Jan 2022 11:03:30 -0500 Subject: [PATCH 9/9] PCI: brcmstb: Do not turn off WOL regulators on suspend If any downstream device can be a wakeup device, do not turn off the regulators as the device will need them on. Link: https://lore.kernel.org/r/20220106160332.2143-8-jim2101024@gmail.com Signed-off-by: Jim Quinlan Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas --- drivers/pci/controller/pcie-brcmstb.c | 53 ++++++++++++++++++++++----- 1 file changed, 44 insertions(+), 9 deletions(-) diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c index 5a7ee482ab9a..1cba6e668150 100644 --- a/drivers/pci/controller/pcie-brcmstb.c +++ b/drivers/pci/controller/pcie-brcmstb.c @@ -310,6 +310,7 @@ struct brcm_pcie { void (*bridge_sw_init_set)(struct brcm_pcie *pcie, u32 val); bool refusal_mode; struct subdev_regulators *sr; + bool ep_wakeup_capable; }; /* @@ -1278,9 +1279,21 @@ static void brcm_pcie_turn_off(struct brcm_pcie *pcie) pcie->bridge_sw_init_set(pcie, 1); } +static int pci_dev_may_wakeup(struct pci_dev *dev, void *data) +{ + bool *ret = data; + + if (device_may_wakeup(&dev->dev)) { + *ret = true; + dev_info(&dev->dev, "disable cancelled for wake-up device\n"); + } + return (int) *ret; +} + static int brcm_pcie_suspend(struct device *dev) { struct brcm_pcie *pcie = dev_get_drvdata(dev); + struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie); int ret; brcm_pcie_turn_off(pcie); @@ -1299,11 +1312,22 @@ static int brcm_pcie_suspend(struct device *dev) } if (pcie->sr) { - ret = regulator_bulk_disable(pcie->sr->num_supplies, pcie->sr->supplies); - if (ret) { - dev_err(dev, "Could not turn off regulators\n"); - reset_control_reset(pcie->rescal); - return ret; + /* + * Now turn off the regulators, but if at least one + * downstream device is enabled as a wake-up source, do not + * turn off regulators. + */ + pcie->ep_wakeup_capable = false; + pci_walk_bus(bridge->bus, pci_dev_may_wakeup, + &pcie->ep_wakeup_capable); + if (!pcie->ep_wakeup_capable) { + ret = regulator_bulk_disable(pcie->sr->num_supplies, + pcie->sr->supplies); + if (ret) { + dev_err(dev, "Could not turn off regulators\n"); + reset_control_reset(pcie->rescal); + return ret; + } } } clk_disable_unprepare(pcie->clk); @@ -1324,10 +1348,21 @@ static int brcm_pcie_resume(struct device *dev) return ret; if (pcie->sr) { - ret = regulator_bulk_enable(pcie->sr->num_supplies, pcie->sr->supplies); - if (ret) { - dev_err(dev, "Could not turn on regulators\n"); - goto err_disable_clk; + if (pcie->ep_wakeup_capable) { + /* + * We are resuming from a suspend. In the suspend we + * did not disable the power supplies, so there is + * no need to enable them (and falsely increase their + * usage count). + */ + pcie->ep_wakeup_capable = false; + } else { + ret = regulator_bulk_enable(pcie->sr->num_supplies, + pcie->sr->supplies); + if (ret) { + dev_err(dev, "Could not turn on regulators\n"); + goto err_disable_clk; + } } }