From 364b3f1ff8f096d45f042a9c85daf7a1fc78413e Mon Sep 17 00:00:00 2001 From: Remi Pommarel Date: Wed, 22 May 2019 23:33:51 +0200 Subject: PCI: aardvark: Use LTSSM state to build link training flag Aardvark's PCI_EXP_LNKSTA_LT flag in its link status register is not implemented and does not reflect the actual link training state (the flag is always set to 0). In order to support link re-training feature this flag has to be emulated. The Link Training and Status State Machine (LTSSM) flag in Aardvark LMI config register could be used as a link training indicator. Indeed if the LTSSM is in L0 or upper state then link training has completed (see [1]). Unfortunately because after asking a link retraining it takes a while for the LTSSM state to become less than 0x10 (due to L0s to recovery state transition delays), LTSSM can still be in L0 while link training has not finished yet. So this waits for link to be in recovery or lesser state before returning after asking for a link retrain. [1] "PCI Express Base Specification", REV. 4.0 PCI Express, February 19 2014, Table 4-14 Fixes: 8a3ebd8de328 ("PCI: aardvark: Implement emulated root PCI bridge config space") Tested-by: Marc Zyngier Signed-off-by: Remi Pommarel Signed-off-by: Lorenzo Pieralisi Reviewed-by: Andrew Murray Acked-by: Thomas Petazzoni --- drivers/pci/controller/pci-aardvark.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index fc0fe4d4de49..fe471861f801 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -180,6 +180,8 @@ #define LINK_WAIT_MAX_RETRIES 10 #define LINK_WAIT_USLEEP_MIN 90000 #define LINK_WAIT_USLEEP_MAX 100000 +#define RETRAIN_WAIT_MAX_RETRIES 10 +#define RETRAIN_WAIT_USLEEP_US 2000 #define MSI_IRQ_NUM 32 @@ -239,6 +241,17 @@ static int advk_pcie_wait_for_link(struct advk_pcie *pcie) return -ETIMEDOUT; } +static void advk_pcie_wait_for_retrain(struct advk_pcie *pcie) +{ + size_t retries; + + for (retries = 0; retries < RETRAIN_WAIT_MAX_RETRIES; ++retries) { + if (!advk_pcie_link_up(pcie)) + break; + udelay(RETRAIN_WAIT_USLEEP_US); + } +} + static void advk_pcie_setup_hw(struct advk_pcie *pcie) { u32 reg; @@ -426,11 +439,20 @@ advk_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge, return PCI_BRIDGE_EMUL_HANDLED; } + case PCI_EXP_LNKCTL: { + /* u32 contains both PCI_EXP_LNKCTL and PCI_EXP_LNKSTA */ + u32 val = advk_readl(pcie, PCIE_CORE_PCIEXP_CAP + reg) & + ~(PCI_EXP_LNKSTA_LT << 16); + if (!advk_pcie_link_up(pcie)) + val |= (PCI_EXP_LNKSTA_LT << 16); + *value = val; + return PCI_BRIDGE_EMUL_HANDLED; + } + case PCI_CAP_LIST_ID: case PCI_EXP_DEVCAP: case PCI_EXP_DEVCTL: case PCI_EXP_LNKCAP: - case PCI_EXP_LNKCTL: *value = advk_readl(pcie, PCIE_CORE_PCIEXP_CAP + reg); return PCI_BRIDGE_EMUL_HANDLED; default: @@ -447,8 +469,13 @@ advk_pci_bridge_emul_pcie_conf_write(struct pci_bridge_emul *bridge, switch (reg) { case PCI_EXP_DEVCTL: + advk_writel(pcie, new, PCIE_CORE_PCIEXP_CAP + reg); + break; + case PCI_EXP_LNKCTL: advk_writel(pcie, new, PCIE_CORE_PCIEXP_CAP + reg); + if (new & PCI_EXP_LNKCTL_RL) + advk_pcie_wait_for_retrain(pcie); break; case PCI_EXP_RTCTL: -- cgit v1.2.3 From f4c7d053d7f77cd5c1a1ba7c7ce085ddba13d1d7 Mon Sep 17 00:00:00 2001 From: Remi Pommarel Date: Wed, 22 May 2019 23:33:50 +0200 Subject: PCI: aardvark: Wait for endpoint to be ready before training link When configuring pcie reset pin from gpio (e.g. initially set by u-boot) to pcie function this pin goes low for a brief moment asserting the PERST# signal. Thus connected device enters fundamental reset process and link configuration can only begin after a minimal 100ms delay (see [1]). Because the pin configuration comes from the "default" pinctrl it is implicitly configured before the probe callback is called: driver_probe_device() really_probe() ... pinctrl_bind_pins() /* Here pin goes from gpio to PCIE reset function and PERST# is asserted */ ... drv->probe() [1] "PCI Express Base Specification", REV. 4.0 PCI Express, February 19 2014, 6.6.1 Conventional Reset Signed-off-by: Remi Pommarel Signed-off-by: Lorenzo Pieralisi Acked-by: Thomas Petazzoni --- drivers/pci/controller/pci-aardvark.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index fe471861f801..78c39320def4 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -337,6 +337,14 @@ static void advk_pcie_setup_hw(struct advk_pcie *pcie) reg |= PIO_CTRL_ADDR_WIN_DISABLE; advk_writel(pcie, reg, PIO_CTRL); + /* + * PERST# signal could have been asserted by pinctrl subsystem before + * probe() callback has been called, making the endpoint going into + * fundamental reset. As required by PCI Express spec a delay for at + * least 100ms after such a reset before link training is needed. + */ + msleep(PCI_PM_D3COLD_WAIT); + /* Start link training */ reg = advk_readl(pcie, PCIE_CORE_LINK_CTRL_STAT_REG); reg |= PCIE_CORE_LINK_TRAINING; -- cgit v1.2.3 From c0f05a6ab52535c1bf5f43272eede3e11c5701a5 Mon Sep 17 00:00:00 2001 From: Remi Pommarel Date: Fri, 14 Jun 2019 12:10:59 +0200 Subject: PCI: aardvark: Fix PCI_EXP_RTCTL register configuration PCI_EXP_RTCTL is used to activate PME interrupt only, so writing into it should not modify other interrupts' mask. The ISR mask polarity was also inverted, when PCI_EXP_RTCTL_PMEIE is set PCIE_MSG_PM_PME_MASK mask bit should actually be cleared. Fixes: 8a3ebd8de328 ("PCI: aardvark: Implement emulated root PCI bridge config space") Signed-off-by: Remi Pommarel Signed-off-by: Lorenzo Pieralisi Acked-by: Thomas Petazzoni --- drivers/pci/controller/pci-aardvark.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 78c39320def4..cb4327657136 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -436,7 +436,7 @@ advk_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge, case PCI_EXP_RTCTL: { u32 val = advk_readl(pcie, PCIE_ISR0_MASK_REG); - *value = (val & PCIE_MSG_PM_PME_MASK) ? PCI_EXP_RTCTL_PMEIE : 0; + *value = (val & PCIE_MSG_PM_PME_MASK) ? 0 : PCI_EXP_RTCTL_PMEIE; return PCI_BRIDGE_EMUL_HANDLED; } @@ -486,10 +486,15 @@ advk_pci_bridge_emul_pcie_conf_write(struct pci_bridge_emul *bridge, advk_pcie_wait_for_retrain(pcie); break; - case PCI_EXP_RTCTL: - new = (new & PCI_EXP_RTCTL_PMEIE) << 3; - advk_writel(pcie, new, PCIE_ISR0_MASK_REG); + case PCI_EXP_RTCTL: { + /* Only mask/unmask PME interrupt */ + u32 val = advk_readl(pcie, PCIE_ISR0_MASK_REG) & + ~PCIE_MSG_PM_PME_MASK; + if ((new & PCI_EXP_RTCTL_PMEIE) == 0) + val |= PCIE_MSG_PM_PME_MASK; + advk_writel(pcie, val, PCIE_ISR0_MASK_REG); break; + } case PCI_EXP_RTSTA: new = (new & PCI_EXP_RTSTA_PME) >> 9; -- cgit v1.2.3 From 7fbcb5da811be7d47468417c7795405058abb3da Mon Sep 17 00:00:00 2001 From: Remi Pommarel Date: Fri, 27 Sep 2019 10:55:02 +0200 Subject: PCI: aardvark: Don't rely on jiffies while holding spinlock advk_pcie_wait_pio() can be called while holding a spinlock (from pci_bus_read_config_dword()), then depends on jiffies in order to timeout while polling on PIO state registers. In the case the PIO transaction failed, the timeout will never happen and will also cause the cpu to stall. This decrements a variable and wait instead of using jiffies. Signed-off-by: Remi Pommarel Signed-off-by: Lorenzo Pieralisi Reviewed-by: Andrew Murray Acked-by: Thomas Petazzoni --- drivers/pci/controller/pci-aardvark.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index cb4327657136..79be0afc9b1e 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -175,7 +175,8 @@ (PCIE_CONF_BUS(bus) | PCIE_CONF_DEV(PCI_SLOT(devfn)) | \ PCIE_CONF_FUNC(PCI_FUNC(devfn)) | PCIE_CONF_REG(where)) -#define PIO_TIMEOUT_MS 1 +#define PIO_RETRY_CNT 500 +#define PIO_RETRY_DELAY 2 /* 2 us*/ #define LINK_WAIT_MAX_RETRIES 10 #define LINK_WAIT_USLEEP_MIN 90000 @@ -404,17 +405,16 @@ static void advk_pcie_check_pio_status(struct advk_pcie *pcie) static int advk_pcie_wait_pio(struct advk_pcie *pcie) { struct device *dev = &pcie->pdev->dev; - unsigned long timeout; + int i; - timeout = jiffies + msecs_to_jiffies(PIO_TIMEOUT_MS); - - while (time_before(jiffies, timeout)) { + for (i = 0; i < PIO_RETRY_CNT; i++) { u32 start, isr; start = advk_readl(pcie, PIO_START); isr = advk_readl(pcie, PIO_ISR); if (!start && isr) return 0; + udelay(PIO_RETRY_DELAY); } dev_err(dev, "config read/write timed out\n"); -- cgit v1.2.3 From e078723f9cccd509482fd7f30a4afb1125ca7a2a Mon Sep 17 00:00:00 2001 From: Grzegorz Jaszczyk Date: Tue, 16 Jul 2019 14:12:07 +0200 Subject: PCI: aardvark: Fix big endian support Initialise every multiple-byte field of emulated PCI bridge config space with proper cpu_to_le* macro. This is required since the structure describing config space of emulated bridge assumes little-endian convention. Signed-off-by: Grzegorz Jaszczyk Signed-off-by: Lorenzo Pieralisi --- drivers/pci/controller/pci-aardvark.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 79be0afc9b1e..9f56f3bee39d 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -519,18 +519,20 @@ static void advk_sw_pci_bridge_init(struct advk_pcie *pcie) { struct pci_bridge_emul *bridge = &pcie->bridge; - bridge->conf.vendor = advk_readl(pcie, PCIE_CORE_DEV_ID_REG) & 0xffff; - bridge->conf.device = advk_readl(pcie, PCIE_CORE_DEV_ID_REG) >> 16; + bridge->conf.vendor = + cpu_to_le16(advk_readl(pcie, PCIE_CORE_DEV_ID_REG) & 0xffff); + bridge->conf.device = + cpu_to_le16(advk_readl(pcie, PCIE_CORE_DEV_ID_REG) >> 16); bridge->conf.class_revision = - advk_readl(pcie, PCIE_CORE_DEV_REV_REG) & 0xff; + cpu_to_le32(advk_readl(pcie, PCIE_CORE_DEV_REV_REG) & 0xff); /* Support 32 bits I/O addressing */ bridge->conf.iobase = PCI_IO_RANGE_TYPE_32; bridge->conf.iolimit = PCI_IO_RANGE_TYPE_32; /* Support 64 bits memory pref */ - bridge->conf.pref_mem_base = PCI_PREF_RANGE_TYPE_64; - bridge->conf.pref_mem_limit = PCI_PREF_RANGE_TYPE_64; + bridge->conf.pref_mem_base = cpu_to_le16(PCI_PREF_RANGE_TYPE_64); + bridge->conf.pref_mem_limit = cpu_to_le16(PCI_PREF_RANGE_TYPE_64); /* Support interrupt A for MSI feature */ bridge->conf.intpin = PCIE_CORE_INT_A_ASSERT_ENABLE; -- cgit v1.2.3 From e0d9d30b73548fbfe5c024ed630169bdc9a08aee Mon Sep 17 00:00:00 2001 From: Grzegorz Jaszczyk Date: Tue, 16 Jul 2019 14:13:46 +0200 Subject: PCI: pci-bridge-emul: Fix big-endian support Perform conversion to little-endian before every write to configuration space and convert it back to CPU endianness on reads. Additionally, initialise every multiple byte field of config space with the cpu_to_le* macro, which is required since the structure describing config space of emulated bridge assumes little-endian convention. Signed-off-by: Grzegorz Jaszczyk Signed-off-by: Lorenzo Pieralisi --- drivers/pci/pci-bridge-emul.c | 25 +++++++------- drivers/pci/pci-bridge-emul.h | 78 +++++++++++++++++++++---------------------- 2 files changed, 52 insertions(+), 51 deletions(-) diff --git a/drivers/pci/pci-bridge-emul.c b/drivers/pci/pci-bridge-emul.c index 5fd90105510d..fffa77093c08 100644 --- a/drivers/pci/pci-bridge-emul.c +++ b/drivers/pci/pci-bridge-emul.c @@ -270,10 +270,10 @@ static const struct pci_bridge_reg_behavior pcie_cap_regs_behavior[] = { int pci_bridge_emul_init(struct pci_bridge_emul *bridge, unsigned int flags) { - bridge->conf.class_revision |= PCI_CLASS_BRIDGE_PCI << 16; + bridge->conf.class_revision |= cpu_to_le32(PCI_CLASS_BRIDGE_PCI << 16); bridge->conf.header_type = PCI_HEADER_TYPE_BRIDGE; bridge->conf.cache_line_size = 0x10; - bridge->conf.status = PCI_STATUS_CAP_LIST; + bridge->conf.status = cpu_to_le16(PCI_STATUS_CAP_LIST); bridge->pci_regs_behavior = kmemdup(pci_regs_behavior, sizeof(pci_regs_behavior), GFP_KERNEL); @@ -284,8 +284,9 @@ int pci_bridge_emul_init(struct pci_bridge_emul *bridge, bridge->conf.capabilities_pointer = PCI_CAP_PCIE_START; bridge->pcie_conf.cap_id = PCI_CAP_ID_EXP; /* Set PCIe v2, root port, slot support */ - bridge->pcie_conf.cap = PCI_EXP_TYPE_ROOT_PORT << 4 | 2 | - PCI_EXP_FLAGS_SLOT; + bridge->pcie_conf.cap = + cpu_to_le16(PCI_EXP_TYPE_ROOT_PORT << 4 | 2 | + PCI_EXP_FLAGS_SLOT); bridge->pcie_cap_regs_behavior = kmemdup(pcie_cap_regs_behavior, sizeof(pcie_cap_regs_behavior), @@ -327,7 +328,7 @@ int pci_bridge_emul_conf_read(struct pci_bridge_emul *bridge, int where, int reg = where & ~3; pci_bridge_emul_read_status_t (*read_op)(struct pci_bridge_emul *bridge, int reg, u32 *value); - u32 *cfgspace; + __le32 *cfgspace; const struct pci_bridge_reg_behavior *behavior; if (bridge->has_pcie && reg >= PCI_CAP_PCIE_END) { @@ -343,11 +344,11 @@ int pci_bridge_emul_conf_read(struct pci_bridge_emul *bridge, int where, if (bridge->has_pcie && reg >= PCI_CAP_PCIE_START) { reg -= PCI_CAP_PCIE_START; read_op = bridge->ops->read_pcie; - cfgspace = (u32 *) &bridge->pcie_conf; + cfgspace = (__le32 *) &bridge->pcie_conf; behavior = bridge->pcie_cap_regs_behavior; } else { read_op = bridge->ops->read_base; - cfgspace = (u32 *) &bridge->conf; + cfgspace = (__le32 *) &bridge->conf; behavior = bridge->pci_regs_behavior; } @@ -357,7 +358,7 @@ int pci_bridge_emul_conf_read(struct pci_bridge_emul *bridge, int where, ret = PCI_BRIDGE_EMUL_NOT_HANDLED; if (ret == PCI_BRIDGE_EMUL_NOT_HANDLED) - *value = cfgspace[reg / 4]; + *value = le32_to_cpu(cfgspace[reg / 4]); /* * Make sure we never return any reserved bit with a value @@ -387,7 +388,7 @@ int pci_bridge_emul_conf_write(struct pci_bridge_emul *bridge, int where, int mask, ret, old, new, shift; void (*write_op)(struct pci_bridge_emul *bridge, int reg, u32 old, u32 new, u32 mask); - u32 *cfgspace; + __le32 *cfgspace; const struct pci_bridge_reg_behavior *behavior; if (bridge->has_pcie && reg >= PCI_CAP_PCIE_END) @@ -414,11 +415,11 @@ int pci_bridge_emul_conf_write(struct pci_bridge_emul *bridge, int where, if (bridge->has_pcie && reg >= PCI_CAP_PCIE_START) { reg -= PCI_CAP_PCIE_START; write_op = bridge->ops->write_pcie; - cfgspace = (u32 *) &bridge->pcie_conf; + cfgspace = (__le32 *) &bridge->pcie_conf; behavior = bridge->pcie_cap_regs_behavior; } else { write_op = bridge->ops->write_base; - cfgspace = (u32 *) &bridge->conf; + cfgspace = (__le32 *) &bridge->conf; behavior = bridge->pci_regs_behavior; } @@ -431,7 +432,7 @@ int pci_bridge_emul_conf_write(struct pci_bridge_emul *bridge, int where, /* Clear the W1C bits */ new &= ~((value << shift) & (behavior[reg / 4].w1c & mask)); - cfgspace[reg / 4] = new; + cfgspace[reg / 4] = cpu_to_le32(new); if (write_op) write_op(bridge, reg, old, new, mask); diff --git a/drivers/pci/pci-bridge-emul.h b/drivers/pci/pci-bridge-emul.h index e65b1b79899d..b31883022a8e 100644 --- a/drivers/pci/pci-bridge-emul.h +++ b/drivers/pci/pci-bridge-emul.h @@ -6,65 +6,65 @@ /* PCI configuration space of a PCI-to-PCI bridge. */ struct pci_bridge_emul_conf { - u16 vendor; - u16 device; - u16 command; - u16 status; - u32 class_revision; + __le16 vendor; + __le16 device; + __le16 command; + __le16 status; + __le32 class_revision; u8 cache_line_size; u8 latency_timer; u8 header_type; u8 bist; - u32 bar[2]; + __le32 bar[2]; u8 primary_bus; u8 secondary_bus; u8 subordinate_bus; u8 secondary_latency_timer; u8 iobase; u8 iolimit; - u16 secondary_status; - u16 membase; - u16 memlimit; - u16 pref_mem_base; - u16 pref_mem_limit; - u32 prefbaseupper; - u32 preflimitupper; - u16 iobaseupper; - u16 iolimitupper; + __le16 secondary_status; + __le16 membase; + __le16 memlimit; + __le16 pref_mem_base; + __le16 pref_mem_limit; + __le32 prefbaseupper; + __le32 preflimitupper; + __le16 iobaseupper; + __le16 iolimitupper; u8 capabilities_pointer; u8 reserve[3]; - u32 romaddr; + __le32 romaddr; u8 intline; u8 intpin; - u16 bridgectrl; + __le16 bridgectrl; }; /* PCI configuration space of the PCIe capabilities */ struct pci_bridge_emul_pcie_conf { u8 cap_id; u8 next; - u16 cap; - u32 devcap; - u16 devctl; - u16 devsta; - u32 lnkcap; - u16 lnkctl; - u16 lnksta; - u32 slotcap; - u16 slotctl; - u16 slotsta; - u16 rootctl; - u16 rsvd; - u32 rootsta; - u32 devcap2; - u16 devctl2; - u16 devsta2; - u32 lnkcap2; - u16 lnkctl2; - u16 lnksta2; - u32 slotcap2; - u16 slotctl2; - u16 slotsta2; + __le16 cap; + __le32 devcap; + __le16 devctl; + __le16 devsta; + __le32 lnkcap; + __le16 lnkctl; + __le16 lnksta; + __le32 slotcap; + __le16 slotctl; + __le16 slotsta; + __le16 rootctl; + __le16 rsvd; + __le32 rootsta; + __le32 devcap2; + __le16 devctl2; + __le16 devsta2; + __le32 lnkcap2; + __le16 lnkctl2; + __le16 lnksta2; + __le32 slotcap2; + __le16 slotctl2; + __le16 slotsta2; }; struct pci_bridge_emul; -- cgit v1.2.3