diff options
Diffstat (limited to 'drivers/pci/controller/pcie-cadence-ep.c')
| -rw-r--r-- | drivers/pci/controller/pcie-cadence-ep.c | 549 |
1 files changed, 549 insertions, 0 deletions
diff --git a/drivers/pci/controller/pcie-cadence-ep.c b/drivers/pci/controller/pcie-cadence-ep.c new file mode 100644 index 000000000000..3d8283e450a9 --- /dev/null +++ b/drivers/pci/controller/pcie-cadence-ep.c @@ -0,0 +1,549 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2017 Cadence +// Cadence PCIe endpoint controller driver. +// Author: Cyrille Pitchen <cyrille.pitchen@free-electrons.com> + +#include <linux/delay.h> +#include <linux/kernel.h> +#include <linux/of.h> +#include <linux/pci-epc.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/sizes.h> + +#include "pcie-cadence.h" + +#define CDNS_PCIE_EP_MIN_APERTURE 128 /* 128 bytes */ +#define CDNS_PCIE_EP_IRQ_PCI_ADDR_NONE 0x1 +#define CDNS_PCIE_EP_IRQ_PCI_ADDR_LEGACY 0x3 + +/** + * struct cdns_pcie_ep - private data for this PCIe endpoint controller driver + * @pcie: Cadence PCIe controller + * @max_regions: maximum number of regions supported by hardware + * @ob_region_map: bitmask of mapped outbound regions + * @ob_addr: base addresses in the AXI bus where the outbound regions start + * @irq_phys_addr: base address on the AXI bus where the MSI/legacy IRQ + * dedicated outbound regions is mapped. + * @irq_cpu_addr: base address in the CPU space where a write access triggers + * the sending of a memory write (MSI) / normal message (legacy + * IRQ) TLP through the PCIe bus. + * @irq_pci_addr: used to save the current mapping of the MSI/legacy IRQ + * dedicated outbound region. + * @irq_pci_fn: the latest PCI function that has updated the mapping of + * the MSI/legacy IRQ dedicated outbound region. + * @irq_pending: bitmask of asserted legacy IRQs. + */ +struct cdns_pcie_ep { + struct cdns_pcie pcie; + u32 max_regions; + unsigned long ob_region_map; + phys_addr_t *ob_addr; + phys_addr_t irq_phys_addr; + void __iomem *irq_cpu_addr; + u64 irq_pci_addr; + u8 irq_pci_fn; + u8 irq_pending; +}; + +static int cdns_pcie_ep_write_header(struct pci_epc *epc, u8 fn, + struct pci_epf_header *hdr) +{ + struct cdns_pcie_ep *ep = epc_get_drvdata(epc); + struct cdns_pcie *pcie = &ep->pcie; + + cdns_pcie_ep_fn_writew(pcie, fn, PCI_DEVICE_ID, hdr->deviceid); + cdns_pcie_ep_fn_writeb(pcie, fn, PCI_REVISION_ID, hdr->revid); + cdns_pcie_ep_fn_writeb(pcie, fn, PCI_CLASS_PROG, hdr->progif_code); + cdns_pcie_ep_fn_writew(pcie, fn, PCI_CLASS_DEVICE, + hdr->subclass_code | hdr->baseclass_code << 8); + cdns_pcie_ep_fn_writeb(pcie, fn, PCI_CACHE_LINE_SIZE, + hdr->cache_line_size); + cdns_pcie_ep_fn_writew(pcie, fn, PCI_SUBSYSTEM_ID, hdr->subsys_id); + cdns_pcie_ep_fn_writeb(pcie, fn, PCI_INTERRUPT_PIN, hdr->interrupt_pin); + + /* + * Vendor ID can only be modified from function 0, all other functions + * use the same vendor ID as function 0. + */ + if (fn == 0) { + /* Update the vendor IDs. */ + u32 id = CDNS_PCIE_LM_ID_VENDOR(hdr->vendorid) | + CDNS_PCIE_LM_ID_SUBSYS(hdr->subsys_vendor_id); + + cdns_pcie_writel(pcie, CDNS_PCIE_LM_ID, id); + } + + return 0; +} + +static int cdns_pcie_ep_set_bar(struct pci_epc *epc, u8 fn, + struct pci_epf_bar *epf_bar) +{ + struct cdns_pcie_ep *ep = epc_get_drvdata(epc); + struct cdns_pcie *pcie = &ep->pcie; + dma_addr_t bar_phys = epf_bar->phys_addr; + enum pci_barno bar = epf_bar->barno; + int flags = epf_bar->flags; + u32 addr0, addr1, reg, cfg, b, aperture, ctrl; + u64 sz; + + /* BAR size is 2^(aperture + 7) */ + sz = max_t(size_t, epf_bar->size, CDNS_PCIE_EP_MIN_APERTURE); + /* + * roundup_pow_of_two() returns an unsigned long, which is not suited + * for 64bit values. + */ + sz = 1ULL << fls64(sz - 1); + aperture = ilog2(sz) - 7; /* 128B -> 0, 256B -> 1, 512B -> 2, ... */ + + if ((flags & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) { + ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_IO_32BITS; + } else { + bool is_prefetch = !!(flags & PCI_BASE_ADDRESS_MEM_PREFETCH); + bool is_64bits = sz > SZ_2G; + + if (is_64bits && (bar & 1)) + return -EINVAL; + + if (is_64bits && !(flags & PCI_BASE_ADDRESS_MEM_TYPE_64)) + epf_bar->flags |= PCI_BASE_ADDRESS_MEM_TYPE_64; + + if (is_64bits && is_prefetch) + ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_PREFETCH_MEM_64BITS; + else if (is_prefetch) + ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_PREFETCH_MEM_32BITS; + else if (is_64bits) + ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_MEM_64BITS; + else + ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_MEM_32BITS; + } + + addr0 = lower_32_bits(bar_phys); + addr1 = upper_32_bits(bar_phys); + cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR0(fn, bar), + addr0); + cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR1(fn, bar), + addr1); + + if (bar < BAR_4) { + reg = CDNS_PCIE_LM_EP_FUNC_BAR_CFG0(fn); + b = bar; + } else { + reg = CDNS_PCIE_LM_EP_FUNC_BAR_CFG1(fn); + b = bar - BAR_4; + } + + cfg = cdns_pcie_readl(pcie, reg); + cfg &= ~(CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_APERTURE_MASK(b) | + CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL_MASK(b)); + cfg |= (CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_APERTURE(b, aperture) | + CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL(b, ctrl)); + cdns_pcie_writel(pcie, reg, cfg); + + return 0; +} + +static void cdns_pcie_ep_clear_bar(struct pci_epc *epc, u8 fn, + struct pci_epf_bar *epf_bar) +{ + struct cdns_pcie_ep *ep = epc_get_drvdata(epc); + struct cdns_pcie *pcie = &ep->pcie; + enum pci_barno bar = epf_bar->barno; + u32 reg, cfg, b, ctrl; + + if (bar < BAR_4) { + reg = CDNS_PCIE_LM_EP_FUNC_BAR_CFG0(fn); + b = bar; + } else { + reg = CDNS_PCIE_LM_EP_FUNC_BAR_CFG1(fn); + b = bar - BAR_4; + } + + ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_DISABLED; + cfg = cdns_pcie_readl(pcie, reg); + cfg &= ~(CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_APERTURE_MASK(b) | + CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL_MASK(b)); + cfg |= CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL(b, ctrl); + cdns_pcie_writel(pcie, reg, cfg); + + cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR0(fn, bar), 0); + cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR1(fn, bar), 0); +} + +static int cdns_pcie_ep_map_addr(struct pci_epc *epc, u8 fn, phys_addr_t addr, + u64 pci_addr, size_t size) +{ + struct cdns_pcie_ep *ep = epc_get_drvdata(epc); + struct cdns_pcie *pcie = &ep->pcie; + u32 r; + + r = find_first_zero_bit(&ep->ob_region_map, + sizeof(ep->ob_region_map) * BITS_PER_LONG); + if (r >= ep->max_regions - 1) { + dev_err(&epc->dev, "no free outbound region\n"); + return -EINVAL; + } + + cdns_pcie_set_outbound_region(pcie, fn, r, false, addr, pci_addr, size); + + set_bit(r, &ep->ob_region_map); + ep->ob_addr[r] = addr; + + return 0; +} + +static void cdns_pcie_ep_unmap_addr(struct pci_epc *epc, u8 fn, + phys_addr_t addr) +{ + struct cdns_pcie_ep *ep = epc_get_drvdata(epc); + struct cdns_pcie *pcie = &ep->pcie; + u32 r; + + for (r = 0; r < ep->max_regions - 1; r++) + if (ep->ob_addr[r] == addr) + break; + + if (r == ep->max_regions - 1) + return; + + cdns_pcie_reset_outbound_region(pcie, r); + + ep->ob_addr[r] = 0; + clear_bit(r, &ep->ob_region_map); +} + +static int cdns_pcie_ep_set_msi(struct pci_epc *epc, u8 fn, u8 mmc) +{ + struct cdns_pcie_ep *ep = epc_get_drvdata(epc); + struct cdns_pcie *pcie = &ep->pcie; + u32 cap = CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET; + u16 flags; + + /* + * Set the Multiple Message Capable bitfield into the Message Control + * register. + */ + flags = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSI_FLAGS); + flags = (flags & ~PCI_MSI_FLAGS_QMASK) | (mmc << 1); + flags |= PCI_MSI_FLAGS_64BIT; + flags &= ~PCI_MSI_FLAGS_MASKBIT; + cdns_pcie_ep_fn_writew(pcie, fn, cap + PCI_MSI_FLAGS, flags); + + return 0; +} + +static int cdns_pcie_ep_get_msi(struct pci_epc *epc, u8 fn) +{ + struct cdns_pcie_ep *ep = epc_get_drvdata(epc); + struct cdns_pcie *pcie = &ep->pcie; + u32 cap = CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET; + u16 flags, mmc, mme; + + /* Validate that the MSI feature is actually enabled. */ + flags = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSI_FLAGS); + if (!(flags & PCI_MSI_FLAGS_ENABLE)) + return -EINVAL; + + /* + * Get the Multiple Message Enable bitfield from the Message Control + * register. + */ + mmc = (flags & PCI_MSI_FLAGS_QMASK) >> 1; + mme = (flags & PCI_MSI_FLAGS_QSIZE) >> 4; + + return mme; +} + +static void cdns_pcie_ep_assert_intx(struct cdns_pcie_ep *ep, u8 fn, + u8 intx, bool is_asserted) +{ + struct cdns_pcie *pcie = &ep->pcie; + u32 r = ep->max_regions - 1; + u32 offset; + u16 status; + u8 msg_code; + + intx &= 3; + + /* Set the outbound region if needed. */ + if (unlikely(ep->irq_pci_addr != CDNS_PCIE_EP_IRQ_PCI_ADDR_LEGACY || + ep->irq_pci_fn != fn)) { + /* Last region was reserved for IRQ writes. */ + cdns_pcie_set_outbound_region_for_normal_msg(pcie, fn, r, + ep->irq_phys_addr); + ep->irq_pci_addr = CDNS_PCIE_EP_IRQ_PCI_ADDR_LEGACY; + ep->irq_pci_fn = fn; + } + + if (is_asserted) { + ep->irq_pending |= BIT(intx); + msg_code = MSG_CODE_ASSERT_INTA + intx; + } else { + ep->irq_pending &= ~BIT(intx); + msg_code = MSG_CODE_DEASSERT_INTA + intx; + } + + status = cdns_pcie_ep_fn_readw(pcie, fn, PCI_STATUS); + if (((status & PCI_STATUS_INTERRUPT) != 0) ^ (ep->irq_pending != 0)) { + status ^= PCI_STATUS_INTERRUPT; + cdns_pcie_ep_fn_writew(pcie, fn, PCI_STATUS, status); + } + + offset = CDNS_PCIE_NORMAL_MSG_ROUTING(MSG_ROUTING_LOCAL) | + CDNS_PCIE_NORMAL_MSG_CODE(msg_code) | + CDNS_PCIE_MSG_NO_DATA; + writel(0, ep->irq_cpu_addr + offset); +} + +static int cdns_pcie_ep_send_legacy_irq(struct cdns_pcie_ep *ep, u8 fn, u8 intx) +{ + u16 cmd; + + cmd = cdns_pcie_ep_fn_readw(&ep->pcie, fn, PCI_COMMAND); + if (cmd & PCI_COMMAND_INTX_DISABLE) + return -EINVAL; + + cdns_pcie_ep_assert_intx(ep, fn, intx, true); + /* + * The mdelay() value was taken from dra7xx_pcie_raise_legacy_irq() + * from drivers/pci/dwc/pci-dra7xx.c + */ + mdelay(1); + cdns_pcie_ep_assert_intx(ep, fn, intx, false); + return 0; +} + +static int cdns_pcie_ep_send_msi_irq(struct cdns_pcie_ep *ep, u8 fn, + u8 interrupt_num) +{ + struct cdns_pcie *pcie = &ep->pcie; + u32 cap = CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET; + u16 flags, mme, data, data_mask; + u8 msi_count; + u64 pci_addr, pci_addr_mask = 0xff; + + /* Check whether the MSI feature has been enabled by the PCI host. */ + flags = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSI_FLAGS); + if (!(flags & PCI_MSI_FLAGS_ENABLE)) + return -EINVAL; + + /* Get the number of enabled MSIs */ + mme = (flags & PCI_MSI_FLAGS_QSIZE) >> 4; + msi_count = 1 << mme; + if (!interrupt_num || interrupt_num > msi_count) + return -EINVAL; + + /* Compute the data value to be written. */ + data_mask = msi_count - 1; + data = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSI_DATA_64); + data = (data & ~data_mask) | ((interrupt_num - 1) & data_mask); + + /* Get the PCI address where to write the data into. */ + pci_addr = cdns_pcie_ep_fn_readl(pcie, fn, cap + PCI_MSI_ADDRESS_HI); + pci_addr <<= 32; + pci_addr |= cdns_pcie_ep_fn_readl(pcie, fn, cap + PCI_MSI_ADDRESS_LO); + pci_addr &= GENMASK_ULL(63, 2); + + /* Set the outbound region if needed. */ + if (unlikely(ep->irq_pci_addr != (pci_addr & ~pci_addr_mask) || + ep->irq_pci_fn != fn)) { + /* Last region was reserved for IRQ writes. */ + cdns_pcie_set_outbound_region(pcie, fn, ep->max_regions - 1, + false, + ep->irq_phys_addr, + pci_addr & ~pci_addr_mask, + pci_addr_mask + 1); + ep->irq_pci_addr = (pci_addr & ~pci_addr_mask); + ep->irq_pci_fn = fn; + } + writew(data, ep->irq_cpu_addr + (pci_addr & pci_addr_mask)); + + return 0; +} + +static int cdns_pcie_ep_raise_irq(struct pci_epc *epc, u8 fn, + enum pci_epc_irq_type type, u8 interrupt_num) +{ + struct cdns_pcie_ep *ep = epc_get_drvdata(epc); + + switch (type) { + case PCI_EPC_IRQ_LEGACY: + return cdns_pcie_ep_send_legacy_irq(ep, fn, 0); + + case PCI_EPC_IRQ_MSI: + return cdns_pcie_ep_send_msi_irq(ep, fn, interrupt_num); + + default: + break; + } + + return -EINVAL; +} + +static int cdns_pcie_ep_start(struct pci_epc *epc) +{ + struct cdns_pcie_ep *ep = epc_get_drvdata(epc); + struct cdns_pcie *pcie = &ep->pcie; + struct pci_epf *epf; + u32 cfg; + + /* + * BIT(0) is hardwired to 1, hence function 0 is always enabled + * and can't be disabled anyway. + */ + cfg = BIT(0); + list_for_each_entry(epf, &epc->pci_epf, list) + cfg |= BIT(epf->func_no); + cdns_pcie_writel(pcie, CDNS_PCIE_LM_EP_FUNC_CFG, cfg); + + /* + * The PCIe links are automatically established by the controller + * once for all at powerup: the software can neither start nor stop + * those links later at runtime. + * + * Then we only have to notify the EP core that our links are already + * established. However we don't call directly pci_epc_linkup() because + * we've already locked the epc->lock. + */ + list_for_each_entry(epf, &epc->pci_epf, list) + pci_epf_linkup(epf); + + return 0; +} + +static const struct pci_epc_ops cdns_pcie_epc_ops = { + .write_header = cdns_pcie_ep_write_header, + .set_bar = cdns_pcie_ep_set_bar, + .clear_bar = cdns_pcie_ep_clear_bar, + .map_addr = cdns_pcie_ep_map_addr, + .unmap_addr = cdns_pcie_ep_unmap_addr, + .set_msi = cdns_pcie_ep_set_msi, + .get_msi = cdns_pcie_ep_get_msi, + .raise_irq = cdns_pcie_ep_raise_irq, + .start = cdns_pcie_ep_start, +}; + +static const struct of_device_id cdns_pcie_ep_of_match[] = { + { .compatible = "cdns,cdns-pcie-ep" }, + + { }, +}; + +static int cdns_pcie_ep_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct cdns_pcie_ep *ep; + struct cdns_pcie *pcie; + struct pci_epc *epc; + struct resource *res; + int ret; + + ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL); + if (!ep) + return -ENOMEM; + + pcie = &ep->pcie; + pcie->is_rc = false; + + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "reg"); + pcie->reg_base = devm_ioremap_resource(dev, res); + if (IS_ERR(pcie->reg_base)) { + dev_err(dev, "missing \"reg\"\n"); + return PTR_ERR(pcie->reg_base); + } + + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mem"); + if (!res) { + dev_err(dev, "missing \"mem\"\n"); + return -EINVAL; + } + pcie->mem_res = res; + + ret = of_property_read_u32(np, "cdns,max-outbound-regions", + &ep->max_regions); + if (ret < 0) { + dev_err(dev, "missing \"cdns,max-outbound-regions\"\n"); + return ret; + } + ep->ob_addr = devm_kzalloc(dev, ep->max_regions * sizeof(*ep->ob_addr), + GFP_KERNEL); + if (!ep->ob_addr) + return -ENOMEM; + + pm_runtime_enable(dev); + ret = pm_runtime_get_sync(dev); + if (ret < 0) { + dev_err(dev, "pm_runtime_get_sync() failed\n"); + goto err_get_sync; + } + + /* Disable all but function 0 (anyway BIT(0) is hardwired to 1). */ + cdns_pcie_writel(pcie, CDNS_PCIE_LM_EP_FUNC_CFG, BIT(0)); + + epc = devm_pci_epc_create(dev, &cdns_pcie_epc_ops); + if (IS_ERR(epc)) { + dev_err(dev, "failed to create epc device\n"); + ret = PTR_ERR(epc); + goto err_init; + } + + epc_set_drvdata(epc, ep); + + if (of_property_read_u8(np, "max-functions", &epc->max_functions) < 0) + epc->max_functions = 1; + + ret = pci_epc_mem_init(epc, pcie->mem_res->start, + resource_size(pcie->mem_res)); + if (ret < 0) { + dev_err(dev, "failed to initialize the memory space\n"); + goto err_init; + } + + ep->irq_cpu_addr = pci_epc_mem_alloc_addr(epc, &ep->irq_phys_addr, + SZ_128K); + if (!ep->irq_cpu_addr) { + dev_err(dev, "failed to reserve memory space for MSI\n"); + ret = -ENOMEM; + goto free_epc_mem; + } + ep->irq_pci_addr = CDNS_PCIE_EP_IRQ_PCI_ADDR_NONE; + + return 0; + + free_epc_mem: + pci_epc_mem_exit(epc); + + err_init: + pm_runtime_put_sync(dev); + + err_get_sync: + pm_runtime_disable(dev); + + return ret; +} + +static void cdns_pcie_ep_shutdown(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + int ret; + + ret = pm_runtime_put_sync(dev); + if (ret < 0) + dev_dbg(dev, "pm_runtime_put_sync failed\n"); + + pm_runtime_disable(dev); + + /* The PCIe controller can't be disabled. */ +} + +static struct platform_driver cdns_pcie_ep_driver = { + .driver = { + .name = "cdns-pcie-ep", + .of_match_table = cdns_pcie_ep_of_match, + }, + .probe = cdns_pcie_ep_probe, + .shutdown = cdns_pcie_ep_shutdown, +}; +builtin_platform_driver(cdns_pcie_ep_driver); |