Instead of relying on the vendor specific implementations to send the PME_Turn_Off message, let's introduce a generic way of sending the message using the MSG TLP. This is achieved by reserving a region for MSG TLP of size 'pci->region_align', at the end of the first IORESOURCE_MEM window of the host bridge. And then sending the PME_Turn_Off message during system suspend with the help of iATU. The reason for reserving the MSG TLP region at the end of the IORESOURCE_MEM is to avoid generating holes in between. Because, when the region is allocated using allocate_resource(), memory will be allocated from the start of the window. Later, if memory gets allocated for an endpoint of size bigger than 'region_align', there will be a hole between MSG TLP region and endpoint memory. It should be noted that this generic implementation is optional for the glue drivers and can be overridden by a custom 'pme_turn_off' callback. Signed-off-by: Frank Li <Frank.Li@xxxxxxx> --- drivers/pci/controller/dwc/pcie-designware-host.c | 95 +++++++++++++++++++++-- drivers/pci/controller/dwc/pcie-designware.h | 3 + 2 files changed, 93 insertions(+), 5 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c index 3a9cb4be22ab2..a0822d5371bc5 100644 --- a/drivers/pci/controller/dwc/pcie-designware-host.c +++ b/drivers/pci/controller/dwc/pcie-designware-host.c @@ -398,6 +398,32 @@ static int dw_pcie_msi_host_init(struct dw_pcie_rp *pp) return 0; } +static void dw_pcie_host_request_msg_tlp_res(struct dw_pcie_rp *pp) +{ + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + struct resource_entry *win; + struct resource *res; + + win = resource_list_first_type(&pp->bridge->windows, IORESOURCE_MEM); + if (win) { + res = devm_kzalloc(pci->dev, sizeof(*res), GFP_KERNEL); + if (!res) + return; + + /* + * Allocate MSG TLP region of size 'region_align' at the end of + * the host bridge window. + */ + res->start = win->res->end - pci->region_align + 1; + res->end = win->res->end; + res->name = "msg"; + res->flags = win->res->flags | IORESOURCE_BUSY; + + if (!devm_request_resource(pci->dev, win->res, res)) + pp->msg_res = res; + } +} + int dw_pcie_host_init(struct dw_pcie_rp *pp) { struct dw_pcie *pci = to_dw_pcie_from_pp(pp); @@ -484,6 +510,18 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp) dw_pcie_iatu_detect(pci); + /* + * Allocate the resource for MSG TLP before programming the iATU + * outbound window in dw_pcie_setup_rc(). Since the allocation depends + * on the value of 'region_align', this has to be done after + * dw_pcie_iatu_detect(). + * + * Glue drivers need to set 'use_atu_msg' before dw_pcie_host_init() to + * make use of the generic MSG TLP implementation. + */ + if (pp->use_atu_msg) + dw_pcie_host_request_msg_tlp_res(pp); + ret = dw_pcie_edma_detect(pci); if (ret) goto err_free_msi; @@ -700,7 +738,13 @@ static int dw_pcie_iatu_setup(struct dw_pcie_rp *pp) atu.type = PCIE_ATU_TYPE_MEM; atu.cpu_addr = entry->res->start; atu.pci_addr = entry->res->start - entry->offset; - atu.size = resource_size(entry->res); + + /* Adjust iATU size if MSG TLP region was allocated before */ + if (pp->msg_res && pp->msg_res->parent == entry->res) + atu.size = resource_size(entry->res) - + resource_size(pp->msg_res); + else + atu.size = resource_size(entry->res); ret = dw_pcie_prog_outbound_atu(pci, &atu); if (ret) { @@ -733,6 +777,8 @@ static int dw_pcie_iatu_setup(struct dw_pcie_rp *pp) dev_warn(pci->dev, "Ranges exceed outbound iATU size (%d)\n", pci->num_ob_windows); + pp->msg_atu_index = i; + i = 0; resource_list_for_each_entry(entry, &pp->bridge->dma_ranges) { if (resource_type(entry->res) != IORESOURCE_MEM) @@ -838,11 +884,47 @@ int dw_pcie_setup_rc(struct dw_pcie_rp *pp) } EXPORT_SYMBOL_GPL(dw_pcie_setup_rc); +static int dw_pcie_pme_turn_off(struct dw_pcie *pci) +{ + struct dw_pcie_ob_atu_cfg atu = { 0 }; + void __iomem *mem; + int ret; + + if (pci->num_ob_windows <= pci->pp.msg_atu_index) + return -ENOSPC; + + if (!pci->pp.msg_res) + return -ENOSPC; + + atu.code = PCIE_MSG_CODE_PME_TURN_OFF; + atu.routing = PCIE_MSG_TYPE_R_BC; + atu.type = PCIE_ATU_TYPE_MSG; + atu.size = resource_size(pci->pp.msg_res); + atu.index = pci->pp.msg_atu_index; + + atu.cpu_addr = pci->pp.msg_res->start; + + ret = dw_pcie_prog_outbound_atu(pci, &atu); + if (ret) + return ret; + + mem = ioremap(atu.cpu_addr, pci->region_align); + if (!mem) + return -ENOMEM; + + /* A dummy write is converted to a Msg TLP */ + writel(0, mem); + + iounmap(mem); + + return 0; +} + int dw_pcie_suspend_noirq(struct dw_pcie *pci) { u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); u32 val; - int ret; + int ret = 0; /* * If L1SS is supported, then do not put the link into L2 as some @@ -854,10 +936,13 @@ int dw_pcie_suspend_noirq(struct dw_pcie *pci) if (dw_pcie_get_ltssm(pci) <= DW_PCIE_LTSSM_DETECT_ACT) return 0; - if (!pci->pp.ops->pme_turn_off) - return 0; + if (pci->pp.ops->pme_turn_off) + pci->pp.ops->pme_turn_off(&pci->pp); + else + ret = dw_pcie_pme_turn_off(pci); - pci->pp.ops->pme_turn_off(&pci->pp); + if (ret) + return ret; ret = read_poll_timeout(dw_pcie_get_ltssm, val, val == DW_PCIE_LTSSM_L2_IDLE, PCIE_PME_TO_L2_TIMEOUT_US/10, diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h index 703b50bc5e0f1..dca5de4c6e877 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -341,6 +341,9 @@ struct dw_pcie_rp { struct pci_host_bridge *bridge; raw_spinlock_t lock; DECLARE_BITMAP(msi_irq_in_use, MAX_MSI_IRQS); + bool use_atu_msg; + int msg_atu_index; + struct resource *msg_res; }; struct dw_pcie_ep_ops { -- 2.34.1