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5e7705df28
Explain the rationale of not overlapping the 64-bit DMA window with the PA range. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
233 lines
6.7 KiB
C
233 lines
6.7 KiB
C
/*
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* Copyright 2010 Tilera Corporation. All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, version 2.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for
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* more details.
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*/
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#ifndef _ASM_TILE_PCI_H
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#define _ASM_TILE_PCI_H
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#include <linux/dma-mapping.h>
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#include <linux/pci.h>
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#include <asm-generic/pci_iomap.h>
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#ifndef __tilegx__
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/*
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* Structure of a PCI controller (host bridge)
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*/
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struct pci_controller {
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int index; /* PCI domain number */
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struct pci_bus *root_bus;
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int last_busno;
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int hv_cfg_fd[2]; /* config{0,1} fds for this PCIe controller */
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int hv_mem_fd; /* fd to Hypervisor for MMIO operations */
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struct pci_ops *ops;
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int irq_base; /* Base IRQ from the Hypervisor */
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int plx_gen1; /* flag for PLX Gen 1 configuration */
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/* Address ranges that are routed to this controller/bridge. */
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struct resource mem_resources[3];
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};
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/*
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* This flag tells if the platform is TILEmpower that needs
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* special configuration for the PLX switch chip.
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*/
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extern int tile_plx_gen1;
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static inline void pci_iounmap(struct pci_dev *dev, void __iomem *addr) {}
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#define TILE_NUM_PCIE 2
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/*
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* The hypervisor maps the entirety of CPA-space as bus addresses, so
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* bus addresses are physical addresses. The networking and block
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* device layers use this boolean for bounce buffer decisions.
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*/
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#define PCI_DMA_BUS_IS_PHYS 1
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/* generic pci stuff */
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#include <asm-generic/pci.h>
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#else
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#include <asm/page.h>
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#include <gxio/trio.h>
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/**
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* We reserve the hugepage-size address range at the top of the 64-bit address
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* space to serve as the PCI window, emulating the BAR0 space of an endpoint
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* device. This window is used by the chip-to-chip applications running on
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* the RC node. The reason for carving out this window is that Mem-Maps that
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* back up this window will not overlap with those that map the real physical
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* memory.
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*/
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#define PCIE_HOST_BAR0_SIZE HPAGE_SIZE
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#define PCIE_HOST_BAR0_START HPAGE_MASK
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/**
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* The first PAGE_SIZE of the above "BAR" window is mapped to the
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* gxpci_host_regs structure.
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*/
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#define PCIE_HOST_REGS_SIZE PAGE_SIZE
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/*
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* This is the PCI address where the Mem-Map interrupt regions start.
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* We use the 2nd to the last huge page of the 64-bit address space.
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* The last huge page is used for the rootcomplex "bar", for C2C purpose.
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*/
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#define MEM_MAP_INTR_REGIONS_BASE (HPAGE_MASK - HPAGE_SIZE)
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/*
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* Each Mem-Map interrupt region occupies 4KB.
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*/
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#define MEM_MAP_INTR_REGION_SIZE (1 << TRIO_MAP_MEM_LIM__ADDR_SHIFT)
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/*
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* Allocate the PCI BAR window right below 4GB.
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*/
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#define TILE_PCI_BAR_WINDOW_TOP (1ULL << 32)
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/*
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* Allocate 1GB for the PCI BAR window.
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*/
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#define TILE_PCI_BAR_WINDOW_SIZE (1 << 30)
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/*
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* This is the highest bus address targeting the host memory that
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* can be generated by legacy PCI devices with 32-bit or less
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* DMA capability, dictated by the BAR window size and location.
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*/
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#define TILE_PCI_MAX_DIRECT_DMA_ADDRESS \
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(TILE_PCI_BAR_WINDOW_TOP - TILE_PCI_BAR_WINDOW_SIZE - 1)
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/*
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* We shift the PCI bus range for all the physical memory up by the whole PA
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* range. The corresponding CPA of an incoming PCI request will be the PCI
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* address minus TILE_PCI_MEM_MAP_BASE_OFFSET. This also implies
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* that the 64-bit capable devices will be given DMA addresses as
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* the CPA plus TILE_PCI_MEM_MAP_BASE_OFFSET. To support 32-bit
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* devices, we create a separate map region that handles the low
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* 4GB.
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*
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* This design lets us avoid the "PCI hole" problem where the host bridge
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* won't pass DMA traffic with target addresses that happen to fall within the
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* BAR space. This enables us to use all the physical memory for DMA, instead
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* of wasting the same amount of physical memory as the BAR window size.
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*/
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#define TILE_PCI_MEM_MAP_BASE_OFFSET (1ULL << CHIP_PA_WIDTH())
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/*
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* Start of the PCI memory resource, which starts at the end of the
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* maximum system physical RAM address.
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*/
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#define TILE_PCI_MEM_START (1ULL << CHIP_PA_WIDTH())
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/*
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* Structure of a PCI controller (host bridge) on Gx.
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*/
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struct pci_controller {
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/* Pointer back to the TRIO that this PCIe port is connected to. */
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gxio_trio_context_t *trio;
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int mac; /* PCIe mac index on the TRIO shim */
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int trio_index; /* Index of TRIO shim that contains the MAC. */
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int pio_mem_index; /* PIO region index for memory access */
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#ifdef CONFIG_TILE_PCI_IO
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int pio_io_index; /* PIO region index for I/O space access */
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#endif
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/*
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* Mem-Map regions for all the memory controllers so that Linux can
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* map all of its physical memory space to the PCI bus.
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*/
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int mem_maps[MAX_NUMNODES];
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int index; /* PCI domain number */
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struct pci_bus *root_bus;
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/* PCI I/O space resource for this controller. */
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struct resource io_space;
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char io_space_name[32];
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/* PCI memory space resource for this controller. */
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struct resource mem_space;
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char mem_space_name[32];
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uint64_t mem_offset; /* cpu->bus memory mapping offset. */
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int first_busno;
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struct pci_ops *ops;
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/* Table that maps the INTx numbers to Linux irq numbers. */
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int irq_intx_table[4];
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};
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extern struct pci_controller pci_controllers[TILEGX_NUM_TRIO * TILEGX_TRIO_PCIES];
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extern gxio_trio_context_t trio_contexts[TILEGX_NUM_TRIO];
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extern int num_trio_shims;
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extern void pci_iounmap(struct pci_dev *dev, void __iomem *);
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/*
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* The PCI address space does not equal the physical memory address
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* space (we have an IOMMU). The IDE and SCSI device layers use this
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* boolean for bounce buffer decisions.
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*/
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#define PCI_DMA_BUS_IS_PHYS 0
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#endif /* __tilegx__ */
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int __init tile_pci_init(void);
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int __init pcibios_init(void);
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void pcibios_fixup_bus(struct pci_bus *bus);
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#define pci_domain_nr(bus) (((struct pci_controller *)(bus)->sysdata)->index)
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/*
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* This decides whether to display the domain number in /proc.
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*/
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static inline int pci_proc_domain(struct pci_bus *bus)
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{
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return 1;
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}
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/*
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* pcibios_assign_all_busses() tells whether or not the bus numbers
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* should be reassigned, in case the BIOS didn't do it correctly, or
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* in case we don't have a BIOS and we want to let Linux do it.
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*/
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static inline int pcibios_assign_all_busses(void)
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{
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return 1;
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}
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#define PCIBIOS_MIN_MEM 0
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/* Minimum PCI I/O address, starting at the page boundary. */
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#define PCIBIOS_MIN_IO PAGE_SIZE
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/* Use any cpu for PCI. */
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#define cpumask_of_pcibus(bus) cpu_online_mask
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/* implement the pci_ DMA API in terms of the generic device dma_ one */
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#include <asm-generic/pci-dma-compat.h>
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#endif /* _ASM_TILE_PCI_H */
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