From aac5073d768926322ec38ca7153fd8f14e20a88e Mon Sep 17 00:00:00 2001 From: Ian Moffett Date: Sat, 20 Sep 2025 17:20:14 -0400 Subject: kern: pci: Add bus framework and PCI BAR mapper Signed-off-by: Ian Moffett --- src/sys/arch/amd64/io/pci/bar.c | 30 +++++++++++++++ src/sys/arch/amd64/os/os_bus.c | 84 +++++++++++++++++++++++++++++++++++++++++ src/sys/include/io/pci/bar.h | 14 +++++++ src/sys/include/os/bus.h | 73 +++++++++++++++++++++++++++++++++++ 4 files changed, 201 insertions(+) create mode 100644 src/sys/arch/amd64/os/os_bus.c create mode 100644 src/sys/include/os/bus.h (limited to 'src/sys') diff --git a/src/sys/arch/amd64/io/pci/bar.c b/src/sys/arch/amd64/io/pci/bar.c index 265d873..1a7e766 100644 --- a/src/sys/arch/amd64/io/pci/bar.c +++ b/src/sys/arch/amd64/io/pci/bar.c @@ -65,3 +65,33 @@ pci_bar_size(struct pci_device *dev, uint8_t bar) pci_writel(dev, barreg, reg_tmp); return reg; } + +/* + * Map a BAR into host memory + */ +int +pci_map_bar(struct pci_device *dev, uint8_t bar, struct bus_space *bs_res) +{ + size_t len; + bus_addr_t pa; + uint8_t barreg = pci_get_barreg(bar); + uintptr_t tmp; + + if (dev == NULL || bs_res == NULL) { + return -EINVAL; + } + + if (barreg == 0) { + return -EINVAL; + } + + /* This must be MMIO */ + tmp = pci_readl(dev, barreg); + if (PCI_BAR_IO(tmp)) { + return -EINVAL; + } + + pa = tmp & ~0x7; + len = pci_bar_size(dev, bar); + return bus_space_map(bs_res, pa, len); +} diff --git a/src/sys/arch/amd64/os/os_bus.c b/src/sys/arch/amd64/os/os_bus.c new file mode 100644 index 0000000..96f841d --- /dev/null +++ b/src/sys/arch/amd64/os/os_bus.c @@ -0,0 +1,84 @@ +/* + * Copyright (c) 2025 Ian Marco Moffett and L5 engineers + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the project nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * Map a BAR address into host memory + */ +int +bus_space_map(struct bus_space *bp, bus_addr_t pa, size_t len) +{ + static size_t PSIZE = DEFAULT_PAGESIZE; + struct vm_vas vas; + struct mmu_map spec; + vaddr_t va; + int error; + + if (bp == NULL || pa == 0) { + return -EINVAL; + } + + /* Get the current VAS */ + error = mmu_this_vas(&vas); + if (error < 0) { + printf("bus_space_map: could not read VAS\n"); + return error; + } + + spec.pa = pa; + spec.va = va; + error = vm_map(&vas, &spec, len, PROT_READ | PROT_WRITE); + if (error < 0) { + printf("bus_space_map: could not map base\n"); + return error; + } + + /* Mark uncachable and global */ + pmap_set_cache( + &vas, pa, + MMU_CACHE_UC | + MMU_CACHE_GL + ); + + /* Identity mapped */ + bp->va_base = (void *)pa; + bp->length = len; + bp->type = BUS_PCI_PCI; + return 0; +} diff --git a/src/sys/include/io/pci/bar.h b/src/sys/include/io/pci/bar.h index 6bb4367..14164ef 100644 --- a/src/sys/include/io/pci/bar.h +++ b/src/sys/include/io/pci/bar.h @@ -32,6 +32,7 @@ #include #include +#include #include #include @@ -68,4 +69,17 @@ pci_get_barreg(uint8_t bar) */ ssize_t pci_bar_size(struct pci_device *dev, uint8_t bar); +/* + * Map a BAR into host address space for the current + * process. + * + * @dev: Device of BAR to map + * @bar: BAR number of BAR to map + * @bs_res: Result is written here + * + * Returns zero on success, otherwise a less than + * zero value to indicate failure. + */ +int pci_map_bar(struct pci_device *dev, uint8_t bar, struct bus_space *bs_res); + #endif /* !_PCI_BAR_H_ */ diff --git a/src/sys/include/os/bus.h b/src/sys/include/os/bus.h new file mode 100644 index 0000000..86b1a75 --- /dev/null +++ b/src/sys/include/os/bus.h @@ -0,0 +1,73 @@ +/* + * Copyright (c) 2025 Ian Marco Moffett and L5 engineers + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the project nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef _OS_BUS_H_ +#define _OS_BUS_H_ + +#include + +typedef enum { + BUS_PCI_NONE, + BUS_PCI_PCI, +} bus_type_t; + +/* + * Represents a physical or virtual MMIO address that + * allows tranmission and reception on the bus. + */ +typedef uintptr_t bus_addr_t; + +/* + * Represents a bus space that can be used with certain + * bus interfaces + * + * @va_base: Virtual address base + * @length: Length at buffer + * @type: Type of the space space (see BUS_*) + */ +struct bus_space { + void *va_base; + size_t length; + bus_type_t type; +}; + +/* + * Initialize a bus space descriptor and map a physical + * bus address. + * + * @bp: Bus space descriptor to use + * @pa: Physical bus address to map. + * @len: Length of mapping to use + * + * Returns zero on success, otherwise a less than zero + * value. + */ +int bus_space_map(struct bus_space *bp, bus_addr_t pa, size_t len); + +#endif /* !_OS_BUS_H_ */ -- cgit v1.2.3