From e0f2e9d42981da51f7252f88abfa2122eabf3a04 Mon Sep 17 00:00:00 2001 From: Ian Moffett Date: Wed, 19 Feb 2025 19:30:44 -0500 Subject: kernel/amd64: bus: Add bus resource interface This commit introduces a bus resource abstraction. A bus resource encapsulates bus specific information and semantics. Along with abstracting away bus specific details and providing an overall smoother interface, this additionally provides flexibility, access control and security by keeping track of permissions and allowing things to be turned on or off. Signed-off-by: Ian Moffett --- sys/arch/amd64/amd64/bus_machdep.c | 74 +++++++++++++++++ sys/arch/amd64/pci/pci_resource.c | 159 +++++++++++++++++++++++++++++++++++++ sys/include/arch/amd64/bus.h | 57 +++++++++++++ sys/include/dev/pci/resource.h | 51 ++++++++++++ 4 files changed, 341 insertions(+) create mode 100644 sys/arch/amd64/pci/pci_resource.c create mode 100644 sys/include/dev/pci/resource.h diff --git a/sys/arch/amd64/amd64/bus_machdep.c b/sys/arch/amd64/amd64/bus_machdep.c index d542821..89ef317 100644 --- a/sys/arch/amd64/amd64/bus_machdep.c +++ b/sys/arch/amd64/amd64/bus_machdep.c @@ -34,6 +34,52 @@ #include #include #include +#include +#include +#include + +#define BUS_PCI "PCI" +#define BUS_LPC "LPC" + +/* + * Set bus specific fields + * + * @brp: Bus resource pointer. + * @type: Bus name/signature + * + * XXX: Assumes brp->base has already been set to + * a valid bus address. + */ +static int +bus_set(struct bus_resource *brp, const char *type) +{ + struct bus_op *io = &brp->io; + + switch (*type) { + case 'P': + if (strcmp(type, BUS_PCI) == 0) { + /* + * Bus addresses for 64-bit PCI can theoretically + * span 2^64 bytes (i.e., the full 64-bit address space) + */ + brp->dma_max = (bus_addr_t)-1; + brp->dma_min = 0; + + /* Set hooks */ + io->enable_dma = pcir_enable_dma; + io->disable_dma = pcir_disable_dma; + io->set_sem = pcir_set_sem; + io->clr_sem = pcir_clr_sem; + io->dma_alloc = pcir_dma_alloc; + io->dma_free = pcir_dma_free; + io->dma_in = pcir_dma_in; + io->dma_out = pcir_dma_out; + return 0; + } + } + + return -ENODEV; +} /* * Map a physical device address into the kernel address @@ -78,3 +124,31 @@ bus_map(bus_addr_t addr, size_t size, int flags, void **vap) *vap = (void *)va; return 0; } + +/* + * Associate a specific bus with a 'bus_resource` + * structure. + * + * @name: Signature. + */ +struct bus_resource * +bus_establish(const char *name) +{ + struct bus_resource *brp; + size_t siglen; + + siglen = strlen(name); + if (siglen > RSIG_MAX) { + return NULL; + } + + /* Allocate a new bus resource handle */ + if ((brp = dynalloc(sizeof(*brp))) == NULL) { + return NULL; + } + + memset(brp, 0, sizeof(*brp)); + memcpy(brp->signature, name, siglen); + bus_set(brp, name); + return brp; +} diff --git a/sys/arch/amd64/pci/pci_resource.c b/sys/arch/amd64/pci/pci_resource.c new file mode 100644 index 0000000..5ca597b --- /dev/null +++ b/sys/arch/amd64/pci/pci_resource.c @@ -0,0 +1,159 @@ +/* + * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team. + * 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 Hyra 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 + +// #define DEBUG 1 + +#define pr_trace(fmt, ...) kprintf("pci: " fmt, ##__VA_ARGS__) +#define pr_error(...) pr_trace(__VA_ARGS__) + +#if defined(DEBUG) +#define pr_debug(...) pr_trace(__VA_ARGS__) +#else +#define pr_debug(...) __nothing +#endif + +/* + * Enables bus mastering for a specific PCI device. + * + * @brp: Pointer to bus resource handle. + * @devp: Pointer to `pci_device' structure. + * + * XXX: If the bus resource is MMIO capable, PCI + * memory space access will become set within + * the command/status register + */ +int +pcir_enable_dma(struct bus_resource *brp, void *devp) +{ + struct pci_device *dev = devp; + uint32_t tmp; + + if (brp == NULL || dev == NULL) { + return -EINVAL; + } + + /* + * Make sure that we are allowed to perform DMA. This + * will fail if the bus isn't DMA-capable or if DMA + * is disabled. + */ + if (!ISSET(brp->sem, BUS_DMA)) { + pr_trace("Bus marked non DMA capable, DMA not enabled\n"); + return -EACCES; + } + + tmp = pci_readl(dev, PCIREG_CMDSTATUS); + tmp |= PCI_BUS_MASTERING; + tmp |= ISSET(brp->sem, BUS_MMIO); + pci_writel(dev, PCIREG_CMDSTATUS, tmp); + return 0; +} + +/* + * Disables bus mastering for a specific PCI device. + * + * @brp: Pointer to bus resource handle. + * @devp: Pointer to `pci_device' structure. + * + * XXX: If the bus resource is not MMIO capable, PCI + * memory space access will become unset within + * the command/status register + */ +int +pcir_disable_dma(struct bus_resource *brp, void *devp) +{ + struct pci_device *dev = devp; + uint32_t tmp; + + if (brp == NULL || dev == NULL) { + return -EINVAL; + } + + tmp = pci_readl(dev, PCIREG_CMDSTATUS); + tmp &= ~PCI_BUS_MASTERING; + tmp &= ~ISSET(brp->sem, BUS_MMIO); + pci_writel(dev, PCIREG_CMDSTATUS, tmp); + return 0; +} + +int +pcir_set_sem(struct bus_resource *brp, bus_sem_t sem) +{ + /* + * BUS_PIO and BUS_MMIO are two different things + * and must be mutually exclusive... + */ + if (ISSET(sem, BUS_MMIO) && ISSET(sem, BUS_PIO)) { + pr_debug("Bad semantics (sem=%x)\n", sem); + return -EINVAL; + } + + brp->sem |= sem; + return 0; +} + +int +pcir_clr_sem(struct bus_resource *brp, bus_sem_t sem) +{ + brp->sem &= ~sem; + return 0; +} + +__unused int +pcir_dma_alloc(struct bus_resource *brp, void *res) +{ + return 0; +} + +__unused int +pcir_dma_free(struct bus_resource *brp, void *p) +{ + return 0; +} + +ssize_t +pcir_dma_in(struct bus_resource *brp, void *p) +{ + return 0; +} + +ssize_t +pcir_dma_out(struct bus_resource *brp, void *p) +{ + return 0; +} diff --git a/sys/include/arch/amd64/bus.h b/sys/include/arch/amd64/bus.h index c99d13f..00cb3ba 100644 --- a/sys/include/arch/amd64/bus.h +++ b/sys/include/arch/amd64/bus.h @@ -31,6 +31,10 @@ #define _MACHINE_BUS_H_ #include +#include +#include + +struct bus_resource; /* * Hyra assumes that the bootloader uses PDE[256] for some @@ -40,8 +44,61 @@ */ #define MMIO_OFFSET (VM_HIGHER_HALF + 0x8000000000) +/* Resource signature size max */ +#define RSIG_MAX 16 + +/* + * Basic bus resource semantics + * + * BUS_PIO: If set, this resource uses port I/O + * BUS_MMIO: If set, this resource uses memory-mapped I/O + * BUS_WRITABLE: If unset, this resource is read-only + * BUS_DMA: If set, this resource is DMA-capable + */ +#define BUS_PIO BIT(0) +#define BUS_MMIO BIT(1) +#define BUS_WRITABLE BIT(2) +#define BUS_DMA BIT(3) + +/* + * Common bus types. + * + * bus_addr_t: Physical MMIO address + * bus_sem_t: Resource semantics + */ typedef uint64_t bus_addr_t; +typedef uint64_t bus_sem_t; + +struct bus_op { + /* Enable/disable DMA */ + int(*enable_dma)(struct bus_resource *brp, void *arg); + int(*disable_dma)(struct bus_resource *brp, void *arg); + + /* Set/unset flags */ + int(*set_sem)(struct bus_resource *brp, bus_sem_t sem); + int(*clr_sem)(struct bus_resource *brp, bus_sem_t sem); + + /* DMA buffer related operations */ + int(*dma_alloc)(struct bus_resource *brp, void *res); + int(*dma_free)(struct bus_resource *brp, void *p); + + /* DMA transfer related operations */ + ssize_t(*dma_in)(struct bus_resource *brp, void *p); + ssize_t(*dma_out)(struct bus_resource *brp, void *p); +}; + +struct bus_resource { + char signature[RSIG_MAX]; /* e.g., "PCI\0", "ISA\0", "LPC\0", etc */ + off_t align; /* Alignment required (0: none) */ + bus_addr_t dma_max; /* Maximum address possible for DMA */ + bus_addr_t dma_min; /* Minimum address possible for DMA */ + bus_addr_t base; /* Resource base [physical] address */ + bus_sem_t sem; /* Resource semantics */ + struct bus_op io; /* I/O operations */ + struct spinlock lock; /* Protects this structure */ +}; int bus_map(bus_addr_t addr, size_t size, int flags, void **vap); +struct bus_resource *bus_establish(const char *name); #endif /* !_MACHINE_BUS_H_ */ diff --git a/sys/include/dev/pci/resource.h b/sys/include/dev/pci/resource.h new file mode 100644 index 0000000..b469e8f --- /dev/null +++ b/sys/include/dev/pci/resource.h @@ -0,0 +1,51 @@ +/* + * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team. + * 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 Hyra 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 _PCI_RESOURCE_H_ +#define _PCI_RESOURCE_H_ + +#include + +/* Enable/disable DMA (bus mastering in this case) */ +int pcir_enable_dma(struct bus_resource *brp, void *devp); +int pcir_disable_dma(struct bus_resource *brp, void *devp); + +/* Set/unset bus resource semantics */ +int pcir_set_sem(struct bus_resource *brp, bus_sem_t sem); +int pcir_clr_sem(struct bus_resource *brp, bus_sem_t sem); + +/* DMA buffer helpers (XXX: unused for now) */ +int pcir_dma_alloc(struct bus_resource *brp, void *res); +int pcir_dma_free(struct bus_resource *brp, void *p); + +/* DMA transaction helpers (XXX: unused for now) */ +ssize_t pcir_dma_in(struct bus_resource *brp, void *p); +ssize_t pcir_dma_out(struct bus_resource *brp, void *p); + +#endif /* !_PCI_RESOURCE_H_ */ -- cgit v1.2.3