freebsd-skq/sys/kern/subr_devmap.c
Kristof Provost 1d95443818 Generalize ARM specific comments in devmap
The comments in devmap are very ARM specific, this generalizes them for other
architectures.

Submitted by:	Nicholas O'Brien <nickisobrien_gmail.com>
Reviewed by:	manu, philip
Sponsored by:	Axiado
Differential Revision:	https://reviews.freebsd.org/D22035
2019-10-15 23:21:52 +00:00

352 lines
9.7 KiB
C

/*-
* Copyright (c) 2013 Ian Lepore <ian@freebsd.org>
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/* Routines for mapping device memory. */
#include "opt_ddb.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/devmap.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
#include <vm/pmap.h>
#include <machine/vmparam.h>
static const struct devmap_entry *devmap_table;
static boolean_t devmap_bootstrap_done = false;
/*
* The allocated-kva (akva) devmap table and metadata. Platforms can call
* devmap_add_entry() to add static device mappings to this table using
* automatically allocated virtual addresses carved out of the top of kva space.
* Allocation begins immediately below the max kernel virtual address.
*/
#define AKVA_DEVMAP_MAX_ENTRIES 32
static struct devmap_entry akva_devmap_entries[AKVA_DEVMAP_MAX_ENTRIES];
static u_int akva_devmap_idx;
static vm_offset_t akva_devmap_vaddr = DEVMAP_MAX_VADDR;
#if defined(__aarch64__) || defined(__riscv)
extern int early_boot;
#endif
/*
* Print the contents of the static mapping table using the provided printf-like
* output function (which will be either printf or db_printf).
*/
static void
devmap_dump_table(int (*prfunc)(const char *, ...))
{
const struct devmap_entry *pd;
if (devmap_table == NULL || devmap_table[0].pd_size == 0) {
prfunc("No static device mappings.\n");
return;
}
prfunc("Static device mappings:\n");
for (pd = devmap_table; pd->pd_size != 0; ++pd) {
prfunc(" 0x%08x - 0x%08x mapped at VA 0x%08x\n",
pd->pd_pa, pd->pd_pa + pd->pd_size - 1, pd->pd_va);
}
}
/*
* Print the contents of the static mapping table. Used for bootverbose.
*/
void
devmap_print_table()
{
devmap_dump_table(printf);
}
/*
* Return the "last" kva address used by the registered devmap table. It's
* actually the lowest address used by the static mappings, i.e., the address of
* the first unusable byte of KVA.
*/
vm_offset_t
devmap_lastaddr()
{
const struct devmap_entry *pd;
vm_offset_t lowaddr;
if (akva_devmap_idx > 0)
return (akva_devmap_vaddr);
lowaddr = DEVMAP_MAX_VADDR;
for (pd = devmap_table; pd != NULL && pd->pd_size != 0; ++pd) {
if (lowaddr > pd->pd_va)
lowaddr = pd->pd_va;
}
return (lowaddr);
}
/*
* Add an entry to the internal "akva" static devmap table using the given
* physical address and size and a virtual address allocated from the top of
* kva. This automatically registers the akva table on the first call, so all a
* platform has to do is call this routine to install as many mappings as it
* needs and when the platform-specific init function calls devmap_bootstrap()
* it will pick up all the entries in the akva table automatically.
*/
void
devmap_add_entry(vm_paddr_t pa, vm_size_t sz)
{
struct devmap_entry *m;
if (devmap_bootstrap_done)
panic("devmap_add_entry() after devmap_bootstrap()");
if (akva_devmap_idx == (AKVA_DEVMAP_MAX_ENTRIES - 1))
panic("AKVA_DEVMAP_MAX_ENTRIES is too small");
if (akva_devmap_idx == 0)
devmap_register_table(akva_devmap_entries);
/* Allocate virtual address space from the top of kva downwards. */
#ifdef __arm__
/*
* If the range being mapped is aligned and sized to 1MB boundaries then
* also align the virtual address to the next-lower 1MB boundary so that
* we end with a nice efficient section mapping.
*/
if ((pa & 0x000fffff) == 0 && (sz & 0x000fffff) == 0) {
akva_devmap_vaddr = trunc_1mpage(akva_devmap_vaddr - sz);
} else
#endif
{
akva_devmap_vaddr = trunc_page(akva_devmap_vaddr - sz);
}
m = &akva_devmap_entries[akva_devmap_idx++];
m->pd_va = akva_devmap_vaddr;
m->pd_pa = pa;
m->pd_size = sz;
}
/*
* Register the given table as the one to use in devmap_bootstrap().
*/
void
devmap_register_table(const struct devmap_entry *table)
{
devmap_table = table;
}
/*
* Map all of the static regions in the devmap table, and remember the devmap
* table so the mapdev, ptov, and vtop functions can do lookups later.
*
* If a non-NULL table pointer is given it is used unconditionally, otherwise
* the previously-registered table is used. This smooths transition from legacy
* code that fills in a local table then calls this function passing that table,
* and newer code that uses devmap_register_table() in platform-specific
* code, then lets the common platform-specific init function call this function
* with a NULL pointer.
*/
void
devmap_bootstrap(vm_offset_t l1pt, const struct devmap_entry *table)
{
const struct devmap_entry *pd;
devmap_bootstrap_done = true;
/*
* If given a table pointer, use it. Otherwise, if a table was
* previously registered, use it. Otherwise, no work to do.
*/
if (table != NULL)
devmap_table = table;
else if (devmap_table == NULL)
return;
for (pd = devmap_table; pd->pd_size != 0; ++pd) {
#if defined(__arm__)
#if __ARM_ARCH >= 6
pmap_preboot_map_attr(pd->pd_pa, pd->pd_va, pd->pd_size,
VM_PROT_READ | VM_PROT_WRITE, VM_MEMATTR_DEVICE);
#else
pmap_map_chunk(l1pt, pd->pd_va, pd->pd_pa, pd->pd_size,
VM_PROT_READ | VM_PROT_WRITE, PTE_DEVICE);
#endif
#elif defined(__aarch64__) || defined(__riscv)
pmap_kenter_device(pd->pd_va, pd->pd_size, pd->pd_pa);
#endif
}
}
/*
* Look up the given physical address in the static mapping data and return the
* corresponding virtual address, or NULL if not found.
*/
void *
devmap_ptov(vm_paddr_t pa, vm_size_t size)
{
const struct devmap_entry *pd;
if (devmap_table == NULL)
return (NULL);
for (pd = devmap_table; pd->pd_size != 0; ++pd) {
if (pa >= pd->pd_pa && pa + size <= pd->pd_pa + pd->pd_size)
return ((void *)(pd->pd_va + (pa - pd->pd_pa)));
}
return (NULL);
}
/*
* Look up the given virtual address in the static mapping data and return the
* corresponding physical address, or DEVMAP_PADDR_NOTFOUND if not found.
*/
vm_paddr_t
devmap_vtop(void * vpva, vm_size_t size)
{
const struct devmap_entry *pd;
vm_offset_t va;
if (devmap_table == NULL)
return (DEVMAP_PADDR_NOTFOUND);
va = (vm_offset_t)vpva;
for (pd = devmap_table; pd->pd_size != 0; ++pd) {
if (va >= pd->pd_va && va + size <= pd->pd_va + pd->pd_size)
return ((vm_paddr_t)(pd->pd_pa + (va - pd->pd_va)));
}
return (DEVMAP_PADDR_NOTFOUND);
}
/*
* Map a set of physical memory pages into the kernel virtual address space.
* Return a pointer to where it is mapped.
*
* This uses a pre-established static mapping if one exists for the requested
* range, otherwise it allocates kva space and maps the physical pages into it.
*
* This routine is intended to be used for mapping device memory, NOT real
* memory; the mapping type is inherently VM_MEMATTR_DEVICE in
* pmap_kenter_device().
*/
void *
pmap_mapdev(vm_offset_t pa, vm_size_t size)
{
vm_offset_t va, offset;
void * rva;
/* First look in the static mapping table. */
if ((rva = devmap_ptov(pa, size)) != NULL)
return (rva);
offset = pa & PAGE_MASK;
pa = trunc_page(pa);
size = round_page(size + offset);
#if defined(__aarch64__) || defined(__riscv)
if (early_boot) {
akva_devmap_vaddr = trunc_page(akva_devmap_vaddr - size);
va = akva_devmap_vaddr;
KASSERT(va >= VM_MAX_KERNEL_ADDRESS - L2_SIZE,
("Too many early devmap mappings"));
} else
#endif
va = kva_alloc(size);
if (!va)
panic("pmap_mapdev: Couldn't alloc kernel virtual memory");
pmap_kenter_device(va, size, pa);
return ((void *)(va + offset));
}
#if defined(__aarch64__)
void *
pmap_mapdev_attr(vm_offset_t pa, vm_size_t size, vm_memattr_t ma)
{
vm_offset_t va, offset;
void * rva;
/* First look in the static mapping table. */
if ((rva = devmap_ptov(pa, size)) != NULL)
return (rva);
offset = pa & PAGE_MASK;
pa = trunc_page(pa);
size = round_page(size + offset);
if (early_boot) {
akva_devmap_vaddr = trunc_page(akva_devmap_vaddr - size);
va = akva_devmap_vaddr;
KASSERT(va >= (VM_MAX_KERNEL_ADDRESS - (PMAP_MAPDEV_EARLY_SIZE)),
("Too many early devmap mappings 2"));
} else
va = kva_alloc(size);
if (!va)
panic("pmap_mapdev: Couldn't alloc kernel virtual memory");
pmap_kenter(va, size, pa, ma);
return ((void *)(va + offset));
}
#endif
/*
* Unmap device memory and free the kva space.
*/
void
pmap_unmapdev(vm_offset_t va, vm_size_t size)
{
vm_offset_t offset;
/* Nothing to do if we find the mapping in the static table. */
if (devmap_vtop((void*)va, size) != DEVMAP_PADDR_NOTFOUND)
return;
offset = va & PAGE_MASK;
va = trunc_page(va);
size = round_page(size + offset);
pmap_kremove_device(va, size);
kva_free(va, size);
}
#ifdef DDB
#include <ddb/ddb.h>
DB_SHOW_COMMAND(devmap, db_show_devmap)
{
devmap_dump_table(db_printf);
}
#endif /* DDB */