Files
libsst/libsst-os/SST_SysMem_POSIX.c
2026-04-03 00:22:39 -05:00

148 lines
3.5 KiB
C

/*
SST_SysMem_POSIX.c
Author: Patrick Baggett <ptb1@762studios.com>
Created: 12/23/2011
Purpose:
libsst-os system memory allocation functions for POSIX platforms
License:
This program is free software. It comes without any warranty, to
the extent permitted by applicable law. You can redistribute it
and/or modify it under the terms of the Do What The Fuck You Want
To Public License, Version 2, as published by Sam Hocevar. See
http://sam.zoy.org/wtfpl/COPYING for more details.
*/
#include "POSIXPrivate.h"
#include <SST/SST_SysMem.h>
#include <SST/SST_Assert.h>
#ifdef __APPLE__
#include<sys/sysctl.h>
#endif
static uint32_t cached_pagesize;
void __libsst_init_pagesize()
{
uint32_t pgsz = (uint32_t)-1;
#ifdef _SC_PAGESIZE
pgsz = (uint32_t)sysconf(_SC_PAGESIZE);
#elif defined(_SC_PAGE_SIZE)
if(pgsz == (uint32_t)-1)
pgsz = (uint32_t)sysconf(_SC_PAGE_SIZE);
#endif
cached_pagesize = pgsz;
}
/******************************************************************************/
uint64_t SST_OS_GetMemorySize()
{
#ifdef __APPLE__
int param[2] = { CTL_HW, HW_MEMSIZE };
uint64_t mem;
size_t size = sizeof(mem);
sysctl(param, 2, &mem, &size, NULL, 0);
return mem;
#else
uint32_t pagesize = SST_OS_GetPageSize();
uint32_t pages;
pages = sysconf(_SC_PHYS_PAGES);
if(pages == (uint32_t)-1)
return 0;
return (uint64_t)pages*(uint64_t)pagesize;
#endif
}
/******************************************************************************/
uint32_t SST_OS_GetPageSize()
{
return cached_pagesize;
}
/******************************************************************************/
void* SST_OS_AllocPages(size_t allocBytes)
{
void* addr;
#if defined(MAP_ANON) && !defined(MAP_ANONYMOUS)
int flags = MAP_SHARED | MAP_ANON;
#else
int flags = MAP_SHARED | MAP_ANONYMOUS;
#endif
SST_OS_DebugAssert(allocBytes > 0, "Allocating 0 bytes is not allowed");
#ifdef MAP_UNINITIALIZED /* Linux only, 2.6.33+, don't zero pages */
flags |= MAP_UNINITIALIZED;
#endif
addr = mmap(NULL, allocBytes, PROT_READ | PROT_WRITE, flags, -1, 0);
if(addr == MAP_FAILED)
return NULL;
return addr;
}
/******************************************************************************/
int SST_OS_FreePages(void* pageBase, size_t nrBytes)
{
uintptr_t addr;
uint32_t pageSize;
SST_OS_DebugAssert(pageBase != NULL, "Base address may not be NULL");
SST_OS_DebugAssert(nrBytes > 0, "The number of bytes to free may not be zero");
addr = (uintptr_t)pageBase;
pageSize = SST_OS_GetPageSize();
/* Check if address is aligned to page boundary */
if(addr & (pageSize-1))
return -1;
/* Free the pages */
return (munmap(pageBase, nrBytes) == 0);
}
/******************************************************************************/
int SST_OS_ProtectPages(void* pageBase, size_t nrBytes, int protectFlags)
{
uintptr_t addr;
uint32_t pageSize;
int newFlags = 0;
SST_OS_DebugAssert(pageBase != NULL, "Base address may not be NULL");
SST_OS_DebugAssert(nrBytes > 0, "The number of bytes to free may not be zero");
SST_OS_DebugAssert((protectFlags & (~(SST_PROTECT_READ|SST_PROTECT_WRITE|SST_PROTECT_EXEC))) == 0, "Protect flags contain invalid bits");
addr = (uintptr_t)pageBase;
pageSize = SST_OS_GetPageSize();
/* Check if address is aligned to page boundary */
if(addr & (pageSize-1))
return -1;
if(protectFlags & SST_PROTECT_READ)
newFlags |= PROT_READ;
if(protectFlags & SST_PROTECT_WRITE)
newFlags |= PROT_WRITE;
if(protectFlags & SST_PROTECT_EXEC)
newFlags |= PROT_EXEC;
return (mprotect(pageBase, nrBytes, newFlags) == 0);
}