physmap: rename to hwaccess_physmap, create own header

Line up physmap with the other hwaccess related code.

Change-Id: Ieba6f4e94cfc3e668fcb8b3c978de5908aed2592
Signed-off-by: Thomas Heijligen <thomas.heijligen@secunet.com>
Original-Reviewed-on: https://review.coreboot.org/c/flashrom/+/60113
Original-Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/72267
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/hwaccess_physmap.c b/hwaccess_physmap.c
new file mode 100644
index 0000000..42c3c3e
--- /dev/null
+++ b/hwaccess_physmap.c
@@ -0,0 +1,363 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright (C) 2009 Peter Stuge <peter@stuge.se>
+ * Copyright (C) 2009 coresystems GmbH
+ * Copyright (C) 2010 Carl-Daniel Hailfinger
+ * Copyright (C) 2010 Rudolf Marek <r.marek@assembler.cz>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <unistd.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include "flash.h"
+#include "hwaccess_physmap.h"
+
+#if !defined(__DJGPP__) && !defined(__LIBPAYLOAD__)
+/* No file access needed/possible to get mmap access permissions or access MSR. */
+#include <sys/stat.h>
+#include <fcntl.h>
+#endif
+
+#ifdef __DJGPP__
+#include <dpmi.h>
+#include <malloc.h>
+#include <sys/nearptr.h>
+
+#define ONE_MEGABYTE (1024 * 1024)
+#define MEM_DEV "dpmi"
+
+static void *realmem_map_aligned;
+
+static void *map_first_meg(uintptr_t phys_addr, size_t len)
+{
+	void *realmem_map;
+	size_t pagesize;
+
+	if (realmem_map_aligned)
+		return realmem_map_aligned + phys_addr;
+
+	/* valloc() from DJGPP 2.05 does not work properly */
+	pagesize = getpagesize();
+
+	realmem_map = malloc(ONE_MEGABYTE + pagesize);
+
+	if (!realmem_map)
+		return ERROR_PTR;
+
+	realmem_map_aligned = (void *)(((size_t) realmem_map +
+		(pagesize - 1)) & ~(pagesize - 1));
+
+	if (__djgpp_map_physical_memory(realmem_map_aligned, ONE_MEGABYTE, 0)) {
+		free(realmem_map);
+		realmem_map_aligned = NULL;
+		return ERROR_PTR;
+	}
+
+	return realmem_map_aligned + phys_addr;
+}
+
+static void *sys_physmap(uintptr_t phys_addr, size_t len)
+{
+	int ret;
+	__dpmi_meminfo mi;
+
+	/* Enable 4GB limit on DS descriptor. */
+	if (!__djgpp_nearptr_enable())
+		return ERROR_PTR;
+
+	if ((phys_addr + len - 1) < ONE_MEGABYTE) {
+		/* We need to use another method to map first 1MB. */
+		return map_first_meg(phys_addr, len);
+	}
+
+	mi.address = phys_addr;
+	mi.size = len;
+	ret = __dpmi_physical_address_mapping(&mi);
+
+	if (ret != 0)
+		return ERROR_PTR;
+
+	return (void *) mi.address + __djgpp_conventional_base;
+}
+
+#define sys_physmap_rw_uncached	sys_physmap
+#define sys_physmap_ro_cached	sys_physmap
+
+static void sys_physunmap_unaligned(void *virt_addr, size_t len)
+{
+	__dpmi_meminfo mi;
+
+	/* There is no known way to unmap the first 1 MB. The DPMI server will
+	 * do this for us on exit.
+	 */
+	if ((virt_addr >= realmem_map_aligned) &&
+	    ((virt_addr + len) <= (realmem_map_aligned + ONE_MEGABYTE))) {
+		return;
+	}
+
+	mi.address = (unsigned long) virt_addr;
+	__dpmi_free_physical_address_mapping(&mi);
+}
+
+#elif defined(__LIBPAYLOAD__)
+#include <arch/virtual.h>
+
+#define MEM_DEV ""
+
+void *sys_physmap(uintptr_t phys_addr, size_t len)
+{
+	return (void *)phys_to_virt(phys_addr);
+}
+
+#define sys_physmap_rw_uncached	sys_physmap
+#define sys_physmap_ro_cached	sys_physmap
+
+static void sys_physunmap_unaligned(void *virt_addr, size_t len)
+{
+}
+#elif defined(__MACH__) && defined(__APPLE__)
+
+#define MEM_DEV "DirectHW"
+
+static void *sys_physmap(uintptr_t phys_addr, size_t len)
+{
+	/* The short form of ?: is a GNU extension.
+	 * FIXME: map_physical returns NULL both for errors and for success
+	 * if the region is mapped at virtual address zero. If in doubt, report
+	 * an error until a better interface exists.
+	 */
+	return map_physical(phys_addr, len) ? : ERROR_PTR;
+}
+
+/* The OS X driver does not differentiate between mapping types. */
+#define sys_physmap_rw_uncached	sys_physmap
+#define sys_physmap_ro_cached	sys_physmap
+
+static void sys_physunmap_unaligned(void *virt_addr, size_t len)
+{
+	unmap_physical(virt_addr, len);
+}
+
+#else
+#include <sys/mman.h>
+
+#if defined (__sun) && (defined(__i386) || defined(__amd64))
+#  define MEM_DEV "/dev/xsvc"
+#else
+#  define MEM_DEV "/dev/mem"
+#endif
+
+static int fd_mem = -1;
+static int fd_mem_cached = -1;
+
+/* For MMIO access. Must be uncached, doesn't make sense to restrict to ro. */
+static void *sys_physmap_rw_uncached(uintptr_t phys_addr, size_t len)
+{
+	void *virt_addr;
+
+	if (-1 == fd_mem) {
+		/* Open the memory device UNCACHED. Important for MMIO. */
+		if (-1 == (fd_mem = open(MEM_DEV, O_RDWR | O_SYNC))) {
+			msg_perr("Critical error: open(" MEM_DEV "): %s\n", strerror(errno));
+			return ERROR_PTR;
+		}
+	}
+
+	virt_addr = mmap(NULL, len, PROT_WRITE | PROT_READ, MAP_SHARED, fd_mem, (off_t)phys_addr);
+	return MAP_FAILED == virt_addr ? ERROR_PTR : virt_addr;
+}
+
+/* For reading DMI/coreboot/whatever tables. We should never write, and we
+ * do not care about caching.
+ */
+static void *sys_physmap_ro_cached(uintptr_t phys_addr, size_t len)
+{
+	void *virt_addr;
+
+	if (-1 == fd_mem_cached) {
+		/* Open the memory device CACHED. */
+		if (-1 == (fd_mem_cached = open(MEM_DEV, O_RDWR))) {
+			msg_perr("Critical error: open(" MEM_DEV "): %s\n", strerror(errno));
+			return ERROR_PTR;
+		}
+	}
+
+	virt_addr = mmap(NULL, len, PROT_READ, MAP_SHARED, fd_mem_cached, (off_t)phys_addr);
+	return MAP_FAILED == virt_addr ? ERROR_PTR : virt_addr;
+}
+
+static void sys_physunmap_unaligned(void *virt_addr, size_t len)
+{
+	munmap(virt_addr, len);
+}
+#endif
+
+#define PHYSM_RW	0
+#define PHYSM_RO	1
+#define PHYSM_NOCLEANUP	0
+#define PHYSM_CLEANUP	1
+#define PHYSM_EXACT	0
+#define PHYSM_ROUND	1
+
+/* Round start to nearest page boundary below and set len so that the resulting address range ends at the lowest
+ * possible page boundary where the original address range is still entirely contained. It returns the
+ * difference between the rounded start address and the original start address. */
+static uintptr_t round_to_page_boundaries(uintptr_t *start, size_t *len)
+{
+	uintptr_t page_size = getpagesize();
+	uintptr_t page_mask = ~(page_size-1);
+	uintptr_t end = *start + *len;
+	uintptr_t old_start = *start;
+	msg_gspew("page_size=%" PRIxPTR "\n", page_size);
+	msg_gspew("pre-rounding:  start=0x%0*" PRIxPTR ", len=0x%zx, end=0x%0*" PRIxPTR "\n",
+		  PRIxPTR_WIDTH, *start, *len, PRIxPTR_WIDTH, end);
+	*start = *start & page_mask;
+	end = (end + page_size - 1) & page_mask;
+	*len = end - *start;
+	msg_gspew("post-rounding: start=0x%0*" PRIxPTR ", len=0x%zx, end=0x%0*" PRIxPTR "\n",
+		  PRIxPTR_WIDTH, *start, *len, PRIxPTR_WIDTH, *start + *len);
+	return old_start - *start;
+}
+
+struct undo_physmap_data {
+	void *virt_addr;
+	size_t len;
+};
+
+static int undo_physmap(void *data)
+{
+	if (data == NULL) {
+		msg_perr("%s: tried to physunmap without valid data!\n", __func__);
+		return 1;
+	}
+	struct undo_physmap_data *d = data;
+	physunmap_unaligned(d->virt_addr, d->len);
+	free(data);
+	return 0;
+}
+
+static void *physmap_common(const char *descr, uintptr_t phys_addr, size_t len, bool readonly, bool autocleanup,
+			    bool round)
+{
+	void *virt_addr;
+	uintptr_t offset = 0;
+
+	if (len == 0) {
+		msg_pspew("Not mapping %s, zero size at 0x%0*" PRIxPTR ".\n", descr, PRIxPTR_WIDTH, phys_addr);
+		return ERROR_PTR;
+	}
+
+	if (round)
+		offset = round_to_page_boundaries(&phys_addr, &len);
+
+	if (readonly)
+		virt_addr = sys_physmap_ro_cached(phys_addr, len);
+	else
+		virt_addr = sys_physmap_rw_uncached(phys_addr, len);
+
+	if (ERROR_PTR == virt_addr) {
+		if (NULL == descr)
+			descr = "memory";
+		msg_perr("Error accessing %s, 0x%zx bytes at 0x%0*" PRIxPTR "\n",
+			 descr, len, PRIxPTR_WIDTH, phys_addr);
+		msg_perr(MEM_DEV " mmap failed: %s\n", strerror(errno));
+#ifdef __linux__
+		if (EINVAL == errno) {
+			msg_perr("In Linux this error can be caused by the CONFIG_NONPROMISC_DEVMEM (<2.6.27),\n");
+			msg_perr("CONFIG_STRICT_DEVMEM (>=2.6.27) and CONFIG_X86_PAT kernel options.\n");
+			msg_perr("Please check if either is enabled in your kernel before reporting a failure.\n");
+			msg_perr("You can override CONFIG_X86_PAT at boot with the nopat kernel parameter but\n");
+			msg_perr("disabling the other option unfortunately requires a kernel recompile. Sorry!\n");
+		}
+#elif defined (__OpenBSD__)
+		msg_perr("Please set securelevel=-1 in /etc/rc.securelevel "
+			 "and reboot, or reboot into\n"
+			 "single user mode.\n");
+#endif
+		return ERROR_PTR;
+	}
+
+	if (autocleanup) {
+		struct undo_physmap_data *d = malloc(sizeof(*d));
+		if (d == NULL) {
+			msg_perr("%s: Out of memory!\n", __func__);
+			physunmap_unaligned(virt_addr, len);
+			return ERROR_PTR;
+		}
+
+		d->virt_addr = virt_addr;
+		d->len = len;
+		if (register_shutdown(undo_physmap, d) != 0) {
+			msg_perr("%s: Could not register shutdown function!\n", __func__);
+			physunmap_unaligned(virt_addr, len);
+			return ERROR_PTR;
+		}
+	}
+
+	return virt_addr + offset;
+}
+
+void physunmap_unaligned(void *virt_addr, size_t len)
+{
+	/* No need to check for zero size, such mappings would have yielded ERROR_PTR. */
+	if (virt_addr == ERROR_PTR) {
+		msg_perr("Trying to unmap a nonexisting mapping!\n"
+			 "Please report a bug at flashrom-stable@flashrom.org\n");
+		return;
+	}
+
+	sys_physunmap_unaligned(virt_addr, len);
+}
+
+void physunmap(void *virt_addr, size_t len)
+{
+	uintptr_t tmp;
+
+	/* No need to check for zero size, such mappings would have yielded ERROR_PTR. */
+	if (virt_addr == ERROR_PTR) {
+		msg_perr("Trying to unmap a nonexisting mapping!\n"
+			 "Please report a bug at flashrom-stable@flashrom.org\n");
+		return;
+	}
+	tmp = (uintptr_t)virt_addr;
+	/* We assume that the virtual address of a page-aligned physical address is page-aligned as well. By
+	 * extension, rounding a virtual unaligned address as returned by physmap should yield the same offset
+	 * between rounded and original virtual address as between rounded and original physical address.
+	 */
+	round_to_page_boundaries(&tmp, &len);
+	virt_addr = (void *)tmp;
+	physunmap_unaligned(virt_addr, len);
+}
+
+void *physmap(const char *descr, uintptr_t phys_addr, size_t len)
+{
+	return physmap_common(descr, phys_addr, len, PHYSM_RW, PHYSM_NOCLEANUP, PHYSM_ROUND);
+}
+
+void *rphysmap(const char *descr, uintptr_t phys_addr, size_t len)
+{
+	return physmap_common(descr, phys_addr, len, PHYSM_RW, PHYSM_CLEANUP, PHYSM_ROUND);
+}
+
+void *physmap_ro(const char *descr, uintptr_t phys_addr, size_t len)
+{
+	return physmap_common(descr, phys_addr, len, PHYSM_RO, PHYSM_NOCLEANUP, PHYSM_ROUND);
+}
+
+void *physmap_ro_unaligned(const char *descr, uintptr_t phys_addr, size_t len)
+{
+	return physmap_common(descr, phys_addr, len, PHYSM_RO, PHYSM_NOCLEANUP, PHYSM_EXACT);
+}