GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-07-23 07:12:09 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

xen/balloon: Share common memory reservation routines

Browse source 
Memory {increase|decrease}_reservation and VA mappings update/reset
code used in balloon driver can be made common, so other drivers can
also re-use the same functionality without open-coding.
Create a dedicated file for the shared code and export corresponding
symbols for other kernel modules.

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
This commit is contained in:
Oleksandr Andrushchenko 2018-07-20 12:01:44 +03:00 • committed by Boris Ostrovsky
parent 8c3799ee25
commit ae4c51a50c
4 changed files with 184 additions and 69 deletions
Download patch file Download diff file Expand all files Collapse all files

118
drivers/xen/mem-reservation.c Normal file
View file

@ -0,0 +1,118 @@
// SPDX-License-Identifier: GPL-2.0
/******************************************************************************
* Xen memory reservation utilities.
*
* Copyright (c) 2003, B Dragovic
* Copyright (c) 2003-2004, M Williamson, K Fraser
* Copyright (c) 2005 Dan M. Smith, IBM Corporation
* Copyright (c) 2010 Daniel Kiper
* Copyright (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.
*/
#include <asm/xen/hypercall.h>
#include <xen/interface/memory.h>
#include <xen/mem-reservation.h>
/*
* Use one extent per PAGE_SIZE to avoid to break down the page into
* multiple frame.
*/
#define EXTENT_ORDER (fls(XEN_PFN_PER_PAGE) - 1)
#ifdef CONFIG_XEN_HAVE_PVMMU
void __xenmem_reservation_va_mapping_update(unsigned long count,
struct page **pages,
xen_pfn_t *frames)
{
int i;
for (i = 0; i < count; i++) {
struct page *page = pages[i];
unsigned long pfn = page_to_pfn(page);
BUG_ON(!page);
/*
* We don't support PV MMU when Linux and Xen is using
* different page granularity.
*/
BUILD_BUG_ON(XEN_PAGE_SIZE != PAGE_SIZE);
set_phys_to_machine(pfn, frames[i]);
/* Link back into the page tables if not highmem. */
if (!PageHighMem(page)) {
int ret;
ret = HYPERVISOR_update_va_mapping(
(unsigned long)__va(pfn << PAGE_SHIFT),
mfn_pte(frames[i], PAGE_KERNEL),
0);
BUG_ON(ret);
}
}
}
EXPORT_SYMBOL_GPL(__xenmem_reservation_va_mapping_update);
void __xenmem_reservation_va_mapping_reset(unsigned long count,
struct page **pages)
{
int i;
for (i = 0; i < count; i++) {
struct page *page = pages[i];
unsigned long pfn = page_to_pfn(page);
/*
* We don't support PV MMU when Linux and Xen are using
* different page granularity.
*/
BUILD_BUG_ON(XEN_PAGE_SIZE != PAGE_SIZE);
if (!PageHighMem(page)) {
int ret;
ret = HYPERVISOR_update_va_mapping(
(unsigned long)__va(pfn << PAGE_SHIFT),
__pte_ma(0), 0);
BUG_ON(ret);
}
__set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
}
}
EXPORT_SYMBOL_GPL(__xenmem_reservation_va_mapping_reset);
#endif /* CONFIG_XEN_HAVE_PVMMU */
/* @frames is an array of PFNs */
int xenmem_reservation_increase(int count, xen_pfn_t *frames)
{
struct xen_memory_reservation reservation = {
.address_bits = 0,
.extent_order = EXTENT_ORDER,
.domid = DOMID_SELF
};
/* XENMEM_populate_physmap requires a PFN based on Xen granularity. */
set_xen_guest_handle(reservation.extent_start, frames);
reservation.nr_extents = count;
return HYPERVISOR_memory_op(XENMEM_populate_physmap, &reservation);
}
EXPORT_SYMBOL_GPL(xenmem_reservation_increase);
/* @frames is an array of GFNs */
int xenmem_reservation_decrease(int count, xen_pfn_t *frames)
{
struct xen_memory_reservation reservation = {
.address_bits = 0,
.extent_order = EXTENT_ORDER,
.domid = DOMID_SELF
};
/* XENMEM_decrease_reservation requires a GFN */
set_xen_guest_handle(reservation.extent_start, frames);
reservation.nr_extents = count;
return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);
}
EXPORT_SYMBOL_GPL(xenmem_reservation_decrease);