mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
396 lines
11 KiB
396 lines
11 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* adi_64.c: support for ADI (Application Data Integrity) feature on |
|
* sparc m7 and newer processors. This feature is also known as |
|
* SSM (Silicon Secured Memory). |
|
* |
|
* Copyright (C) 2016 Oracle and/or its affiliates. All rights reserved. |
|
* Author: Khalid Aziz ([email protected]) |
|
*/ |
|
#include <linux/init.h> |
|
#include <linux/slab.h> |
|
#include <linux/mm_types.h> |
|
#include <asm/mdesc.h> |
|
#include <asm/adi_64.h> |
|
#include <asm/mmu_64.h> |
|
#include <asm/pgtable_64.h> |
|
|
|
/* Each page of storage for ADI tags can accommodate tags for 128 |
|
* pages. When ADI enabled pages are being swapped out, it would be |
|
* prudent to allocate at least enough tag storage space to accommodate |
|
* SWAPFILE_CLUSTER number of pages. Allocate enough tag storage to |
|
* store tags for four SWAPFILE_CLUSTER pages to reduce need for |
|
* further allocations for same vma. |
|
*/ |
|
#define TAG_STORAGE_PAGES 8 |
|
|
|
struct adi_config adi_state; |
|
EXPORT_SYMBOL(adi_state); |
|
|
|
/* mdesc_adi_init() : Parse machine description provided by the |
|
* hypervisor to detect ADI capabilities |
|
* |
|
* Hypervisor reports ADI capabilities of platform in "hwcap-list" property |
|
* for "cpu" node. If the platform supports ADI, "hwcap-list" property |
|
* contains the keyword "adp". If the platform supports ADI, "platform" |
|
* node will contain "adp-blksz", "adp-nbits" and "ue-on-adp" properties |
|
* to describe the ADI capabilities. |
|
*/ |
|
void __init mdesc_adi_init(void) |
|
{ |
|
struct mdesc_handle *hp = mdesc_grab(); |
|
const char *prop; |
|
u64 pn, *val; |
|
int len; |
|
|
|
if (!hp) |
|
goto adi_not_found; |
|
|
|
pn = mdesc_node_by_name(hp, MDESC_NODE_NULL, "cpu"); |
|
if (pn == MDESC_NODE_NULL) |
|
goto adi_not_found; |
|
|
|
prop = mdesc_get_property(hp, pn, "hwcap-list", &len); |
|
if (!prop) |
|
goto adi_not_found; |
|
|
|
/* |
|
* Look for "adp" keyword in hwcap-list which would indicate |
|
* ADI support |
|
*/ |
|
adi_state.enabled = false; |
|
while (len) { |
|
int plen; |
|
|
|
if (!strcmp(prop, "adp")) { |
|
adi_state.enabled = true; |
|
break; |
|
} |
|
|
|
plen = strlen(prop) + 1; |
|
prop += plen; |
|
len -= plen; |
|
} |
|
|
|
if (!adi_state.enabled) |
|
goto adi_not_found; |
|
|
|
/* Find the ADI properties in "platform" node. If all ADI |
|
* properties are not found, ADI support is incomplete and |
|
* do not enable ADI in the kernel. |
|
*/ |
|
pn = mdesc_node_by_name(hp, MDESC_NODE_NULL, "platform"); |
|
if (pn == MDESC_NODE_NULL) |
|
goto adi_not_found; |
|
|
|
val = (u64 *) mdesc_get_property(hp, pn, "adp-blksz", &len); |
|
if (!val) |
|
goto adi_not_found; |
|
adi_state.caps.blksz = *val; |
|
|
|
val = (u64 *) mdesc_get_property(hp, pn, "adp-nbits", &len); |
|
if (!val) |
|
goto adi_not_found; |
|
adi_state.caps.nbits = *val; |
|
|
|
val = (u64 *) mdesc_get_property(hp, pn, "ue-on-adp", &len); |
|
if (!val) |
|
goto adi_not_found; |
|
adi_state.caps.ue_on_adi = *val; |
|
|
|
/* Some of the code to support swapping ADI tags is written |
|
* assumption that two ADI tags can fit inside one byte. If |
|
* this assumption is broken by a future architecture change, |
|
* that code will have to be revisited. If that were to happen, |
|
* disable ADI support so we do not get unpredictable results |
|
* with programs trying to use ADI and their pages getting |
|
* swapped out |
|
*/ |
|
if (adi_state.caps.nbits > 4) { |
|
pr_warn("WARNING: ADI tag size >4 on this platform. Disabling AADI support\n"); |
|
adi_state.enabled = false; |
|
} |
|
|
|
mdesc_release(hp); |
|
return; |
|
|
|
adi_not_found: |
|
adi_state.enabled = false; |
|
adi_state.caps.blksz = 0; |
|
adi_state.caps.nbits = 0; |
|
if (hp) |
|
mdesc_release(hp); |
|
} |
|
|
|
tag_storage_desc_t *find_tag_store(struct mm_struct *mm, |
|
struct vm_area_struct *vma, |
|
unsigned long addr) |
|
{ |
|
tag_storage_desc_t *tag_desc = NULL; |
|
unsigned long i, max_desc, flags; |
|
|
|
/* Check if this vma already has tag storage descriptor |
|
* allocated for it. |
|
*/ |
|
max_desc = PAGE_SIZE/sizeof(tag_storage_desc_t); |
|
if (mm->context.tag_store) { |
|
tag_desc = mm->context.tag_store; |
|
spin_lock_irqsave(&mm->context.tag_lock, flags); |
|
for (i = 0; i < max_desc; i++) { |
|
if ((addr >= tag_desc->start) && |
|
((addr + PAGE_SIZE - 1) <= tag_desc->end)) |
|
break; |
|
tag_desc++; |
|
} |
|
spin_unlock_irqrestore(&mm->context.tag_lock, flags); |
|
|
|
/* If no matching entries were found, this must be a |
|
* freshly allocated page |
|
*/ |
|
if (i >= max_desc) |
|
tag_desc = NULL; |
|
} |
|
|
|
return tag_desc; |
|
} |
|
|
|
tag_storage_desc_t *alloc_tag_store(struct mm_struct *mm, |
|
struct vm_area_struct *vma, |
|
unsigned long addr) |
|
{ |
|
unsigned char *tags; |
|
unsigned long i, size, max_desc, flags; |
|
tag_storage_desc_t *tag_desc, *open_desc; |
|
unsigned long end_addr, hole_start, hole_end; |
|
|
|
max_desc = PAGE_SIZE/sizeof(tag_storage_desc_t); |
|
open_desc = NULL; |
|
hole_start = 0; |
|
hole_end = ULONG_MAX; |
|
end_addr = addr + PAGE_SIZE - 1; |
|
|
|
/* Check if this vma already has tag storage descriptor |
|
* allocated for it. |
|
*/ |
|
spin_lock_irqsave(&mm->context.tag_lock, flags); |
|
if (mm->context.tag_store) { |
|
tag_desc = mm->context.tag_store; |
|
|
|
/* Look for a matching entry for this address. While doing |
|
* that, look for the first open slot as well and find |
|
* the hole in already allocated range where this request |
|
* will fit in. |
|
*/ |
|
for (i = 0; i < max_desc; i++) { |
|
if (tag_desc->tag_users == 0) { |
|
if (open_desc == NULL) |
|
open_desc = tag_desc; |
|
} else { |
|
if ((addr >= tag_desc->start) && |
|
(tag_desc->end >= (addr + PAGE_SIZE - 1))) { |
|
tag_desc->tag_users++; |
|
goto out; |
|
} |
|
} |
|
if ((tag_desc->start > end_addr) && |
|
(tag_desc->start < hole_end)) |
|
hole_end = tag_desc->start; |
|
if ((tag_desc->end < addr) && |
|
(tag_desc->end > hole_start)) |
|
hole_start = tag_desc->end; |
|
tag_desc++; |
|
} |
|
|
|
} else { |
|
size = sizeof(tag_storage_desc_t)*max_desc; |
|
mm->context.tag_store = kzalloc(size, GFP_NOWAIT|__GFP_NOWARN); |
|
if (mm->context.tag_store == NULL) { |
|
tag_desc = NULL; |
|
goto out; |
|
} |
|
tag_desc = mm->context.tag_store; |
|
for (i = 0; i < max_desc; i++, tag_desc++) |
|
tag_desc->tag_users = 0; |
|
open_desc = mm->context.tag_store; |
|
i = 0; |
|
} |
|
|
|
/* Check if we ran out of tag storage descriptors */ |
|
if (open_desc == NULL) { |
|
tag_desc = NULL; |
|
goto out; |
|
} |
|
|
|
/* Mark this tag descriptor slot in use and then initialize it */ |
|
tag_desc = open_desc; |
|
tag_desc->tag_users = 1; |
|
|
|
/* Tag storage has not been allocated for this vma and space |
|
* is available in tag storage descriptor. Since this page is |
|
* being swapped out, there is high probability subsequent pages |
|
* in the VMA will be swapped out as well. Allocate pages to |
|
* store tags for as many pages in this vma as possible but not |
|
* more than TAG_STORAGE_PAGES. Each byte in tag space holds |
|
* two ADI tags since each ADI tag is 4 bits. Each ADI tag |
|
* covers adi_blksize() worth of addresses. Check if the hole is |
|
* big enough to accommodate full address range for using |
|
* TAG_STORAGE_PAGES number of tag pages. |
|
*/ |
|
size = TAG_STORAGE_PAGES * PAGE_SIZE; |
|
end_addr = addr + (size*2*adi_blksize()) - 1; |
|
/* Check for overflow. If overflow occurs, allocate only one page */ |
|
if (end_addr < addr) { |
|
size = PAGE_SIZE; |
|
end_addr = addr + (size*2*adi_blksize()) - 1; |
|
/* If overflow happens with the minimum tag storage |
|
* allocation as well, adjust ending address for this |
|
* tag storage. |
|
*/ |
|
if (end_addr < addr) |
|
end_addr = ULONG_MAX; |
|
} |
|
if (hole_end < end_addr) { |
|
/* Available hole is too small on the upper end of |
|
* address. Can we expand the range towards the lower |
|
* address and maximize use of this slot? |
|
*/ |
|
unsigned long tmp_addr; |
|
|
|
end_addr = hole_end - 1; |
|
tmp_addr = end_addr - (size*2*adi_blksize()) + 1; |
|
/* Check for underflow. If underflow occurs, allocate |
|
* only one page for storing ADI tags |
|
*/ |
|
if (tmp_addr > addr) { |
|
size = PAGE_SIZE; |
|
tmp_addr = end_addr - (size*2*adi_blksize()) - 1; |
|
/* If underflow happens with the minimum tag storage |
|
* allocation as well, adjust starting address for |
|
* this tag storage. |
|
*/ |
|
if (tmp_addr > addr) |
|
tmp_addr = 0; |
|
} |
|
if (tmp_addr < hole_start) { |
|
/* Available hole is restricted on lower address |
|
* end as well |
|
*/ |
|
tmp_addr = hole_start + 1; |
|
} |
|
addr = tmp_addr; |
|
size = (end_addr + 1 - addr)/(2*adi_blksize()); |
|
size = (size + (PAGE_SIZE-adi_blksize()))/PAGE_SIZE; |
|
size = size * PAGE_SIZE; |
|
} |
|
tags = kzalloc(size, GFP_NOWAIT|__GFP_NOWARN); |
|
if (tags == NULL) { |
|
tag_desc->tag_users = 0; |
|
tag_desc = NULL; |
|
goto out; |
|
} |
|
tag_desc->start = addr; |
|
tag_desc->tags = tags; |
|
tag_desc->end = end_addr; |
|
|
|
out: |
|
spin_unlock_irqrestore(&mm->context.tag_lock, flags); |
|
return tag_desc; |
|
} |
|
|
|
void del_tag_store(tag_storage_desc_t *tag_desc, struct mm_struct *mm) |
|
{ |
|
unsigned long flags; |
|
unsigned char *tags = NULL; |
|
|
|
spin_lock_irqsave(&mm->context.tag_lock, flags); |
|
tag_desc->tag_users--; |
|
if (tag_desc->tag_users == 0) { |
|
tag_desc->start = tag_desc->end = 0; |
|
/* Do not free up the tag storage space allocated |
|
* by the first descriptor. This is persistent |
|
* emergency tag storage space for the task. |
|
*/ |
|
if (tag_desc != mm->context.tag_store) { |
|
tags = tag_desc->tags; |
|
tag_desc->tags = NULL; |
|
} |
|
} |
|
spin_unlock_irqrestore(&mm->context.tag_lock, flags); |
|
kfree(tags); |
|
} |
|
|
|
#define tag_start(addr, tag_desc) \ |
|
((tag_desc)->tags + ((addr - (tag_desc)->start)/(2*adi_blksize()))) |
|
|
|
/* Retrieve any saved ADI tags for the page being swapped back in and |
|
* restore these tags to the newly allocated physical page. |
|
*/ |
|
void adi_restore_tags(struct mm_struct *mm, struct vm_area_struct *vma, |
|
unsigned long addr, pte_t pte) |
|
{ |
|
unsigned char *tag; |
|
tag_storage_desc_t *tag_desc; |
|
unsigned long paddr, tmp, version1, version2; |
|
|
|
/* Check if the swapped out page has an ADI version |
|
* saved. If yes, restore version tag to the newly |
|
* allocated page. |
|
*/ |
|
tag_desc = find_tag_store(mm, vma, addr); |
|
if (tag_desc == NULL) |
|
return; |
|
|
|
tag = tag_start(addr, tag_desc); |
|
paddr = pte_val(pte) & _PAGE_PADDR_4V; |
|
for (tmp = paddr; tmp < (paddr+PAGE_SIZE); tmp += adi_blksize()) { |
|
version1 = (*tag) >> 4; |
|
version2 = (*tag) & 0x0f; |
|
*tag++ = 0; |
|
asm volatile("stxa %0, [%1] %2\n\t" |
|
: |
|
: "r" (version1), "r" (tmp), |
|
"i" (ASI_MCD_REAL)); |
|
tmp += adi_blksize(); |
|
asm volatile("stxa %0, [%1] %2\n\t" |
|
: |
|
: "r" (version2), "r" (tmp), |
|
"i" (ASI_MCD_REAL)); |
|
} |
|
asm volatile("membar #Sync\n\t"); |
|
|
|
/* Check and mark this tag space for release later if |
|
* the swapped in page was the last user of tag space |
|
*/ |
|
del_tag_store(tag_desc, mm); |
|
} |
|
|
|
/* A page is about to be swapped out. Save any ADI tags associated with |
|
* this physical page so they can be restored later when the page is swapped |
|
* back in. |
|
*/ |
|
int adi_save_tags(struct mm_struct *mm, struct vm_area_struct *vma, |
|
unsigned long addr, pte_t oldpte) |
|
{ |
|
unsigned char *tag; |
|
tag_storage_desc_t *tag_desc; |
|
unsigned long version1, version2, paddr, tmp; |
|
|
|
tag_desc = alloc_tag_store(mm, vma, addr); |
|
if (tag_desc == NULL) |
|
return -1; |
|
|
|
tag = tag_start(addr, tag_desc); |
|
paddr = pte_val(oldpte) & _PAGE_PADDR_4V; |
|
for (tmp = paddr; tmp < (paddr+PAGE_SIZE); tmp += adi_blksize()) { |
|
asm volatile("ldxa [%1] %2, %0\n\t" |
|
: "=r" (version1) |
|
: "r" (tmp), "i" (ASI_MCD_REAL)); |
|
tmp += adi_blksize(); |
|
asm volatile("ldxa [%1] %2, %0\n\t" |
|
: "=r" (version2) |
|
: "r" (tmp), "i" (ASI_MCD_REAL)); |
|
*tag = (version1 << 4) | version2; |
|
tag++; |
|
} |
|
|
|
return 0; |
|
}
|
|
|