/*
* CPU-agnostic ARM page table allocator.
*
* ARMv7 Short-descriptor format, supporting
* - Basic memory attributes
* - Simplified access permissions (AP[2:1] model)
* - Backwards-compatible TEX remap
* - Large pages/supersections (if indicated by the caller)
*
* Not supporting:
* - Legacy access permissions (AP[2:0] model)
*
* Almost certainly never supporting:
* - PXN
* - Domains
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Copyright (C) 2014-2015 ARM Limited
* Copyright (c) 2014-2015 MediaTek Inc.
*/
#define pr_fmt(fmt) "arm-v7s io-pgtable: " fmt
#include <linux/atomic.h>
#include <linux/dma-mapping.h>
#include <linux/gfp.h>
#include <linux/iommu.h>
#include <linux/kernel.h>
#include <linux/kmemleak.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <asm/barrier.h>
#include "io-pgtable.h"
/* Struct accessors */
#define io_pgtable_to_data(x) \
container_of((x), struct arm_v7s_io_pgtable, iop)
#define io_pgtable_ops_to_data(x) \
io_pgtable_to_data(io_pgtable_ops_to_pgtable(x))
/*
* We have 32 bits total; 12 bits resolved at level 1, 8 bits at level 2,
* and 12 bits in a page. With some carefully-chosen coefficients we can
* hide the ugly inconsistencies behind these macros and at least let the
* rest of the code pretend to be somewhat sane.
*/
#define ARM_V7S_ADDR_BITS 32
#define _ARM_V7S_LVL_BITS(lvl) (16 - (lvl) * 4)
#define ARM_V7S_LVL_SHIFT(lvl) (ARM_V7S_ADDR_BITS - (4 + 8 * (lvl)))
#define ARM_V7S_TABLE_SHIFT 10
#define ARM_V7S_PTES_PER_LVL(lvl) (1 << _ARM_V7S_LVL_BITS(lvl))
#define ARM_V7S_TABLE_SIZE(lvl) \
(ARM_V7S_PTES_PER_LVL(lvl) * sizeof(arm_v7s_iopte))
#define ARM_V7S_BLOCK_SIZE(lvl) (1UL << ARM_V7S_LVL_SHIFT(lvl))
#define ARM_V7S_LVL_MASK(lvl) ((u32)(~0U << ARM_V7S_LVL_SHIFT(lvl)))
#define ARM_V7S_TABLE_MASK ((u32)(~0U << ARM_V7S_TABLE_SHIFT))
#define _ARM_V7S_IDX_MASK(lvl) (ARM_V7S_PTES_PER_LVL(lvl) - 1)
#define ARM_V7S_LVL_IDX(addr, lvl) ({ \
int _l = lvl; \
((u32)(addr) >> ARM_V7S_LVL_SHIFT(_l)) & _ARM_V7S_IDX_MASK(_l); \
})
/*
* Large page/supersection entries are effectively a block of 16 page/section
* entries, along the lines of the LPAE contiguous hint, but all with the
* same output address. For want of a better common name we'll call them
* "contiguous" versions of their respective page/section entries here, but
* noting the distinction (WRT to TLB maintenance) that they represent *one*
* entry repeated 16 times, not 16 separate entries (as in the LPAE case).
*/
#define ARM_V7S_CONT_PAGES 16
/* PTE type bits: these are all mixed up with XN/PXN bits in most cases */
#define ARM_V7S_PTE_TYPE_TABLE 0x1
#define ARM_V7S_PTE_TYPE_PAGE 0x2
#define ARM_V7S_PTE_TYPE_CONT_PAGE 0x1
#define ARM_V7S_PTE_IS_VALID(pte) (((pte) & 0x3) != 0)
#define ARM_V7S_PTE_IS_TABLE(pte, lvl) \
((lvl) == 1 && (((pte) & 0x3) == ARM_V7S_PTE_TYPE_TABLE))
/* Page table bits */
#define ARM_V7S_ATTR_XN(lvl) BIT(4 * (2 - (lvl)))
#define ARM_V7S_ATTR_B BIT(2)
#define ARM_V7S_ATTR_C BIT(3)
#define ARM_V7S_ATTR_NS_TABLE BIT(3)
#define ARM_V7S_ATTR_NS_SECTION BIT(19)
#define ARM_V7S_CONT_SECTION BIT(18)
#define ARM_V7S_CONT_PAGE_XN_SHIFT 15
/*
* The attribute bits are consistently ordered*, but occupy bits [17:10] of
* a level 1 PTE vs. bits [11:4] at level 2. Thus we define the individual
* fields relative to that 8-bit block, plus a total shift relative to the PTE.
*/
#define ARM_V7S_ATTR_SHIFT(lvl) (16 - (lvl) * 6)
#define ARM_V7S_ATTR_MASK 0xff
#define ARM_V7S_ATTR_AP0 BIT(0)
#define ARM_V7S_ATTR_AP1 BIT(1)
#define ARM_V7S_ATTR_AP2 BIT(5)
#define ARM_V7S_ATTR_S BIT(6)
#define ARM_V7S_ATTR_NG BIT(7)
#define ARM_V7S_TEX_SHIFT 2
#define ARM_V7S_TEX_MASK 0x7
#define ARM_V7S_ATTR_TEX(val) (((val) & ARM_V7S_TEX_MASK) << ARM_V7S_TEX_SHIFT)
#define ARM_V7S_ATTR_MTK_4GB BIT(9) /* MTK extend it for 4GB mode */
/* *well, except for TEX on level 2 large pages, of course :( */
#define ARM_V7S_CONT_PAGE_TEX_SHIFT 6
#define ARM_V7S_CONT_PAGE_TEX_MASK (ARM_V7S_TEX_MASK << ARM_V7S_CONT_PAGE_TEX_SHIFT)
/* Simplified access permissions */
#define ARM_V7S_PTE_AF ARM_V7S_ATTR_AP0
#define ARM_V7S_PTE_AP_UNPRIV ARM_V7S_ATTR_AP1
#define ARM_V7S_PTE_AP_RDONLY ARM_V7S_ATTR_AP2
/* Register bits */
#define ARM_V7S_RGN_NC 0
#define ARM_V7S_RGN_WBWA 1
#define ARM_V7S_RGN_WT 2
#define ARM_V7S_RGN_WB 3
#define ARM_V7S_PRRR_TYPE_DEVICE 1
#define ARM_V7S_PRRR_TYPE_NORMAL 2
#define ARM_V7S_PRRR_TR(n, type) (((type) & 0x3) << ((n) * 2))
#define ARM_V7S_PRRR_DS0 BIT(16)
#define ARM_V7S_PRRR_DS1 BIT(17)
#define ARM_V7S_PRRR_NS0 BIT(18)
#define ARM_V7S_PRRR_NS1 BIT(19)
#define ARM_V7S_PRRR_NOS(n) BIT((n) + 24)
#define ARM_V7S_NMRR_IR(n, attr) (((attr) & 0x3) << ((n) * 2))
#define ARM_V7S_NMRR_OR(n, attr) (((attr) & 0x3) << ((n) * 2 + 16))
#define ARM_V7S_TTBR_S BIT(1)
#define ARM_V7S_TTBR_NOS BIT(5)
#define ARM_V7S_TTBR_ORGN_ATTR(attr) (((attr) & 0x3) << 3)
#define ARM_V7S_TTBR_IRGN_ATTR(attr) \
((((attr) & 0x1) << 6) | (((attr) & 0x2) >> 1))
#define ARM_V7S_TCR_PD1 BIT(5)
typedef u32 arm_v7s_iopte;
static bool selftest_running;
struct arm_v7s_io_pgtable {
struct io_pgtable iop;
arm_v7s_iopte *pgd;
struct kmem_cache *l2_tables;
spinlock_t split_lock;
};
static dma_addr_t __arm_v7s_dma_addr(void *pages)
{
return (dma_addr_t)virt_to_phys(pages);
}
static arm_v7s_iopte *iopte_deref(arm_v7s_iopte pte, int lvl)
{
if (ARM_V7S_PTE_IS_TABLE(pte, lvl))
pte &= ARM_V7S_TABLE_MASK;
else
pte &= ARM_V7S_LVL_MASK(lvl);
return phys_to_virt(pte);
}
static void *__arm_v7s_alloc_table(int lvl, gfp_t gfp,
struct arm_v7s_io_pgtable *data)
{
struct io_pgtable_cfg *cfg = &data->iop.cfg;
struct device *dev = cfg->iommu_dev;
dma_addr_t dma;
size_t size = ARM_V7S_TABLE_SIZE(lvl);
void *table = NULL;
if (lvl == 1)
table = (void *)__get_dma_pages(__GFP_ZERO, get_order(size));
else if (lvl == 2)
table = kmem_cache_zalloc(data->l2_tables, gfp | GFP_DMA);
if (table && !(cfg->quirks & IO_PGTABLE_QUIRK_NO_DMA)) {
dma = dma_map_single(dev, table, size, DMA_TO_DEVICE);
if (dma_mapping_error(dev, dma))
goto out_free;
/*
* We depend on the IOMMU being able to work with any physical
* address directly, so if the DMA layer suggests otherwise by
* translating or truncating them, that bodes very badly...
*/
if (dma != virt_to_phys(table))
goto out_unmap;
}
kmemleak_ignore(table);
return table;
out_unmap:
dev_err(dev, "Cannot accommodate DMA translation for IOMMU page tables\n");
dma_unmap_single(dev, dma, size, DMA_TO_DEVICE);
out_free:
if (lvl == 1)
free_pages((unsigned long)table, get_order(size));
else
kmem_cache_free(data->l2_tables, table);
return NULL;
}
static void __arm_v7s_free_table(void *table, int lvl,
struct arm_v7s_io_pgtable *data)
{
struct io_pgtable_cfg *cfg = &data->iop.cfg;
struct device *dev = cfg->iommu_dev;
size_t size = ARM_V7S_TABLE_SIZE(lvl);
if (!(cfg->quirks & IO_PGTABLE_QUIRK_NO_DMA))
dma_unmap_single(dev, __arm_v7s_dma_addr(table), size,
DMA_TO_DEVICE);
if (lvl == 1)
free_pages((unsigned long)table, get_order(size));
else
kmem_cache_free(data->l2_tables, table);
}
static void __arm_v7s_pte_sync(arm_v7s_iopte *ptep, int num_entries,
struct io_pgtable_cfg *cfg)
{
if (cfg->quirks & IO_PGTABLE_QUIRK_NO_DMA)
return;
dma_sync_single_for_device(cfg->iommu_dev, __arm_v7s_dma_addr(ptep),
num_entries * sizeof(*ptep), DMA_TO_DEVICE);
}
static void __arm_v7s_set_pte(arm_v7s_iopte *ptep, arm_v7s_iopte pte,
int num_entries, struct io_pgtable_cfg *cfg)
{
int i;
for (i = 0; i < num_entries; i++)
ptep[i] = pte;
__arm_v7s_pte_sync(ptep, num_entries, cfg);
}
static arm_v7s_iopte arm_v7s_prot_to_pte(int prot, int lvl,
struct io_pgtable_cfg *cfg)
{
bool ap = !(cfg->quirks & IO_PGTABLE_QUIRK_NO_PERMS);
arm_v7s_iopte pte = ARM_V7S_ATTR_NG | ARM_V7S_ATTR_S;
if (!(prot & IOMMU_MMIO))
pte |= ARM_V7S_ATTR_TEX(1);
if (ap) {
pte |= ARM_V7S_PTE_AF;
if (!(prot & IOMMU_PRIV))
pte |= ARM_V7S_PTE_AP_UNPRIV;
if (!(prot & IOMMU_WRITE))
pte |= ARM_V7S_PTE_AP_RDONLY;
}
pte <<= ARM_V7S_ATTR_SHIFT(lvl);
if ((prot & IOMMU_NOEXEC) && ap)
pte |= ARM_V7S_ATTR_XN(lvl);
if (prot & IOMMU_MMIO)
pte |= ARM_V7S_ATTR_B;
else if (prot & IOMMU_CACHE)
pte |= ARM_V7S_ATTR_B | ARM_V7S_ATTR_C;
pte |= ARM_V7S_PTE_TYPE_PAGE;
if (lvl == 1 && (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS))
pte |= ARM_V7S_ATTR_NS_SECTION;
if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_4GB)
pte |= ARM_V7S_ATTR_MTK_4GB;
return pte;
}
static int arm_v7s_pte_to_prot(arm_v7s_iopte pte, int lvl)
{
int prot = IOMMU_READ;
arm_v7s_iopte attr = pte >> ARM_V7S_ATTR_SHIFT(lvl);
if (!(attr & ARM_V7S_PTE_AP_RDONLY))
prot |= IOMMU_WRITE;
if (!(attr & ARM_V7S_PTE_AP_UNPRIV))
prot |= IOMMU_PRIV;
if ((attr & (ARM_V7S_TEX_MASK << ARM_V7S_TEX_SHIFT)) == 0)
prot |= IOMMU_MMIO;
else if (pte & ARM_V7S_ATTR_C)
prot |= IOMMU_CACHE;
if (pte & ARM_V7S_ATTR_XN(lvl))
prot |= IOMMU_NOEXEC;
return prot;
}
static arm_v7s_iopte arm_v7s_pte_to_cont(arm_v7s_iopte pte, int lvl)
{
if (lvl == 1) {
pte |= ARM_V7S_CONT_SECTION;
} else if (lvl == 2) {
arm_v7s_iopte xn = pte & ARM_V7S_ATTR_XN(lvl);
arm_v7s_iopte tex = pte & ARM_V7S_CONT_PAGE_TEX_MASK;
pte ^= xn | tex | ARM_V7S_PTE_TYPE_PAGE;
pte |= (xn << ARM_V7S_CONT_PAGE_XN_SHIFT) |
(tex << ARM_V7S_CONT_PAGE_TEX_SHIFT) |
ARM_V7S_PTE_TYPE_CONT_PAGE;
}
return pte;
}
static arm_v7s_iopte arm_v7s_cont_to_pte(arm_v7s_iopte pte, int lvl)
{
if (lvl == 1) {
pte &= ~ARM_V7S_CONT_SECTION;
} else if (lvl == 2) {
arm_v7s_iopte xn = pte & BIT(ARM_V7S_CONT_PAGE_XN_SHIFT);
arm_v7s_iopte tex = pte & (ARM_V7S_CONT_PAGE_TEX_MASK <<
ARM_V7S_CONT_PAGE_TEX_SHIFT);
pte ^= xn | tex | ARM_V7S_PTE_TYPE_CONT_PAGE;
pte |= (xn >> ARM_V7S_CONT_PAGE_XN_SHIFT) |
(tex >> ARM_V7S_CONT_PAGE_TEX_SHIFT) |
ARM_V7S_PTE_TYPE_PAGE;
}
return pte;
}
static bool arm_v7s_pte_is_cont(arm_v7s_iopte pte, int lvl)
{
if (lvl == 1 && !ARM_V7S_PTE_IS_TABLE(pte, lvl))
return pte & ARM_V7S_CONT_SECTION;
else if (lvl == 2)
return !(pte & ARM_V7S_PTE_TYPE_PAGE);
return false;
}
static int __arm_v7s_unmap(struct arm_v7s_io_pgtable *, unsigned long,
size_t, int, arm_v7s_iopte *);
static int arm_v7s_init_pte(struct arm_v7s_io_pgtable *data,
unsigned long iova, phys_addr_t paddr, int prot,
int lvl, int num_entries, arm_v7s_iopte *ptep)
{
struct io_pgtable_cfg *cfg = &data->iop.cfg;
arm_v7s_iopte pte;
int i;
for (i = 0; i < num_entries; i++)
if (ARM_V7S_PTE_IS_TABLE(ptep[i], lvl)) {
/*
* We need to unmap and free the old table before
* overwriting it with a block entry.
*/
arm_v7s_iopte *tblp;
size_t sz = ARM_V7S_BLOCK_SIZE(lvl);
tblp = ptep - ARM_V7S_LVL_IDX(iova, lvl);
if (WARN_ON(__arm_v7s_unmap(data, iova + i * sz,
sz, lvl, tblp) != sz))
return -EINVAL;
} else if (ptep[i]) {
/* We require an unmap first */
WARN_ON(!selftest_running);
return -EEXIST;
}
pte = arm_v7s_prot_to_pte(prot, lvl, cfg);
if (num_entries > 1)
pte = arm_v7s_pte_to_cont(pte, lvl);
pte |= paddr & ARM_V7S_LVL_MASK(lvl);
__arm_v7s_set_pte(ptep, pte, num_entries, cfg);
return 0;
}
static arm_v7s_iopte arm_v7s_install_table(arm_v7s_iopte *table,
arm_v7s_iopte *ptep,
arm_v7s_iopte curr,
struct io_pgtable_cfg *cfg)
{
arm_v7s_iopte old, new;
new = virt_to_phys(table) | ARM_V7S_PTE_TYPE_TABLE;
if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_NS)
new |= ARM_V7S_ATTR_NS_TABLE;
/*
* Ensure the table itself is visible before its PTE can be.
* Whilst we could get away with cmpxchg64_release below, this
* doesn't have any ordering semantics when !CONFIG_SMP.
*/
dma_wmb();
old = cmpxchg_relaxed(ptep, curr, new);
__arm_v7s_pte_sync(ptep, 1, cfg);
return old;
}
static int __arm_v7s_map(struct arm_v7s_io_pgtable *data, unsigned long iova,
phys_addr_t paddr, size_t size, int prot,
int lvl, arm_v7s_iopte *ptep)
{
struct io_pgtable_cfg *cfg = &data->iop.cfg;
arm_v7s_iopte pte, *cptep;
int num_entries = size >> ARM_V7S_LVL_SHIFT(lvl);
/* Find our entry at the current level */
ptep += ARM_V7S_LVL_IDX(iova, lvl);
/* If we can install a leaf entry at this level, then do so */
if (num_entries)
return arm_v7s_init_pte(data, iova, paddr, prot,
lvl, num_entries, ptep);
/* We can't allocate tables at the final level */
if (WARN_ON(lvl == 2))
return -EINVAL;
/* Grab a pointer to the next level */
pte = READ_ONCE(*ptep);
if (!pte) {
cptep = __arm_v7s_alloc_table(lvl + 1, GFP_ATOMIC, data);
if (!cptep)
return -ENOMEM;
pte = arm_v7s_install_table(cptep, ptep, 0, cfg);
if (pte)
__arm_v7s_free_table(cptep, lvl + 1, data);
} else {
/* We've no easy way of knowing if it's synced yet, so... */
__arm_v7s_pte_sync(ptep, 1, cfg);
}
if (ARM_V7S_PTE_IS_TABLE(pte, lvl)) {
cptep = iopte_deref(pte, lvl);
} else if (pte) {
/* We require an unmap first */
WARN_ON(!selftest_running);
return -EEXIST;
}
/* Rinse, repeat */
return __arm_v7s_map(data, iova, paddr, size, prot, lvl + 1, cptep);
}
static int arm_v7s_map(struct io_pgtable_ops *ops, unsigned long iova,
phys_addr_t paddr, size_t size, int prot)
{
struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops);
struct io_pgtable *iop = &data->iop;
int ret;
/* If no access, then nothing to do */
if (!(prot & (IOMMU_READ | IOMMU_WRITE)))
return 0;
if (WARN_ON(upper_32_bits(iova) || upper_32_bits(paddr)))
return -ERANGE;
ret = __arm_v7s_map(data, iova, paddr, size, prot, 1, data->pgd);
/*
* Synchronise all PTE updates for the new mapping before there's
* a chance for anything to kick off a table walk for the new iova.
*/
if (iop->cfg.quirks & IO_PGTABLE_QUIRK_TLBI_ON_MAP) {
io_pgtable_tlb_add_flush(iop, iova, size,
ARM_V7S_BLOCK_SIZE(2), false);
io_pgtable_tlb_sync(iop);
} else {
wmb();
}
return ret;
}
static void arm_v7s_free_pgtable(struct io_pgtable *iop)
{
struct arm_v7s_io_pgtable *data = io_pgtable_to_data(iop);
int i;
for (i = 0; i < ARM_V7S_PTES_PER_LVL(1); i++) {
arm_v7s_iopte pte = data->pgd[i];
if (ARM_V7S_PTE_IS_TABLE(pte, 1))
__arm_v7s_free_table(iopte_deref(pte, 1), 2, data);
}
__arm_v7s_free_table(data->pgd, 1, data);
kmem_cache_destroy(data->l2_tables);
kfree(data);
}
static arm_v7s_iopte arm_v7s_split_cont(struct arm_v7s_io_pgtable *data,
unsigned long iova, int idx, int lvl,
arm_v7s_iopte *ptep)
{
struct io_pgtable *iop = &data->iop;
arm_v7s_iopte pte;
size_t size = ARM_V7S_BLOCK_SIZE(lvl);
int i;
/* Check that we didn't lose a race to get the lock */
pte = *ptep;
if (!arm_v7s_pte_is_cont(pte, lvl))
return pte;
ptep -= idx & (ARM_V7S_CONT_PAGES - 1);
pte = arm_v7s_cont_to_pte(pte, lvl);
for (i = 0; i < ARM_V7S_CONT_PAGES; i++)
ptep[i] = pte + i * size;
__arm_v7s_pte_sync(ptep, ARM_V7S_CONT_PAGES, &iop->cfg);
size *= ARM_V7S_CONT_PAGES;
io_pgtable_tlb_add_flush(iop, iova, size, size, true);
io_pgtable_tlb_sync(iop);
return pte;
}
static int arm_v7s_split_blk_unmap(struct arm_v7s_io_pgtable *data,
unsigned long iova, size_t size,
arm_v7s_iopte blk_pte, arm_v7s_iopte *ptep)
{
struct io_pgtable_cfg *cfg = &data->iop.cfg;
arm_v7s_iopte pte, *tablep;
int i, unmap_idx, num_entries, num_ptes;
tablep = __arm_v7s_alloc_table(2, GFP_ATOMIC, data);
if (!tablep)
return 0; /* Bytes unmapped */
num_ptes = ARM_V7S_PTES_PER_LVL(2);
num_entries = size >> ARM_V7S_LVL_SHIFT(2);
unmap_idx = ARM_V7S_LVL_IDX(iova, 2);
pte = arm_v7s_prot_to_pte(arm_v7s_pte_to_prot(blk_pte, 1), 2, cfg);
if (num_entries > 1)
pte = arm_v7s_pte_to_cont(pte, 2);
for (i = 0; i < num_ptes; i += num_entries, pte += size) {
/* Unmap! */
if (i == unmap_idx)
continue;
__arm_v7s_set_pte(&tablep[i], pte, num_entries, cfg);
}
pte = arm_v7s_install_table(tablep, ptep, blk_pte, cfg);
if (pte != blk_pte) {
__arm_v7s_free_table(tablep, 2, data);
if (!ARM_V7S_PTE_IS_TABLE(pte, 1))
return 0;
tablep = iopte_deref(pte, 1);
return __arm_v7s_unmap(data, iova, size, 2, tablep);
}
io_pgtable_tlb_add_flush(&data->iop, iova, size, size, true);
return size;
}
static int __arm_v7s_unmap(struct arm_v7s_io_pgtable *data,
unsigned long iova, size_t size, int lvl,
arm_v7s_iopte *ptep)
{
arm_v7s_iopte pte[ARM_V7S_CONT_PAGES];
struct io_pgtable *iop = &data->iop;
int idx, i = 0, num_entries = size >> ARM_V7S_LVL_SHIFT(lvl);
/* Something went horribly wrong and we ran out of page table */
if (WARN_ON(lvl > 2))
return 0;
idx = ARM_V7S_LVL_IDX(iova, lvl);
ptep += idx;
do {
pte[i] = READ_ONCE(ptep[i]);
if (WARN_ON(!ARM_V7S_PTE_IS_VALID(pte[i])))
return 0;
} while (++i < num_entries);
/*
* If we've hit a contiguous 'large page' entry at this level, it
* needs splitting first, unless we're unmapping the whole lot.
*
* For splitting, we can't rewrite 16 PTEs atomically, and since we
* can't necessarily assume TEX remap we don't have a software bit to
* mark live entries being split. In practice (i.e. DMA API code), we
* will never be splitting large pages anyway, so just wrap this edge
* case in a lock for the sake of correctness and be done with it.
*/
if (num_entries <= 1 && arm_v7s_pte_is_cont(pte[0], lvl)) {
unsigned long flags;
spin_lock_irqsave(&data->split_lock, flags);
pte[0] = arm_v7s_split_cont(data, iova, idx, lvl, ptep);
spin_unlock_irqrestore(&data->split_lock, flags);
}
/* If the size matches this level, we're in the right place */
if (num_entries) {
size_t blk_size = ARM_V7S_BLOCK_SIZE(lvl);
__arm_v7s_set_pte(ptep, 0, num_entries, &iop->cfg);
for (i = 0; i < num_entries; i++) {
if (ARM_V7S_PTE_IS_TABLE(pte[i], lvl)) {
/* Also flush any partial walks */
io_pgtable_tlb_add_flush(iop, iova, blk_size,
ARM_V7S_BLOCK_SIZE(lvl + 1), false);
io_pgtable_tlb_sync(iop);
ptep = iopte_deref(pte[i], lvl);
__arm_v7s_free_table(ptep, lvl + 1, data);
} else {
io_pgtable_tlb_add_flush(iop, iova, blk_size,
blk_size, true);
}
iova += blk_size;
}
return size;
} else if (lvl == 1 && !ARM_V7S_PTE_IS_TABLE(pte[0], lvl)) {
/*
* Insert a table at the next level to map the old region,
* minus the part we want to unmap
*/
return arm_v7s_split_blk_unmap(data, iova, size, pte[0], ptep);
}
/* Keep on walkin' */
ptep = iopte_deref(pte[0], lvl);
return __arm_v7s_unmap(data, iova, size, lvl + 1, ptep);
}
static int arm_v7s_unmap(struct io_pgtable_ops *ops, unsigned long iova,
size_t size)
{
struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops);
size_t unmapped;
if (WARN_ON(upper_32_bits(iova)))
return 0;
unmapped = __arm_v7s_unmap(data, iova, size, 1, data->pgd);
if (unmapped)
io_pgtable_tlb_sync(&data->iop);
return unmapped;
}
static phys_addr_t arm_v7s_iova_to_phys(struct io_pgtable_ops *ops,
unsigned long iova)
{
struct arm_v7s_io_pgtable *data = io_pgtable_ops_to_data(ops);
arm_v7s_iopte *ptep = data->pgd, pte;
int lvl = 0;
u32 mask;
do {
ptep += ARM_V7S_LVL_IDX(iova, ++lvl);
pte = READ_ONCE(*ptep);
ptep = iopte_deref(pte, lvl);
} while (ARM_V7S_PTE_IS_TABLE(pte, lvl));
if (!ARM_V7S_PTE_IS_VALID(pte))
return 0;
mask = ARM_V7S_LVL_MASK(lvl);
if (arm_v7s_pte_is_cont(pte, lvl))
mask *= ARM_V7S_CONT_PAGES;
return (pte & mask) | (iova & ~mask);
}
static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg,
void *cookie)
{
struct arm_v7s_io_pgtable *data;
#ifdef PHYS_OFFSET
if (upper_32_bits(PHYS_OFFSET))
return NULL;
#endif
if (cfg->ias > ARM_V7S_ADDR_BITS || cfg->oas > ARM_V7S_ADDR_BITS)
return NULL;
if (cfg->quirks & ~(IO_PGTABLE_QUIRK_ARM_NS |
IO_PGTABLE_QUIRK_NO_PERMS |
IO_PGTABLE_QUIRK_TLBI_ON_MAP |
IO_PGTABLE_QUIRK_ARM_MTK_4GB |
IO_PGTABLE_QUIRK_NO_DMA))
return NULL;
/* If ARM_MTK_4GB is enabled, the NO_PERMS is also expected. */
if (cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_4GB &&
!(cfg->quirks & IO_PGTABLE_QUIRK_NO_PERMS))
return NULL;
data = kmalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return NULL;
spin_lock_init(&data->split_lock);
data->l2_tables = kmem_cache_create("io-pgtable_armv7s_l2",
ARM_V7S_TABLE_SIZE(2),
ARM_V7S_TABLE_SIZE(2),
SLAB_CACHE_DMA, NULL);
if (!data->l2_tables)
goto out_free_data;
data->iop.ops = (struct io_pgtable_ops) {
.map = arm_v7s_map,
.unmap = arm_v7s_unmap,
.iova_to_phys = arm_v7s_iova_to_phys,
};
/* We have to do this early for __arm_v7s_alloc_table to work... */
data->iop.cfg = *cfg;
/*
* Unless the IOMMU driver indicates supersection support by
* having SZ_16M set in the initial bitmap, they won't be used.
*/
cfg->pgsize_bitmap &= SZ_4K | SZ_64K | SZ_1M | SZ_16M;
/* TCR: T0SZ=0, disable TTBR1 */
cfg->arm_v7s_cfg.tcr = ARM_V7S_TCR_PD1;
/*
* TEX remap: the indices used map to the closest equivalent types
* under the non-TEX-remap interpretation of those attribute bits,
* excepting various implementation-defined aspects of shareability.
*/
cfg->arm_v7s_cfg.prrr = ARM_V7S_PRRR_TR(1, ARM_V7S_PRRR_TYPE_DEVICE) |
ARM_V7S_PRRR_TR(4, ARM_V7S_PRRR_TYPE_NORMAL) |
ARM_V7S_PRRR_TR(7, ARM_V7S_PRRR_TYPE_NORMAL) |
ARM_V7S_PRRR_DS0 | ARM_V7S_PRRR_DS1 |
ARM_V7S_PRRR_NS1 | ARM_V7S_PRRR_NOS(7);
cfg->arm_v7s_cfg.nmrr = ARM_V7S_NMRR_IR(7, ARM_V7S_RGN_WBWA) |
ARM_V7S_NMRR_OR(7, ARM_V7S_RGN_WBWA);
/* Looking good; allocate a pgd */
data->pgd = __arm_v7s_alloc_table(1, GFP_KERNEL, data);
if (!data->pgd)
goto out_free_data;
/* Ensure the empty pgd is visible before any actual TTBR write */
wmb();
/* TTBRs */
cfg->arm_v7s_cfg.ttbr[0] = virt_to_phys(data->pgd) |
ARM_V7S_TTBR_S | ARM_V7S_TTBR_NOS |
ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_WBWA) |
ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_WBWA);
cfg->arm_v7s_cfg.ttbr[1] = 0;
return &data->iop;
out_free_data:
kmem_cache_destroy(data->l2_tables);
kfree(data);
return NULL;
}
struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns = {
.alloc = arm_v7s_alloc_pgtable,
.free = arm_v7s_free_pgtable,
};
#ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S_SELFTEST
static struct io_pgtable_cfg *cfg_cookie;
static void dummy_tlb_flush_all(void *cookie)
{
WARN_ON(cookie != cfg_cookie);
}
static void dummy_tlb_add_flush(unsigned long iova, size_t size,
size_t granule, bool leaf, void *cookie)
{
WARN_ON(cookie != cfg_cookie);
WARN_ON(!(size & cfg_cookie->pgsize_bitmap));
}
static void dummy_tlb_sync(void *cookie)
{
WARN_ON(cookie != cfg_cookie);
}
static const struct iommu_gather_ops dummy_tlb_ops = {
.tlb_flush_all = dummy_tlb_flush_all,
.tlb_add_flush = dummy_tlb_add_flush,
.tlb_sync = dummy_tlb_sync,
};
#define __FAIL(ops) ({ \
WARN(1, "selftest: test failed\n"); \
selftest_running = false; \
-EFAULT; \
})
static int __init arm_v7s_do_selftests(void)
{
struct io_pgtable_ops *ops;
struct io_pgtable_cfg cfg = {
.tlb = &dummy_tlb_ops,
.oas = 32,
.ias = 32,
.quirks = IO_PGTABLE_QUIRK_ARM_NS | IO_PGTABLE_QUIRK_NO_DMA,
.pgsize_bitmap = SZ_4K | SZ_64K | SZ_1M | SZ_16M,
};
unsigned int iova, size, iova_start;
unsigned int i, loopnr = 0;
selftest_running = true;
cfg_cookie = &cfg;
ops = alloc_io_pgtable_ops(ARM_V7S, &cfg, &cfg);
if (!ops) {
pr_err("selftest: failed to allocate io pgtable ops\n");
return -EINVAL;
}
/*
* Initial sanity checks.
* Empty page tables shouldn't provide any translations.
*/
if (ops->iova_to_phys(ops, 42))
return __FAIL(ops);
if (ops->iova_to_phys(ops, SZ_1G + 42))
return __FAIL(ops);
if (ops->iova_to_phys(ops, SZ_2G + 42))
return __FAIL(ops);
/*
* Distinct mappings of different granule sizes.
*/
iova = 0;
for_each_set_bit(i, &cfg.pgsize_bitmap, BITS_PER_LONG) {
size = 1UL << i;
if (ops->map(ops, iova, iova, size, IOMMU_READ |
IOMMU_WRITE |
IOMMU_NOEXEC |
IOMMU_CACHE))
return __FAIL(ops);
/* Overlapping mappings */
if (!ops->map(ops, iova, iova + size, size,
IOMMU_READ | IOMMU_NOEXEC))
return __FAIL(ops);
if (ops->iova_to_phys(ops, iova + 42) != (iova + 42))
return __FAIL(ops);
iova += SZ_16M;
loopnr++;
}
/* Partial unmap */
i = 1;
size = 1UL << __ffs(cfg.pgsize_bitmap);
while (i < loopnr) {
iova_start = i * SZ_16M;
if (ops->unmap(ops, iova_start + size, size) != size)
return __FAIL(ops);
/* Remap of partial unmap */
if (ops->map(ops, iova_start + size, size, size, IOMMU_READ))
return __FAIL(ops);
if (ops->iova_to_phys(ops, iova_start + size + 42)
!= (size + 42))
return __FAIL(ops);
i++;
}
/* Full unmap */
iova = 0;
i = find_first_bit(&cfg.pgsize_bitmap, BITS_PER_LONG);
while (i != BITS_PER_LONG) {
size = 1UL << i;
if (ops->unmap(ops, iova, size) != size)
return __FAIL(ops);
if (ops->iova_to_phys(ops, iova + 42))
return __FAIL(ops);
/* Remap full block */
if (ops->map(ops, iova, iova, size, IOMMU_WRITE))
return __FAIL(ops);
if (ops->iova_to_phys(ops, iova + 42) != (iova + 42))
return __FAIL(ops);
iova += SZ_16M;
i++;
i = find_next_bit(&cfg.pgsize_bitmap, BITS_PER_LONG, i);
}
free_io_pgtable_ops(ops);
selftest_running = false;
pr_info("self test ok\n");
return 0;
}
subsys_initcall(arm_v7s_do_selftests);
#endif
