linux/drivers/iommu/sprd-iommu.c
Niklas Schnelle fa4c450709 iommu: Allow .iotlb_sync_map to fail and handle s390's -ENOMEM return
On s390 when using a paging hypervisor, .iotlb_sync_map is used to sync
mappings by letting the hypervisor inspect the synced IOVA range and
updating a shadow table. This however means that .iotlb_sync_map can
fail as the hypervisor may run out of resources while doing the sync.
This can be due to the hypervisor being unable to pin guest pages, due
to a limit on mapped addresses such as vfio_iommu_type1.dma_entry_limit
or lack of other resources. Either way such a failure to sync a mapping
should result in a DMA_MAPPING_ERROR.

Now especially when running with batched IOTLB flushes for unmap it may
be that some IOVAs have already been invalidated but not yet synced via
.iotlb_sync_map. Thus if the hypervisor indicates running out of
resources, first do a global flush allowing the hypervisor to free
resources associated with these mappings as well a retry creating the
new mappings and only if that also fails report this error to callers.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com> # sun50i
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20230928-dma_iommu-v13-1-9e5fc4dacc36@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2023-10-02 08:42:57 +02:00

546 lines
14 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Unisoc IOMMU driver
*
* Copyright (C) 2020 Unisoc, Inc.
* Author: Chunyan Zhang <chunyan.zhang@unisoc.com>
*/
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/errno.h>
#include <linux/iommu.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#define SPRD_IOMMU_PAGE_SHIFT 12
#define SPRD_IOMMU_PAGE_SIZE SZ_4K
#define SPRD_EX_CFG 0x0
#define SPRD_IOMMU_VAOR_BYPASS BIT(4)
#define SPRD_IOMMU_GATE_EN BIT(1)
#define SPRD_IOMMU_EN BIT(0)
#define SPRD_EX_UPDATE 0x4
#define SPRD_EX_FIRST_VPN 0x8
#define SPRD_EX_VPN_RANGE 0xc
#define SPRD_EX_FIRST_PPN 0x10
#define SPRD_EX_DEFAULT_PPN 0x14
#define SPRD_IOMMU_VERSION 0x0
#define SPRD_VERSION_MASK GENMASK(15, 8)
#define SPRD_VERSION_SHIFT 0x8
#define SPRD_VAU_CFG 0x4
#define SPRD_VAU_UPDATE 0x8
#define SPRD_VAU_AUTH_CFG 0xc
#define SPRD_VAU_FIRST_PPN 0x10
#define SPRD_VAU_DEFAULT_PPN_RD 0x14
#define SPRD_VAU_DEFAULT_PPN_WR 0x18
#define SPRD_VAU_FIRST_VPN 0x1c
#define SPRD_VAU_VPN_RANGE 0x20
enum sprd_iommu_version {
SPRD_IOMMU_EX,
SPRD_IOMMU_VAU,
};
/*
* struct sprd_iommu_device - high-level sprd IOMMU device representation,
* including hardware information and configuration, also driver data, etc
*
* @ver: sprd IOMMU IP version
* @prot_page_va: protect page base virtual address
* @prot_page_pa: protect page base physical address, data would be
* written to here while translation fault
* @base: mapped base address for accessing registers
* @dev: pointer to basic device structure
* @iommu: IOMMU core representation
* @group: IOMMU group
* @eb: gate clock which controls IOMMU access
*/
struct sprd_iommu_device {
struct sprd_iommu_domain *dom;
enum sprd_iommu_version ver;
u32 *prot_page_va;
dma_addr_t prot_page_pa;
void __iomem *base;
struct device *dev;
struct iommu_device iommu;
struct clk *eb;
};
struct sprd_iommu_domain {
spinlock_t pgtlock; /* lock for page table */
struct iommu_domain domain;
u32 *pgt_va; /* page table virtual address base */
dma_addr_t pgt_pa; /* page table physical address base */
struct sprd_iommu_device *sdev;
};
static const struct iommu_ops sprd_iommu_ops;
static struct sprd_iommu_domain *to_sprd_domain(struct iommu_domain *dom)
{
return container_of(dom, struct sprd_iommu_domain, domain);
}
static inline void
sprd_iommu_write(struct sprd_iommu_device *sdev, unsigned int reg, u32 val)
{
writel_relaxed(val, sdev->base + reg);
}
static inline u32
sprd_iommu_read(struct sprd_iommu_device *sdev, unsigned int reg)
{
return readl_relaxed(sdev->base + reg);
}
static inline void
sprd_iommu_update_bits(struct sprd_iommu_device *sdev, unsigned int reg,
u32 mask, u32 shift, u32 val)
{
u32 t = sprd_iommu_read(sdev, reg);
t = (t & (~(mask << shift))) | ((val & mask) << shift);
sprd_iommu_write(sdev, reg, t);
}
static inline int
sprd_iommu_get_version(struct sprd_iommu_device *sdev)
{
int ver = (sprd_iommu_read(sdev, SPRD_IOMMU_VERSION) &
SPRD_VERSION_MASK) >> SPRD_VERSION_SHIFT;
switch (ver) {
case SPRD_IOMMU_EX:
case SPRD_IOMMU_VAU:
return ver;
default:
return -EINVAL;
}
}
static size_t
sprd_iommu_pgt_size(struct iommu_domain *domain)
{
return ((domain->geometry.aperture_end -
domain->geometry.aperture_start + 1) >>
SPRD_IOMMU_PAGE_SHIFT) * sizeof(u32);
}
static struct iommu_domain *sprd_iommu_domain_alloc_paging(struct device *dev)
{
struct sprd_iommu_domain *dom;
dom = kzalloc(sizeof(*dom), GFP_KERNEL);
if (!dom)
return NULL;
spin_lock_init(&dom->pgtlock);
dom->domain.geometry.aperture_start = 0;
dom->domain.geometry.aperture_end = SZ_256M - 1;
dom->domain.geometry.force_aperture = true;
return &dom->domain;
}
static void sprd_iommu_first_vpn(struct sprd_iommu_domain *dom)
{
struct sprd_iommu_device *sdev = dom->sdev;
u32 val;
unsigned int reg;
if (sdev->ver == SPRD_IOMMU_EX)
reg = SPRD_EX_FIRST_VPN;
else
reg = SPRD_VAU_FIRST_VPN;
val = dom->domain.geometry.aperture_start >> SPRD_IOMMU_PAGE_SHIFT;
sprd_iommu_write(sdev, reg, val);
}
static void sprd_iommu_vpn_range(struct sprd_iommu_domain *dom)
{
struct sprd_iommu_device *sdev = dom->sdev;
u32 val;
unsigned int reg;
if (sdev->ver == SPRD_IOMMU_EX)
reg = SPRD_EX_VPN_RANGE;
else
reg = SPRD_VAU_VPN_RANGE;
val = (dom->domain.geometry.aperture_end -
dom->domain.geometry.aperture_start) >> SPRD_IOMMU_PAGE_SHIFT;
sprd_iommu_write(sdev, reg, val);
}
static void sprd_iommu_first_ppn(struct sprd_iommu_domain *dom)
{
u32 val = dom->pgt_pa >> SPRD_IOMMU_PAGE_SHIFT;
struct sprd_iommu_device *sdev = dom->sdev;
unsigned int reg;
if (sdev->ver == SPRD_IOMMU_EX)
reg = SPRD_EX_FIRST_PPN;
else
reg = SPRD_VAU_FIRST_PPN;
sprd_iommu_write(sdev, reg, val);
}
static void sprd_iommu_default_ppn(struct sprd_iommu_device *sdev)
{
u32 val = sdev->prot_page_pa >> SPRD_IOMMU_PAGE_SHIFT;
if (sdev->ver == SPRD_IOMMU_EX) {
sprd_iommu_write(sdev, SPRD_EX_DEFAULT_PPN, val);
} else if (sdev->ver == SPRD_IOMMU_VAU) {
sprd_iommu_write(sdev, SPRD_VAU_DEFAULT_PPN_RD, val);
sprd_iommu_write(sdev, SPRD_VAU_DEFAULT_PPN_WR, val);
}
}
static void sprd_iommu_hw_en(struct sprd_iommu_device *sdev, bool en)
{
unsigned int reg_cfg;
u32 mask, val;
if (sdev->ver == SPRD_IOMMU_EX)
reg_cfg = SPRD_EX_CFG;
else
reg_cfg = SPRD_VAU_CFG;
mask = SPRD_IOMMU_EN | SPRD_IOMMU_GATE_EN;
val = en ? mask : 0;
sprd_iommu_update_bits(sdev, reg_cfg, mask, 0, val);
}
static void sprd_iommu_cleanup(struct sprd_iommu_domain *dom)
{
size_t pgt_size;
/* Nothing need to do if the domain hasn't been attached */
if (!dom->sdev)
return;
pgt_size = sprd_iommu_pgt_size(&dom->domain);
dma_free_coherent(dom->sdev->dev, pgt_size, dom->pgt_va, dom->pgt_pa);
dom->sdev = NULL;
sprd_iommu_hw_en(dom->sdev, false);
}
static void sprd_iommu_domain_free(struct iommu_domain *domain)
{
struct sprd_iommu_domain *dom = to_sprd_domain(domain);
sprd_iommu_cleanup(dom);
kfree(dom);
}
static int sprd_iommu_attach_device(struct iommu_domain *domain,
struct device *dev)
{
struct sprd_iommu_device *sdev = dev_iommu_priv_get(dev);
struct sprd_iommu_domain *dom = to_sprd_domain(domain);
size_t pgt_size = sprd_iommu_pgt_size(domain);
/* The device is attached to this domain */
if (sdev->dom == dom)
return 0;
/* The first time that domain is attaching to a device */
if (!dom->pgt_va) {
dom->pgt_va = dma_alloc_coherent(sdev->dev, pgt_size, &dom->pgt_pa, GFP_KERNEL);
if (!dom->pgt_va)
return -ENOMEM;
dom->sdev = sdev;
}
sdev->dom = dom;
/*
* One sprd IOMMU serves one client device only, disabled it before
* configure mapping table to avoid access conflict in case other
* mapping table is stored in.
*/
sprd_iommu_hw_en(sdev, false);
sprd_iommu_first_ppn(dom);
sprd_iommu_first_vpn(dom);
sprd_iommu_vpn_range(dom);
sprd_iommu_default_ppn(sdev);
sprd_iommu_hw_en(sdev, true);
return 0;
}
static int sprd_iommu_map(struct iommu_domain *domain, unsigned long iova,
phys_addr_t paddr, size_t pgsize, size_t pgcount,
int prot, gfp_t gfp, size_t *mapped)
{
struct sprd_iommu_domain *dom = to_sprd_domain(domain);
size_t size = pgcount * SPRD_IOMMU_PAGE_SIZE;
unsigned long flags;
unsigned int i;
u32 *pgt_base_iova;
u32 pabase = (u32)paddr;
unsigned long start = domain->geometry.aperture_start;
unsigned long end = domain->geometry.aperture_end;
if (!dom->sdev) {
pr_err("No sprd_iommu_device attached to the domain\n");
return -EINVAL;
}
if (iova < start || (iova + size) > (end + 1)) {
dev_err(dom->sdev->dev, "(iova(0x%lx) + size(%zx)) are not in the range!\n",
iova, size);
return -EINVAL;
}
pgt_base_iova = dom->pgt_va + ((iova - start) >> SPRD_IOMMU_PAGE_SHIFT);
spin_lock_irqsave(&dom->pgtlock, flags);
for (i = 0; i < pgcount; i++) {
pgt_base_iova[i] = pabase >> SPRD_IOMMU_PAGE_SHIFT;
pabase += SPRD_IOMMU_PAGE_SIZE;
}
spin_unlock_irqrestore(&dom->pgtlock, flags);
*mapped = size;
return 0;
}
static size_t sprd_iommu_unmap(struct iommu_domain *domain, unsigned long iova,
size_t pgsize, size_t pgcount,
struct iommu_iotlb_gather *iotlb_gather)
{
struct sprd_iommu_domain *dom = to_sprd_domain(domain);
unsigned long flags;
u32 *pgt_base_iova;
size_t size = pgcount * SPRD_IOMMU_PAGE_SIZE;
unsigned long start = domain->geometry.aperture_start;
unsigned long end = domain->geometry.aperture_end;
if (iova < start || (iova + size) > (end + 1))
return 0;
pgt_base_iova = dom->pgt_va + ((iova - start) >> SPRD_IOMMU_PAGE_SHIFT);
spin_lock_irqsave(&dom->pgtlock, flags);
memset(pgt_base_iova, 0, pgcount * sizeof(u32));
spin_unlock_irqrestore(&dom->pgtlock, flags);
return size;
}
static int sprd_iommu_sync_map(struct iommu_domain *domain,
unsigned long iova, size_t size)
{
struct sprd_iommu_domain *dom = to_sprd_domain(domain);
unsigned int reg;
if (dom->sdev->ver == SPRD_IOMMU_EX)
reg = SPRD_EX_UPDATE;
else
reg = SPRD_VAU_UPDATE;
/* clear IOMMU TLB buffer after page table updated */
sprd_iommu_write(dom->sdev, reg, 0xffffffff);
return 0;
}
static void sprd_iommu_sync(struct iommu_domain *domain,
struct iommu_iotlb_gather *iotlb_gather)
{
sprd_iommu_sync_map(domain, 0, 0);
}
static phys_addr_t sprd_iommu_iova_to_phys(struct iommu_domain *domain,
dma_addr_t iova)
{
struct sprd_iommu_domain *dom = to_sprd_domain(domain);
unsigned long flags;
phys_addr_t pa;
unsigned long start = domain->geometry.aperture_start;
unsigned long end = domain->geometry.aperture_end;
if (WARN_ON(iova < start || iova > end))
return 0;
spin_lock_irqsave(&dom->pgtlock, flags);
pa = *(dom->pgt_va + ((iova - start) >> SPRD_IOMMU_PAGE_SHIFT));
pa = (pa << SPRD_IOMMU_PAGE_SHIFT) + ((iova - start) & (SPRD_IOMMU_PAGE_SIZE - 1));
spin_unlock_irqrestore(&dom->pgtlock, flags);
return pa;
}
static struct iommu_device *sprd_iommu_probe_device(struct device *dev)
{
struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
struct sprd_iommu_device *sdev;
if (!fwspec || fwspec->ops != &sprd_iommu_ops)
return ERR_PTR(-ENODEV);
sdev = dev_iommu_priv_get(dev);
return &sdev->iommu;
}
static int sprd_iommu_of_xlate(struct device *dev, struct of_phandle_args *args)
{
struct platform_device *pdev;
if (!dev_iommu_priv_get(dev)) {
pdev = of_find_device_by_node(args->np);
dev_iommu_priv_set(dev, platform_get_drvdata(pdev));
platform_device_put(pdev);
}
return 0;
}
static const struct iommu_ops sprd_iommu_ops = {
.domain_alloc_paging = sprd_iommu_domain_alloc_paging,
.probe_device = sprd_iommu_probe_device,
.device_group = generic_single_device_group,
.of_xlate = sprd_iommu_of_xlate,
.pgsize_bitmap = SPRD_IOMMU_PAGE_SIZE,
.owner = THIS_MODULE,
.default_domain_ops = &(const struct iommu_domain_ops) {
.attach_dev = sprd_iommu_attach_device,
.map_pages = sprd_iommu_map,
.unmap_pages = sprd_iommu_unmap,
.iotlb_sync_map = sprd_iommu_sync_map,
.iotlb_sync = sprd_iommu_sync,
.iova_to_phys = sprd_iommu_iova_to_phys,
.free = sprd_iommu_domain_free,
}
};
static const struct of_device_id sprd_iommu_of_match[] = {
{ .compatible = "sprd,iommu-v1" },
{ },
};
MODULE_DEVICE_TABLE(of, sprd_iommu_of_match);
/*
* Clock is not required, access to some of IOMMUs is controlled by gate
* clk, enabled clocks for that kind of IOMMUs before accessing.
* Return 0 for success or no clocks found.
*/
static int sprd_iommu_clk_enable(struct sprd_iommu_device *sdev)
{
struct clk *eb;
eb = devm_clk_get_optional(sdev->dev, NULL);
if (!eb)
return 0;
if (IS_ERR(eb))
return PTR_ERR(eb);
sdev->eb = eb;
return clk_prepare_enable(eb);
}
static void sprd_iommu_clk_disable(struct sprd_iommu_device *sdev)
{
if (sdev->eb)
clk_disable_unprepare(sdev->eb);
}
static int sprd_iommu_probe(struct platform_device *pdev)
{
struct sprd_iommu_device *sdev;
struct device *dev = &pdev->dev;
void __iomem *base;
int ret;
sdev = devm_kzalloc(dev, sizeof(*sdev), GFP_KERNEL);
if (!sdev)
return -ENOMEM;
base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(base)) {
dev_err(dev, "Failed to get ioremap resource.\n");
return PTR_ERR(base);
}
sdev->base = base;
sdev->prot_page_va = dma_alloc_coherent(dev, SPRD_IOMMU_PAGE_SIZE,
&sdev->prot_page_pa, GFP_KERNEL);
if (!sdev->prot_page_va)
return -ENOMEM;
platform_set_drvdata(pdev, sdev);
sdev->dev = dev;
ret = iommu_device_sysfs_add(&sdev->iommu, dev, NULL, dev_name(dev));
if (ret)
goto free_page;
ret = iommu_device_register(&sdev->iommu, &sprd_iommu_ops, dev);
if (ret)
goto remove_sysfs;
ret = sprd_iommu_clk_enable(sdev);
if (ret)
goto unregister_iommu;
ret = sprd_iommu_get_version(sdev);
if (ret < 0) {
dev_err(dev, "IOMMU version(%d) is invalid.\n", ret);
goto disable_clk;
}
sdev->ver = ret;
return 0;
disable_clk:
sprd_iommu_clk_disable(sdev);
unregister_iommu:
iommu_device_unregister(&sdev->iommu);
remove_sysfs:
iommu_device_sysfs_remove(&sdev->iommu);
free_page:
dma_free_coherent(sdev->dev, SPRD_IOMMU_PAGE_SIZE, sdev->prot_page_va, sdev->prot_page_pa);
return ret;
}
static void sprd_iommu_remove(struct platform_device *pdev)
{
struct sprd_iommu_device *sdev = platform_get_drvdata(pdev);
dma_free_coherent(sdev->dev, SPRD_IOMMU_PAGE_SIZE, sdev->prot_page_va, sdev->prot_page_pa);
platform_set_drvdata(pdev, NULL);
iommu_device_sysfs_remove(&sdev->iommu);
iommu_device_unregister(&sdev->iommu);
}
static struct platform_driver sprd_iommu_driver = {
.driver = {
.name = "sprd-iommu",
.of_match_table = sprd_iommu_of_match,
.suppress_bind_attrs = true,
},
.probe = sprd_iommu_probe,
.remove_new = sprd_iommu_remove,
};
module_platform_driver(sprd_iommu_driver);
MODULE_DESCRIPTION("IOMMU driver for Unisoc SoCs");
MODULE_ALIAS("platform:sprd-iommu");
MODULE_LICENSE("GPL");