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linux/drivers/iommu/rockchip-iommu.c
Marc Zyngier 1a4e90f25b iommu/rockchip: Perform a reset on shutdown 
Trying to do a kexec whilst the iommus are still on is proving to be
a challenging exercise. It is terribly unsafe, as we're reusing the
memory allocated for the page tables, leading to a likely crash.

Let's implement a shutdown method that will at least try to stop
DMA from going crazy behind our back. Note that we need to be
extra cautious when doing so, as the IOMMU may not be clocked
if controlled by a another master, as typical on Rockchip system.

Suggested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2018-03-15 15:11:56 +01:00

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/*
* 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.
*/
#include <linux/compiler.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dma-iommu.h>
#include <linux/dma-mapping.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iommu.h>
#include <linux/jiffies.h>
#include <linux/list.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
/** MMU register offsets */
#define RK_MMU_DTE_ADDR 0x00 /* Directory table address */
#define RK_MMU_STATUS 0x04
#define RK_MMU_COMMAND 0x08
#define RK_MMU_PAGE_FAULT_ADDR 0x0C /* IOVA of last page fault */
#define RK_MMU_ZAP_ONE_LINE 0x10 /* Shootdown one IOTLB entry */
#define RK_MMU_INT_RAWSTAT 0x14 /* IRQ status ignoring mask */
#define RK_MMU_INT_CLEAR 0x18 /* Acknowledge and re-arm irq */
#define RK_MMU_INT_MASK 0x1C /* IRQ enable */
#define RK_MMU_INT_STATUS 0x20 /* IRQ status after masking */
#define RK_MMU_AUTO_GATING 0x24
#define DTE_ADDR_DUMMY 0xCAFEBABE
#define FORCE_RESET_TIMEOUT 100 /* ms */
/* RK_MMU_STATUS fields */
#define RK_MMU_STATUS_PAGING_ENABLED BIT(0)
#define RK_MMU_STATUS_PAGE_FAULT_ACTIVE BIT(1)
#define RK_MMU_STATUS_STALL_ACTIVE BIT(2)
#define RK_MMU_STATUS_IDLE BIT(3)
#define RK_MMU_STATUS_REPLAY_BUFFER_EMPTY BIT(4)
#define RK_MMU_STATUS_PAGE_FAULT_IS_WRITE BIT(5)
#define RK_MMU_STATUS_STALL_NOT_ACTIVE BIT(31)
/* RK_MMU_COMMAND command values */
#define RK_MMU_CMD_ENABLE_PAGING 0 /* Enable memory translation */
#define RK_MMU_CMD_DISABLE_PAGING 1 /* Disable memory translation */
#define RK_MMU_CMD_ENABLE_STALL 2 /* Stall paging to allow other cmds */
#define RK_MMU_CMD_DISABLE_STALL 3 /* Stop stall re-enables paging */
#define RK_MMU_CMD_ZAP_CACHE 4 /* Shoot down entire IOTLB */
#define RK_MMU_CMD_PAGE_FAULT_DONE 5 /* Clear page fault */
#define RK_MMU_CMD_FORCE_RESET 6 /* Reset all registers */
/* RK_MMU_INT_* register fields */
#define RK_MMU_IRQ_PAGE_FAULT 0x01 /* page fault */
#define RK_MMU_IRQ_BUS_ERROR 0x02 /* bus read error */
#define RK_MMU_IRQ_MASK (RK_MMU_IRQ_PAGE_FAULT | RK_MMU_IRQ_BUS_ERROR)
#define NUM_DT_ENTRIES 1024
#define NUM_PT_ENTRIES 1024
#define SPAGE_ORDER 12
#define SPAGE_SIZE (1 << SPAGE_ORDER)
/*
* Support mapping any size that fits in one page table:
* 4 KiB to 4 MiB
*/
#define RK_IOMMU_PGSIZE_BITMAP 0x007ff000
#define IOMMU_REG_POLL_COUNT_FAST 1000
struct rk_iommu_domain {
struct list_head iommus;
struct platform_device *pdev;
u32 *dt; /* page directory table */
dma_addr_t dt_dma;
spinlock_t iommus_lock; /* lock for iommus list */
spinlock_t dt_lock; /* lock for modifying page directory table */
struct iommu_domain domain;
};
struct rk_iommu {
struct device *dev;
void __iomem **bases;
int num_mmu;
int *irq;
int num_irq;
bool reset_disabled;
struct iommu_device iommu;
struct list_head node; /* entry in rk_iommu_domain.iommus */
struct iommu_domain *domain; /* domain to which iommu is attached */
};
static inline void rk_table_flush(struct rk_iommu_domain *dom, dma_addr_t dma,
unsigned int count)
{
size_t size = count * sizeof(u32); /* count of u32 entry */
dma_sync_single_for_device(&dom->pdev->dev, dma, size, DMA_TO_DEVICE);
}
static struct rk_iommu_domain *to_rk_domain(struct iommu_domain *dom)
{
return container_of(dom, struct rk_iommu_domain, domain);
}
/**
* Inspired by _wait_for in intel_drv.h
* This is NOT safe for use in interrupt context.
*
* Note that it's important that we check the condition again after having
* timed out, since the timeout could be due to preemption or similar and
* we've never had a chance to check the condition before the timeout.
*/
#define rk_wait_for(COND, MS) ({ \
unsigned long timeout__ = jiffies + msecs_to_jiffies(MS) + 1; \
int ret__ = 0; \
while (!(COND)) { \
if (time_after(jiffies, timeout__)) { \
ret__ = (COND) ? 0 : -ETIMEDOUT; \
break; \
} \
usleep_range(50, 100); \
} \
ret__; \
})
/*
* The Rockchip rk3288 iommu uses a 2-level page table.
* The first level is the "Directory Table" (DT).
* The DT consists of 1024 4-byte Directory Table Entries (DTEs), each pointing
* to a "Page Table".
* The second level is the 1024 Page Tables (PT).
* Each PT consists of 1024 4-byte Page Table Entries (PTEs), each pointing to
* a 4 KB page of physical memory.
*
* The DT and each PT fits in a single 4 KB page (4-bytes * 1024 entries).
* Each iommu device has a MMU_DTE_ADDR register that contains the physical
* address of the start of the DT page.
*
* The structure of the page table is as follows:
*
* DT
* MMU_DTE_ADDR -> +-----+
* | |
* +-----+ PT
* | DTE | -> +-----+
* +-----+ | | Memory
* | | +-----+ Page
* | | | PTE | -> +-----+
* +-----+ +-----+ | |
* | | | |
* | | | |
* +-----+ | |
* | |
* | |
* +-----+
*/
/*
* Each DTE has a PT address and a valid bit:
* +---------------------+-----------+-+
* | PT address | Reserved |V|
* +---------------------+-----------+-+
* 31:12 - PT address (PTs always starts on a 4 KB boundary)
* 11: 1 - Reserved
* 0 - 1 if PT @ PT address is valid
*/
#define RK_DTE_PT_ADDRESS_MASK 0xfffff000
#define RK_DTE_PT_VALID BIT(0)
static inline phys_addr_t rk_dte_pt_address(u32 dte)
{
return (phys_addr_t)dte & RK_DTE_PT_ADDRESS_MASK;
}
static inline bool rk_dte_is_pt_valid(u32 dte)
{
return dte & RK_DTE_PT_VALID;
}
static inline u32 rk_mk_dte(dma_addr_t pt_dma)
{
return (pt_dma & RK_DTE_PT_ADDRESS_MASK) | RK_DTE_PT_VALID;
}
/*
* Each PTE has a Page address, some flags and a valid bit:
* +---------------------+---+-------+-+
* | Page address |Rsv| Flags |V|
* +---------------------+---+-------+-+
* 31:12 - Page address (Pages always start on a 4 KB boundary)
* 11: 9 - Reserved
* 8: 1 - Flags
* 8 - Read allocate - allocate cache space on read misses
* 7 - Read cache - enable cache & prefetch of data
* 6 - Write buffer - enable delaying writes on their way to memory
* 5 - Write allocate - allocate cache space on write misses
* 4 - Write cache - different writes can be merged together
* 3 - Override cache attributes
* if 1, bits 4-8 control cache attributes
* if 0, the system bus defaults are used
* 2 - Writable
* 1 - Readable
* 0 - 1 if Page @ Page address is valid
*/
#define RK_PTE_PAGE_ADDRESS_MASK 0xfffff000
#define RK_PTE_PAGE_FLAGS_MASK 0x000001fe
#define RK_PTE_PAGE_WRITABLE BIT(2)
#define RK_PTE_PAGE_READABLE BIT(1)
#define RK_PTE_PAGE_VALID BIT(0)
static inline phys_addr_t rk_pte_page_address(u32 pte)
{
return (phys_addr_t)pte & RK_PTE_PAGE_ADDRESS_MASK;
}
static inline bool rk_pte_is_page_valid(u32 pte)
{
return pte & RK_PTE_PAGE_VALID;
}
/* TODO: set cache flags per prot IOMMU_CACHE */
static u32 rk_mk_pte(phys_addr_t page, int prot)
{
u32 flags = 0;
flags |= (prot & IOMMU_READ) ? RK_PTE_PAGE_READABLE : 0;
flags |= (prot & IOMMU_WRITE) ? RK_PTE_PAGE_WRITABLE : 0;
page &= RK_PTE_PAGE_ADDRESS_MASK;
return page | flags | RK_PTE_PAGE_VALID;
}
static u32 rk_mk_pte_invalid(u32 pte)
{
return pte & ~RK_PTE_PAGE_VALID;
}
/*
* rk3288 iova (IOMMU Virtual Address) format
* 31 22.21 12.11 0
* +-----------+-----------+-------------+
* | DTE index | PTE index | Page offset |
* +-----------+-----------+-------------+
* 31:22 - DTE index - index of DTE in DT
* 21:12 - PTE index - index of PTE in PT @ DTE.pt_address
* 11: 0 - Page offset - offset into page @ PTE.page_address
*/
#define RK_IOVA_DTE_MASK 0xffc00000
#define RK_IOVA_DTE_SHIFT 22
#define RK_IOVA_PTE_MASK 0x003ff000
#define RK_IOVA_PTE_SHIFT 12
#define RK_IOVA_PAGE_MASK 0x00000fff
#define RK_IOVA_PAGE_SHIFT 0
static u32 rk_iova_dte_index(dma_addr_t iova)
{
return (u32)(iova & RK_IOVA_DTE_MASK) >> RK_IOVA_DTE_SHIFT;
}
static u32 rk_iova_pte_index(dma_addr_t iova)
{
return (u32)(iova & RK_IOVA_PTE_MASK) >> RK_IOVA_PTE_SHIFT;
}
static u32 rk_iova_page_offset(dma_addr_t iova)
{
return (u32)(iova & RK_IOVA_PAGE_MASK) >> RK_IOVA_PAGE_SHIFT;
}
static u32 rk_iommu_read(void __iomem *base, u32 offset)
{
return readl(base + offset);
}
static void rk_iommu_write(void __iomem *base, u32 offset, u32 value)
{
writel(value, base + offset);
}
static void rk_iommu_command(struct rk_iommu *iommu, u32 command)
{
int i;
for (i = 0; i < iommu->num_mmu; i++)
writel(command, iommu->bases[i] + RK_MMU_COMMAND);
}
static void rk_iommu_base_command(void __iomem *base, u32 command)
{
writel(command, base + RK_MMU_COMMAND);
}
static void rk_iommu_zap_lines(struct rk_iommu *iommu, dma_addr_t iova,
size_t size)
{
int i;
dma_addr_t iova_end = iova + size;
/*
* TODO(djkurtz): Figure out when it is more efficient to shootdown the
* entire iotlb rather than iterate over individual iovas.
*/
for (i = 0; i < iommu->num_mmu; i++)
for (; iova < iova_end; iova += SPAGE_SIZE)
rk_iommu_write(iommu->bases[i], RK_MMU_ZAP_ONE_LINE, iova);
}
static bool rk_iommu_is_stall_active(struct rk_iommu *iommu)
{
bool active = true;
int i;
for (i = 0; i < iommu->num_mmu; i++)
active &= !!(rk_iommu_read(iommu->bases[i], RK_MMU_STATUS) &
RK_MMU_STATUS_STALL_ACTIVE);
return active;
}
static bool rk_iommu_is_paging_enabled(struct rk_iommu *iommu)
{
bool enable = true;
int i;
for (i = 0; i < iommu->num_mmu; i++)
enable &= !!(rk_iommu_read(iommu->bases[i], RK_MMU_STATUS) &
RK_MMU_STATUS_PAGING_ENABLED);
return enable;
}
static int rk_iommu_enable_stall(struct rk_iommu *iommu)
{
int ret, i;
if (rk_iommu_is_stall_active(iommu))
return 0;
/* Stall can only be enabled if paging is enabled */
if (!rk_iommu_is_paging_enabled(iommu))
return 0;
rk_iommu_command(iommu, RK_MMU_CMD_ENABLE_STALL);
ret = rk_wait_for(rk_iommu_is_stall_active(iommu), 1);
if (ret)
for (i = 0; i < iommu->num_mmu; i++)
dev_err(iommu->dev, "Enable stall request timed out, status: %#08x\n",
rk_iommu_read(iommu->bases[i], RK_MMU_STATUS));
return ret;
}
static int rk_iommu_disable_stall(struct rk_iommu *iommu)
{
int ret, i;
if (!rk_iommu_is_stall_active(iommu))
return 0;
rk_iommu_command(iommu, RK_MMU_CMD_DISABLE_STALL);
ret = rk_wait_for(!rk_iommu_is_stall_active(iommu), 1);
if (ret)
for (i = 0; i < iommu->num_mmu; i++)
dev_err(iommu->dev, "Disable stall request timed out, status: %#08x\n",
rk_iommu_read(iommu->bases[i], RK_MMU_STATUS));
return ret;
}
static int rk_iommu_enable_paging(struct rk_iommu *iommu)
{
int ret, i;
if (rk_iommu_is_paging_enabled(iommu))
return 0;
rk_iommu_command(iommu, RK_MMU_CMD_ENABLE_PAGING);
ret = rk_wait_for(rk_iommu_is_paging_enabled(iommu), 1);
if (ret)
for (i = 0; i < iommu->num_mmu; i++)
dev_err(iommu->dev, "Enable paging request timed out, status: %#08x\n",
rk_iommu_read(iommu->bases[i], RK_MMU_STATUS));
return ret;
}
static int rk_iommu_disable_paging(struct rk_iommu *iommu)
{
int ret, i;
if (!rk_iommu_is_paging_enabled(iommu))
return 0;
rk_iommu_command(iommu, RK_MMU_CMD_DISABLE_PAGING);
ret = rk_wait_for(!rk_iommu_is_paging_enabled(iommu), 1);
if (ret)
for (i = 0; i < iommu->num_mmu; i++)
dev_err(iommu->dev, "Disable paging request timed out, status: %#08x\n",
rk_iommu_read(iommu->bases[i], RK_MMU_STATUS));
return ret;
}
static int rk_iommu_force_reset(struct rk_iommu *iommu)
{
int ret, i;
u32 dte_addr;
if (iommu->reset_disabled)
return 0;
/*
* Check if register DTE_ADDR is working by writing DTE_ADDR_DUMMY
* and verifying that upper 5 nybbles are read back.
*/
for (i = 0; i < iommu->num_mmu; i++) {
rk_iommu_write(iommu->bases[i], RK_MMU_DTE_ADDR, DTE_ADDR_DUMMY);
dte_addr = rk_iommu_read(iommu->bases[i], RK_MMU_DTE_ADDR);
if (dte_addr != (DTE_ADDR_DUMMY & RK_DTE_PT_ADDRESS_MASK)) {
dev_err(iommu->dev, "Error during raw reset. MMU_DTE_ADDR is not functioning\n");
return -EFAULT;
}
}
rk_iommu_command(iommu, RK_MMU_CMD_FORCE_RESET);
for (i = 0; i < iommu->num_mmu; i++) {
ret = rk_wait_for(rk_iommu_read(iommu->bases[i], RK_MMU_DTE_ADDR) == 0x00000000,
FORCE_RESET_TIMEOUT);
if (ret) {
dev_err(iommu->dev, "FORCE_RESET command timed out\n");
return ret;
}
}
return 0;
}
static void log_iova(struct rk_iommu *iommu, int index, dma_addr_t iova)
{
void __iomem *base = iommu->bases[index];
u32 dte_index, pte_index, page_offset;
u32 mmu_dte_addr;
phys_addr_t mmu_dte_addr_phys, dte_addr_phys;
u32 *dte_addr;
u32 dte;
phys_addr_t pte_addr_phys = 0;
u32 *pte_addr = NULL;
u32 pte = 0;
phys_addr_t page_addr_phys = 0;
u32 page_flags = 0;
dte_index = rk_iova_dte_index(iova);
pte_index = rk_iova_pte_index(iova);
page_offset = rk_iova_page_offset(iova);
mmu_dte_addr = rk_iommu_read(base, RK_MMU_DTE_ADDR);
mmu_dte_addr_phys = (phys_addr_t)mmu_dte_addr;
dte_addr_phys = mmu_dte_addr_phys + (4 * dte_index);
dte_addr = phys_to_virt(dte_addr_phys);
dte = *dte_addr;
if (!rk_dte_is_pt_valid(dte))
goto print_it;
pte_addr_phys = rk_dte_pt_address(dte) + (pte_index * 4);
pte_addr = phys_to_virt(pte_addr_phys);
pte = *pte_addr;
if (!rk_pte_is_page_valid(pte))
goto print_it;
page_addr_phys = rk_pte_page_address(pte) + page_offset;
page_flags = pte & RK_PTE_PAGE_FLAGS_MASK;
print_it:
dev_err(iommu->dev, "iova = %pad: dte_index: %#03x pte_index: %#03x page_offset: %#03x\n",
&iova, dte_index, pte_index, page_offset);
dev_err(iommu->dev, "mmu_dte_addr: %pa dte@%pa: %#08x valid: %u pte@%pa: %#08x valid: %u page@%pa flags: %#03x\n",
&mmu_dte_addr_phys, &dte_addr_phys, dte,
rk_dte_is_pt_valid(dte), &pte_addr_phys, pte,
rk_pte_is_page_valid(pte), &page_addr_phys, page_flags);
}
static irqreturn_t rk_iommu_irq(int irq, void *dev_id)
{
struct rk_iommu *iommu = dev_id;
u32 status;
u32 int_status;
dma_addr_t iova;
irqreturn_t ret = IRQ_NONE;
int i;
for (i = 0; i < iommu->num_mmu; i++) {
int_status = rk_iommu_read(iommu->bases[i], RK_MMU_INT_STATUS);
if (int_status == 0)
continue;
ret = IRQ_HANDLED;
iova = rk_iommu_read(iommu->bases[i], RK_MMU_PAGE_FAULT_ADDR);
if (int_status & RK_MMU_IRQ_PAGE_FAULT) {
int flags;
status = rk_iommu_read(iommu->bases[i], RK_MMU_STATUS);
flags = (status & RK_MMU_STATUS_PAGE_FAULT_IS_WRITE) ?
IOMMU_FAULT_WRITE : IOMMU_FAULT_READ;
dev_err(iommu->dev, "Page fault at %pad of type %s\n",
&iova,
(flags == IOMMU_FAULT_WRITE) ? "write" : "read");
log_iova(iommu, i, iova);
/*
* Report page fault to any installed handlers.
* Ignore the return code, though, since we always zap cache
* and clear the page fault anyway.
*/
if (iommu->domain)
report_iommu_fault(iommu->domain, iommu->dev, iova,
flags);
else
dev_err(iommu->dev, "Page fault while iommu not attached to domain?\n");
rk_iommu_base_command(iommu->bases[i], RK_MMU_CMD_ZAP_CACHE);
rk_iommu_base_command(iommu->bases[i], RK_MMU_CMD_PAGE_FAULT_DONE);
}
if (int_status & RK_MMU_IRQ_BUS_ERROR)
dev_err(iommu->dev, "BUS_ERROR occurred at %pad\n", &iova);
if (int_status & ~RK_MMU_IRQ_MASK)
dev_err(iommu->dev, "unexpected int_status: %#08x\n",
int_status);
rk_iommu_write(iommu->bases[i], RK_MMU_INT_CLEAR, int_status);
}
return ret;
}
static phys_addr_t rk_iommu_iova_to_phys(struct iommu_domain *domain,
dma_addr_t iova)
{
struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
unsigned long flags;
phys_addr_t pt_phys, phys = 0;
u32 dte, pte;
u32 *page_table;
spin_lock_irqsave(&rk_domain->dt_lock, flags);
dte = rk_domain->dt[rk_iova_dte_index(iova)];
if (!rk_dte_is_pt_valid(dte))
goto out;
pt_phys = rk_dte_pt_address(dte);
page_table = (u32 *)phys_to_virt(pt_phys);
pte = page_table[rk_iova_pte_index(iova)];
if (!rk_pte_is_page_valid(pte))
goto out;
phys = rk_pte_page_address(pte) + rk_iova_page_offset(iova);
out:
spin_unlock_irqrestore(&rk_domain->dt_lock, flags);
return phys;
}
static void rk_iommu_zap_iova(struct rk_iommu_domain *rk_domain,
dma_addr_t iova, size_t size)
{
struct list_head *pos;
unsigned long flags;
/* shootdown these iova from all iommus using this domain */
spin_lock_irqsave(&rk_domain->iommus_lock, flags);
list_for_each(pos, &rk_domain->iommus) {
struct rk_iommu *iommu;
iommu = list_entry(pos, struct rk_iommu, node);
rk_iommu_zap_lines(iommu, iova, size);
}
spin_unlock_irqrestore(&rk_domain->iommus_lock, flags);
}
static void rk_iommu_zap_iova_first_last(struct rk_iommu_domain *rk_domain,
dma_addr_t iova, size_t size)
{
rk_iommu_zap_iova(rk_domain, iova, SPAGE_SIZE);
if (size > SPAGE_SIZE)
rk_iommu_zap_iova(rk_domain, iova + size - SPAGE_SIZE,
SPAGE_SIZE);
}
static u32 *rk_dte_get_page_table(struct rk_iommu_domain *rk_domain,
dma_addr_t iova)
{
struct device *dev = &rk_domain->pdev->dev;
u32 *page_table, *dte_addr;
u32 dte_index, dte;
phys_addr_t pt_phys;
dma_addr_t pt_dma;
assert_spin_locked(&rk_domain->dt_lock);
dte_index = rk_iova_dte_index(iova);
dte_addr = &rk_domain->dt[dte_index];
dte = *dte_addr;
if (rk_dte_is_pt_valid(dte))
goto done;
page_table = (u32 *)get_zeroed_page(GFP_ATOMIC | GFP_DMA32);
if (!page_table)
return ERR_PTR(-ENOMEM);
pt_dma = dma_map_single(dev, page_table, SPAGE_SIZE, DMA_TO_DEVICE);
if (dma_mapping_error(dev, pt_dma)) {
dev_err(dev, "DMA mapping error while allocating page table\n");
free_page((unsigned long)page_table);
return ERR_PTR(-ENOMEM);
}
dte = rk_mk_dte(pt_dma);
*dte_addr = dte;
rk_table_flush(rk_domain, pt_dma, NUM_PT_ENTRIES);
rk_table_flush(rk_domain,
rk_domain->dt_dma + dte_index * sizeof(u32), 1);
done:
pt_phys = rk_dte_pt_address(dte);
return (u32 *)phys_to_virt(pt_phys);
}
static size_t rk_iommu_unmap_iova(struct rk_iommu_domain *rk_domain,
u32 *pte_addr, dma_addr_t pte_dma,
size_t size)
{
unsigned int pte_count;
unsigned int pte_total = size / SPAGE_SIZE;
assert_spin_locked(&rk_domain->dt_lock);
for (pte_count = 0; pte_count < pte_total; pte_count++) {
u32 pte = pte_addr[pte_count];
if (!rk_pte_is_page_valid(pte))
break;
pte_addr[pte_count] = rk_mk_pte_invalid(pte);
}
rk_table_flush(rk_domain, pte_dma, pte_count);
return pte_count * SPAGE_SIZE;
}
static int rk_iommu_map_iova(struct rk_iommu_domain *rk_domain, u32 *pte_addr,
dma_addr_t pte_dma, dma_addr_t iova,
phys_addr_t paddr, size_t size, int prot)
{
unsigned int pte_count;
unsigned int pte_total = size / SPAGE_SIZE;
phys_addr_t page_phys;
assert_spin_locked(&rk_domain->dt_lock);
for (pte_count = 0; pte_count < pte_total; pte_count++) {
u32 pte = pte_addr[pte_count];
if (rk_pte_is_page_valid(pte))
goto unwind;
pte_addr[pte_count] = rk_mk_pte(paddr, prot);
paddr += SPAGE_SIZE;
}
rk_table_flush(rk_domain, pte_dma, pte_total);
/*
* Zap the first and last iova to evict from iotlb any previously
* mapped cachelines holding stale values for its dte and pte.
* We only zap the first and last iova, since only they could have
* dte or pte shared with an existing mapping.
*/
rk_iommu_zap_iova_first_last(rk_domain, iova, size);
return 0;
unwind:
/* Unmap the range of iovas that we just mapped */
rk_iommu_unmap_iova(rk_domain, pte_addr, pte_dma,
pte_count * SPAGE_SIZE);
iova += pte_count * SPAGE_SIZE;
page_phys = rk_pte_page_address(pte_addr[pte_count]);
pr_err("iova: %pad already mapped to %pa cannot remap to phys: %pa prot: %#x\n",
&iova, &page_phys, &paddr, prot);
return -EADDRINUSE;
}
static int rk_iommu_map(struct iommu_domain *domain, unsigned long _iova,
phys_addr_t paddr, size_t size, int prot)
{
struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
unsigned long flags;
dma_addr_t pte_dma, iova = (dma_addr_t)_iova;
u32 *page_table, *pte_addr;
u32 dte_index, pte_index;
int ret;
spin_lock_irqsave(&rk_domain->dt_lock, flags);
/*
* pgsize_bitmap specifies iova sizes that fit in one page table
* (1024 4-KiB pages = 4 MiB).
* So, size will always be 4096 <= size <= 4194304.
* Since iommu_map() guarantees that both iova and size will be
* aligned, we will always only be mapping from a single dte here.
*/
page_table = rk_dte_get_page_table(rk_domain, iova);
if (IS_ERR(page_table)) {
spin_unlock_irqrestore(&rk_domain->dt_lock, flags);
return PTR_ERR(page_table);
}
dte_index = rk_domain->dt[rk_iova_dte_index(iova)];
pte_index = rk_iova_pte_index(iova);
pte_addr = &page_table[pte_index];
pte_dma = rk_dte_pt_address(dte_index) + pte_index * sizeof(u32);
ret = rk_iommu_map_iova(rk_domain, pte_addr, pte_dma, iova,
paddr, size, prot);
spin_unlock_irqrestore(&rk_domain->dt_lock, flags);
return ret;
}
static size_t rk_iommu_unmap(struct iommu_domain *domain, unsigned long _iova,
size_t size)
{
struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
unsigned long flags;
dma_addr_t pte_dma, iova = (dma_addr_t)_iova;
phys_addr_t pt_phys;
u32 dte;
u32 *pte_addr;
size_t unmap_size;
spin_lock_irqsave(&rk_domain->dt_lock, flags);
/*
* pgsize_bitmap specifies iova sizes that fit in one page table
* (1024 4-KiB pages = 4 MiB).
* So, size will always be 4096 <= size <= 4194304.
* Since iommu_unmap() guarantees that both iova and size will be
* aligned, we will always only be unmapping from a single dte here.
*/
dte = rk_domain->dt[rk_iova_dte_index(iova)];
/* Just return 0 if iova is unmapped */
if (!rk_dte_is_pt_valid(dte)) {
spin_unlock_irqrestore(&rk_domain->dt_lock, flags);
return 0;
}
pt_phys = rk_dte_pt_address(dte);
pte_addr = (u32 *)phys_to_virt(pt_phys) + rk_iova_pte_index(iova);
pte_dma = pt_phys + rk_iova_pte_index(iova) * sizeof(u32);
unmap_size = rk_iommu_unmap_iova(rk_domain, pte_addr, pte_dma, size);
spin_unlock_irqrestore(&rk_domain->dt_lock, flags);
/* Shootdown iotlb entries for iova range that was just unmapped */
rk_iommu_zap_iova(rk_domain, iova, unmap_size);
return unmap_size;
}
static struct rk_iommu *rk_iommu_from_dev(struct device *dev)
{
struct iommu_group *group;
struct device *iommu_dev;
struct rk_iommu *rk_iommu;
group = iommu_group_get(dev);
if (!group)
return NULL;
iommu_dev = iommu_group_get_iommudata(group);
rk_iommu = dev_get_drvdata(iommu_dev);
iommu_group_put(group);
return rk_iommu;
}
static int rk_iommu_attach_device(struct iommu_domain *domain,
struct device *dev)
{
struct rk_iommu *iommu;
struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
unsigned long flags;
int ret, i;
/*
* Allow 'virtual devices' (e.g., drm) to attach to domain.
* Such a device does not belong to an iommu group.
*/
iommu = rk_iommu_from_dev(dev);
if (!iommu)
return 0;
ret = rk_iommu_enable_stall(iommu);
if (ret)
return ret;
ret = rk_iommu_force_reset(iommu);
if (ret)
return ret;
iommu->domain = domain;
for (i = 0; i < iommu->num_irq; i++) {
ret = devm_request_irq(iommu->dev, iommu->irq[i], rk_iommu_irq,
IRQF_SHARED, dev_name(dev), iommu);
if (ret)
return ret;
}
for (i = 0; i < iommu->num_mmu; i++) {
rk_iommu_write(iommu->bases[i], RK_MMU_DTE_ADDR,
rk_domain->dt_dma);
rk_iommu_base_command(iommu->bases[i], RK_MMU_CMD_ZAP_CACHE);
rk_iommu_write(iommu->bases[i], RK_MMU_INT_MASK, RK_MMU_IRQ_MASK);
}
ret = rk_iommu_enable_paging(iommu);
if (ret)
return ret;
spin_lock_irqsave(&rk_domain->iommus_lock, flags);
list_add_tail(&iommu->node, &rk_domain->iommus);
spin_unlock_irqrestore(&rk_domain->iommus_lock, flags);
dev_dbg(dev, "Attached to iommu domain\n");
rk_iommu_disable_stall(iommu);
return 0;
}
static void rk_iommu_detach_device(struct iommu_domain *domain,
struct device *dev)
{
struct rk_iommu *iommu;
struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
unsigned long flags;
int i;
/* Allow 'virtual devices' (eg drm) to detach from domain */
iommu = rk_iommu_from_dev(dev);
if (!iommu)
return;
spin_lock_irqsave(&rk_domain->iommus_lock, flags);
list_del_init(&iommu->node);
spin_unlock_irqrestore(&rk_domain->iommus_lock, flags);
/* Ignore error while disabling, just keep going */
rk_iommu_enable_stall(iommu);
rk_iommu_disable_paging(iommu);
for (i = 0; i < iommu->num_mmu; i++) {
rk_iommu_write(iommu->bases[i], RK_MMU_INT_MASK, 0);
rk_iommu_write(iommu->bases[i], RK_MMU_DTE_ADDR, 0);
}
rk_iommu_disable_stall(iommu);
for (i = 0; i < iommu->num_irq; i++)
devm_free_irq(iommu->dev, iommu->irq[i], iommu);
iommu->domain = NULL;
dev_dbg(dev, "Detached from iommu domain\n");
}
static struct iommu_domain *rk_iommu_domain_alloc(unsigned type)
{
struct rk_iommu_domain *rk_domain;
struct platform_device *pdev;
struct device *iommu_dev;
if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA)
return NULL;
/* Register a pdev per domain, so DMA API can base on this *dev
* even some virtual master doesn't have an iommu slave
*/
pdev = platform_device_register_simple("rk_iommu_domain",
PLATFORM_DEVID_AUTO, NULL, 0);
if (IS_ERR(pdev))
return NULL;
rk_domain = devm_kzalloc(&pdev->dev, sizeof(*rk_domain), GFP_KERNEL);
if (!rk_domain)
goto err_unreg_pdev;
rk_domain->pdev = pdev;
if (type == IOMMU_DOMAIN_DMA &&
iommu_get_dma_cookie(&rk_domain->domain))
goto err_unreg_pdev;
/*
* rk32xx iommus use a 2 level pagetable.
* Each level1 (dt) and level2 (pt) table has 1024 4-byte entries.
* Allocate one 4 KiB page for each table.
*/
rk_domain->dt = (u32 *)get_zeroed_page(GFP_KERNEL | GFP_DMA32);
if (!rk_domain->dt)
goto err_put_cookie;
iommu_dev = &pdev->dev;
rk_domain->dt_dma = dma_map_single(iommu_dev, rk_domain->dt,
SPAGE_SIZE, DMA_TO_DEVICE);
if (dma_mapping_error(iommu_dev, rk_domain->dt_dma)) {
dev_err(iommu_dev, "DMA map error for DT\n");
goto err_free_dt;
}
rk_table_flush(rk_domain, rk_domain->dt_dma, NUM_DT_ENTRIES);
spin_lock_init(&rk_domain->iommus_lock);
spin_lock_init(&rk_domain->dt_lock);
INIT_LIST_HEAD(&rk_domain->iommus);
rk_domain->domain.geometry.aperture_start = 0;
rk_domain->domain.geometry.aperture_end = DMA_BIT_MASK(32);
rk_domain->domain.geometry.force_aperture = true;
return &rk_domain->domain;
err_free_dt:
free_page((unsigned long)rk_domain->dt);
err_put_cookie:
if (type == IOMMU_DOMAIN_DMA)
iommu_put_dma_cookie(&rk_domain->domain);
err_unreg_pdev:
platform_device_unregister(pdev);
return NULL;
}
static void rk_iommu_domain_free(struct iommu_domain *domain)
{
struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
int i;
WARN_ON(!list_empty(&rk_domain->iommus));
for (i = 0; i < NUM_DT_ENTRIES; i++) {
u32 dte = rk_domain->dt[i];
if (rk_dte_is_pt_valid(dte)) {
phys_addr_t pt_phys = rk_dte_pt_address(dte);
u32 *page_table = phys_to_virt(pt_phys);
dma_unmap_single(&rk_domain->pdev->dev, pt_phys,
SPAGE_SIZE, DMA_TO_DEVICE);
free_page((unsigned long)page_table);
}
}
dma_unmap_single(&rk_domain->pdev->dev, rk_domain->dt_dma,
SPAGE_SIZE, DMA_TO_DEVICE);
free_page((unsigned long)rk_domain->dt);
if (domain->type == IOMMU_DOMAIN_DMA)
iommu_put_dma_cookie(&rk_domain->domain);
platform_device_unregister(rk_domain->pdev);
}
static bool rk_iommu_is_dev_iommu_master(struct device *dev)
{
struct device_node *np = dev->of_node;
int ret;
/*
* An iommu master has an iommus property containing a list of phandles
* to iommu nodes, each with an #iommu-cells property with value 0.
*/
ret = of_count_phandle_with_args(np, "iommus", "#iommu-cells");
return (ret > 0);
}
static int rk_iommu_group_set_iommudata(struct iommu_group *group,
struct device *dev)
{
struct device_node *np = dev->of_node;
struct platform_device *pd;
int ret;
struct of_phandle_args args;
/*
* An iommu master has an iommus property containing a list of phandles
* to iommu nodes, each with an #iommu-cells property with value 0.
*/
ret = of_parse_phandle_with_args(np, "iommus", "#iommu-cells", 0,
&args);
if (ret) {
dev_err(dev, "of_parse_phandle_with_args(%pOF) => %d\n",
np, ret);
return ret;
}
if (args.args_count != 0) {
dev_err(dev, "incorrect number of iommu params found for %pOF (found %d, expected 0)\n",
args.np, args.args_count);
return -EINVAL;
}
pd = of_find_device_by_node(args.np);
of_node_put(args.np);
if (!pd) {
dev_err(dev, "iommu %pOF not found\n", args.np);
return -EPROBE_DEFER;
}
/* TODO(djkurtz): handle multiple slave iommus for a single master */
iommu_group_set_iommudata(group, &pd->dev, NULL);
return 0;
}
static int rk_iommu_add_device(struct device *dev)
{
struct iommu_group *group;
struct rk_iommu *iommu;
int ret;
if (!rk_iommu_is_dev_iommu_master(dev))
return -ENODEV;
group = iommu_group_get(dev);
if (!group) {
group = iommu_group_alloc();
if (IS_ERR(group)) {
dev_err(dev, "Failed to allocate IOMMU group\n");
return PTR_ERR(group);
}
}
ret = iommu_group_add_device(group, dev);
if (ret)
goto err_put_group;
ret = rk_iommu_group_set_iommudata(group, dev);
if (ret)
goto err_remove_device;
iommu = rk_iommu_from_dev(dev);
if (iommu)
iommu_device_link(&iommu->iommu, dev);
iommu_group_put(group);
return 0;
err_remove_device:
iommu_group_remove_device(dev);
err_put_group:
iommu_group_put(group);
return ret;
}
static void rk_iommu_remove_device(struct device *dev)
{
struct rk_iommu *iommu;
if (!rk_iommu_is_dev_iommu_master(dev))
return;
iommu = rk_iommu_from_dev(dev);
if (iommu)
iommu_device_unlink(&iommu->iommu, dev);
iommu_group_remove_device(dev);
}
static const struct iommu_ops rk_iommu_ops = {
.domain_alloc = rk_iommu_domain_alloc,
.domain_free = rk_iommu_domain_free,
.attach_dev = rk_iommu_attach_device,
.detach_dev = rk_iommu_detach_device,
.map = rk_iommu_map,
.unmap = rk_iommu_unmap,
.map_sg = default_iommu_map_sg,
.add_device = rk_iommu_add_device,
.remove_device = rk_iommu_remove_device,
.iova_to_phys = rk_iommu_iova_to_phys,
.pgsize_bitmap = RK_IOMMU_PGSIZE_BITMAP,
};
static int rk_iommu_domain_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms), GFP_KERNEL);
if (!dev->dma_parms)
return -ENOMEM;
/* Set dma_ops for dev, otherwise it would be dummy_dma_ops */
arch_setup_dma_ops(dev, 0, DMA_BIT_MASK(32), NULL, false);
dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
return 0;
}
static struct platform_driver rk_iommu_domain_driver = {
.probe = rk_iommu_domain_probe,
.driver = {
.name = "rk_iommu_domain",
},
};
static int rk_iommu_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct rk_iommu *iommu;
struct resource *res;
int num_res = pdev->num_resources;
int err, i;
iommu = devm_kzalloc(dev, sizeof(*iommu), GFP_KERNEL);
if (!iommu)
return -ENOMEM;
platform_set_drvdata(pdev, iommu);
iommu->dev = dev;
iommu->num_mmu = 0;
iommu->bases = devm_kzalloc(dev, sizeof(*iommu->bases) * num_res,
GFP_KERNEL);
if (!iommu->bases)
return -ENOMEM;
for (i = 0; i < num_res; i++) {
res = platform_get_resource(pdev, IORESOURCE_MEM, i);
if (!res)
continue;
iommu->bases[i] = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(iommu->bases[i]))
continue;
iommu->num_mmu++;
}
if (iommu->num_mmu == 0)
return PTR_ERR(iommu->bases[0]);
iommu->num_irq = platform_irq_count(pdev);
if (iommu->num_irq < 0)
return iommu->num_irq;
if (iommu->num_irq == 0)
return -ENXIO;
iommu->irq = devm_kcalloc(dev, iommu->num_irq, sizeof(*iommu->irq),
GFP_KERNEL);
if (!iommu->irq)
return -ENOMEM;
for (i = 0; i < iommu->num_irq; i++) {
iommu->irq[i] = platform_get_irq(pdev, i);
if (iommu->irq[i] < 0) {
dev_err(dev, "Failed to get IRQ, %d\n", iommu->irq[i]);
return -ENXIO;
}
}
iommu->reset_disabled = device_property_read_bool(dev,
"rockchip,disable-mmu-reset");
err = iommu_device_sysfs_add(&iommu->iommu, dev, NULL, dev_name(dev));
if (err)
return err;
iommu_device_set_ops(&iommu->iommu, &rk_iommu_ops);
err = iommu_device_register(&iommu->iommu);
return err;
}
static int rk_iommu_remove(struct platform_device *pdev)
{
struct rk_iommu *iommu = platform_get_drvdata(pdev);
if (iommu) {
iommu_device_sysfs_remove(&iommu->iommu);
iommu_device_unregister(&iommu->iommu);
}
return 0;
}
static void rk_iommu_shutdown(struct platform_device *pdev)
{
struct rk_iommu *iommu = platform_get_drvdata(pdev);
/*
* Be careful not to try to shutdown an otherwise unused
* IOMMU, as it is likely not to be clocked, and accessing it
* would just block. An IOMMU without a domain is likely to be
* unused, so let's use this as a (weak) guard.
*/
if (iommu && iommu->domain) {
rk_iommu_enable_stall(iommu);
rk_iommu_disable_paging(iommu);
rk_iommu_force_reset(iommu);
}
}
static const struct of_device_id rk_iommu_dt_ids[] = {
{ .compatible = "rockchip,iommu" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, rk_iommu_dt_ids);
static struct platform_driver rk_iommu_driver = {
.probe = rk_iommu_probe,
.remove = rk_iommu_remove,
.shutdown = rk_iommu_shutdown,
.driver = {
.name = "rk_iommu",
.of_match_table = rk_iommu_dt_ids,
},
};
static int __init rk_iommu_init(void)
{
struct device_node *np;
int ret;
np = of_find_matching_node(NULL, rk_iommu_dt_ids);
if (!np)
return 0;
of_node_put(np);
ret = bus_set_iommu(&platform_bus_type, &rk_iommu_ops);
if (ret)
return ret;
ret = platform_driver_register(&rk_iommu_domain_driver);
if (ret)
return ret;
ret = platform_driver_register(&rk_iommu_driver);
if (ret)
platform_driver_unregister(&rk_iommu_domain_driver);
return ret;
}
static void __exit rk_iommu_exit(void)
{
platform_driver_unregister(&rk_iommu_driver);
platform_driver_unregister(&rk_iommu_domain_driver);
}
subsys_initcall(rk_iommu_init);
module_exit(rk_iommu_exit);
MODULE_DESCRIPTION("IOMMU API for Rockchip");
MODULE_AUTHOR("Simon Xue <xxm@rock-chips.com> and Daniel Kurtz <djkurtz@chromium.org>");
MODULE_ALIAS("platform:rockchip-iommu");
MODULE_LICENSE("GPL v2");
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