iommu: Add driver for Renesas VMSA-compatible IPMMU
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
new file mode 100644
index 0000000..b084530
--- /dev/null
+++ b/drivers/iommu/ipmmu-vmsa.c
@@ -0,0 +1,1070 @@
+/*
+ * IPMMU VMSA
+ *
+ * Copyright (C) 2014 Renesas Electronics Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ */
+
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iommu.h>
+#include <linux/module.h>
+#include <linux/platform_data/ipmmu-vmsa.h>
+#include <linux/platform_device.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+
+#include <asm/dma-iommu.h>
+#include <asm/pgalloc.h>
+
+struct ipmmu_vmsa_device {
+ struct device *dev;
+ void __iomem *base;
+ struct list_head list;
+
+ const struct ipmmu_vmsa_platform_data *pdata;
+ unsigned int num_utlbs;
+
+ struct dma_iommu_mapping *mapping;
+};
+
+struct ipmmu_vmsa_domain {
+ struct ipmmu_vmsa_device *mmu;
+ struct iommu_domain *io_domain;
+
+ unsigned int context_id;
+ spinlock_t lock; /* Protects mappings */
+ pgd_t *pgd;
+};
+
+static DEFINE_SPINLOCK(ipmmu_devices_lock);
+static LIST_HEAD(ipmmu_devices);
+
+#define TLB_LOOP_TIMEOUT 100 /* 100us */
+
+/* -----------------------------------------------------------------------------
+ * Registers Definition
+ */
+
+#define IM_CTX_SIZE 0x40
+
+#define IMCTR 0x0000
+#define IMCTR_TRE (1 << 17)
+#define IMCTR_AFE (1 << 16)
+#define IMCTR_RTSEL_MASK (3 << 4)
+#define IMCTR_RTSEL_SHIFT 4
+#define IMCTR_TREN (1 << 3)
+#define IMCTR_INTEN (1 << 2)
+#define IMCTR_FLUSH (1 << 1)
+#define IMCTR_MMUEN (1 << 0)
+
+#define IMCAAR 0x0004
+
+#define IMTTBCR 0x0008
+#define IMTTBCR_EAE (1 << 31)
+#define IMTTBCR_PMB (1 << 30)
+#define IMTTBCR_SH1_NON_SHAREABLE (0 << 28)
+#define IMTTBCR_SH1_OUTER_SHAREABLE (2 << 28)
+#define IMTTBCR_SH1_INNER_SHAREABLE (3 << 28)
+#define IMTTBCR_SH1_MASK (3 << 28)
+#define IMTTBCR_ORGN1_NC (0 << 26)
+#define IMTTBCR_ORGN1_WB_WA (1 << 26)
+#define IMTTBCR_ORGN1_WT (2 << 26)
+#define IMTTBCR_ORGN1_WB (3 << 26)
+#define IMTTBCR_ORGN1_MASK (3 << 26)
+#define IMTTBCR_IRGN1_NC (0 << 24)
+#define IMTTBCR_IRGN1_WB_WA (1 << 24)
+#define IMTTBCR_IRGN1_WT (2 << 24)
+#define IMTTBCR_IRGN1_WB (3 << 24)
+#define IMTTBCR_IRGN1_MASK (3 << 24)
+#define IMTTBCR_TSZ1_MASK (7 << 16)
+#define IMTTBCR_TSZ1_SHIFT 16
+#define IMTTBCR_SH0_NON_SHAREABLE (0 << 12)
+#define IMTTBCR_SH0_OUTER_SHAREABLE (2 << 12)
+#define IMTTBCR_SH0_INNER_SHAREABLE (3 << 12)
+#define IMTTBCR_SH0_MASK (3 << 12)
+#define IMTTBCR_ORGN0_NC (0 << 10)
+#define IMTTBCR_ORGN0_WB_WA (1 << 10)
+#define IMTTBCR_ORGN0_WT (2 << 10)
+#define IMTTBCR_ORGN0_WB (3 << 10)
+#define IMTTBCR_ORGN0_MASK (3 << 10)
+#define IMTTBCR_IRGN0_NC (0 << 8)
+#define IMTTBCR_IRGN0_WB_WA (1 << 8)
+#define IMTTBCR_IRGN0_WT (2 << 8)
+#define IMTTBCR_IRGN0_WB (3 << 8)
+#define IMTTBCR_IRGN0_MASK (3 << 8)
+#define IMTTBCR_SL0_LVL_2 (0 << 4)
+#define IMTTBCR_SL0_LVL_1 (1 << 4)
+#define IMTTBCR_TSZ0_MASK (7 << 0)
+#define IMTTBCR_TSZ0_SHIFT O
+
+#define IMBUSCR 0x000c
+#define IMBUSCR_DVM (1 << 2)
+#define IMBUSCR_BUSSEL_SYS (0 << 0)
+#define IMBUSCR_BUSSEL_CCI (1 << 0)
+#define IMBUSCR_BUSSEL_IMCAAR (2 << 0)
+#define IMBUSCR_BUSSEL_CCI_IMCAAR (3 << 0)
+#define IMBUSCR_BUSSEL_MASK (3 << 0)
+
+#define IMTTLBR0 0x0010
+#define IMTTUBR0 0x0014
+#define IMTTLBR1 0x0018
+#define IMTTUBR1 0x001c
+
+#define IMSTR 0x0020
+#define IMSTR_ERRLVL_MASK (3 << 12)
+#define IMSTR_ERRLVL_SHIFT 12
+#define IMSTR_ERRCODE_TLB_FORMAT (1 << 8)
+#define IMSTR_ERRCODE_ACCESS_PERM (4 << 8)
+#define IMSTR_ERRCODE_SECURE_ACCESS (5 << 8)
+#define IMSTR_ERRCODE_MASK (7 << 8)
+#define IMSTR_MHIT (1 << 4)
+#define IMSTR_ABORT (1 << 2)
+#define IMSTR_PF (1 << 1)
+#define IMSTR_TF (1 << 0)
+
+#define IMMAIR0 0x0028
+#define IMMAIR1 0x002c
+#define IMMAIR_ATTR_MASK 0xff
+#define IMMAIR_ATTR_DEVICE 0x04
+#define IMMAIR_ATTR_NC 0x44
+#define IMMAIR_ATTR_WBRWA 0xff
+#define IMMAIR_ATTR_SHIFT(n) ((n) << 3)
+#define IMMAIR_ATTR_IDX_NC 0
+#define IMMAIR_ATTR_IDX_WBRWA 1
+#define IMMAIR_ATTR_IDX_DEV 2
+
+#define IMEAR 0x0030
+
+#define IMPCTR 0x0200
+#define IMPSTR 0x0208
+#define IMPEAR 0x020c
+#define IMPMBA(n) (0x0280 + ((n) * 4))
+#define IMPMBD(n) (0x02c0 + ((n) * 4))
+
+#define IMUCTR(n) (0x0300 + ((n) * 16))
+#define IMUCTR_FIXADDEN (1 << 31)
+#define IMUCTR_FIXADD_MASK (0xff << 16)
+#define IMUCTR_FIXADD_SHIFT 16
+#define IMUCTR_TTSEL_MMU(n) ((n) << 4)
+#define IMUCTR_TTSEL_PMB (8 << 4)
+#define IMUCTR_TTSEL_MASK (15 << 4)
+#define IMUCTR_FLUSH (1 << 1)
+#define IMUCTR_MMUEN (1 << 0)
+
+#define IMUASID(n) (0x0308 + ((n) * 16))
+#define IMUASID_ASID8_MASK (0xff << 8)
+#define IMUASID_ASID8_SHIFT 8
+#define IMUASID_ASID0_MASK (0xff << 0)
+#define IMUASID_ASID0_SHIFT 0
+
+/* -----------------------------------------------------------------------------
+ * Page Table Bits
+ */
+
+/*
+ * VMSA states in section B3.6.3 "Control of Secure or Non-secure memory access,
+ * Long-descriptor format" that the NStable bit being set in a table descriptor
+ * will result in the NStable and NS bits of all child entries being ignored and
+ * considered as being set. The IPMMU seems not to comply with this, as it
+ * generates a secure access page fault if any of the NStable and NS bits isn't
+ * set when running in non-secure mode.
+ */
+#ifndef PMD_NSTABLE
+#define PMD_NSTABLE (_AT(pmdval_t, 1) << 63)
+#endif
+
+#define ARM_VMSA_PTE_XN (((pteval_t)3) << 53)
+#define ARM_VMSA_PTE_CONT (((pteval_t)1) << 52)
+#define ARM_VMSA_PTE_AF (((pteval_t)1) << 10)
+#define ARM_VMSA_PTE_SH_NS (((pteval_t)0) << 8)
+#define ARM_VMSA_PTE_SH_OS (((pteval_t)2) << 8)
+#define ARM_VMSA_PTE_SH_IS (((pteval_t)3) << 8)
+#define ARM_VMSA_PTE_NS (((pteval_t)1) << 5)
+#define ARM_VMSA_PTE_PAGE (((pteval_t)3) << 0)
+
+/* Stage-1 PTE */
+#define ARM_VMSA_PTE_AP_UNPRIV (((pteval_t)1) << 6)
+#define ARM_VMSA_PTE_AP_RDONLY (((pteval_t)2) << 6)
+#define ARM_VMSA_PTE_ATTRINDX_SHIFT 2
+#define ARM_VMSA_PTE_nG (((pteval_t)1) << 11)
+
+/* Stage-2 PTE */
+#define ARM_VMSA_PTE_HAP_FAULT (((pteval_t)0) << 6)
+#define ARM_VMSA_PTE_HAP_READ (((pteval_t)1) << 6)
+#define ARM_VMSA_PTE_HAP_WRITE (((pteval_t)2) << 6)
+#define ARM_VMSA_PTE_MEMATTR_OIWB (((pteval_t)0xf) << 2)
+#define ARM_VMSA_PTE_MEMATTR_NC (((pteval_t)0x5) << 2)
+#define ARM_VMSA_PTE_MEMATTR_DEV (((pteval_t)0x1) << 2)
+
+/* -----------------------------------------------------------------------------
+ * Read/Write Access
+ */
+
+static u32 ipmmu_read(struct ipmmu_vmsa_device *mmu, unsigned int offset)
+{
+ return ioread32(mmu->base + offset);
+}
+
+static void ipmmu_write(struct ipmmu_vmsa_device *mmu, unsigned int offset,
+ u32 data)
+{
+ iowrite32(data, mmu->base + offset);
+}
+
+static u32 ipmmu_ctx_read(struct ipmmu_vmsa_domain *domain, unsigned int reg)
+{
+ return ipmmu_read(domain->mmu, domain->context_id * IM_CTX_SIZE + reg);
+}
+
+static void ipmmu_ctx_write(struct ipmmu_vmsa_domain *domain, unsigned int reg,
+ u32 data)
+{
+ ipmmu_write(domain->mmu, domain->context_id * IM_CTX_SIZE + reg, data);
+}
+
+/* -----------------------------------------------------------------------------
+ * TLB and microTLB Management
+ */
+
+/* Wait for any pending TLB invalidations to complete */
+static void ipmmu_tlb_sync(struct ipmmu_vmsa_domain *domain)
+{
+ unsigned int count = 0;
+
+ while (ipmmu_ctx_read(domain, IMCTR) & IMCTR_FLUSH) {
+ cpu_relax();
+ if (++count == TLB_LOOP_TIMEOUT) {
+ dev_err_ratelimited(domain->mmu->dev,
+ "TLB sync timed out -- MMU may be deadlocked\n");
+ return;
+ }
+ udelay(1);
+ }
+}
+
+static void ipmmu_tlb_invalidate(struct ipmmu_vmsa_domain *domain)
+{
+ u32 reg;
+
+ reg = ipmmu_ctx_read(domain, IMCTR);
+ reg |= IMCTR_FLUSH;
+ ipmmu_ctx_write(domain, IMCTR, reg);
+
+ ipmmu_tlb_sync(domain);
+}
+
+/*
+ * Enable MMU translation for the microTLB.
+ */
+static void ipmmu_utlb_enable(struct ipmmu_vmsa_domain *domain,
+ const struct ipmmu_vmsa_master *master)
+{
+ struct ipmmu_vmsa_device *mmu = domain->mmu;
+
+ /* TODO: What should we set the ASID to ? */
+ ipmmu_write(mmu, IMUASID(master->utlb), 0);
+ /* TODO: Do we need to flush the microTLB ? */
+ ipmmu_write(mmu, IMUCTR(master->utlb),
+ IMUCTR_TTSEL_MMU(domain->context_id) | IMUCTR_FLUSH |
+ IMUCTR_MMUEN);
+}
+
+/*
+ * Disable MMU translation for the microTLB.
+ */
+static void ipmmu_utlb_disable(struct ipmmu_vmsa_domain *domain,
+ const struct ipmmu_vmsa_master *master)
+{
+ struct ipmmu_vmsa_device *mmu = domain->mmu;
+
+ ipmmu_write(mmu, IMUCTR(master->utlb), 0);
+}
+
+static void ipmmu_flush_pgtable(struct ipmmu_vmsa_device *mmu, void *addr,
+ size_t size)
+{
+ unsigned long offset = (unsigned long)addr & ~PAGE_MASK;
+
+ /*
+ * TODO: Add support for coherent walk through CCI with DVM and remove
+ * cache handling.
+ */
+ dma_map_page(mmu->dev, virt_to_page(addr), offset, size, DMA_TO_DEVICE);
+}
+
+/* -----------------------------------------------------------------------------
+ * Domain/Context Management
+ */
+
+static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
+{
+ phys_addr_t ttbr;
+ u32 reg;
+
+ /*
+ * TODO: When adding support for multiple contexts, find an unused
+ * context.
+ */
+ domain->context_id = 0;
+
+ /* TTBR0 */
+ ipmmu_flush_pgtable(domain->mmu, domain->pgd,
+ PTRS_PER_PGD * sizeof(*domain->pgd));
+ ttbr = __pa(domain->pgd);
+ ipmmu_ctx_write(domain, IMTTLBR0, ttbr);
+ ipmmu_ctx_write(domain, IMTTUBR0, ttbr >> 32);
+
+ /*
+ * TTBCR
+ * We use long descriptors with inner-shareable WBWA tables and allocate
+ * the whole 32-bit VA space to TTBR0.
+ */
+ ipmmu_ctx_write(domain, IMTTBCR, IMTTBCR_EAE |
+ IMTTBCR_SH0_INNER_SHAREABLE | IMTTBCR_ORGN0_WB_WA |
+ IMTTBCR_IRGN0_WB_WA | IMTTBCR_SL0_LVL_1);
+
+ /*
+ * MAIR0
+ * We need three attributes only, non-cacheable, write-back read/write
+ * allocate and device memory.
+ */
+ reg = (IMMAIR_ATTR_NC << IMMAIR_ATTR_SHIFT(IMMAIR_ATTR_IDX_NC))
+ | (IMMAIR_ATTR_WBRWA << IMMAIR_ATTR_SHIFT(IMMAIR_ATTR_IDX_WBRWA))
+ | (IMMAIR_ATTR_DEVICE << IMMAIR_ATTR_SHIFT(IMMAIR_ATTR_IDX_DEV));
+ ipmmu_ctx_write(domain, IMMAIR0, reg);
+
+ /* IMBUSCR */
+ ipmmu_ctx_write(domain, IMBUSCR,
+ ipmmu_ctx_read(domain, IMBUSCR) &
+ ~(IMBUSCR_DVM | IMBUSCR_BUSSEL_MASK));
+
+ /*
+ * IMSTR
+ * Clear all interrupt flags.
+ */
+ ipmmu_ctx_write(domain, IMSTR, ipmmu_ctx_read(domain, IMSTR));
+
+ /*
+ * IMCTR
+ * Enable the MMU and interrupt generation. The long-descriptor
+ * translation table format doesn't use TEX remapping. Don't enable AF
+ * software management as we have no use for it. Flush the TLB as
+ * required when modifying the context registers.
+ */
+ ipmmu_ctx_write(domain, IMCTR, IMCTR_INTEN | IMCTR_FLUSH | IMCTR_MMUEN);
+
+ return 0;
+}
+
+static void ipmmu_domain_destroy_context(struct ipmmu_vmsa_domain *domain)
+{
+ /*
+ * Disable the context. Flush the TLB as required when modifying the
+ * context registers.
+ *
+ * TODO: Is TLB flush really needed ?
+ */
+ ipmmu_ctx_write(domain, IMCTR, IMCTR_FLUSH);
+ ipmmu_tlb_sync(domain);
+}
+
+/* -----------------------------------------------------------------------------
+ * Fault Handling
+ */
+
+static irqreturn_t ipmmu_domain_irq(struct ipmmu_vmsa_domain *domain)
+{
+ const u32 err_mask = IMSTR_MHIT | IMSTR_ABORT | IMSTR_PF | IMSTR_TF;
+ struct ipmmu_vmsa_device *mmu = domain->mmu;
+ u32 status;
+ u32 iova;
+
+ status = ipmmu_ctx_read(domain, IMSTR);
+ if (!(status & err_mask))
+ return IRQ_NONE;
+
+ iova = ipmmu_ctx_read(domain, IMEAR);
+
+ /*
+ * Clear the error status flags. Unlike traditional interrupt flag
+ * registers that must be cleared by writing 1, this status register
+ * seems to require 0. The error address register must be read before,
+ * otherwise its value will be 0.
+ */
+ ipmmu_ctx_write(domain, IMSTR, 0);
+
+ /* Log fatal errors. */
+ if (status & IMSTR_MHIT)
+ dev_err_ratelimited(mmu->dev, "Multiple TLB hits @0x%08x\n",
+ iova);
+ if (status & IMSTR_ABORT)
+ dev_err_ratelimited(mmu->dev, "Page Table Walk Abort @0x%08x\n",
+ iova);
+
+ if (!(status & (IMSTR_PF | IMSTR_TF)))
+ return IRQ_NONE;
+
+ /*
+ * Try to handle page faults and translation faults.
+ *
+ * TODO: We need to look up the faulty device based on the I/O VA. Use
+ * the IOMMU device for now.
+ */
+ if (!report_iommu_fault(domain->io_domain, mmu->dev, iova, 0))
+ return IRQ_HANDLED;
+
+ dev_err_ratelimited(mmu->dev,
+ "Unhandled fault: status 0x%08x iova 0x%08x\n",
+ status, iova);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t ipmmu_irq(int irq, void *dev)
+{
+ struct ipmmu_vmsa_device *mmu = dev;
+ struct iommu_domain *io_domain;
+ struct ipmmu_vmsa_domain *domain;
+
+ if (!mmu->mapping)
+ return IRQ_NONE;
+
+ io_domain = mmu->mapping->domain;
+ domain = io_domain->priv;
+
+ return ipmmu_domain_irq(domain);
+}
+
+/* -----------------------------------------------------------------------------
+ * Page Table Management
+ */
+
+static void ipmmu_free_ptes(pmd_t *pmd)
+{
+ pgtable_t table = pmd_pgtable(*pmd);
+ __free_page(table);
+}
+
+static void ipmmu_free_pmds(pud_t *pud)
+{
+ pmd_t *pmd, *pmd_base = pmd_offset(pud, 0);
+ unsigned int i;
+
+ pmd = pmd_base;
+ for (i = 0; i < PTRS_PER_PMD; ++i) {
+ if (pmd_none(*pmd))
+ continue;
+
+ ipmmu_free_ptes(pmd);
+ pmd++;
+ }
+
+ pmd_free(NULL, pmd_base);
+}
+
+static void ipmmu_free_puds(pgd_t *pgd)
+{
+ pud_t *pud, *pud_base = pud_offset(pgd, 0);
+ unsigned int i;
+
+ pud = pud_base;
+ for (i = 0; i < PTRS_PER_PUD; ++i) {
+ if (pud_none(*pud))
+ continue;
+
+ ipmmu_free_pmds(pud);
+ pud++;
+ }
+
+ pud_free(NULL, pud_base);
+}
+
+static void ipmmu_free_pgtables(struct ipmmu_vmsa_domain *domain)
+{
+ pgd_t *pgd, *pgd_base = domain->pgd;
+ unsigned int i;
+
+ /*
+ * Recursively free the page tables for this domain. We don't care about
+ * speculative TLB filling, because the TLB will be nuked next time this
+ * context bank is re-allocated and no devices currently map to these
+ * tables.
+ */
+ pgd = pgd_base;
+ for (i = 0; i < PTRS_PER_PGD; ++i) {
+ if (pgd_none(*pgd))
+ continue;
+ ipmmu_free_puds(pgd);
+ pgd++;
+ }
+
+ kfree(pgd_base);
+}
+
+/*
+ * We can't use the (pgd|pud|pmd|pte)_populate or the set_(pgd|pud|pmd|pte)
+ * functions as they would flush the CPU TLB.
+ */
+
+static int ipmmu_alloc_init_pte(struct ipmmu_vmsa_device *mmu, pmd_t *pmd,
+ unsigned long addr, unsigned long end,
+ phys_addr_t phys, int prot)
+{
+ unsigned long pfn = __phys_to_pfn(phys);
+ pteval_t pteval = ARM_VMSA_PTE_PAGE | ARM_VMSA_PTE_NS | ARM_VMSA_PTE_AF
+ | ARM_VMSA_PTE_XN;
+ pte_t *pte, *start;
+
+ if (pmd_none(*pmd)) {
+ /* Allocate a new set of tables */
+ pte = (pte_t *)get_zeroed_page(GFP_ATOMIC);
+ if (!pte)
+ return -ENOMEM;
+
+ ipmmu_flush_pgtable(mmu, pte, PAGE_SIZE);
+ *pmd = __pmd(__pa(pte) | PMD_NSTABLE | PMD_TYPE_TABLE);
+ ipmmu_flush_pgtable(mmu, pmd, sizeof(*pmd));
+
+ pte += pte_index(addr);
+ } else
+ pte = pte_offset_kernel(pmd, addr);
+
+ pteval |= ARM_VMSA_PTE_AP_UNPRIV | ARM_VMSA_PTE_nG;
+ if (!(prot & IOMMU_WRITE) && (prot & IOMMU_READ))
+ pteval |= ARM_VMSA_PTE_AP_RDONLY;
+
+ if (prot & IOMMU_CACHE)
+ pteval |= (IMMAIR_ATTR_IDX_WBRWA <<
+ ARM_VMSA_PTE_ATTRINDX_SHIFT);
+
+ /* If no access, create a faulting entry to avoid TLB fills */
+ if (prot & IOMMU_EXEC)
+ pteval &= ~ARM_VMSA_PTE_XN;
+ else if (!(prot & (IOMMU_READ | IOMMU_WRITE)))
+ pteval &= ~ARM_VMSA_PTE_PAGE;
+
+ pteval |= ARM_VMSA_PTE_SH_IS;
+ start = pte;
+
+ /* Install the page table entries. */
+ do {
+ *pte++ = pfn_pte(pfn++, __pgprot(pteval));
+ addr += PAGE_SIZE;
+ } while (addr != end);
+
+ ipmmu_flush_pgtable(mmu, start, sizeof(*pte) * (pte - start));
+ return 0;
+}
+
+static int ipmmu_alloc_init_pmd(struct ipmmu_vmsa_device *mmu, pud_t *pud,
+ unsigned long addr, unsigned long end,
+ phys_addr_t phys, int prot)
+{
+ unsigned long next;
+ pmd_t *pmd;
+ int ret;
+
+#ifndef __PAGETABLE_PMD_FOLDED
+ if (pud_none(*pud)) {
+ pmd = (pmd_t *)get_zeroed_page(GFP_ATOMIC);
+ if (!pmd)
+ return -ENOMEM;
+
+ ipmmu_flush_pgtable(mmu, pmd, PAGE_SIZE);
+ *pud = __pud(__pa(pmd) | PMD_NSTABLE | PMD_TYPE_TABLE);
+ ipmmu_flush_pgtable(mmu, pud, sizeof(*pud));
+
+ pmd += pmd_index(addr);
+ } else
+#endif
+ pmd = pmd_offset(pud, addr);
+
+ do {
+ next = pmd_addr_end(addr, end);
+ ret = ipmmu_alloc_init_pte(mmu, pmd, addr, end, phys, prot);
+ phys += next - addr;
+ } while (pmd++, addr = next, addr < end);
+
+ return ret;
+}
+
+static int ipmmu_alloc_init_pud(struct ipmmu_vmsa_device *mmu, pgd_t *pgd,
+ unsigned long addr, unsigned long end,
+ phys_addr_t phys, int prot)
+{
+ unsigned long next;
+ pud_t *pud;
+ int ret;
+
+#ifndef __PAGETABLE_PUD_FOLDED
+ if (pgd_none(*pgd)) {
+ pud = (pud_t *)get_zeroed_page(GFP_ATOMIC);
+ if (!pud)
+ return -ENOMEM;
+
+ ipmmu_flush_pgtable(mmu, pud, PAGE_SIZE);
+ *pgd = __pgd(__pa(pud) | PMD_NSTABLE | PMD_TYPE_TABLE);
+ ipmmu_flush_pgtable(mmu, pgd, sizeof(*pgd));
+
+ pud += pud_index(addr);
+ } else
+#endif
+ pud = pud_offset(pgd, addr);
+
+ do {
+ next = pud_addr_end(addr, end);
+ ret = ipmmu_alloc_init_pmd(mmu, pud, addr, next, phys, prot);
+ phys += next - addr;
+ } while (pud++, addr = next, addr < end);
+
+ return ret;
+}
+
+static int ipmmu_handle_mapping(struct ipmmu_vmsa_domain *domain,
+ unsigned long iova, phys_addr_t paddr,
+ size_t size, int prot)
+{
+ struct ipmmu_vmsa_device *mmu = domain->mmu;
+ pgd_t *pgd = domain->pgd;
+ unsigned long flags;
+ unsigned long end;
+ int ret;
+
+ if (!pgd)
+ return -EINVAL;
+
+ if (size & ~PAGE_MASK)
+ return -EINVAL;
+
+ if (paddr & ~((1ULL << 40) - 1))
+ return -ERANGE;
+
+ spin_lock_irqsave(&domain->lock, flags);
+
+ pgd += pgd_index(iova);
+ end = iova + size;
+
+ do {
+ unsigned long next = pgd_addr_end(iova, end);
+
+ ret = ipmmu_alloc_init_pud(mmu, pgd, iova, next, paddr, prot);
+ if (ret)
+ break;
+
+ paddr += next - iova;
+ iova = next;
+ } while (pgd++, iova != end);
+
+ spin_unlock_irqrestore(&domain->lock, flags);
+
+ ipmmu_tlb_invalidate(domain);
+
+ return ret;
+}
+
+/* -----------------------------------------------------------------------------
+ * IOMMU Operations
+ */
+
+static const struct ipmmu_vmsa_master *
+ipmmu_find_master(struct ipmmu_vmsa_device *ipmmu, struct device *dev)
+{
+ const struct ipmmu_vmsa_master *master = ipmmu->pdata->masters;
+ const char *devname = dev_name(dev);
+ unsigned int i;
+
+ for (i = 0; i < ipmmu->pdata->num_masters; ++i, ++master) {
+ if (strcmp(master->name, devname) == 0)
+ return master;
+ }
+
+ return NULL;
+}
+
+static int ipmmu_domain_init(struct iommu_domain *io_domain)
+{
+ struct ipmmu_vmsa_domain *domain;
+
+ domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+ if (!domain)
+ return -ENOMEM;
+
+ spin_lock_init(&domain->lock);
+
+ domain->pgd = kzalloc(PTRS_PER_PGD * sizeof(pgd_t), GFP_KERNEL);
+ if (!domain->pgd) {
+ kfree(domain);
+ return -ENOMEM;
+ }
+
+ io_domain->priv = domain;
+ domain->io_domain = io_domain;
+
+ return 0;
+}
+
+static void ipmmu_domain_destroy(struct iommu_domain *io_domain)
+{
+ struct ipmmu_vmsa_domain *domain = io_domain->priv;
+
+ /*
+ * Free the domain resources. We assume that all devices have already
+ * been detached.
+ */
+ ipmmu_domain_destroy_context(domain);
+ ipmmu_free_pgtables(domain);
+ kfree(domain);
+}
+
+static int ipmmu_attach_device(struct iommu_domain *io_domain,
+ struct device *dev)
+{
+ struct ipmmu_vmsa_device *mmu = dev->archdata.iommu;
+ struct ipmmu_vmsa_domain *domain = io_domain->priv;
+ const struct ipmmu_vmsa_master *master;
+ unsigned long flags;
+ int ret = 0;
+
+ if (!mmu) {
+ dev_err(dev, "Cannot attach to IPMMU\n");
+ return -ENXIO;
+ }
+
+ spin_lock_irqsave(&domain->lock, flags);
+
+ if (!domain->mmu) {
+ /* The domain hasn't been used yet, initialize it. */
+ domain->mmu = mmu;
+ ret = ipmmu_domain_init_context(domain);
+ } else if (domain->mmu != mmu) {
+ /*
+ * Something is wrong, we can't attach two devices using
+ * different IOMMUs to the same domain.
+ */
+ dev_err(dev, "Can't attach IPMMU %s to domain on IPMMU %s\n",
+ dev_name(mmu->dev), dev_name(domain->mmu->dev));
+ ret = -EINVAL;
+ }
+
+ spin_unlock_irqrestore(&domain->lock, flags);
+
+ if (ret < 0)
+ return ret;
+
+ master = ipmmu_find_master(mmu, dev);
+ if (!master)
+ return -EINVAL;
+
+ ipmmu_utlb_enable(domain, master);
+
+ return 0;
+}
+
+static void ipmmu_detach_device(struct iommu_domain *io_domain,
+ struct device *dev)
+{
+ struct ipmmu_vmsa_domain *domain = io_domain->priv;
+ const struct ipmmu_vmsa_master *master;
+
+ master = ipmmu_find_master(domain->mmu, dev);
+ if (!master)
+ return;
+
+ ipmmu_utlb_disable(domain, master);
+
+ /*
+ * TODO: Optimize by disabling the context when no device is attached.
+ */
+}
+
+static int ipmmu_map(struct iommu_domain *io_domain, unsigned long iova,
+ phys_addr_t paddr, size_t size, int prot)
+{
+ struct ipmmu_vmsa_domain *domain = io_domain->priv;
+
+ if (!domain)
+ return -ENODEV;
+
+ return ipmmu_handle_mapping(domain, iova, paddr, size, prot);
+}
+
+static size_t ipmmu_unmap(struct iommu_domain *io_domain, unsigned long iova,
+ size_t size)
+{
+ struct ipmmu_vmsa_domain *domain = io_domain->priv;
+ int ret;
+
+ ret = ipmmu_handle_mapping(domain, iova, 0, size, 0);
+ return ret ? 0 : size;
+}
+
+static phys_addr_t ipmmu_iova_to_phys(struct iommu_domain *io_domain,
+ dma_addr_t iova)
+{
+ struct ipmmu_vmsa_domain *domain = io_domain->priv;
+ pgd_t pgd;
+ pud_t pud;
+ pmd_t pmd;
+ pte_t pte;
+
+ /* TODO: Is locking needed ? */
+
+ if (!domain->pgd)
+ return 0;
+
+ pgd = *(domain->pgd + pgd_index(iova));
+ if (pgd_none(pgd))
+ return 0;
+
+ pud = *pud_offset(&pgd, iova);
+ if (pud_none(pud))
+ return 0;
+
+ pmd = *pmd_offset(&pud, iova);
+ if (pmd_none(pmd))
+ return 0;
+
+ pte = *(pmd_page_vaddr(pmd) + pte_index(iova));
+ if (pte_none(pte))
+ return 0;
+
+ return __pfn_to_phys(pte_pfn(pte)) | (iova & ~PAGE_MASK);
+}
+
+static int ipmmu_add_device(struct device *dev)
+{
+ const struct ipmmu_vmsa_master *master = NULL;
+ struct ipmmu_vmsa_device *mmu;
+ struct iommu_group *group;
+ int ret;
+
+ if (dev->archdata.iommu) {
+ dev_warn(dev, "IOMMU driver already assigned to device %s\n",
+ dev_name(dev));
+ return -EINVAL;
+ }
+
+ /* Find the master corresponding to the device. */
+ spin_lock(&ipmmu_devices_lock);
+
+ list_for_each_entry(mmu, &ipmmu_devices, list) {
+ master = ipmmu_find_master(mmu, dev);
+ if (master) {
+ /*
+ * TODO Take a reference to the master to protect
+ * against device removal.
+ */
+ break;
+ }
+ }
+
+ spin_unlock(&ipmmu_devices_lock);
+
+ if (!master)
+ return -ENODEV;
+
+ if (!master->utlb >= mmu->num_utlbs)
+ return -EINVAL;
+
+ /* Create a device group and add the device to it. */
+ 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);
+ iommu_group_put(group);
+
+ if (ret < 0) {
+ dev_err(dev, "Failed to add device to IPMMU group\n");
+ return ret;
+ }
+
+ dev->archdata.iommu = mmu;
+
+ /*
+ * Create the ARM mapping, used by the ARM DMA mapping core to allocate
+ * VAs. This will allocate a corresponding IOMMU domain.
+ *
+ * TODO:
+ * - Create one mapping per context (TLB).
+ * - Make the mapping size configurable ? We currently use a 2GB mapping
+ * at a 1GB offset to ensure that NULL VAs will fault.
+ */
+ if (!mmu->mapping) {
+ struct dma_iommu_mapping *mapping;
+
+ mapping = arm_iommu_create_mapping(&platform_bus_type,
+ SZ_1G, SZ_2G, 0);
+ if (IS_ERR(mapping)) {
+ dev_err(mmu->dev, "failed to create ARM IOMMU mapping\n");
+ return PTR_ERR(mapping);
+ }
+
+ mmu->mapping = mapping;
+ }
+
+ /* Attach the ARM VA mapping to the device. */
+ ret = arm_iommu_attach_device(dev, mmu->mapping);
+ if (ret < 0) {
+ dev_err(dev, "Failed to attach device to VA mapping\n");
+ goto error;
+ }
+
+ return 0;
+
+error:
+ dev->archdata.iommu = NULL;
+ iommu_group_remove_device(dev);
+ return ret;
+}
+
+static void ipmmu_remove_device(struct device *dev)
+{
+ arm_iommu_detach_device(dev);
+ iommu_group_remove_device(dev);
+ dev->archdata.iommu = NULL;
+}
+
+static struct iommu_ops ipmmu_ops = {
+ .domain_init = ipmmu_domain_init,
+ .domain_destroy = ipmmu_domain_destroy,
+ .attach_dev = ipmmu_attach_device,
+ .detach_dev = ipmmu_detach_device,
+ .map = ipmmu_map,
+ .unmap = ipmmu_unmap,
+ .iova_to_phys = ipmmu_iova_to_phys,
+ .add_device = ipmmu_add_device,
+ .remove_device = ipmmu_remove_device,
+ .pgsize_bitmap = SZ_1M | SZ_64K | SZ_4K,
+};
+
+/* -----------------------------------------------------------------------------
+ * Probe/remove and init
+ */
+
+static void ipmmu_device_reset(struct ipmmu_vmsa_device *mmu)
+{
+ unsigned int i;
+
+ /* Disable all contexts. */
+ for (i = 0; i < 4; ++i)
+ ipmmu_write(mmu, i * IM_CTX_SIZE + IMCTR, 0);
+}
+
+static int ipmmu_probe(struct platform_device *pdev)
+{
+ struct ipmmu_vmsa_device *mmu;
+ struct resource *res;
+ int irq;
+ int ret;
+
+ if (!pdev->dev.platform_data) {
+ dev_err(&pdev->dev, "missing platform data\n");
+ return -EINVAL;
+ }
+
+ mmu = devm_kzalloc(&pdev->dev, sizeof(*mmu), GFP_KERNEL);
+ if (!mmu) {
+ dev_err(&pdev->dev, "cannot allocate device data\n");
+ return -ENOMEM;
+ }
+
+ mmu->dev = &pdev->dev;
+ mmu->pdata = pdev->dev.platform_data;
+ mmu->num_utlbs = 32;
+
+ /* Map I/O memory and request IRQ. */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ mmu->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(mmu->base))
+ return PTR_ERR(mmu->base);
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "no IRQ found\n");
+ return irq;
+ }
+
+ ret = devm_request_irq(&pdev->dev, irq, ipmmu_irq, 0,
+ dev_name(&pdev->dev), mmu);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to request IRQ %d\n", irq);
+ return irq;
+ }
+
+ ipmmu_device_reset(mmu);
+
+ /*
+ * We can't create the ARM mapping here as it requires the bus to have
+ * an IOMMU, which only happens when bus_set_iommu() is called in
+ * ipmmu_init() after the probe function returns.
+ */
+
+ spin_lock(&ipmmu_devices_lock);
+ list_add(&mmu->list, &ipmmu_devices);
+ spin_unlock(&ipmmu_devices_lock);
+
+ platform_set_drvdata(pdev, mmu);
+
+ return 0;
+}
+
+static int ipmmu_remove(struct platform_device *pdev)
+{
+ struct ipmmu_vmsa_device *mmu = platform_get_drvdata(pdev);
+
+ spin_lock(&ipmmu_devices_lock);
+ list_del(&mmu->list);
+ spin_unlock(&ipmmu_devices_lock);
+
+ arm_iommu_release_mapping(mmu->mapping);
+
+ ipmmu_device_reset(mmu);
+
+ return 0;
+}
+
+static struct platform_driver ipmmu_driver = {
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "ipmmu-vmsa",
+ },
+ .probe = ipmmu_probe,
+ .remove = ipmmu_remove,
+};
+
+static int __init ipmmu_init(void)
+{
+ int ret;
+
+ ret = platform_driver_register(&ipmmu_driver);
+ if (ret < 0)
+ return ret;
+
+ if (!iommu_present(&platform_bus_type))
+ bus_set_iommu(&platform_bus_type, &ipmmu_ops);
+
+ return 0;
+}
+
+static void __exit ipmmu_exit(void)
+{
+ return platform_driver_unregister(&ipmmu_driver);
+}
+
+subsys_initcall(ipmmu_init);
+module_exit(ipmmu_exit);
+
+MODULE_DESCRIPTION("IOMMU API for Renesas VMSA-compatible IPMMU");
+MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
+MODULE_LICENSE("GPL v2");