Re: [PATCH v4] arm: msm: Add MSM IOMMU support.

[Konrad Rzeszutek Wilk]

I did a very brief look.

> +static void __flush_iotlb(struct iommu_domain *domain)
> +{
> +	struct msm_priv *priv = domain->priv;
> +	struct msm_iommu_drvdata *iommu_drvdata;
> +	struct msm_iommu_ctx_drvdata *ctx_drvdata;
> +
> +#ifndef CONFIG_IOMMU_PGTABLES_L2
> +	unsigned long *fl_table = priv->pgtable;
> +	int i;
> +
> +	dmac_flush_range(fl_table, fl_table + SZ_16K);
> +
> +	for (i = 0; i < 4096; i++)

Can you use a #define for the 4096? Will that value ever change?

> +		if ((fl_table[i] & 0x03) == FL_TYPE_TABLE) {
> +			void *sl_table = __va(fl_table[i] & 0xFFFFFC00);

Does it make sense to define say:
#define MASK_XX (x) x & 0xFFFFFC00
and
#define MASK_XY (x) x & 0xFFFF0000

and use those instead of these hard-coded values?

> +			dmac_flush_range(sl_table, sl_table + SZ_4K);
> +		}
> +#endif
> +
> +	list_for_each_entry(ctx_drvdata, &priv->list_attached, attached_elm) {
> +		if (!ctx_drvdata->pdev || !ctx_drvdata->pdev->dev.parent)
> +			BUG();
> +
> +		iommu_drvdata = dev_get_drvdata(ctx_drvdata->pdev->dev.parent);
> +		SET_CTX_TLBIALL(iommu_drvdata->base, ctx_drvdata->num, 0);
> +	}
> +}
> +
> +static void __reset_context(void __iomem *base, int ctx)
> +{
> +	SET_BPRCOSH(base, ctx, 0);
> +	SET_BPRCISH(base, ctx, 0);
> +	SET_BPRCNSH(base, ctx, 0);
> +	SET_BPSHCFG(base, ctx, 0);
> +	SET_BPMTCFG(base, ctx, 0);
> +	SET_ACTLR(base, ctx, 0);
> +	SET_SCTLR(base, ctx, 0);
> +	SET_FSRRESTORE(base, ctx, 0);
> +	SET_TTBR0(base, ctx, 0);
> +	SET_TTBR1(base, ctx, 0);
> +	SET_TTBCR(base, ctx, 0);
> +	SET_BFBCR(base, ctx, 0);
> +	SET_PAR(base, ctx, 0);
> +	SET_FAR(base, ctx, 0);
> +	SET_CTX_TLBIALL(base, ctx, 0);
> +	SET_TLBFLPTER(base, ctx, 0);
> +	SET_TLBSLPTER(base, ctx, 0);
> +	SET_TLBLKCR(base, ctx, 0);
> +	SET_PRRR(base, ctx, 0);
> +	SET_NMRR(base, ctx, 0);
> +	SET_CONTEXTIDR(base, ctx, 0);
> +}
> +
> +static void __program_context(void __iomem *base, int ctx, phys_addr_t pgtable)
> +{
> +	__reset_context(base, ctx);
> +
> +	/* Set up HTW mode */
> +	/* TLB miss configuration: perform HTW on miss */
> +	SET_TLBMCFG(base, ctx, 0x3);
> +
> +	/* V2P configuration: HTW for access */
> +	SET_V2PCFG(base, ctx, 0x3);
> +
> +	SET_TTBCR(base, ctx, 0);
> +	SET_TTBR0_PA(base, ctx, (pgtable >> 14));
> +
> +	/* Invalidate the TLB for this context */
> +	SET_CTX_TLBIALL(base, ctx, 0);
> +
> +	/* Set interrupt number to "secure" interrupt */
> +	SET_IRPTNDX(base, ctx, 0);
> +
> +	/* Enable context fault interrupt */
> +	SET_CFEIE(base, ctx, 1);
> +
> +	/* Stall access on a context fault and let the handler deal with it */
> +	SET_CFCFG(base, ctx, 1);
> +
> +	/* Redirect all cacheable requests to L2 slave port. */
> +	SET_RCISH(base, ctx, 1);
> +	SET_RCOSH(base, ctx, 1);
> +	SET_RCNSH(base, ctx, 1);
> +
> +	/* Turn on TEX Remap */
> +	SET_TRE(base, ctx, 1);
> +
> +	/* Do not configure PRRR / NMRR on the IOMMU for now. We will assume
> +	 * TEX class 0 for everything until attributes are properly worked out
> +	 */
> +	SET_PRRR(base, ctx, 0);
> +	SET_NMRR(base, ctx, 0);
> +
> +	/* Turn on BFB prefetch */
> +	SET_BFBDFE(base, ctx, 1);
> +
> +#ifdef CONFIG_IOMMU_PGTABLES_L2
> +	/* Configure page tables as inner-cacheable and shareable to reduce
> +	 * the TLB miss penalty.
> +	 */
> +	SET_TTBR0_SH(base, ctx, 1);
> +	SET_TTBR1_SH(base, ctx, 1);
> +
> +	SET_TTBR0_NOS(base, ctx, 1);
> +	SET_TTBR1_NOS(base, ctx, 1);
> +
> +	SET_TTBR0_IRGNH(base, ctx, 0); /* WB, WA */
> +	SET_TTBR0_IRGNL(base, ctx, 1);
> +
> +	SET_TTBR1_IRGNH(base, ctx, 0); /* WB, WA */
> +	SET_TTBR1_IRGNL(base, ctx, 1);
> +
> +	SET_TTBR0_ORGN(base, ctx, 1); /* WB, WA */
> +	SET_TTBR1_ORGN(base, ctx, 1); /* WB, WA */
> +#endif
> +
> +	/* Enable the MMU */
> +	SET_M(base, ctx, 1);
> +}
> +
> +static int msm_iommu_domain_init(struct iommu_domain *domain)
> +{
> +	struct msm_priv *priv = kzalloc(sizeof(*priv), GFP_KERNEL);
> +
> +	if (!priv)
> +		goto fail_nomem;
> +
> +	INIT_LIST_HEAD(&priv->list_attached);
> +	priv->pgtable = (unsigned long *)__get_free_pages(GFP_KERNEL, 2);

Ugh.  Can you use get_order(SZ_16K) instead?

> +
> +	if (!priv->pgtable)
> +		goto fail_nomem;
> +
> +	memset(priv->pgtable, 0, SZ_16K);
> +	domain->priv = priv;
> +	return 0;
> +
> +fail_nomem:
> +	kfree(priv);
> +	return -ENOMEM;
> +}
> +
> +static void msm_iommu_domain_destroy(struct iommu_domain *domain)
> +{
> +	struct msm_priv *priv;
> +	unsigned long flags;
> +	unsigned long *fl_table;
> +	int i;
> +
> +	spin_lock_irqsave(&msm_iommu_lock, flags);
> +	priv = domain->priv;
> +	domain->priv = NULL;
> +
> +	if (priv) {
> +		fl_table = priv->pgtable;
> +
> +		for (i = 0; i < 4096; i++)

Ditto
> +			if ((fl_table[i] & 0x03) == FL_TYPE_TABLE)
> +				free_page((unsigned long) __va(((fl_table[i]) &
> +								0xFFFFFC00)));
> +
> +		free_pages((unsigned long)priv->pgtable, 2);

And here as well.
> +		priv->pgtable = NULL;
> +	}
> +
> +	kfree(priv);
> +	spin_unlock_irqrestore(&msm_iommu_lock, flags);
> +}
> +
> +static int msm_iommu_attach_dev(struct iommu_domain *domain, struct device *dev)
> +{
> +	struct msm_priv *priv;
> +	struct msm_iommu_ctx_dev *ctx_dev;
> +	struct msm_iommu_drvdata *iommu_drvdata;
> +	struct msm_iommu_ctx_drvdata *ctx_drvdata;
> +	struct msm_iommu_ctx_drvdata *tmp_drvdata;
> +	int ret = 0;
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&msm_iommu_lock, flags);
> +
> +	priv = domain->priv;
> +
> +	if (!priv || !dev) {
> +		ret = -EINVAL;
> +		goto fail;
> +	}
> +
> +	iommu_drvdata = dev_get_drvdata(dev->parent);
> +	ctx_drvdata = dev_get_drvdata(dev);
> +	ctx_dev = dev->platform_data;
> +
> +	if (!iommu_drvdata || !ctx_drvdata || !ctx_dev) {
> +		ret = -EINVAL;
> +		goto fail;
> +	}
> +
> +	list_for_each_entry(tmp_drvdata, &priv->list_attached, attached_elm)
> +		if (tmp_drvdata == ctx_drvdata) {
> +			ret = -EBUSY;
> +			goto fail;
> +		}
> +
> +	__program_context(iommu_drvdata->base, ctx_dev->num,
> +			  __pa(priv->pgtable));
> +
> +	list_add(&(ctx_drvdata->attached_elm), &priv->list_attached);
> +	__flush_iotlb(domain);
> +
> +fail:
> +	spin_unlock_irqrestore(&msm_iommu_lock, flags);
> +	return ret;
> +}
> +
> +static void msm_iommu_detach_dev(struct iommu_domain *domain,
> +				 struct device *dev)
> +{
> +	struct msm_priv *priv;
> +	struct msm_iommu_ctx_dev *ctx_dev;
> +	struct msm_iommu_drvdata *iommu_drvdata;
> +	struct msm_iommu_ctx_drvdata *ctx_drvdata;
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&msm_iommu_lock, flags);
> +	priv = domain->priv;
> +
> +	if (!priv || !dev)
> +		goto fail;
> +
> +	iommu_drvdata = dev_get_drvdata(dev->parent);
> +	ctx_drvdata = dev_get_drvdata(dev);
> +	ctx_dev = dev->platform_data;
> +
> +	if (!iommu_drvdata || !ctx_drvdata || !ctx_dev)
> +		goto fail;
> +
> +	__flush_iotlb(domain);
> +	__reset_context(iommu_drvdata->base, ctx_dev->num);
> +	list_del_init(&ctx_drvdata->attached_elm);
> +
> +fail:
> +	spin_unlock_irqrestore(&msm_iommu_lock, flags);
> +}
> +
> +static int msm_iommu_map(struct iommu_domain *domain, unsigned long va,
> +			 phys_addr_t pa, int order, int prot)
> +{
> +	struct msm_priv *priv;
> +	unsigned long flags;
> +	unsigned long *fl_table;
> +	unsigned long *fl_pte;
> +	unsigned long fl_offset;
> +	unsigned long *sl_table;
> +	unsigned long *sl_pte;
> +	unsigned long sl_offset;
> +	size_t len = 0x1000UL << order;
> +	int ret = 0;
> +
> +	spin_lock_irqsave(&msm_iommu_lock, flags);
> +	priv = domain->priv;
> +
> +	if (!priv) {
> +		ret = -EINVAL;
> +		goto fail;
> +	}
> +
> +	fl_table = priv->pgtable;
> +
> +	if (len != SZ_16M && len != SZ_1M &&
> +	    len != SZ_64K && len != SZ_4K) {
> +		pr_debug("Bad size: %d\n", len);
> +		ret = -EINVAL;
> +		goto fail;
> +	}
> +
> +	if (!fl_table) {
> +		pr_debug("Null page table\n");
> +		ret = -EINVAL;
> +		goto fail;
> +	}
> +
> +	fl_offset = FL_OFFSET(va);	/* Upper 12 bits */
> +	fl_pte = fl_table + fl_offset;	/* int pointers, 4 bytes */
> +
> +	if (len == SZ_16M) {
> +		int i = 0;
> +		for (i = 0; i < 16; i++)
> +			*(fl_pte+i) = (pa & 0xFF000000) | FL_SUPERSECTION |
> +				  FL_AP_READ | FL_AP_WRITE | FL_TYPE_SECT |
> +				  FL_SHARED;
> +	}
> +
> +	if (len == SZ_1M)
> +		*fl_pte = (pa & 0xFFF00000) | FL_AP_READ | FL_AP_WRITE |
> +						FL_TYPE_SECT | FL_SHARED;
> +
> +	/* Need a 2nd level table */
> +	if ((len == SZ_4K || len == SZ_64K) && (*fl_pte) == 0) {
> +		unsigned long *sl;
> +		sl = (unsigned long *) __get_free_pages(GFP_KERNEL, 0);

get_order(SZ_4K)

> +
> +		if (!sl) {
> +			pr_debug("Could not allocate second level table\n");
> +			ret = -ENOMEM;
> +			goto fail;
> +		}
> +
> +		memset(sl, 0, SZ_4K);
> +		*fl_pte = ((((int)__pa(sl)) & 0xFFFFFC00) | FL_TYPE_TABLE);
> +	}
> +
> +	sl_table = (unsigned long *) __va(((*fl_pte) & 0xFFFFFC00));
> +	sl_offset = SL_OFFSET(va);
> +	sl_pte = sl_table + sl_offset;
> +
> +
> +	if (len == SZ_4K)
> +		*sl_pte = (pa & 0xFFFFF000) | SL_AP0 | SL_AP1 |	SL_SHARED |
> +					      SL_TYPE_SMALL;
> +
> +	if (len == SZ_64K) {
> +		int i;
> +
> +		for (i = 0; i < 16; i++)
> +			*(sl_pte+i) = (pa & 0xFFFF0000) | SL_AP0 | SL_AP1 |
> +					      SL_SHARED | SL_TYPE_LARGE;
> +	}
> +
> +	__flush_iotlb(domain);
> +fail:
> +	spin_unlock_irqrestore(&msm_iommu_lock, flags);
> +	return ret;
> +}
> +
> +static int msm_iommu_unmap(struct iommu_domain *domain, unsigned long va,
> +			    int order)
> +{
> +	struct msm_priv *priv;
> +	unsigned long flags;
> +	unsigned long *fl_table;
> +	unsigned long *fl_pte;
> +	unsigned long fl_offset;
> +	unsigned long *sl_table;
> +	unsigned long *sl_pte;
> +	unsigned long sl_offset;
> +	size_t len = 0x1000UL << order;
> +	int i, ret = 0;
> +
> +	spin_lock_irqsave(&msm_iommu_lock, flags);
> +
> +	priv = domain->priv;
> +
> +	if (!priv) {
> +		ret = -ENODEV;
> +		goto fail;
> +	}
> +
> +	fl_table = priv->pgtable;
> +
> +	if (len != SZ_16M && len != SZ_1M &&
> +	    len != SZ_64K && len != SZ_4K) {
> +		pr_debug("Bad length: %d\n", len);
> +		ret = -EINVAL;
> +		goto fail;
> +	}
> +
> +	if (!fl_table) {
> +		pr_debug("Null page table\n");
> +		ret = -EINVAL;
> +		goto fail;
> +	}
> +
> +	fl_offset = FL_OFFSET(va);	/* Upper 12 bits */
> +	fl_pte = fl_table + fl_offset;	/* int pointers, 4 bytes */
> +
> +	if (*fl_pte == 0) {
> +		pr_debug("First level PTE is 0\n");
> +		ret = -ENODEV;
> +		goto fail;
> +	}
> +
> +	/* Unmap supersection */
> +	if (len == SZ_16M)
> +		for (i = 0; i < 16; i++)
> +			*(fl_pte+i) = 0;
> +
> +	if (len == SZ_1M)
> +		*fl_pte = 0;
> +
> +	sl_table = (unsigned long *) __va(((*fl_pte) & 0xFFFFFC00));
> +	sl_offset = SL_OFFSET(va);
> +	sl_pte = sl_table + sl_offset;
> +
> +	if (len == SZ_64K) {
> +		for (i = 0; i < 16; i++)
> +			*(sl_pte+i) = 0;
> +	}
> +
> +	if (len == SZ_4K)
> +		*sl_pte = 0;
> +
> +	if (len == SZ_4K || len == SZ_64K) {
> +		int used = 0;
> +
> +		for (i = 0; i < 256; i++)
> +			if (sl_table[i])
> +				used = 1;
> +		if (!used) {
> +			free_page((unsigned long)sl_table);
> +			*fl_pte = 0;
> +		}
> +	}
> +
> +	__flush_iotlb(domain);
> +fail:
> +	spin_unlock_irqrestore(&msm_iommu_lock, flags);
> +	return ret;
> +}
> +
> +static phys_addr_t msm_iommu_iova_to_phys(struct iommu_domain *domain,
> +					  unsigned long va)
> +{
> +	struct msm_priv *priv;
> +	struct msm_iommu_drvdata *iommu_drvdata;
> +	struct msm_iommu_ctx_drvdata *ctx_drvdata;
> +	unsigned int par;
> +	unsigned long flags;
> +	void __iomem *base;
> +	phys_addr_t ret = 0;
> +	int ctx;
> +
> +	spin_lock_irqsave(&msm_iommu_lock, flags);
> +
> +	priv = domain->priv;
> +	if (list_empty(&priv->list_attached))
> +		goto fail;
> +
> +	ctx_drvdata = list_entry(priv->list_attached.next,
> +				 struct msm_iommu_ctx_drvdata, attached_elm);
> +	iommu_drvdata = dev_get_drvdata(ctx_drvdata->pdev->dev.parent);
> +
> +	base = iommu_drvdata->base;
> +	ctx = ctx_drvdata->num;
> +
> +	/* Invalidate context TLB */
> +	SET_CTX_TLBIALL(base, ctx, 0);
> +	SET_V2PPR_VA(base, ctx, va >> 12);

Hmm, PAGE_SHIFT can't be used? Or some other #define?
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