Re: [PATCH v11 08/27] iommu/exynos: always use a single clock descriptor

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




Hi KyongHo,

On 14.03.2014 06:05, Cho KyongHo wrote:
System MMU driver is changed to control only a single instance of
System MMU at a time. Since a single instance of System MMU has only
a single clock descriptor for its clock gating, there is no need to
obtain two or more clock descriptors.


This patch does much more than just making the driver use a single clock descriptor. Please update the subject and description accordingly.

Signed-off-by: Cho KyongHo <pullip.cho@xxxxxxxxxxx>
---
  drivers/iommu/exynos-iommu.c |  223 ++++++++++++++----------------------------
  1 file changed, 72 insertions(+), 151 deletions(-)

diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index 8dc7031..a4499b2 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -171,9 +171,8 @@ struct sysmmu_drvdata {
  	struct device *sysmmu;	/* System MMU's device descriptor */
  	struct device *dev;	/* Owner of system MMU */
  	char *dbgname;
-	int nsfrs;
-	void __iomem **sfrbases;
-	struct clk *clk[2];
+	void __iomem *sfrbase;
+	struct clk *clk;
  	int activations;
  	rwlock_t lock;
  	struct iommu_domain *domain;
@@ -294,56 +293,39 @@ static irqreturn_t exynos_sysmmu_irq(int irq, void *dev_id)
  {
  	/* SYSMMU is in blocked when interrupt occurred. */
  	struct sysmmu_drvdata *data = dev_id;
-	struct resource *irqres;
-	struct platform_device *pdev;
  	enum exynos_sysmmu_inttype itype;
  	unsigned long addr = -1;
-
-	int i, ret = -ENOSYS;
+	int ret = -ENOSYS;

  	read_lock(&data->lock);

  	WARN_ON(!is_sysmmu_active(data));

-	pdev = to_platform_device(data->sysmmu);
-	for (i = 0; i < (pdev->num_resources / 2); i++) {
-		irqres = platform_get_resource(pdev, IORESOURCE_IRQ, i);
-		if (irqres && ((int)irqres->start == irq))
-			break;
-	}
-
-	if (i == pdev->num_resources) {
+	itype = (enum exynos_sysmmu_inttype)
+		__ffs(__raw_readl(data->sfrbase + REG_INT_STATUS));
+	if (WARN_ON(!((itype >= 0) && (itype < SYSMMU_FAULT_UNKNOWN))))
  		itype = SYSMMU_FAULT_UNKNOWN;
-	} else {
-		itype = (enum exynos_sysmmu_inttype)
-			__ffs(__raw_readl(data->sfrbases[i] + REG_INT_STATUS));
-		if (WARN_ON(!((itype >= 0) && (itype < SYSMMU_FAULT_UNKNOWN))))
-			itype = SYSMMU_FAULT_UNKNOWN;
-		else
-			addr = __raw_readl(
-				data->sfrbases[i] + fault_reg_offset[itype]);
-	}
+	else
+		addr = __raw_readl(data->sfrbase + fault_reg_offset[itype]);

  	if (data->domain)
-		ret = report_iommu_fault(data->domain, data->dev,
-				addr, itype);
+		ret = report_iommu_fault(data->domain, data->dev, addr, itype);

  	if ((ret == -ENOSYS) && data->fault_handler) {
  		unsigned long base = data->pgtable;
  		if (itype != SYSMMU_FAULT_UNKNOWN)
-			base = __raw_readl(
-					data->sfrbases[i] + REG_PT_BASE_ADDR);
+			base = __raw_readl(data->sfrbase + REG_PT_BASE_ADDR);
  		ret = data->fault_handler(itype, base, addr);
  	}

  	if (!ret && (itype != SYSMMU_FAULT_UNKNOWN))
-		__raw_writel(1 << itype, data->sfrbases[i] + REG_INT_CLEAR);
+		__raw_writel(1 << itype, data->sfrbase + REG_INT_CLEAR);
  	else
  		dev_dbg(data->sysmmu, "(%s) %s is not handled.\n",
  				data->dbgname, sysmmu_fault_name[itype]);

  	if (itype != SYSMMU_FAULT_UNKNOWN)
-		sysmmu_unblock(data->sfrbases[i]);
+		sysmmu_unblock(data->sfrbase);

  	read_unlock(&data->lock);

@@ -354,20 +336,16 @@ static bool __exynos_sysmmu_disable(struct sysmmu_drvdata *data)
  {
  	unsigned long flags;
  	bool disabled = false;
-	int i;

  	write_lock_irqsave(&data->lock, flags);

  	if (!set_sysmmu_inactive(data))
  		goto finish;

-	for (i = 0; i < data->nsfrs; i++)
-		__raw_writel(CTRL_DISABLE, data->sfrbases[i] + REG_MMU_CTRL);
+	__raw_writel(CTRL_DISABLE, data->sfrbase + REG_MMU_CTRL);

-	if (data->clk[1])
-		clk_disable(data->clk[1]);
-	if (data->clk[0])
-		clk_disable(data->clk[0]);
+	if (data->clk)

I know this is already in the driver, but checking (struct clk *) for NULL is incorrect. NULL is a valid pointer for dummy clocks on platforms which do not provide particular clocks, to make this transparent to drivers. IS_ERR() should be used to check whether a clock pointer is valid.

This patch is changing all the clock code anyway, so this change could be squashed into it to fix this.

+		clk_disable(data->clk);

  	disabled = true;
  	data->pgtable = 0;
@@ -393,7 +371,7 @@ finish:
  static int __exynos_sysmmu_enable(struct sysmmu_drvdata *data,
  			unsigned long pgtable, struct iommu_domain *domain)
  {
-	int i, ret = 0;
+	int ret = 0;
  	unsigned long flags;

  	write_lock_irqsave(&data->lock, flags);
@@ -410,17 +388,14 @@ static int __exynos_sysmmu_enable(struct sysmmu_drvdata *data,
  		goto finish;
  	}

-	if (data->clk[0])
-		clk_enable(data->clk[0]);
-	if (data->clk[1])
-		clk_enable(data->clk[1]);
+	if (data->clk)
+		clk_enable(data->clk);

  	data->pgtable = pgtable;

-	for (i = 0; i < data->nsfrs; i++) {
-		__sysmmu_set_ptbase(data->sfrbases[i], pgtable);
-		__raw_writel(CTRL_ENABLE, data->sfrbases[i] + REG_MMU_CTRL);
-	}
+	__sysmmu_set_ptbase(data->sfrbase, pgtable);
+
+	__raw_writel(CTRL_ENABLE, data->sfrbase + REG_MMU_CTRL);

  	data->domain = domain;

@@ -477,28 +452,26 @@ static void sysmmu_tlb_invalidate_entry(struct device *dev, unsigned long iova,
  	read_lock_irqsave(&data->lock, flags);

  	if (is_sysmmu_active(data)) {
-		int i;
-		for (i = 0; i < data->nsfrs; i++) {
-			unsigned int maj;
-			unsigned int num_inv = 1;
-			maj = __raw_readl(data->sfrbases[i] + REG_MMU_VERSION);
-			/*
-			 * L2TLB invalidation required
-			 * 4KB page: 1 invalidation
-			 * 64KB page: 16 invalidation
-			 * 1MB page: 64 invalidation
-			 * because it is set-associative TLB
-			 * with 8-way and 64 sets.
-			 * 1MB page can be cached in one of all sets.
-			 * 64KB page can be one of 16 consecutive sets.
-			 */
-			if ((maj >> 28) == 2) /* major version number */
-				num_inv = min_t(unsigned int, size / PAGE_SIZE, 64);
-			if (sysmmu_block(data->sfrbases[i])) {
-				__sysmmu_tlb_invalidate_entry(
-					data->sfrbases[i], iova, num_inv);
-				sysmmu_unblock(data->sfrbases[i]);
-			}
+		unsigned int maj;
+		unsigned int num_inv = 1;
+		maj = __raw_readl(data->sfrbase + REG_MMU_VERSION);
+		/*
+		 * L2TLB invalidation required
+		 * 4KB page: 1 invalidation
+		 * 64KB page: 16 invalidation
+		 * 1MB page: 64 invalidation
+		 * because it is set-associative TLB
+		 * with 8-way and 64 sets.
+		 * 1MB page can be cached in one of all sets.
+		 * 64KB page can be one of 16 consecutive sets.
+		 */
+		if ((maj >> 28) == 2) /* major version number */
+			num_inv = min_t(unsigned int, size / PAGE_SIZE, 64);
+
+		if (sysmmu_block(data->sfrbase)) {
+			__sysmmu_tlb_invalidate_entry(data->sfrbase, iova,
+							num_inv);
+			sysmmu_unblock(data->sfrbase);
  		}
  	} else {
  		dev_dbg(data->sysmmu,
@@ -517,12 +490,9 @@ void exynos_sysmmu_tlb_invalidate(struct device *dev)
  	read_lock_irqsave(&data->lock, flags);

  	if (is_sysmmu_active(data)) {
-		int i;
-		for (i = 0; i < data->nsfrs; i++) {
-			if (sysmmu_block(data->sfrbases[i])) {
-				__sysmmu_tlb_invalidate(data->sfrbases[i]);
-				sysmmu_unblock(data->sfrbases[i]);
-			}
+		if (sysmmu_block(data->sfrbase)) {
+			__sysmmu_tlb_invalidate(data->sfrbase);
+			sysmmu_unblock(data->sfrbase);
  		}
  	} else {
  		dev_dbg(data->sysmmu,
@@ -535,11 +505,10 @@ void exynos_sysmmu_tlb_invalidate(struct device *dev)

  static int exynos_sysmmu_probe(struct platform_device *pdev)
  {
-	int i, ret;
-	struct device *dev;
+	int ret;
+	struct device *dev = &pdev->dev;
  	struct sysmmu_drvdata *data;
-
-	dev = &pdev->dev;
+	struct resource *res;

  	data = kzalloc(sizeof(*data), GFP_KERNEL);
  	if (!data) {
@@ -548,82 +517,39 @@ static int exynos_sysmmu_probe(struct platform_device *pdev)
  		goto err_alloc;
  	}

-	ret = dev_set_drvdata(dev, data);
-	if (ret) {
-		dev_dbg(dev, "Unabled to initialize driver data\n");
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_dbg(dev, "Unable to find IOMEM region\n");
+		ret = -ENOENT;
  		goto err_init;
  	}

-	data->nsfrs = pdev->num_resources / 2;
-	data->sfrbases = kmalloc(sizeof(*data->sfrbases) * data->nsfrs,
-								GFP_KERNEL);
-	if (data->sfrbases == NULL) {
-		dev_dbg(dev, "Not enough memory\n");
-		ret = -ENOMEM;
-		goto err_init;
+	data->sfrbase = ioremap(res->start, resource_size(res));
+	if (!data->sfrbase) {
+		dev_dbg(dev, "Unable to map IOMEM @ PA:%#x\n", res->start);
+		ret = -ENOENT;
+		goto err_res;
  	}

-	for (i = 0; i < data->nsfrs; i++) {
-		struct resource *res;
-		res = platform_get_resource(pdev, IORESOURCE_MEM, i);
-		if (!res) {
-			dev_dbg(dev, "Unable to find IOMEM region\n");
-			ret = -ENOENT;
-			goto err_res;
-		}
-
-		data->sfrbases[i] = ioremap(res->start, resource_size(res));
-		if (!data->sfrbases[i]) {
-			dev_dbg(dev, "Unable to map IOMEM @ PA:%#x\n",
-							res->start);
-			ret = -ENOENT;
-			goto err_res;
-		}
+	ret = platform_get_irq(pdev, 0);
+	if (ret <= 0) {
+		dev_dbg(dev, "Unable to find IRQ resource\n");
+		goto err_irq;
  	}

-	for (i = 0; i < data->nsfrs; i++) {
-		ret = platform_get_irq(pdev, i);
-		if (ret <= 0) {
-			dev_dbg(dev, "Unable to find IRQ resource\n");
-			goto err_irq;
-		}
-
-		ret = request_irq(ret, exynos_sysmmu_irq, 0,
-					dev_name(dev), data);
-		if (ret) {
-			dev_dbg(dev, "Unabled to register interrupt handler\n");
-			goto err_irq;
-		}
+	ret = request_irq(ret, exynos_sysmmu_irq, 0,
+				dev_name(dev), data);
+	if (ret) {
+		dev_dbg(dev, "Unabled to register interrupt handler\n");
+		goto err_irq;
  	}

  	if (dev_get_platdata(dev)) {
-		char *deli, *beg;
-		struct sysmmu_platform_data *platdata = dev_get_platdata(dev);
-
-		beg = platdata->clockname;
-
-		for (deli = beg; (*deli != '\0') && (*deli != ','); deli++)
-			/* NOTHING */;
-
-		if (*deli == '\0')
-			deli = NULL;
-		else
-			*deli = '\0';
-
-		data->clk[0] = clk_get(dev, beg);
-		if (IS_ERR(data->clk[0])) {
-			data->clk[0] = NULL;
+		data->clk = clk_get(dev, "sysmmu");
+		if (IS_ERR(data->clk)) {
+			data->clk = NULL;

This is incorrect. IS_ERR() should be used through the driver and the error value here should not be replaced with NULL.

--
Best regards,
Tomasz
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]
  Powered by Linux