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Message-id: <5322FF14.5040908@samsung.com>
Date: Fri, 14 Mar 2014 14:07:32 +0100
From: Tomasz Figa <t.figa@...sung.com>
To: Cho KyongHo <pullip.cho@...sung.com>,
Linux ARM Kernel <linux-arm-kernel@...ts.infradead.org>,
Linux DeviceTree <devicetree@...r.kernel.org>,
Linux IOMMU <iommu@...ts.linux-foundation.org>,
Linux Kernel <linux-kernel@...r.kernel.org>,
Linux Samsung SOC <linux-samsung-soc@...r.kernel.org>
Cc: Antonios Motakis <a.motakis@...tualopensystems.com>,
Grant Grundler <grundler@...omium.org>,
Joerg Roedel <joro@...tes.org>,
Kukjin Kim <kgene.kim@...sung.com>,
Prathyush <prathyush.k@...sung.com>,
Rahul Sharma <rahul.sharma@...sung.com>,
Sachin Kamat <sachin.kamat@...aro.org>,
Sylwester Nawrocki <s.nawrocki@...sung.com>,
Varun Sethi <Varun.Sethi@...escale.com>
Subject: Re: [PATCH v11 08/27] iommu/exynos: always use a single clock
descriptor
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@...sung.com>
> ---
> 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
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