[PATCHv3 3/4] iommu/tegra: smmu: Refrain from accessing to AHB

From: Hiroshi DOYU
Date: Thu May 03 2012 - 12:06:39 EST


Use "tegra_ahb_enable_smmu()" to inform AHB that SMMU is
ready, instead of directly aceessing AHB registers.

Signed-off-by: Hiroshi DOYU <hdoyu@xxxxxxxxxx>
---
drivers/iommu/tegra-smmu.c | 60 +++++++++++++++++--------------------------
1 files changed, 24 insertions(+), 36 deletions(-)

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index ecd6790..c70e4e7 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -30,12 +30,14 @@
#include <linux/sched.h>
#include <linux/iommu.h>
#include <linux/io.h>
+#include <linux/of.h>

#include <asm/page.h>
#include <asm/cacheflush.h>

#include <mach/iomap.h>
#include <mach/smmu.h>
+#include <mach/tegra-ahb.h>

/* bitmap of the page sizes currently supported */
#define SMMU_IOMMU_PGSIZES (SZ_4K)
@@ -111,11 +113,6 @@

#define SMMU_PDE_NEXT_SHIFT 28

-/* AHB Arbiter Registers */
-#define AHB_XBAR_CTRL 0xe0
-#define AHB_XBAR_CTRL_SMMU_INIT_DONE_DONE 1
-#define AHB_XBAR_CTRL_SMMU_INIT_DONE_SHIFT 17
-
#define SMMU_NUM_ASIDS 4
#define SMMU_TLB_FLUSH_VA_SECTION__MASK 0xffc00000
#define SMMU_TLB_FLUSH_VA_SECTION__SHIFT 12 /* right shift */
@@ -235,7 +232,7 @@ struct smmu_as {
* Per SMMU device - IOMMU device
*/
struct smmu_device {
- void __iomem *regs, *regs_ahbarb;
+ void __iomem *regs;
unsigned long iovmm_base; /* remappable base address */
unsigned long page_count; /* total remappable size */
spinlock_t lock;
@@ -252,12 +249,14 @@ struct smmu_device {
unsigned long translation_enable_1;
unsigned long translation_enable_2;
unsigned long asid_security;
+
+ struct device_node *ahb;
};

static struct smmu_device *smmu_handle; /* unique for a system */

/*
- * SMMU/AHB register accessors
+ * SMMU register accessors
*/
static inline u32 smmu_read(struct smmu_device *smmu, size_t offs)
{
@@ -268,15 +267,6 @@ static inline void smmu_write(struct smmu_device *smmu, u32 val, size_t offs)
writel(val, smmu->regs + offs);
}

-static inline u32 ahb_read(struct smmu_device *smmu, size_t offs)
-{
- return readl(smmu->regs_ahbarb + offs);
-}
-static inline void ahb_write(struct smmu_device *smmu, u32 val, size_t offs)
-{
- writel(val, smmu->regs_ahbarb + offs);
-}
-
#define VA_PAGE_TO_PA(va, page) \
(page_to_phys(page) + ((unsigned long)(va) & ~PAGE_MASK))

@@ -370,9 +360,9 @@ static void smmu_flush_regs(struct smmu_device *smmu, int enable)
FLUSH_SMMU_REGS(smmu);
}

-static void smmu_setup_regs(struct smmu_device *smmu)
+static int smmu_setup_regs(struct smmu_device *smmu)
{
- int i;
+ int i, err;
u32 val;

for (i = 0; i < smmu->num_as; i++) {
@@ -398,10 +388,8 @@ static void smmu_setup_regs(struct smmu_device *smmu)

smmu_flush_regs(smmu, 1);

- val = ahb_read(smmu, AHB_XBAR_CTRL);
- val |= AHB_XBAR_CTRL_SMMU_INIT_DONE_DONE <<
- AHB_XBAR_CTRL_SMMU_INIT_DONE_SHIFT;
- ahb_write(smmu, val, AHB_XBAR_CTRL);
+ err = tegra_ahb_enable_smmu(smmu->ahb);
+ return err;
}

static void flush_ptc_and_tlb(struct smmu_device *smmu,
@@ -873,17 +861,18 @@ static int tegra_smmu_resume(struct device *dev)
{
struct smmu_device *smmu = dev_get_drvdata(dev);
unsigned long flags;
+ int err;

spin_lock_irqsave(&smmu->lock, flags);
- smmu_setup_regs(smmu);
+ err = smmu_setup_regs(smmu);
spin_unlock_irqrestore(&smmu->lock, flags);
- return 0;
+ return err;
}

static int tegra_smmu_probe(struct platform_device *pdev)
{
struct smmu_device *smmu;
- struct resource *regs, *regs2, *window;
+ struct resource *regs, *window;
struct device *dev = &pdev->dev;
int i, err = 0;

@@ -893,9 +882,8 @@ static int tegra_smmu_probe(struct platform_device *pdev)
BUILD_BUG_ON(PAGE_SHIFT != SMMU_PAGE_SHIFT);

regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- regs2 = platform_get_resource(pdev, IORESOURCE_MEM, 1);
- window = platform_get_resource(pdev, IORESOURCE_MEM, 2);
- if (!regs || !regs2 || !window) {
+ window = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+ if (!regs || !window) {
dev_err(dev, "No SMMU resources\n");
return -ENODEV;
}
@@ -911,14 +899,16 @@ static int tegra_smmu_probe(struct platform_device *pdev)
smmu->iovmm_base = (unsigned long)window->start;
smmu->page_count = resource_size(window) >> SMMU_PAGE_SHIFT;
smmu->regs = devm_ioremap(dev, regs->start, resource_size(regs));
- smmu->regs_ahbarb = devm_ioremap(dev, regs2->start,
- resource_size(regs2));
- if (!smmu->regs || !smmu->regs_ahbarb) {
+ if (!smmu->regs) {
dev_err(dev, "failed to remap SMMU registers\n");
err = -ENXIO;
goto fail;
}

+ smmu->ahb = of_parse_phandle(pdev->dev.of_node, "ahb", 0);
+ if (!smmu->ahb)
+ return -ENODEV;
+
smmu->translation_enable_0 = ~0;
smmu->translation_enable_1 = ~0;
smmu->translation_enable_2 = ~0;
@@ -945,7 +935,9 @@ static int tegra_smmu_probe(struct platform_device *pdev)
INIT_LIST_HEAD(&as->client);
}
spin_lock_init(&smmu->lock);
- smmu_setup_regs(smmu);
+ err = smmu_setup_regs(smmu);
+ if (err)
+ goto fail;
platform_set_drvdata(pdev, smmu);

smmu->avp_vector_page = alloc_page(GFP_KERNEL);
@@ -960,8 +952,6 @@ fail:
__free_page(smmu->avp_vector_page);
if (smmu->regs)
devm_iounmap(dev, smmu->regs);
- if (smmu->regs_ahbarb)
- devm_iounmap(dev, smmu->regs_ahbarb);
if (smmu && smmu->as) {
for (i = 0; i < smmu->num_as; i++) {
if (smmu->as[i].pdir_page) {
@@ -993,8 +983,6 @@ static int tegra_smmu_remove(struct platform_device *pdev)
__free_page(smmu->avp_vector_page);
if (smmu->regs)
devm_iounmap(dev, smmu->regs);
- if (smmu->regs_ahbarb)
- devm_iounmap(dev, smmu->regs_ahbarb);
devm_kfree(dev, smmu);
smmu_handle = NULL;
return 0;
--
1.7.5.4

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