On Friday 20 May 2016 13:44:10 Arnd Bergmann wrote:

quoted

 #define GET_CTX_REG(reg, base, ctx) \
                              (readl((base) + (reg) + ((ctx) << CTX_SHIFT)))
 
-#define SET_GLOBAL_REG(reg, base, val)       writel((val), ((base) + (reg)))
+/*
+ * The writes to the global/context registers needs to be synced only after
+ * all the configuration writes are done. So use relaxed accessors and
+ * a barrier at the end.
+ */
+#define SET_GLOBAL_REG_RELAXED(reg, base, val) \
+                            writel_relaxed((val), ((base) + (reg)))
 
-#define SET_CTX_REG(reg, base, ctx, val) \
-                     writel((val), ((base) + (reg) + ((ctx) << CTX_SHIFT)))
+#define SET_CTX_REG_RELAXED(reg, base, ctx, val) \
+             writel_relaxed((val), ((base) + (reg) + ((ctx) << CTX_SHIFT)))

Please add the relaxed accessors first in a separate patch, and then
change over one user at a time before you remove the non-relaxed ones.

It's hard to believe that all users are actually performance critical,
so start with the ones that gain the most performance. As commented above,
some of the conversions seem particularly fishy and it's likely that
a slow reset() function should not be fixed by making reset() faster
but by calling it less often.

One more thing, please also convert them into inline functions when you modify
them, and use normal names such as

static inline void msm_iommu_write(struct msm_iommu_dev *iommu, unsigned int reg, u32 val)
{
	writel(val, iommu->base + reg);
}

static inline void msm_iommu_context_write(struct msm_iommu_ctx_dev *ctx, unsigned int reg, u32 val)
{
	writel(val, ctx->iommu->base + ctx << CTX_SHIFT + reg, val);
}

	Arnd