On Thu, 08 Aug 2013 15:54:50 +0200, Tomasz Figa wrote: > On Thursday 08 of August 2013 18:37:43 Cho KyongHo wrote: > > This prevents allocating lv2 page table for the lv1 page table entry > ^ What this is this this about? :) > As you might indicate, 'this' means this patch :) > > that already has 1MB page mapping. In addition, changed to BUG_ON > > instead of returning -EADDRINUSE. > > The change mentioned in last sentence should be a separate patch. > Ok :) > > Signed-off-by: Cho KyongHo <pullip.cho@xxxxxxxxxxx> > > --- > > drivers/iommu/exynos-iommu.c | 68 > > ++++++++++++++++++++++++----------------- 1 files changed, 40 > > insertions(+), 28 deletions(-) > > > > diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c > > index d545a25..d90e6fa 100644 > > --- a/drivers/iommu/exynos-iommu.c > > +++ b/drivers/iommu/exynos-iommu.c > > @@ -52,11 +52,11 @@ > > #define lv2ent_large(pent) ((*(pent) & 3) == 1) > > > > #define section_phys(sent) (*(sent) & SECT_MASK) > > -#define section_offs(iova) ((iova) & 0xFFFFF) > > +#define section_offs(iova) ((iova) & ~SECT_MASK) > > #define lpage_phys(pent) (*(pent) & LPAGE_MASK) > > -#define lpage_offs(iova) ((iova) & 0xFFFF) > > +#define lpage_offs(iova) ((iova) & ~LPAGE_MASK) > > #define spage_phys(pent) (*(pent) & SPAGE_MASK) > > -#define spage_offs(iova) ((iova) & 0xFFF) > > +#define spage_offs(iova) ((iova) & ~SPAGE_MASK) > > > > #define lv1ent_offset(iova) ((iova) >> SECT_ORDER) > > #define lv2ent_offset(iova) (((iova) & 0xFF000) >> SPAGE_ORDER) > > @@ -856,13 +856,15 @@ finish: > > static unsigned long *alloc_lv2entry(unsigned long *sent, unsigned long > > iova, short *pgcounter) > > { > > + BUG_ON(lv1ent_section(sent)); > > Is this condition really a critical one, to the point that the system > should not continue execution? > Discussed with Grant. He thought that creating mapping on a valid mapping is just a BUG and I finally agreed with him. Is there a case that the condition in BUG_ON is true intentionally? > > + > > if (lv1ent_fault(sent)) { > > unsigned long *pent; > > > > pent = kzalloc(LV2TABLE_SIZE, GFP_ATOMIC); > > BUG_ON((unsigned long)pent & (LV2TABLE_SIZE - 1)); > > if (!pent) > > - return NULL; > > + return ERR_PTR(-ENOMEM); > > > > *sent = mk_lv1ent_page(__pa(pent)); > > *pgcounter = NUM_LV2ENTRIES; > > @@ -875,15 +877,11 @@ static unsigned long *alloc_lv2entry(unsigned long > > *sent, unsigned long iova, > > > > static int lv1set_section(unsigned long *sent, phys_addr_t paddr, short > > *pgcnt) { > > - if (lv1ent_section(sent)) > > - return -EADDRINUSE; > > + BUG_ON(lv1ent_section(sent)); > > Ditto. > > > if (lv1ent_page(sent)) { > > - if (*pgcnt != NUM_LV2ENTRIES) > > - return -EADDRINUSE; > > - > > + BUG_ON(*pgcnt != NUM_LV2ENTRIES); > > Ditto. > > > kfree(page_entry(sent, 0)); > > - > > *pgcnt = 0; > > } > > > > @@ -894,24 +892,24 @@ static int lv1set_section(unsigned long *sent, > > phys_addr_t paddr, short *pgcnt) return 0; > > } > > > > +static void clear_page_table(unsigned long *ent, int n) > > +{ > > + if (n > 0) > > + memset(ent, 0, sizeof(*ent) * n); > > +} > > I don't see the point of creating this function. It seems to be used only > once, in addition with a constant as n, so the check for n > 0 is > unnecessary. > > And even if there is a need for this change, it should be done in separate > patch, as this one is not about stylistic changes, but fixing page table > maintenance (at least based on your commit message). > I know what you are concerning about. It was introduced in v8 patches to recover previous fault entries before returning -EADDRINUSE. It is still remained though "return -EADDRINUSE" is changed into BUG_ON(). I also think that it needs to be removed. > > static int lv2set_page(unsigned long *pent, phys_addr_t paddr, size_t > > size, short *pgcnt) > > { > > if (size == SPAGE_SIZE) { > > - if (!lv2ent_fault(pent)) > > - return -EADDRINUSE; > > - > > + BUG_ON(!lv2ent_fault(pent)); > > Ditto. > > > *pent = mk_lv2ent_spage(paddr); > > pgtable_flush(pent, pent + 1); > > *pgcnt -= 1; > > } else { /* size == LPAGE_SIZE */ > > int i; > > for (i = 0; i < SPAGES_PER_LPAGE; i++, pent++) { > > - if (!lv2ent_fault(pent)) { > > - memset(pent, 0, sizeof(*pent) * i); > > - return -EADDRINUSE; > > - } > > - > > + BUG_ON(!lv2ent_fault(pent)); > > Ditto. > > > *pent = mk_lv2ent_lpage(paddr); > > } > > pgtable_flush(pent - SPAGES_PER_LPAGE, pent); > > @@ -944,17 +942,16 @@ static int exynos_iommu_map(struct iommu_domain > > *domain, unsigned long iova, pent = alloc_lv2entry(entry, iova, > > &priv->lv2entcnt[lv1ent_offset(iova)]); > > > > - if (!pent) > > - ret = -ENOMEM; > > + if (IS_ERR(pent)) > > + ret = PTR_ERR(pent); > > else > > ret = lv2set_page(pent, paddr, size, > > &priv->lv2entcnt[lv1ent_offset(iova)]); > > } > > > > - if (ret) { > > - pr_debug("%s: Failed to map iova 0x%lx/0x%x bytes\n", > > - __func__, iova, size); > > - } > > + if (ret) > > + pr_err("%s: Failed(%d) to map 0x%#x bytes @ %#lx\n", > > + __func__, ret, size, iova); > > > > spin_unlock_irqrestore(&priv->pgtablelock, flags); > > > > @@ -968,6 +965,7 @@ static size_t exynos_iommu_unmap(struct iommu_domain > > *domain, struct sysmmu_drvdata *data; > > unsigned long flags; > > unsigned long *ent; > > + size_t err_pgsize; > > > > BUG_ON(priv->pgtable == NULL); > > > > @@ -976,7 +974,10 @@ static size_t exynos_iommu_unmap(struct iommu_domain > > *domain, ent = section_entry(priv->pgtable, iova); > > > > if (lv1ent_section(ent)) { > > - BUG_ON(size < SECT_SIZE); > > + if (WARN_ON(size < SECT_SIZE)) { > > + err_pgsize = SECT_SIZE; > > + goto err; > > + } > > > > *ent = 0; > > pgtable_flush(ent, ent + 1); > > @@ -1008,9 +1009,12 @@ static size_t exynos_iommu_unmap(struct > > iommu_domain *domain, } > > > > /* lv1ent_large(ent) == true here */ > > - BUG_ON(size < LPAGE_SIZE); > > + if (WARN_ON(size < LPAGE_SIZE)) { > > + err_pgsize = LPAGE_SIZE; > > + goto err; > > + } > > > > - memset(ent, 0, sizeof(*ent) * SPAGES_PER_LPAGE); > > + clear_page_table(ent, SPAGES_PER_LPAGE); > > This seems to be the only use of the introduced clear_page_table() > function. Is there a need to replace the memset with it? > Agree. > > pgtable_flush(ent, ent + SPAGES_PER_LPAGE); > > > > size = LPAGE_SIZE; > > @@ -1023,8 +1027,16 @@ done: > > sysmmu_tlb_invalidate_entry(data->dev, iova); > > spin_unlock_irqrestore(&priv->lock, flags); > > > > - > > return size; > > +err: > > + spin_unlock_irqrestore(&priv->pgtablelock, flags); > > + > > + pr_err("%s: Failed due to size(%#x) @ %#lx is"\ > > + " smaller than page size %#x\n", > > + __func__, size, iova, err_pgsize); > > + > > + return 0; > > + > > nit: Stray blank line. > Oh. I didn't catch that. Thanks. KyongHo > Best regards, > Tomasz > > > } > > > > static phys_addr_t exynos_iommu_iova_to_phys(struct iommu_domain > > *domain, -- 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