Hi Hari, From: "ext Kanigeri, Hari" <[email protected]> Subject: [PATCH] ARM: OMAP add TLB preservation support to IOMMU Date: Fri, 16 Apr 2010 18:18:59 +0200
> From bcdd232666a163d2661d704f9c21d055bacfd178 Mon Sep 17 00:00:00 2001 > From: Hari Kanigeri <[email protected]> > Date: Mon, 8 Mar 2010 18:00:36 -0600 > Subject: [PATCH] ARM: OMAP add TLB preservation support to IOMMU > > This patch adds TLB preservation support to IOMMU module > > Signed-off-by: Hari Kanigeri <[email protected]> > --- > arch/arm/mach-omap2/iommu2.c | 7 +++++-- > arch/arm/plat-omap/iommu.c | 16 +++++++++------- > 2 files changed, 14 insertions(+), 9 deletions(-) > > diff --git a/arch/arm/mach-omap2/iommu2.c b/arch/arm/mach-omap2/iommu2.c > index 6f4b7cc..2735bd7 100644 > --- a/arch/arm/mach-omap2/iommu2.c > +++ b/arch/arm/mach-omap2/iommu2.c > @@ -146,6 +146,8 @@ static u32 omap2_iommu_fault_isr(struct iommu *obj, u32 > *ra) > printk("\n"); > > iommu_write_reg(obj, stat, MMU_IRQSTATUS); > + /* Disable MMU to stop continuous generation of MMU faults */ > + omap2_iommu_disable(obj); The above comment may look a bit redundant. > return stat; > } > > @@ -183,7 +185,7 @@ static struct cr_regs *omap2_alloc_cr(struct iommu *obj, > struct iotlb_entry *e) > if (!cr) > return ERR_PTR(-ENOMEM); > > - cr->cam = (e->da & MMU_CAM_VATAG_MASK) | e->prsvd | e->pgsz; > + cr->cam = (e->da & MMU_CAM_VATAG_MASK) | e->prsvd | e->pgsz | e->valid; > cr->ram = e->pa | e->endian | e->elsz | e->mixed; Good finding. This can be a separate patch. > return cr; > @@ -211,7 +213,8 @@ static ssize_t omap2_dump_cr(struct iommu *obj, struct > cr_regs *cr, char *buf) > char *p = buf; > > /* FIXME: Need more detail analysis of cam/ram */ > - p += sprintf(p, "%08x %08x\n", cr->cam, cr->ram); > + p += sprintf(p, "%08x %08x %01x\n", cr->cam, cr->ram, > + (cr->cam & MMU_CAM_P) ? 1 : 0); This is ok for now. As described in FIXME comment, this cam/ram whole anaylysis can be improved/implemented in order to display all items/bits in the end. > return p - buf; > } > diff --git a/arch/arm/plat-omap/iommu.c b/arch/arm/plat-omap/iommu.c > index 5186728..64d676e 100644 > --- a/arch/arm/plat-omap/iommu.c > +++ b/arch/arm/plat-omap/iommu.c > @@ -171,15 +171,12 @@ static void iotlb_lock_get(struct iommu *obj, struct > iotlb_lock *l) > l->base = MMU_LOCK_BASE(val); > l->vict = MMU_LOCK_VICT(val); > > - BUG_ON(l->base != 0); /* Currently no preservation is used */ > } > > static void iotlb_lock_set(struct iommu *obj, struct iotlb_lock *l) > { > u32 val; > > - BUG_ON(l->base != 0); /* Currently no preservation is used */ > - > val = (l->base << MMU_LOCK_BASE_SHIFT); > val |= (l->vict << MMU_LOCK_VICT_SHIFT); > > @@ -241,7 +238,7 @@ int load_iotlb_entry(struct iommu *obj, struct > iotlb_entry *e) > break; > } > > - if (i == obj->nr_tlb_entries) { > + if (i == obj->nr_tlb_entries || (l.base == obj->nr_tlb_entries)) { The above should be dealt separately, since no vacant entry is normal, but no room to be replaced because of preservation should be warned, at least. > dev_dbg(obj->dev, "%s: full: no entry\n", __func__); > err = -EBUSY; > goto out; > @@ -252,13 +249,18 @@ int load_iotlb_entry(struct iommu *obj, struct > iotlb_entry *e) > clk_disable(obj->clk); > return PTR_ERR(cr); > } > - > iotlb_load_cr(obj, cr); > kfree(cr); > > + /* Increment base number if preservation is set */ > + if (e->prsvd) > + l.base++; redundant comment? It tells what the code does. > /* increment victim for next tlb load */ Although the above is my comment, this looks redundant now too. > - if (++l.vict == obj->nr_tlb_entries) > - l.vict = 0; > + if (++l.vict == obj->nr_tlb_entries) { > + l.vict = l.base; > + goto out; > + } Does the above work? > + > iotlb_lock_set(obj, &l); > out: > clk_disable(obj->clk); > -- > 1.7.0 > > > Thank you, > Best regards, > Hari > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
