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Date: Thu, 07 May 2015 16:33:22 +0800
From: "Li, ZhenHua" <zhen-hual@...com>
To: Baoquan He <bhe@...hat.com>
CC: dwmw2@...radead.org, indou.takao@...fujitsu.com, joro@...tes.org,
vgoyal@...hat.com, dyoung@...hat.com,
iommu@...ts.linux-foundation.org, linux-kernel@...r.kernel.org,
linux-pci@...r.kernel.org, kexec@...ts.infradead.org,
alex.williamson@...hat.com, ddutile@...hat.com,
ishii.hironobu@...fujitsu.com, bhelgaas@...gle.com,
doug.hatch@...com, jerry.hoemann@...com, tom.vaden@...com,
li.zhang6@...com, lisa.mitchell@...com, billsumnerlinux@...il.com,
rwright@...com
Subject: Re: [PATCH v10 04/10] iommu/vt-d: functions to copy data from old
mem
It is called in
static int copy_root_entry_table(struct intel_iommu *iommu);
On 05/07/2015 03:49 PM, Baoquan He wrote:
> On 04/10/15 at 04:42pm, Li, Zhen-Hua wrote:
>> Add some functions to copy the data from old kernel.
>> These functions are used to copy context tables and page tables.
>>
>> To avoid calling iounmap between spin_lock_irqsave and spin_unlock_irqrestore,
>> use a link here, store the pointers , and then use iounmap to free them in
>> another place.
>>
>> Li, Zhen-hua:
>> The functions and logics.
>>
>> Takao Indoh:
>> Check if pfn is ram:
>> if (page_is_ram(pfn))
>>
>> Signed-off-by: Li, Zhen-Hua <zhen-hual@...com>
>> Signed-off-by: Takao Indoh <indou.takao@...fujitsu.com>
>> ---
>> drivers/iommu/intel-iommu.c | 102 ++++++++++++++++++++++++++++++++++++++++++++
>> include/linux/intel-iommu.h | 6 +++
>> 2 files changed, 108 insertions(+)
>>
>> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
>> index ff5ac04..5ba403a 100644
>> --- a/drivers/iommu/intel-iommu.c
>> +++ b/drivers/iommu/intel-iommu.c
>> @@ -373,6 +373,17 @@ static struct context_entry *device_to_existing_context_entry(
>> struct intel_iommu *iommu,
>> u8 bus, u8 devfn);
>>
>> +/*
>> + * A structure used to store the address allocated by ioremap();
>> + * The we need to call iounmap() to free them out of spin_lock_irqsave/unlock;
>> + */
>> +struct iommu_remapped_entry {
>> + struct list_head list;
>> + void __iomem *mem;
>> +};
>> +static LIST_HEAD(__iommu_remapped_mem);
>> +static DEFINE_MUTEX(__iommu_mem_list_lock);
>> +
>>
>> /*
>> * This domain is a statically identity mapping domain.
>> @@ -4817,3 +4828,94 @@ static struct context_entry *device_to_existing_context_entry(
>> return ret;
>> }
>>
>> +/*
>> + * Copy memory from a physically-addressed area into a virtually-addressed area
>> + */
>
> I don't find where __iommu_load_from_oldmem is called. Obsolete code of
> this patch?
>
>> +int __iommu_load_from_oldmem(void *to, unsigned long from, unsigned long size)
>> +{
>> + unsigned long pfn; /* Page Frame Number */
>> + size_t csize = (size_t)size; /* Num(bytes to copy) */
>> + unsigned long offset; /* Lower 12 bits of to */
>> + void __iomem *virt_mem;
>> + struct iommu_remapped_entry *mapped;
>> +
>> + pfn = from >> VTD_PAGE_SHIFT;
>> + offset = from & (~VTD_PAGE_MASK);
>> +
>> + if (page_is_ram(pfn)) {
>> + memcpy(to, pfn_to_kaddr(pfn) + offset, csize);
>> + } else{
>> +
>> + mapped = kzalloc(sizeof(struct iommu_remapped_entry),
>> + GFP_KERNEL);
>> + if (!mapped)
>> + return -ENOMEM;
>> +
>> + virt_mem = ioremap_cache((unsigned long)from, size);
>> + if (!virt_mem) {
>> + kfree(mapped);
>> + return -ENOMEM;
>> + }
>> + memcpy(to, virt_mem, size);
>> +
>> + mutex_lock(&__iommu_mem_list_lock);
>> + mapped->mem = virt_mem;
>> + list_add_tail(&mapped->list, &__iommu_remapped_mem);
>> + mutex_unlock(&__iommu_mem_list_lock);
>> + }
>> + return size;
>> +}
>> +
>> +/*
>> + * Copy memory from a virtually-addressed area into a physically-addressed area
>> + */
>> +int __iommu_save_to_oldmem(unsigned long to, void *from, unsigned long size)
>> +{
>> + unsigned long pfn; /* Page Frame Number */
>> + size_t csize = (size_t)size; /* Num(bytes to copy) */
>> + unsigned long offset; /* Lower 12 bits of to */
>> + void __iomem *virt_mem;
>> + struct iommu_remapped_entry *mapped;
>> +
>> + pfn = to >> VTD_PAGE_SHIFT;
>> + offset = to & (~VTD_PAGE_MASK);
>> +
>> + if (page_is_ram(pfn)) {
>> + memcpy(pfn_to_kaddr(pfn) + offset, from, csize);
>> + } else{
>> + mapped = kzalloc(sizeof(struct iommu_remapped_entry),
>> + GFP_KERNEL);
>> + if (!mapped)
>> + return -ENOMEM;
>> +
>> + virt_mem = ioremap_cache((unsigned long)to, size);
>> + if (!virt_mem) {
>> + kfree(mapped);
>> + return -ENOMEM;
>> + }
>> + memcpy(virt_mem, from, size);
>> + mutex_lock(&__iommu_mem_list_lock);
>> + mapped->mem = virt_mem;
>> + list_add_tail(&mapped->list, &__iommu_remapped_mem);
>> + mutex_unlock(&__iommu_mem_list_lock);
>> + }
>> + return size;
>> +}
>> +
>> +/*
>> + * Free the mapped memory for ioremap;
>> + */
>> +int __iommu_free_mapped_mem(void)
>> +{
>> + struct iommu_remapped_entry *mem_entry, *tmp;
>> +
>> + mutex_lock(&__iommu_mem_list_lock);
>> + list_for_each_entry_safe(mem_entry, tmp, &__iommu_remapped_mem, list) {
>> + iounmap(mem_entry->mem);
>> + list_del(&mem_entry->list);
>> + kfree(mem_entry);
>> + }
>> + mutex_unlock(&__iommu_mem_list_lock);
>> + return 0;
>> +}
>> +
>> diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
>> index a65208a..4bca7b5 100644
>> --- a/include/linux/intel-iommu.h
>> +++ b/include/linux/intel-iommu.h
>> @@ -368,4 +368,10 @@ extern int dmar_ir_support(void);
>>
>> extern const struct attribute_group *intel_iommu_groups[];
>>
>> +extern int __iommu_load_from_oldmem(void *to, unsigned long from,
>> + unsigned long size);
>> +extern int __iommu_save_to_oldmem(unsigned long to, void *from,
>> + unsigned long size);
>> +extern int __iommu_free_mapped_mem(void);
>> +
>> #endif
>> --
>> 2.0.0-rc0
>>
--
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