Re: [RFC PATCH v4 25/28] x86: Access the setup data through sysfs decrypted

Tom Lendacky
2017-03-17T20:30:19Z

On 3/8/2017 1:09 AM, Dave Young wrote:
> On 02/16/17 at 09:47am, Tom Lendacky wrote:
>> Use memremap() to map the setup data. This will make the appropriate
>> decision as to whether a RAM remapping can be done or if a fallback to
>> ioremap_cache() is needed (similar to the setup data debugfs support).
>>
>> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
>> ---
>> arch/x86/kernel/ksysfs.c | 27 ++++++++++++++-------------
>> 1 file changed, 14 insertions(+), 13 deletions(-)
>>
>> diff --git a/arch/x86/kernel/ksysfs.c b/arch/x86/kernel/ksysfs.c
>> index 4afc67f..d653b3e 100644
>> --- a/arch/x86/kernel/ksysfs.c
>> +++ b/arch/x86/kernel/ksysfs.c
>> @@ -16,6 +16,7 @@
>> #include <linux/stat.h>
>> #include <linux/slab.h>
>> #include <linux/mm.h>
>> +#include <linux/io.h>
>>
>> #include <asm/io.h>
>> #include <asm/setup.h>
>> @@ -79,12 +80,12 @@ static int get_setup_data_paddr(int nr, u64 *paddr)
>> *paddr = pa_data;
>> return 0;
>> }
>> - data = ioremap_cache(pa_data, sizeof(*data));
>> + data = memremap(pa_data, sizeof(*data), MEMREMAP_WB);
>> if (!data)
>> return -ENOMEM;
>>
>> pa_data = data->next;
>> - iounmap(data);
>> + memunmap(data);
>> i++;
>> }
>> return -EINVAL;
>> @@ -97,17 +98,17 @@ static int __init get_setup_data_size(int nr, size_t *size)
>> u64 pa_data = boot_params.hdr.setup_data;
>>
>> while (pa_data) {
>> - data = ioremap_cache(pa_data, sizeof(*data));
>> + data = memremap(pa_data, sizeof(*data), MEMREMAP_WB);
>> if (!data)
>> return -ENOMEM;
>> if (nr == i) {
>> *size = data->len;
>> - iounmap(data);
>> + memunmap(data);
>> return 0;
>> }
>>
>> pa_data = data->next;
>> - iounmap(data);
>> + memunmap(data);
>> i++;
>> }
>> return -EINVAL;
>> @@ -127,12 +128,12 @@ static ssize_t type_show(struct kobject *kobj,
>> ret = get_setup_data_paddr(nr, &paddr);
>> if (ret)
>> return ret;
>> - data = ioremap_cache(paddr, sizeof(*data));
>> + data = memremap(paddr, sizeof(*data), MEMREMAP_WB);
>> if (!data)
>> return -ENOMEM;
>>
>> ret = sprintf(buf, "0x%x\n", data->type);
>> - iounmap(data);
>> + memunmap(data);
>> return ret;
>> }
>>
>> @@ -154,7 +155,7 @@ static ssize_t setup_data_data_read(struct file *fp,
>> ret = get_setup_data_paddr(nr, &paddr);
>> if (ret)
>> return ret;
>> - data = ioremap_cache(paddr, sizeof(*data));
>> + data = memremap(paddr, sizeof(*data), MEMREMAP_WB);
>> if (!data)
>> return -ENOMEM;
>>
>> @@ -170,15 +171,15 @@ static ssize_t setup_data_data_read(struct file *fp,
>> goto out;
>>
>> ret = count;
>> - p = ioremap_cache(paddr + sizeof(*data), data->len);
>> + p = memremap(paddr + sizeof(*data), data->len, MEMREMAP_WB);
>> if (!p) {
>> ret = -ENOMEM;
>> goto out;
>> }
>> memcpy(buf, p + off, count);
>> - iounmap(p);
>> + memunmap(p);
>> out:
>> - iounmap(data);
>> + memunmap(data);
>> return ret;
>> }
>>
>> @@ -250,13 +251,13 @@ static int __init get_setup_data_total_num(u64 pa_data, int *nr)
>> *nr = 0;
>> while (pa_data) {
>> *nr += 1;
>> - data = ioremap_cache(pa_data, sizeof(*data));
>> + data = memremap(pa_data, sizeof(*data), MEMREMAP_WB);
>> if (!data) {
>> ret = -ENOMEM;
>> goto out;
>> }
>> pa_data = data->next;
>> - iounmap(data);
>> + memunmap(data);
>> }
>>
>> out:
>>
>
> It would be better that these cleanup patches are sent separately.

Bjorn suggested something along the same line so I've combined all the
changes from ioremap to memremap as a single pre-patch in the series.
I could send them separately if needed.

Thanks,
Tom

>
> Acked-by: Dave Young <dyoung@redhat.com>
>
> Thanks
> Dave
>