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

[Tom Lendacky]

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.lenda...@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 <dyo...@redhat.com>

Thanks
Dave

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