On 06/23/2016 05:30 AM, Ronit halder wrote:
Signed-off-by: Ronit Halder <[email protected]>


The patch doesn't apply cleanly, are you copying and pasting the patch into
a mail client? That's prone to breakage. Try using git-send-email, see
http://kernelnewbies.org/Outreachyfirstpatch for tutorials on getting that
set up.

---
 arch/x86/kernel/setup.c | 37 +++++++++++------------
 include/linux/kexec.h   |  8 ++++-
 kernel/kexec_core.c     | 80 +++++++++++++++++++++++++++++++++++++++++++++++++
 kernel/ksysfs.c         | 14 +++++++--
 4 files changed, 117 insertions(+), 22 deletions(-)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index c4e7b39..e48ff40 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -69,6 +69,7 @@
 #include <linux/crash_dump.h>
 #include <linux/tboot.h>
 #include <linux/jiffies.h>
+#include <linux/cma.h>

 #include <video/edid.h>

@@ -124,6 +125,8 @@
 unsigned long max_low_pfn_mapped;
 unsigned long max_pfn_mapped;

+struct cma *crashk_cma;
+struct cma *crashk_cma_low;
 #ifdef CONFIG_DMI
 RESERVE_BRK(dmi_alloc, 65536);
 #endif
@@ -541,9 +544,9 @@ static int __init reserve_crashkernel_low(void)
                return -ENOMEM;
        }

-       ret = memblock_reserve(low_base, low_size);
+       ret =  cma_declare_contiguous(low_base, low_size, 0, CRASH_ALIGN, 0, 1, 
&crashk_cma_low);
        if (ret) {
-               pr_err("%s: Error reserving crashkernel low memblock.\n", 
__func__);
+               pr_err("%s: Error reserving CMA area for crashkernel low.\n", 
__func__);
                return ret;
        }

@@ -552,9 +555,7 @@ static int __init reserve_crashkernel_low(void)
                (unsigned long)(low_base >> 20),
                (unsigned long)(total_low_mem >> 20));

-       crashk_low_res.start = low_base;
-       crashk_low_res.end   = low_base + low_size - 1;
-       insert_resource(&iomem_resource, &crashk_low_res);
+
 #endif
        return 0;
 }
@@ -565,6 +566,8 @@ static void __init reserve_crashkernel(void)
        bool high = false;
        int ret;

+       crashk_cma = NULL;
+       crashk_cma_low = NULL;
        total_mem = memblock_phys_mem_size();

        /* crashkernel=XM */
@@ -587,8 +590,10 @@ static void __init reserve_crashkernel(void)
                                                    high ? CRASH_ADDR_HIGH_MAX
                                                         : CRASH_ADDR_LOW_MAX,
                                                    crash_size, CRASH_ALIGN);
+               pr_info("Crash_base %llu crash_size %llu\n", crash_base, 
crash_size);
+
                if (!crash_base) {
-                       pr_info("crashkernel reservation failed - No suitable area 
found.\n");
+                       pr_info("Crashkernel reservation failed - No suitable area 
found.\n");
                        return;
                }

@@ -598,19 +603,17 @@ static void __init reserve_crashkernel(void)
                start = memblock_find_in_range(crash_base,
                                               crash_base + crash_size,
                                               crash_size, 1 << 20);
+               pr_info("Base_mentioned crash_base %llu crash_size %llu\n", 
crash_base, crash_size);
                if (start != crash_base) {
                        pr_info("crashkernel reservation failed - memory is in 
use.\n");
                        return;
                }
        }
-       ret = memblock_reserve(crash_base, crash_size);
-       if (ret) {
-               pr_err("%s: Error reserving crashkernel memblock.\n", __func__);
+       if (crash_base >= (1ULL << 32) && reserve_crashkernel_low())
                return;
-       }
-
-       if (crash_base >= (1ULL << 32) && reserve_crashkernel_low()) {
-               memblock_free(crash_base, crash_size);
+       ret =  cma_declare_contiguous(crash_base, crash_size, 0, CRASH_ALIGN, 0, 1, 
&crashk_cma);
+       if (ret) {
+               pr_err("%s: Error reserving CMA area for crashkernel.\n", 
__func__);
                return;
        }

@@ -618,10 +621,6 @@ static void __init reserve_crashkernel(void)
                (unsigned long)(crash_size >> 20),
                (unsigned long)(crash_base >> 20),
                (unsigned long)(total_mem >> 20));
-
-       crashk_res.start = crash_base;
-       crashk_res.end   = crash_base + crash_size - 1;
-       insert_resource(&iomem_resource, &crashk_res);
 }
 #else
 static void __init reserve_crashkernel(void)
@@ -729,7 +728,7 @@ static void __init trim_snb_memory(void)
         * already been reserved.
         */
        memblock_reserve(0, 1<<20);
-       
+
        for (i = 0; i < ARRAY_SIZE(bad_pages); i++) {
                if (memblock_reserve(bad_pages[i], PAGE_SIZE))
                        printk(KERN_WARNING "failed to reserve 0x%08lx\n",
@@ -821,7 +820,7 @@ static void __init trim_low_memory_range(void)
 {
        memblock_reserve(0, ALIGN(reserve_low, PAGE_SIZE));
 }
-       
+
 /*
  * Dump out kernel offset information on panic.
  */
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index e8acb2b..b940cbe 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -294,7 +294,7 @@ extern size_t vmcoreinfo_max_size;

 /* flag to track if kexec reboot is in progress */
 extern bool kexec_in_progress;
-
+extern struct cma *crashk_cma, *crashk_cma_low;
 int __init parse_crashkernel(char *cmdline, unsigned long long system_ram,
                unsigned long long *crash_size, unsigned long long *crash_base);
 int parse_crashkernel_high(char *cmdline, unsigned long long system_ram,
@@ -305,6 +305,12 @@ int crash_shrink_memory(unsigned long new_size);
 size_t crash_get_memory_size(void);
 void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);

+int crash_free_memory(unsigned int size);
+int crash_alloc_memory(unsigned int size);
+int crash_alloc_memory_low(void);
+int crash_free_memory_low(void);
+size_t crash_get_memory_size_low(void);
+
 int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
                                         unsigned long buf_len);
 void * __weak arch_kexec_kernel_image_load(struct kimage *image);
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index 56b3ed0..a3323ab 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -39,6 +39,7 @@
 #include <linux/compiler.h>
 #include <linux/hugetlb.h>

+#include <linux/cma.h>
 #include <asm/page.h>
 #include <asm/sections.h>

@@ -46,7 +47,9 @@
 #include <crypto/sha.h>
 #include "kexec_internal.h"

+#define CRASH_ALIGN            (16 << 20)
 DEFINE_MUTEX(kexec_mutex);
+DEFINE_MUTEX(kexec_mutex_low);

 /* Per cpu memory for storing cpu states in case of system crash. */
 note_buf_t __percpu *crash_notes;
@@ -57,6 +60,7 @@ u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
 size_t vmcoreinfo_size;
 size_t vmcoreinfo_max_size = sizeof(vmcoreinfo_data);

+static struct page *pages, *pages_low;
 /* Flag to indicate we are going to kexec a new kernel */
 bool kexec_in_progress = false;

@@ -915,6 +919,17 @@ size_t crash_get_memory_size(void)
        return size;
 }

+size_t crash_get_memory_size_low(void)
+{
+       size_t size = 0;
+
+       mutex_lock(&kexec_mutex_low);
+       if (crashk_low_res.end != crashk_low_res.start)
+               size = resource_size(&crashk_low_res);
+       mutex_unlock(&kexec_mutex_low);
+       return size;
+}
+
 void __weak crash_free_reserved_phys_range(unsigned long begin,
                                           unsigned long end)
 {
@@ -972,6 +987,71 @@ unlock:
        mutex_unlock(&kexec_mutex);
        return ret;
 }
+int crash_free_memory(unsigned int size)
+{
+       int ret;
+
+       if (!crashk_cma)
+               return 0;
+       ret = cma_release(crashk_cma, pages, size >> PAGE_SHIFT);
+
+       if (!ret) {
+               pr_info("Crash memory release failed");
+               return 0;
+       }
+       release_resource(&crashk_res);
+       return 1;
+}
+
+int crash_alloc_memory(unsigned int size)
+{
+       if (!crashk_cma)
+               return 0;
+       pages = cma_alloc(crashk_cma, size >> PAGE_SHIFT, 
KEXEC_CRASH_MEM_ALIGN);
+
+       if (!pages) {
+               pr_info("Memory for crash kernel not allocated");
+               return 0;
+       }
+
+       crashk_res.start = page_to_pfn(pages) << PAGE_SHIFT;
+       crashk_res.end = crashk_res.start + size - 1;
+       insert_resource(&iomem_resource, &crashk_res);
+       return 1;
+}
+
+int crash_free_memory_low(void)
+{
+       int ret;
+
+       if (!crashk_cma_low)
+               return 0;
+       ret = cma_release(crashk_cma_low, pages_low, cma_get_size(crashk_cma_low) 
>> PAGE_SHIFT);
+
+       if (!ret) {
+               pr_info("Crash low memory release failed");
+               return 0;
+       }
+       release_resource(&crashk_low_res);
+       return 1;
+}
+
+int crash_alloc_memory_low(void)
+{
+       if (!crashk_cma_low)
+               return 0;
+       pages = cma_alloc(crashk_cma_low, cma_get_size(crashk_cma_low) >> 
PAGE_SHIFT, KEXEC_CRASH_MEM_ALIGN);
+
+       if (!pages) {
+               pr_info("Low memory for crash kernel not allocated");
+               return 0;
+       }
+
+       crashk_low_res.start = page_to_pfn(pages) << PAGE_SHIFT;
+       crashk_low_res.end = crashk_low_res.start + 
cma_get_size(crashk_cma_low) - 1;
+       insert_resource(&iomem_resource, &crashk_low_res);
+       return 1;
+}

 static u32 *append_elf_note(u32 *buf, char *name, unsigned type, void *data,
                            size_t data_len)
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index 152da4a..07ede25 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -116,12 +116,22 @@ static ssize_t kexec_crash_size_store(struct kobject 
*kobj,
 {
        unsigned long cnt;
        int ret;
+       int size;

        if (kstrtoul(buf, 0, &cnt))
                return -EINVAL;

-       ret = crash_shrink_memory(cnt);
-       return ret < 0 ? ret : count;
+       size = cnt<<20;
+       if (cnt == 0) {
+               crash_free_memory_low();
+               ret = crash_free_memory(crash_get_memory_size());
+       } else if (cnt > 0) {
+               if (crash_get_memory_size_low() == 0)
+                       crash_alloc_memory_low();
+               ret = crash_free_memory(crash_get_memory_size());
+               ret = crash_alloc_memory(size);
+       }
+       return count;
 }
 KERNEL_ATTR_RW(kexec_crash_size);

--
2.5.5
_______________________________________________
kernel mailing list
[email protected]
https://lists.fedoraproject.org/admin/lists/[email protected]

_______________________________________________
kernel mailing list
[email protected]
https://lists.fedoraproject.org/admin/lists/[email protected]

Reply via email to