ehea: Detect 16GB hugepages for firmware restriction

All kernel memory which is used for kernel/hardware data transfer must
be registered with firmware using "memory regions". 16GB hugepages
may not be part of a memory region due to firmware restrictions.
This patch modifies the walk_memory_resource callback fn to filter
hugepages and add only standard memory to the busmap which is later
on used for MR registration.

Signed-off-by: Thomas Klein <tklein@de.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

diff --git a/drivers/net/ehea/ehea.h b/drivers/net/ehea/ehea.h
index 82dd1a891ce71aa7c88b8509a45d186f6f86d084..002d918fb4c742fc4a66af17a1d427e19959cbe0 100644 (file)
--- a/drivers/net/ehea/ehea.h
+++ b/drivers/net/ehea/ehea.h
@@ -40,7 +40,7 @@
 #include <asm/io.h>
 
 #define DRV_NAME       "ehea"
-#define DRV_VERSION    "EHEA_0094"
+#define DRV_VERSION    "EHEA_0095"
 
 /* eHEA capability flags */
 #define DLPAR_PORT_ADD_REM 1

diff --git a/drivers/net/ehea/ehea_qmr.c b/drivers/net/ehea/ehea_qmr.c
index 9b61dc9865d19039ef5fb0c0dced4a7b5a7b5aeb..9d006878f0459db1dfe30c079639638ae2025fcf 100644 (file)
--- a/drivers/net/ehea/ehea_qmr.c
+++ b/drivers/net/ehea/ehea_qmr.c
@@ -632,10 +632,13 @@ static void ehea_rebuild_busmap(void)
        }
 }
 
-static int ehea_update_busmap(unsigned long pfn, unsigned long pgnum, int add)
+static int ehea_update_busmap(unsigned long pfn, unsigned long nr_pages, int add)
 {
        unsigned long i, start_section, end_section;
 
+       if (!nr_pages)
+               return 0;
+
        if (!ehea_bmap) {
                ehea_bmap = kzalloc(sizeof(struct ehea_bmap), GFP_KERNEL);
                if (!ehea_bmap)
@@ -643,7 +646,7 @@ static int ehea_update_busmap(unsigned long pfn, unsigned long pgnum, int add)
        }
 
        start_section = (pfn * PAGE_SIZE) / EHEA_SECTSIZE;
-       end_section = start_section + ((pgnum * PAGE_SIZE) / EHEA_SECTSIZE);
+       end_section = start_section + ((nr_pages * PAGE_SIZE) / EHEA_SECTSIZE);
        /* Mark entries as valid or invalid only; address is assigned later */
        for (i = start_section; i < end_section; i++) {
                u64 flag;
@@ -692,10 +695,54 @@ int ehea_rem_sect_bmap(unsigned long pfn, unsigned long nr_pages)
        return ret;
 }
 
-static int ehea_create_busmap_callback(unsigned long pfn,
-                                      unsigned long nr_pages, void *arg)
+static int ehea_is_hugepage(unsigned long pfn)
+{
+       int page_order;
+
+       if (pfn & EHEA_HUGEPAGE_PFN_MASK)
+               return 0;
+
+       page_order = compound_order(pfn_to_page(pfn));
+       if (page_order + PAGE_SHIFT != EHEA_HUGEPAGESHIFT)
+               return 0;
+
+       return 1;
+}
+
+static int ehea_create_busmap_callback(unsigned long initial_pfn,
+                                      unsigned long total_nr_pages, void *arg)
 {
-       return ehea_update_busmap(pfn, nr_pages, EHEA_BUSMAP_ADD_SECT);
+       int ret;
+       unsigned long pfn, start_pfn, end_pfn, nr_pages;
+
+       if ((total_nr_pages * PAGE_SIZE) < EHEA_HUGEPAGE_SIZE)
+               return ehea_update_busmap(initial_pfn, total_nr_pages,
+                                         EHEA_BUSMAP_ADD_SECT);
+
+       /* Given chunk is >= 16GB -> check for hugepages */
+       start_pfn = initial_pfn;
+       end_pfn = initial_pfn + total_nr_pages;
+       pfn = start_pfn;
+
+       while (pfn < end_pfn) {
+               if (ehea_is_hugepage(pfn)) {
+                       /* Add mem found in front of the hugepage */
+                       nr_pages = pfn - start_pfn;
+                       ret = ehea_update_busmap(start_pfn, nr_pages,
+                                                EHEA_BUSMAP_ADD_SECT);
+                       if (ret)
+                               return ret;
+
+                       /* Skip the hugepage */
+                       pfn += (EHEA_HUGEPAGE_SIZE / PAGE_SIZE);
+                       start_pfn = pfn;
+               } else
+                       pfn += (EHEA_SECTSIZE / PAGE_SIZE);
+       }
+
+       /* Add mem found behind the hugepage(s)  */
+       nr_pages = pfn - start_pfn;
+       return ehea_update_busmap(start_pfn, nr_pages, EHEA_BUSMAP_ADD_SECT);
 }
 
 int ehea_create_busmap(void)

diff --git a/drivers/net/ehea/ehea_qmr.h b/drivers/net/ehea/ehea_qmr.h
index 1e58dc06b7d2cbd6d811b11534fa78025b9eb0a6..0817c1e74a1960470a1823dfdeb45f0087f309bc 100644 (file)
--- a/drivers/net/ehea/ehea_qmr.h
+++ b/drivers/net/ehea/ehea_qmr.h
@@ -40,6 +40,9 @@
 #define EHEA_PAGESIZE          (1UL << EHEA_PAGESHIFT)
 #define EHEA_SECTSIZE          (1UL << 24)
 #define EHEA_PAGES_PER_SECTION (EHEA_SECTSIZE >> EHEA_PAGESHIFT)
+#define EHEA_HUGEPAGESHIFT     34
+#define EHEA_HUGEPAGE_SIZE     (1UL << EHEA_HUGEPAGESHIFT)
+#define EHEA_HUGEPAGE_PFN_MASK ((EHEA_HUGEPAGE_SIZE - 1) >> PAGE_SHIFT)
 
 #if ((1UL << SECTION_SIZE_BITS) < EHEA_SECTSIZE)
 #error eHEA module cannot work if kernel sectionsize < ehea sectionsize