2 files changed, 87 insertions, 6 deletions

diff --git a/arch/x86/kernel/pci-calgary_64.c b/arch/x86/kernel/pci-calgary_64.c
index 151f2d171f7c..19e7fc7c2c4f 100644
--- a/arch/x86/kernel/pci-calgary_64.c
+++ b/arch/x86/kernel/pci-calgary_64.c
@@ -29,6 +29,7 @@
 #include <linux/mm.h>
 #include <linux/spinlock.h>
 #include <linux/string.h>
+#include <linux/crash_dump.h>
 #include <linux/dma-mapping.h>
 #include <linux/bitops.h>
 #include <linux/pci_ids.h>
@@ -167,6 +168,8 @@ static void calgary_dump_error_regs(struct iommu_table *tbl);
 static void calioc2_handle_quirks(struct iommu_table *tbl, struct pci_dev *dev);
 static void calioc2_tce_cache_blast(struct iommu_table *tbl);
 static void calioc2_dump_error_regs(struct iommu_table *tbl);
+static void calgary_init_bitmap_from_tce_table(struct iommu_table *tbl);
+static void get_tce_space_from_tar(void);
 
 static struct cal_chipset_ops calgary_chip_ops = {
         .handle_quirks = calgary_handle_quirks,
@@ -830,7 +833,11 @@ static int __init calgary_setup_tar(struct pci_dev *dev, void __iomem *bbar)
 
         tbl = pci_iommu(dev->bus);
         tbl->it_base = (unsigned long)bus_info[dev->bus->number].tce_space;
-        tce_free(tbl, 0, tbl->it_size);
+
+        if (is_kdump_kernel())
+                calgary_init_bitmap_from_tce_table(tbl);
+        else
+                tce_free(tbl, 0, tbl->it_size);
 
         if (is_calgary(dev->device))
                 tbl->chip_ops = &calgary_chip_ops;
@@ -1209,6 +1216,10 @@ static int __init calgary_init(void)
         if (ret)
                 return ret;
 
+        /* Purely for kdump kernel case */
+        if (is_kdump_kernel())
+                get_tce_space_from_tar();
+
         do {
                 dev = pci_get_device(PCI_VENDOR_ID_IBM, PCI_ANY_ID, dev);
                 if (!dev)
@@ -1339,6 +1350,61 @@ static int __init calgary_bus_has_devices(int bus, unsigned short pci_dev)
         return (val != 0xffffffff);
 }
 
+/*
+ * calgary_init_bitmap_from_tce_table():
+ * Funtion for kdump case. In the second/kdump kernel initialize
+ * the bitmap based on the tce table entries obtained from first kernel
+ */
+static void calgary_init_bitmap_from_tce_table(struct iommu_table *tbl)
+{
+        u64 *tp;
+        unsigned int index;
+        tp = ((u64 *)tbl->it_base);
+        for (index = 0 ; index < tbl->it_size; index++) {
+                if (*tp != 0x0)
+                        set_bit(index, tbl->it_map);
+                tp++;
+        }
+}
+
+/*
+ * get_tce_space_from_tar():
+ * Function for kdump case. Get the tce tables from first kernel
+ * by reading the contents of the base adress register of calgary iommu
+ */
+static void get_tce_space_from_tar()
+{
+        int bus;
+        void __iomem *target;
+        unsigned long tce_space;
+
+        for (bus = 0; bus < MAX_PHB_BUS_NUM; bus++) {
+                struct calgary_bus_info *info = &bus_info[bus];
+                unsigned short pci_device;
+                u32 val;
+
+                val = read_pci_config(bus, 0, 0, 0);
+                pci_device = (val & 0xFFFF0000) >> 16;
+
+                if (!is_cal_pci_dev(pci_device))
+                        continue;
+                if (info->translation_disabled)
+                        continue;
+
+                if (calgary_bus_has_devices(bus, pci_device) ||
+                                                translate_empty_slots) {
+                        target = calgary_reg(bus_info[bus].bbar,
+                                                tar_offset(bus));
+                        tce_space = be64_to_cpu(readq(target));
+                        tce_space = tce_space & TAR_SW_BITS;
+
+                        tce_space = tce_space & (~specified_table_size);
+                        info->tce_space = (u64 *)__va(tce_space);
+                }
+        }
+        return;
+}
+
 void __init detect_calgary(void)
 {
         int bus;
@@ -1394,7 +1460,8 @@ void __init detect_calgary(void)
                 return;
         }
 
-        specified_table_size = determine_tce_table_size(max_pfn * PAGE_SIZE);
+        specified_table_size = determine_tce_table_size((is_kdump_kernel() ?
+                                        saved_max_pfn : max_pfn) * PAGE_SIZE);
 
         for (bus = 0; bus < MAX_PHB_BUS_NUM; bus++) {
                 struct calgary_bus_info *info = &bus_info[bus];
@@ -1412,10 +1479,16 @@ void __init detect_calgary(void)
 
                 if (calgary_bus_has_devices(bus, pci_device) ||
                     translate_empty_slots) {
-                        tbl = alloc_tce_table();
-                        if (!tbl)
-                                goto cleanup;
-                        info->tce_space = tbl;
+                        /*
+                         * If it is kdump kernel, find and use tce tables
+                         * from first kernel, else allocate tce tables here
+                         */
+                        if (!is_kdump_kernel()) {
+                                tbl = alloc_tce_table();
+                                if (!tbl)
+                                        goto cleanup;
+                                info->tce_space = tbl;
+                        }
                         calgary_found = 1;
                 }
         }
diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h
index 22c7ac5cd80c..6cd39a927e1f 100644
--- a/include/linux/crash_dump.h
+++ b/include/linux/crash_dump.h
@@ -22,5 +22,13 @@ extern struct proc_dir_entry *proc_vmcore;
 
 #define vmcore_elf_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
 
+static inline int is_kdump_kernel(void)
+{
+        return (elfcorehdr_addr != ELFCORE_ADDR_MAX) ? 1 : 0;
+}
+#else /* !CONFIG_CRASH_DUMP */
+static inline int is_kdump_kernel(void) { return 0; }
 #endif /* CONFIG_CRASH_DUMP */
+
+extern unsigned long saved_max_pfn;
 #endif /* LINUX_CRASHDUMP_H */