[PATCH] ppc64: support 64k pages

Adds a new CONFIG_PPC_64K_PAGES which, when enabled, changes the kernel
base page size to 64K.  The resulting kernel still boots on any
hardware.  On current machines with 4K pages support only, the kernel
will maintain 16 "subpages" for each 64K page transparently.

Note that while real 64K capable HW has been tested, the current patch
will not enable it yet as such hardware is not released yet, and I'm
still verifying with the firmware architects the proper to get the
information from the newer hypervisors.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 33 insertions, 61 deletions

diff --git a/arch/ppc64/kernel/prom.c b/arch/ppc64/kernel/prom.c
index 97bfceb5353b..dece31e58bc4 100644
--- a/arch/ppc64/kernel/prom.c
+++ b/arch/ppc64/kernel/prom.c
@@ -635,10 +635,10 @@ static inline char *find_flat_dt_string(u32 offset)
  * used to extract the memory informations at boot before we can
  * unflatten the tree
  */
-static int __init scan_flat_dt(int (*it)(unsigned long node,
-                                         const char *uname, int depth,
-                                         void *data),
-                               void *data)
+int __init of_scan_flat_dt(int (*it)(unsigned long node,
+                                     const char *uname, int depth,
+                                     void *data),
+                           void *data)
 {
         unsigned long p = ((unsigned long)initial_boot_params) +
                 initial_boot_params->off_dt_struct;
@@ -695,8 +695,8 @@ static int __init scan_flat_dt(int (*it)(unsigned long node,
  * This  function can be used within scan_flattened_dt callback to get
  * access to properties
  */
-static void* __init get_flat_dt_prop(unsigned long node, const char *name,
-                                     unsigned long *size)
+void* __init of_get_flat_dt_prop(unsigned long node, const char *name,
+                                 unsigned long *size)
 {
         unsigned long p = node;
 
@@ -996,7 +996,7 @@ void __init unflatten_device_tree(void)
 static int __init early_init_dt_scan_cpus(unsigned long node,
                                           const char *uname, int depth, void *data)
 {
-        char *type = get_flat_dt_prop(node, "device_type", NULL);
+        char *type = of_get_flat_dt_prop(node, "device_type", NULL);
         u32 *prop;
         unsigned long size;
 
@@ -1004,17 +1004,6 @@ static int __init early_init_dt_scan_cpus(unsigned long node,
         if (type == NULL || strcmp(type, "cpu") != 0)
                 return 0;
 
-        /* On LPAR, look for the first ibm,pft-size property for the  hash table size
-         */
-        if (systemcfg->platform == PLATFORM_PSERIES_LPAR && ppc64_pft_size == 0) {
-                u32 *pft_size;
-                pft_size = (u32 *)get_flat_dt_prop(node, "ibm,pft-size", NULL);
-                if (pft_size != NULL) {
-                        /* pft_size[0] is the NUMA CEC cookie */
-                        ppc64_pft_size = pft_size[1];
-                }
-        }
-
         if (initial_boot_params && initial_boot_params->version >= 2) {
                 /* version 2 of the kexec param format adds the phys cpuid
                  * of booted proc.
@@ -1023,8 +1012,9 @@ static int __init early_init_dt_scan_cpus(unsigned long node,
                 boot_cpuid = 0;
         } else {
                 /* Check if it's the boot-cpu, set it's hw index in paca now */
-                if (get_flat_dt_prop(node, "linux,boot-cpu", NULL) != NULL) {
-                        u32 *prop = get_flat_dt_prop(node, "reg", NULL);
+                if (of_get_flat_dt_prop(node, "linux,boot-cpu", NULL)
+                    != NULL) {
+                        u32 *prop = of_get_flat_dt_prop(node, "reg", NULL);
                         set_hard_smp_processor_id(0, prop == NULL ? 0 : *prop);
                         boot_cpuid_phys = get_hard_smp_processor_id(0);
                 }
@@ -1032,14 +1022,14 @@ static int __init early_init_dt_scan_cpus(unsigned long node,
 
 #ifdef CONFIG_ALTIVEC
         /* Check if we have a VMX and eventually update CPU features */
-        prop = (u32 *)get_flat_dt_prop(node, "ibm,vmx", NULL);
+        prop = (u32 *)of_get_flat_dt_prop(node, "ibm,vmx", NULL);
         if (prop && (*prop) > 0) {
                 cur_cpu_spec->cpu_features |= CPU_FTR_ALTIVEC;
                 cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_ALTIVEC;
         }
 
         /* Same goes for Apple's "altivec" property */
-        prop = (u32 *)get_flat_dt_prop(node, "altivec", NULL);
+        prop = (u32 *)of_get_flat_dt_prop(node, "altivec", NULL);
         if (prop) {
                 cur_cpu_spec->cpu_features |= CPU_FTR_ALTIVEC;
                 cur_cpu_spec->cpu_user_features |= PPC_FEATURE_HAS_ALTIVEC;
@@ -1051,7 +1041,7 @@ static int __init early_init_dt_scan_cpus(unsigned long node,
          * this by looking at the size of the ibm,ppc-interrupt-server#s
          * property
          */
-        prop = (u32 *)get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s",
+        prop = (u32 *)of_get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s",
                                        &size);
         cur_cpu_spec->cpu_features &= ~CPU_FTR_SMT;
         if (prop && ((size / sizeof(u32)) > 1))
@@ -1072,26 +1062,26 @@ static int __init early_init_dt_scan_chosen(unsigned long node,
                 return 0;
 
         /* get platform type */
-        prop = (u32 *)get_flat_dt_prop(node, "linux,platform", NULL);
+        prop = (u32 *)of_get_flat_dt_prop(node, "linux,platform", NULL);
         if (prop == NULL)
                 return 0;
         systemcfg->platform = *prop;
 
         /* check if iommu is forced on or off */
-        if (get_flat_dt_prop(node, "linux,iommu-off", NULL) != NULL)
+        if (of_get_flat_dt_prop(node, "linux,iommu-off", NULL) != NULL)
                 iommu_is_off = 1;
-        if (get_flat_dt_prop(node, "linux,iommu-force-on", NULL) != NULL)
+        if (of_get_flat_dt_prop(node, "linux,iommu-force-on", NULL) != NULL)
                 iommu_force_on = 1;
 
-        prop64 = (u64*)get_flat_dt_prop(node, "linux,memory-limit", NULL);
+        prop64 = (u64*)of_get_flat_dt_prop(node, "linux,memory-limit", NULL);
         if (prop64)
                 memory_limit = *prop64;
 
-        prop64 = (u64*)get_flat_dt_prop(node, "linux,tce-alloc-start", NULL);
+        prop64 = (u64*)of_get_flat_dt_prop(node, "linux,tce-alloc-start",NULL);
         if (prop64)
                 tce_alloc_start = *prop64;
 
-        prop64 = (u64*)get_flat_dt_prop(node, "linux,tce-alloc-end", NULL);
+        prop64 = (u64*)of_get_flat_dt_prop(node, "linux,tce-alloc-end", NULL);
         if (prop64)
                 tce_alloc_end = *prop64;
 
@@ -1102,9 +1092,12 @@ static int __init early_init_dt_scan_chosen(unsigned long node,
         {
                 u64 *basep, *entryp;
 
-                basep = (u64*)get_flat_dt_prop(node, "linux,rtas-base", NULL);
-                entryp = (u64*)get_flat_dt_prop(node, "linux,rtas-entry", NULL);
-                prop = (u32*)get_flat_dt_prop(node, "linux,rtas-size", NULL);
+                basep = (u64*)of_get_flat_dt_prop(node,
+                                                  "linux,rtas-base", NULL);
+                entryp = (u64*)of_get_flat_dt_prop(node,
+                                                   "linux,rtas-entry", NULL);
+                prop = (u32*)of_get_flat_dt_prop(node,
+                                                 "linux,rtas-size", NULL);
                 if (basep && entryp && prop) {
                         rtas.base = *basep;
                         rtas.entry = *entryp;
@@ -1125,11 +1118,11 @@ static int __init early_init_dt_scan_root(unsigned long node,
         if (depth != 0)
                 return 0;
 
-        prop = (u32 *)get_flat_dt_prop(node, "#size-cells", NULL);
+        prop = (u32 *)of_get_flat_dt_prop(node, "#size-cells", NULL);
         dt_root_size_cells = (prop == NULL) ? 1 : *prop;
         DBG("dt_root_size_cells = %x\n", dt_root_size_cells);
 
-        prop = (u32 *)get_flat_dt_prop(node, "#address-cells", NULL);
+        prop = (u32 *)of_get_flat_dt_prop(node, "#address-cells", NULL);
         dt_root_addr_cells = (prop == NULL) ? 2 : *prop;
         DBG("dt_root_addr_cells = %x\n", dt_root_addr_cells);
         
@@ -1161,7 +1154,7 @@ static unsigned long __init dt_mem_next_cell(int s, cell_t **cellp)
 static int __init early_init_dt_scan_memory(unsigned long node,
                                             const char *uname, int depth, void *data)
 {
-        char *type = get_flat_dt_prop(node, "device_type", NULL);
+        char *type = of_get_flat_dt_prop(node, "device_type", NULL);
         cell_t *reg, *endp;
         unsigned long l;
 
@@ -1169,7 +1162,7 @@ static int __init early_init_dt_scan_memory(unsigned long node,
         if (type == NULL || strcmp(type, "memory") != 0)
                 return 0;
 
-        reg = (cell_t *)get_flat_dt_prop(node, "reg", &l);
+        reg = (cell_t *)of_get_flat_dt_prop(node, "reg", &l);
         if (reg == NULL)
                 return 0;
 
@@ -1225,19 +1218,16 @@ void __init early_init_devtree(void *params)
         /* Setup flat device-tree pointer */
         initial_boot_params = params;
 
-        /* By default, hash size is not set */
-        ppc64_pft_size = 0;
-
         /* Retreive various informations from the /chosen node of the
          * device-tree, including the platform type, initrd location and
          * size, TCE reserve, and more ...
          */
-        scan_flat_dt(early_init_dt_scan_chosen, NULL);
+        of_scan_flat_dt(early_init_dt_scan_chosen, NULL);
 
         /* Scan memory nodes and rebuild LMBs */
         lmb_init();
-        scan_flat_dt(early_init_dt_scan_root, NULL);
-        scan_flat_dt(early_init_dt_scan_memory, NULL);
+        of_scan_flat_dt(early_init_dt_scan_root, NULL);
+        of_scan_flat_dt(early_init_dt_scan_memory, NULL);
         lmb_enforce_memory_limit(memory_limit);
         lmb_analyze();
         systemcfg->physicalMemorySize = lmb_phys_mem_size();
@@ -1253,26 +1243,8 @@ void __init early_init_devtree(void *params)
         /* Retreive hash table size from flattened tree plus other
          * CPU related informations (altivec support, boot CPU ID, ...)
          */
-        scan_flat_dt(early_init_dt_scan_cpus, NULL);
-
-        /* If hash size wasn't obtained above, we calculate it now based on
-         * the total RAM size
-         */
-        if (ppc64_pft_size == 0) {
-                unsigned long rnd_mem_size, pteg_count;
-
-                /* round mem_size up to next power of 2 */
-                rnd_mem_size = 1UL << __ilog2(systemcfg->physicalMemorySize);
-                if (rnd_mem_size < systemcfg->physicalMemorySize)
-                        rnd_mem_size <<= 1;
-
-                /* # pages / 2 */
-                pteg_count = max(rnd_mem_size >> (12 + 1), 1UL << 11);
-
-                ppc64_pft_size = __ilog2(pteg_count << 7);
-        }
+        of_scan_flat_dt(early_init_dt_scan_cpus, NULL);
 
-        DBG("Hash pftSize: %x\n", (int)ppc64_pft_size);
         DBG(" <- early_init_devtree()\n");
 }