powerpc/pseries: Tell firmware our capabilities on new machines

This adds code to call a new firmware method to tell the firmware
what machines and capabilities (such as VMX/Altivec) we support.
This will be needed on POWER5+ and POWER6 machines, and it has no
effect on past and current machines.

Signed-off-by: Paul Mackerras <paulus@samba.org>

diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 7e4d548..00ad7f9 100644 (file)
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -636,10 +636,95 @@ static void __init early_cmdline_parse(void)
 
 #ifdef CONFIG_PPC_PSERIES
 /*
- * To tell the firmware what our capabilities are, we have to pass
- * it a fake 32-bit ELF header containing a couple of PT_NOTE sections
- * that contain structures that contain the actual values.
+ * There are two methods for telling firmware what our capabilities are.
+ * Newer machines have an "ibm,client-architecture-support" method on the
+ * root node.  For older machines, we have to call the "process-elf-header"
+ * method in the /packages/elf-loader node, passing it a fake 32-bit
+ * ELF header containing a couple of PT_NOTE sections that contain
+ * structures that contain various information.
  */
+
+/*
+ * New method - extensible architecture description vector.
+ *
+ * Because the description vector contains a mix of byte and word
+ * values, we declare it as an unsigned char array, and use this
+ * macro to put word values in.
+ */
+#define W(x)   ((x) >> 24) & 0xff, ((x) >> 16) & 0xff, \
+               ((x) >> 8) & 0xff, (x) & 0xff
+
+/* Option vector bits - generic bits in byte 1 */
+#define OV_IGNORE              0x80    /* ignore this vector */
+#define OV_CESSATION_POLICY    0x40    /* halt if unsupported option present*/
+
+/* Option vector 1: processor architectures supported */
+#define OV1_PPC_2_00           0x80    /* set if we support PowerPC 2.00 */
+#define OV1_PPC_2_01           0x40    /* set if we support PowerPC 2.01 */
+#define OV1_PPC_2_02           0x20    /* set if we support PowerPC 2.02 */
+#define OV1_PPC_2_03           0x10    /* set if we support PowerPC 2.03 */
+#define OV1_PPC_2_04           0x08    /* set if we support PowerPC 2.04 */
+#define OV1_PPC_2_05           0x04    /* set if we support PowerPC 2.05 */
+
+/* Option vector 2: Open Firmware options supported */
+#define OV2_REAL_MODE          0x20    /* set if we want OF in real mode */
+
+/* Option vector 3: processor options supported */
+#define OV3_FP                 0x80    /* floating point */
+#define OV3_VMX                        0x40    /* VMX/Altivec */
+
+/* Option vector 5: PAPR/OF options supported */
+#define OV5_LPAR               0x80    /* logical partitioning supported */
+#define OV5_SPLPAR             0x40    /* shared-processor LPAR supported */
+/* ibm,dynamic-reconfiguration-memory property supported */
+#define OV5_DRCONF_MEMORY      0x20
+#define OV5_LARGE_PAGES                0x10    /* large pages supported */
+
+/*
+ * The architecture vector has an array of PVR mask/value pairs,
+ * followed by # option vectors - 1, followed by the option vectors.
+ */
+static unsigned char ibm_architecture_vec[] = {
+       W(0xfffe0000), W(0x003a0000),   /* POWER5/POWER5+ */
+       W(0xfffffffe), W(0x0f000001),   /* all 2.04-compliant and earlier */
+       5 - 1,                          /* 5 option vectors */
+
+       /* option vector 1: processor architectures supported */
+       3 - 1,                          /* length */
+       0,                              /* don't ignore, don't halt */
+       OV1_PPC_2_00 | OV1_PPC_2_01 | OV1_PPC_2_02 | OV1_PPC_2_03 |
+       OV1_PPC_2_04 | OV1_PPC_2_05,
+
+       /* option vector 2: Open Firmware options supported */
+       34 - 1,                         /* length */
+       OV2_REAL_MODE,
+       0, 0,
+       W(0xffffffff),                  /* real_base */
+       W(0xffffffff),                  /* real_size */
+       W(0xffffffff),                  /* virt_base */
+       W(0xffffffff),                  /* virt_size */
+       W(0xffffffff),                  /* load_base */
+       W(64),                          /* 128MB min RMA */
+       W(0xffffffff),                  /* full client load */
+       0,                              /* min RMA percentage of total RAM */
+       48,                             /* max log_2(hash table size) */
+
+       /* option vector 3: processor options supported */
+       3 - 1,                          /* length */
+       0,                              /* don't ignore, don't halt */
+       OV3_FP | OV3_VMX,
+
+       /* option vector 4: IBM PAPR implementation */
+       2 - 1,                          /* length */
+       0,                              /* don't halt */
+
+       /* option vector 5: PAPR/OF options */
+       3 - 1,                          /* length */
+       0,                              /* don't ignore, don't halt */
+       OV5_LPAR | OV5_SPLPAR | OV5_LARGE_PAGES,
+};
+
+/* Old method - ELF header with PT_NOTE sections */
 static struct fake_elf {
        Elf32_Ehdr      elfhdr;
        Elf32_Phdr      phdr[2];
@@ -728,8 +813,26 @@ static struct fake_elf {
 
 static void __init prom_send_capabilities(void)
 {
-       ihandle elfloader;
+       ihandle elfloader, root;
+       prom_arg_t ret;
+
+       root = call_prom("open", 1, 1, ADDR("/"));
+       if (root != 0) {
+               /* try calling the ibm,client-architecture-support method */
+               if (call_prom_ret("call-method", 3, 2, &ret,
+                                 ADDR("ibm,client-architecture-support"),
+                                 ADDR(ibm_architecture_vec)) == 0) {
+                       /* the call exists... */
+                       if (ret)
+                               prom_printf("WARNING: ibm,client-architecture"
+                                           "-support call FAILED!\n");
+                       call_prom("close", 1, 0, root);
+                       return;
+               }
+               call_prom("close", 1, 0, root);
+       }
 
+       /* no ibm,client-architecture-support call, try the old way */
        elfloader = call_prom("open", 1, 1, ADDR("/packages/elf-loader"));
        if (elfloader == 0) {
                prom_printf("couldn't open /packages/elf-loader\n");