#include <linux/config.h>
#include <asm/page.h>
-#include <linux/stringify.h>
-#ifndef __ASSEMBLY__
-
-/* Time to allow for more things here */
-typedef unsigned long mm_context_id_t;
-typedef struct {
- mm_context_id_t id;
-#ifdef CONFIG_HUGETLB_PAGE
- pgd_t *huge_pgdir;
- u16 htlb_segs; /* bitmask */
-#endif
-} mm_context_t;
+/*
+ * Segment table
+ */
#define STE_ESID_V 0x80
#define STE_ESID_KS 0x20
#define STE_VSID_SHIFT 12
-struct stab_entry {
- unsigned long esid_data;
- unsigned long vsid_data;
-};
+/* Location of cpu0's segment table */
+#define STAB0_PAGE 0x9
+#define STAB0_PHYS_ADDR (STAB0_PAGE<<PAGE_SHIFT)
+#define STAB0_VIRT_ADDR (KERNELBASE+STAB0_PHYS_ADDR)
+
+/*
+ * SLB
+ */
-/* Hardware Page Table Entry */
+#define SLB_NUM_BOLTED 3
+#define SLB_CACHE_ENTRIES 8
+
+/* Bits in the SLB ESID word */
+#define SLB_ESID_V ASM_CONST(0x0000000008000000) /* valid */
+
+/* Bits in the SLB VSID word */
+#define SLB_VSID_SHIFT 12
+#define SLB_VSID_KS ASM_CONST(0x0000000000000800)
+#define SLB_VSID_KP ASM_CONST(0x0000000000000400)
+#define SLB_VSID_N ASM_CONST(0x0000000000000200) /* no-execute */
+#define SLB_VSID_L ASM_CONST(0x0000000000000100) /* largepage 16M */
+#define SLB_VSID_C ASM_CONST(0x0000000000000080) /* class */
+
+#define SLB_VSID_KERNEL (SLB_VSID_KP|SLB_VSID_C)
+#define SLB_VSID_USER (SLB_VSID_KP|SLB_VSID_KS)
+
+/*
+ * Hash table
+ */
#define HPTES_PER_GROUP 8
+/* Values for PP (assumes Ks=0, Kp=1) */
+/* pp0 will always be 0 for linux */
+#define PP_RWXX 0 /* Supervisor read/write, User none */
+#define PP_RWRX 1 /* Supervisor read/write, User read */
+#define PP_RWRW 2 /* Supervisor read/write, User read/write */
+#define PP_RXRX 3 /* Supervisor read, User read */
+
+#ifndef __ASSEMBLY__
+
+/* Hardware Page Table Entry */
typedef struct {
unsigned long avpn:57; /* vsid | api == avpn */
unsigned long : 2; /* Software use */
} dw1;
} HPTE;
-/* Values for PP (assumes Ks=0, Kp=1) */
-/* pp0 will always be 0 for linux */
-#define PP_RWXX 0 /* Supervisor read/write, User none */
-#define PP_RWRX 1 /* Supervisor read/write, User read */
-#define PP_RWRW 2 /* Supervisor read/write, User read/write */
-#define PP_RXRX 3 /* Supervisor read, User read */
-
-
extern HPTE * htab_address;
extern unsigned long htab_hash_mask;
extern void htab_finish_init(void);
+extern void hpte_init_native(void);
+extern void hpte_init_lpar(void);
+extern void hpte_init_iSeries(void);
+
+extern long pSeries_lpar_hpte_insert(unsigned long hpte_group,
+ unsigned long va, unsigned long prpn,
+ int secondary, unsigned long hpteflags,
+ int bolted, int large);
+extern long native_hpte_insert(unsigned long hpte_group, unsigned long va,
+ unsigned long prpn, int secondary,
+ unsigned long hpteflags, int bolted, int large);
+
#endif /* __ASSEMBLY__ */
/*
- * Location of cpu0's segment table
+ * VSID allocation
+ *
+ * We first generate a 36-bit "proto-VSID". For kernel addresses this
+ * is equal to the ESID, for user addresses it is:
+ * (context << 15) | (esid & 0x7fff)
+ *
+ * The two forms are distinguishable because the top bit is 0 for user
+ * addresses, whereas the top two bits are 1 for kernel addresses.
+ * Proto-VSIDs with the top two bits equal to 0b10 are reserved for
+ * now.
+ *
+ * The proto-VSIDs are then scrambled into real VSIDs with the
+ * multiplicative hash:
+ *
+ * VSID = (proto-VSID * VSID_MULTIPLIER) % VSID_MODULUS
+ * where VSID_MULTIPLIER = 268435399 = 0xFFFFFC7
+ * VSID_MODULUS = 2^36-1 = 0xFFFFFFFFF
+ *
+ * This scramble is only well defined for proto-VSIDs below
+ * 0xFFFFFFFFF, so both proto-VSID and actual VSID 0xFFFFFFFFF are
+ * reserved. VSID_MULTIPLIER is prime, so in particular it is
+ * co-prime to VSID_MODULUS, making this a 1:1 scrambling function.
+ * Because the modulus is 2^n-1 we can compute it efficiently without
+ * a divide or extra multiply (see below).
+ *
+ * This scheme has several advantages over older methods:
+ *
+ * - We have VSIDs allocated for every kernel address
+ * (i.e. everything above 0xC000000000000000), except the very top
+ * segment, which simplifies several things.
+ *
+ * - We allow for 15 significant bits of ESID and 20 bits of
+ * context for user addresses. i.e. 8T (43 bits) of address space for
+ * up to 1M contexts (although the page table structure and context
+ * allocation will need changes to take advantage of this).
+ *
+ * - The scramble function gives robust scattering in the hash
+ * table (at least based on some initial results). The previous
+ * method was more susceptible to pathological cases giving excessive
+ * hash collisions.
+ */
+/*
+ * WARNING - If you change these you must make sure the asm
+ * implementations in slb_allocate (slb_low.S), do_stab_bolted
+ * (head.S) and ASM_VSID_SCRAMBLE (below) are changed accordingly.
+ *
+ * You'll also need to change the precomputed VSID values in head.S
+ * which are used by the iSeries firmware.
*/
-#define STAB0_PAGE 0x9
-#define STAB0_PHYS_ADDR (STAB0_PAGE<<PAGE_SHIFT)
-#define STAB0_VIRT_ADDR (KERNELBASE+STAB0_PHYS_ADDR)
-
-#define SLB_NUM_BOLTED 3
-#define SLB_CACHE_ENTRIES 8
-
-/* Bits in the SLB ESID word */
-#define SLB_ESID_V 0x0000000008000000 /* entry is valid */
-
-/* Bits in the SLB VSID word */
-#define SLB_VSID_SHIFT 12
-#define SLB_VSID_KS 0x0000000000000800
-#define SLB_VSID_KP 0x0000000000000400
-#define SLB_VSID_N 0x0000000000000200 /* no-execute */
-#define SLB_VSID_L 0x0000000000000100 /* largepage (4M) */
-#define SLB_VSID_C 0x0000000000000080 /* class */
-
-#define SLB_VSID_KERNEL (SLB_VSID_KP|SLB_VSID_C)
-#define SLB_VSID_USER (SLB_VSID_KP|SLB_VSID_KS)
#define VSID_MULTIPLIER ASM_CONST(200730139) /* 28-bit prime */
#define VSID_BITS 36
srdi rx,rx,VSID_BITS; /* extract 2^36 bit */ \
add rt,rt,rx
+
+#ifndef __ASSEMBLY__
+
+typedef unsigned long mm_context_id_t;
+
+typedef struct {
+ mm_context_id_t id;
+#ifdef CONFIG_HUGETLB_PAGE
+ pgd_t *huge_pgdir;
+ u16 htlb_segs; /* bitmask */
+#endif
+} mm_context_t;
+
+
+static inline unsigned long vsid_scramble(unsigned long protovsid)
+{
+#if 0
+ /* The code below is equivalent to this function for arguments
+ * < 2^VSID_BITS, which is all this should ever be called
+ * with. However gcc is not clever enough to compute the
+ * modulus (2^n-1) without a second multiply. */
+ return ((protovsid * VSID_MULTIPLIER) % VSID_MODULUS);
+#else /* 1 */
+ unsigned long x;
+
+ x = protovsid * VSID_MULTIPLIER;
+ x = (x >> VSID_BITS) + (x & VSID_MODULUS);
+ return (x + ((x+1) >> VSID_BITS)) & VSID_MODULUS;
+#endif /* 1 */
+}
+
+/* This is only valid for addresses >= KERNELBASE */
+static inline unsigned long get_kernel_vsid(unsigned long ea)
+{
+ return vsid_scramble(ea >> SID_SHIFT);
+}
+
+/* This is only valid for user addresses (which are below 2^41) */
+static inline unsigned long get_vsid(unsigned long context, unsigned long ea)
+{
+ return vsid_scramble((context << USER_ESID_BITS)
+ | (ea >> SID_SHIFT));
+}
+
+#endif /* __ASSEMBLY */
+
#endif /* _PPC64_MMU_H_ */
git://git.onelab.eu / linux-2.6.git / blobdiff