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+/*
+ * Copyright 2011 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ *
+ * TILE startup code.
+ */
+
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/thread_info.h>
+#include <asm/processor.h>
+#include <asm/asm-offsets.h>
+#include <hv/hypervisor.h>
+#include <arch/chip.h>
+#include <arch/spr_def.h>
+
+/*
+ * This module contains the entry code for kernel images. It performs the
+ * minimal setup needed to call the generic C routines.
+ */
+
+ __HEAD
+ENTRY(_start)
+ /* Notify the hypervisor of what version of the API we want */
+ {
+ movei r1, TILE_CHIP
+ movei r2, TILE_CHIP_REV
+ }
+ {
+ moveli r0, _HV_VERSION
+ jal hv_init
+ }
+ /* Get a reasonable default ASID in r0 */
+ {
+ move r0, zero
+ jal hv_inquire_asid
+ }
+
+ /*
+ * Install the default page table. The relocation required to
+ * statically define the table is a bit too complex, so we have
+ * to plug in the pointer from the L0 to the L1 table by hand.
+ * We only do this on the first cpu to boot, though, since the
+ * other CPUs should see a properly-constructed page table.
+ */
+ {
+ v4int_l r2, zero, r0 /* ASID for hv_install_context */
+ moveli r4, hw1_last(swapper_pgprot - PAGE_OFFSET)
+ }
+ {
+ shl16insli r4, r4, hw0(swapper_pgprot - PAGE_OFFSET)
+ }
+ {
+ ld r1, r4 /* access_pte for hv_install_context */
+ }
+ {
+ moveli r0, hw1_last(.Lsv_data_pmd - PAGE_OFFSET)
+ moveli r6, hw1_last(temp_data_pmd - PAGE_OFFSET)
+ }
+ {
+ /* After initializing swapper_pgprot, HV_PTE_GLOBAL is set. */
+ bfextu r7, r1, HV_PTE_INDEX_GLOBAL, HV_PTE_INDEX_GLOBAL
+ inv r4
+ }
+ bnez r7, .Lno_write
+ {
+ shl16insli r0, r0, hw0(.Lsv_data_pmd - PAGE_OFFSET)
+ shl16insli r6, r6, hw0(temp_data_pmd - PAGE_OFFSET)
+ }
+ {
+ /* Cut off the low bits of the PT address. */
+ shrui r6, r6, HV_LOG2_PAGE_TABLE_ALIGN
+ /* Start with our access pte. */
+ move r5, r1
+ }
+ {
+ /* Stuff the address into the page table pointer slot of the PTE. */
+ bfins r5, r6, HV_PTE_INDEX_PTFN, \
+ HV_PTE_INDEX_PTFN + HV_PTE_PTFN_BITS - 1
+ }
+ {
+ /* Store the L0 data PTE. */
+ st r0, r5
+ addli r6, r6, (temp_code_pmd - temp_data_pmd) >> \
+ HV_LOG2_PAGE_TABLE_ALIGN
+ }
+ {
+ addli r0, r0, .Lsv_code_pmd - .Lsv_data_pmd
+ bfins r5, r6, HV_PTE_INDEX_PTFN, \
+ HV_PTE_INDEX_PTFN + HV_PTE_PTFN_BITS - 1
+ }
+ /* Store the L0 code PTE. */
+ st r0, r5
+
+.Lno_write:
+ moveli lr, hw2_last(1f)
+ {
+ shl16insli lr, lr, hw1(1f)
+ moveli r0, hw1_last(swapper_pg_dir - PAGE_OFFSET)
+ }
+ {
+ shl16insli lr, lr, hw0(1f)
+ shl16insli r0, r0, hw0(swapper_pg_dir - PAGE_OFFSET)
+ }
+ {
+ move r3, zero
+ j hv_install_context
+ }
+1:
+
+ /* Install the interrupt base. */
+ moveli r0, hw2_last(MEM_SV_START)
+ shl16insli r0, r0, hw1(MEM_SV_START)
+ shl16insli r0, r0, hw0(MEM_SV_START)
+ mtspr SPR_INTERRUPT_VECTOR_BASE_K, r0
+
+ /*
+ * Get our processor number and save it away in SAVE_K_0.
+ * Extract stuff from the topology structure: r4 = y, r6 = x,
+ * r5 = width. FIXME: consider whether we want to just make these
+ * 64-bit values (and if so fix smp_topology write below, too).
+ */
+ jal hv_inquire_topology
+ {
+ v4int_l r5, zero, r1 /* r5 = width */
+ shrui r4, r0, 32 /* r4 = y */
+ }
+ {
+ v4int_l r6, zero, r0 /* r6 = x */
+ mul_lu_lu r4, r4, r5
+ }
+ {
+ add r4, r4, r6 /* r4 == cpu == y*width + x */
+ }
+
+#ifdef CONFIG_SMP
+ /*
+ * Load up our per-cpu offset. When the first (master) tile
+ * boots, this value is still zero, so we will load boot_pc
+ * with start_kernel, and boot_sp with init_stack + THREAD_SIZE.
+ * The master tile initializes the per-cpu offset array, so that
+ * when subsequent (secondary) tiles boot, they will instead load
+ * from their per-cpu versions of boot_sp and boot_pc.
+ */
+ moveli r5, hw2_last(__per_cpu_offset)
+ shl16insli r5, r5, hw1(__per_cpu_offset)
+ shl16insli r5, r5, hw0(__per_cpu_offset)
+ shl3add r5, r4, r5
+ ld r5, r5
+ bnez r5, 1f
+
+ /*
+ * Save the width and height to the smp_topology variable
+ * for later use.
+ */
+ moveli r0, hw2_last(smp_topology + HV_TOPOLOGY_WIDTH_OFFSET)
+ shl16insli r0, r0, hw1(smp_topology + HV_TOPOLOGY_WIDTH_OFFSET)
+ shl16insli r0, r0, hw0(smp_topology + HV_TOPOLOGY_WIDTH_OFFSET)
+ st r0, r1
+1:
+#else
+ move r5, zero
+#endif
+
+ /* Load and go with the correct pc and sp. */
+ {
+ moveli r1, hw2_last(boot_sp)
+ moveli r0, hw2_last(boot_pc)
+ }
+ {
+ shl16insli r1, r1, hw1(boot_sp)
+ shl16insli r0, r0, hw1(boot_pc)
+ }
+ {
+ shl16insli r1, r1, hw0(boot_sp)
+ shl16insli r0, r0, hw0(boot_pc)
+ }
+ {
+ add r1, r1, r5
+ add r0, r0, r5
+ }
+ ld r0, r0
+ ld sp, r1
+ or r4, sp, r4
+ mtspr SPR_SYSTEM_SAVE_K_0, r4 /* save ksp0 + cpu */
+ addi sp, sp, -STACK_TOP_DELTA
+ {
+ move lr, zero /* stop backtraces in the called function */
+ jr r0
+ }
+ ENDPROC(_start)
+
+__PAGE_ALIGNED_BSS
+ .align PAGE_SIZE
+ENTRY(empty_zero_page)
+ .fill PAGE_SIZE,1,0
+ END(empty_zero_page)
+
+ .macro PTE cpa, bits1
+ .quad HV_PTE_PAGE | HV_PTE_DIRTY | HV_PTE_PRESENT | HV_PTE_ACCESSED |\
+ HV_PTE_GLOBAL | (HV_PTE_MODE_CACHE_NO_L3 << HV_PTE_INDEX_MODE) |\
+ (\bits1) | (HV_CPA_TO_PFN(\cpa) << HV_PTE_INDEX_PFN)
+ .endm
+
+__PAGE_ALIGNED_DATA
+ .align PAGE_SIZE
+ENTRY(swapper_pg_dir)
+ .org swapper_pg_dir + HV_L0_INDEX(PAGE_OFFSET) * HV_PTE_SIZE
+.Lsv_data_pmd:
+ .quad 0 /* PTE temp_data_pmd - PAGE_OFFSET, 0 */
+ .org swapper_pg_dir + HV_L0_INDEX(MEM_SV_START) * HV_PTE_SIZE
+.Lsv_code_pmd:
+ .quad 0 /* PTE temp_code_pmd - PAGE_OFFSET, 0 */
+ .org swapper_pg_dir + HV_L0_SIZE
+ END(swapper_pg_dir)
+
+ .align HV_PAGE_TABLE_ALIGN
+ENTRY(temp_data_pmd)
+ /*
+ * We fill the PAGE_OFFSET pmd with huge pages with
+ * VA = PA + PAGE_OFFSET. We remap things with more precise access
+ * permissions later.
+ */
+ .set addr, 0
+ .rept HV_L1_ENTRIES
+ PTE addr, HV_PTE_READABLE | HV_PTE_WRITABLE
+ .set addr, addr + HV_PAGE_SIZE_LARGE
+ .endr
+ .org temp_data_pmd + HV_L1_SIZE
+ END(temp_data_pmd)
+
+ .align HV_PAGE_TABLE_ALIGN
+ENTRY(temp_code_pmd)
+ /*
+ * We fill the MEM_SV_START pmd with huge pages with
+ * VA = PA + PAGE_OFFSET. We remap things with more precise access
+ * permissions later.
+ */
+ .set addr, 0
+ .rept HV_L1_ENTRIES
+ PTE addr, HV_PTE_READABLE | HV_PTE_EXECUTABLE
+ .set addr, addr + HV_PAGE_SIZE_LARGE
+ .endr
+ .org temp_code_pmd + HV_L1_SIZE
+ END(temp_code_pmd)
+
+ /*
+ * Isolate swapper_pgprot to its own cache line, since each cpu
+ * starting up will read it using VA-is-PA and local homing.
+ * This would otherwise likely conflict with other data on the cache
+ * line, once we have set its permanent home in the page tables.
+ */
+ __INITDATA
+ .align CHIP_L2_LINE_SIZE()
+ENTRY(swapper_pgprot)
+ .quad HV_PTE_PRESENT | (HV_PTE_MODE_CACHE_NO_L3 << HV_PTE_INDEX_MODE)
+ .align CHIP_L2_LINE_SIZE()
+ END(swapper_pgprot)