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-rw-r--r--arch/parisc/kernel/real2.S292
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+/*
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2000 Hewlett Packard (Paul Bame bame@puffin.external.hp.com)
+ *
+ */
+
+#include <asm/pdc.h>
+#include <asm/psw.h>
+#include <asm/assembly.h>
+#include <asm/asm-offsets.h>
+
+#include <linux/linkage.h>
+
+ .export real_stack
+ .export real64_stack
+ __PAGE_ALIGNED_BSS
+real_stack:
+real64_stack:
+ .block 8192
+
+#define N_SAVED_REGS 9
+ .section .bss
+save_cr_space:
+ .block REG_SZ * N_SAVED_REGS
+save_cr_end:
+
+
+/************************ 32-bit real-mode calls ***********************/
+/* This can be called in both narrow and wide kernels */
+
+ .text
+
+ /* unsigned long real32_call_asm(unsigned int *sp,
+ * unsigned int *arg0p,
+ * unsigned int iodc_fn)
+ * sp is value of stack pointer to adopt before calling PDC (virt)
+ * arg0p points to where saved arg values may be found
+ * iodc_fn is the IODC function to call
+ */
+
+ENTRY_CFI(real32_call_asm)
+ STREG %rp, -RP_OFFSET(%sp) /* save RP */
+#ifdef CONFIG_64BIT
+ callee_save
+ ldo 2*REG_SZ(%sp), %sp /* room for a couple more saves */
+ STREG %r27, -1*REG_SZ(%sp)
+ STREG %r29, -2*REG_SZ(%sp)
+#endif
+ STREG %sp, -REG_SZ(%arg0) /* save SP on real-mode stack */
+ copy %arg0, %sp /* adopt the real-mode SP */
+
+ /* save iodc_fn */
+ copy %arg2, %r31
+
+ /* load up the arg registers from the saved arg area */
+ /* 32-bit calling convention passes first 4 args in registers */
+ ldw 0(%arg1), %arg0 /* note overwriting arg0 */
+ ldw -8(%arg1), %arg2
+ ldw -12(%arg1), %arg3
+ ldw -4(%arg1), %arg1 /* obviously must do this one last! */
+
+ tophys_r1 %sp
+
+ b,l rfi_virt2real,%r2
+ nop
+
+ b,l save_control_regs,%r2 /* modifies r1, r2, r28 */
+ nop
+
+#ifdef CONFIG_64BIT
+ rsm PSW_SM_W, %r0 /* go narrow */
+#endif
+
+ load32 PA(ric_ret), %r2
+ bv 0(%r31)
+ nop
+ric_ret:
+#ifdef CONFIG_64BIT
+ ssm PSW_SM_W, %r0 /* go wide */
+#endif
+ /* restore CRs before going virtual in case we page fault */
+ b,l restore_control_regs, %r2 /* modifies r1, r2, r26 */
+ nop
+
+ b,l rfi_real2virt,%r2
+ nop
+
+ tovirt_r1 %sp
+ LDREG -REG_SZ(%sp), %sp /* restore SP */
+#ifdef CONFIG_64BIT
+ LDREG -1*REG_SZ(%sp), %r27
+ LDREG -2*REG_SZ(%sp), %r29
+ ldo -2*REG_SZ(%sp), %sp
+ callee_rest
+#endif
+ LDREG -RP_OFFSET(%sp), %rp /* restore RP */
+ bv 0(%rp)
+ nop
+ENDPROC_CFI(real32_call_asm)
+
+
+# define PUSH_CR(r, where) mfctl r, %r1 ! STREG,ma %r1, REG_SZ(where)
+# define POP_CR(r, where) LDREG,mb -REG_SZ(where), %r1 ! mtctl %r1, r
+
+ .text
+ENTRY_CFI(save_control_regs)
+ load32 PA(save_cr_space), %r28
+ PUSH_CR(%cr24, %r28)
+ PUSH_CR(%cr25, %r28)
+ PUSH_CR(%cr26, %r28)
+ PUSH_CR(%cr27, %r28)
+ PUSH_CR(%cr28, %r28)
+ PUSH_CR(%cr29, %r28)
+ PUSH_CR(%cr30, %r28)
+ PUSH_CR(%cr31, %r28)
+ PUSH_CR(%cr15, %r28)
+ bv 0(%r2)
+ nop
+ENDPROC_CFI(save_control_regs)
+
+ENTRY_CFI(restore_control_regs)
+ load32 PA(save_cr_end), %r26
+ POP_CR(%cr15, %r26)
+ POP_CR(%cr31, %r26)
+ POP_CR(%cr30, %r26)
+ POP_CR(%cr29, %r26)
+ POP_CR(%cr28, %r26)
+ POP_CR(%cr27, %r26)
+ POP_CR(%cr26, %r26)
+ POP_CR(%cr25, %r26)
+ POP_CR(%cr24, %r26)
+ bv 0(%r2)
+ nop
+ENDPROC_CFI(restore_control_regs)
+
+/* rfi_virt2real() and rfi_real2virt() could perhaps be adapted for
+ * more general-purpose use by the several places which need RFIs
+ */
+ .text
+ .align 128
+ENTRY_CFI(rfi_virt2real)
+#if !defined(BOOTLOADER)
+ /* switch to real mode... */
+ rsm PSW_SM_I,%r0
+ load32 PA(rfi_v2r_1), %r1
+ nop
+ nop
+ nop
+ nop
+ nop
+
+ rsm PSW_SM_Q,%r0 /* disable Q & I bits to load iia queue */
+ mtctl %r0, %cr17 /* Clear IIASQ tail */
+ mtctl %r0, %cr17 /* Clear IIASQ head */
+ mtctl %r1, %cr18 /* IIAOQ head */
+ ldo 4(%r1), %r1
+ mtctl %r1, %cr18 /* IIAOQ tail */
+ load32 REAL_MODE_PSW, %r1
+ mtctl %r1, %cr22
+ rfi
+
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+rfi_v2r_1:
+ tophys_r1 %r2
+#endif /* defined(BOOTLOADER) */
+ bv 0(%r2)
+ nop
+ENDPROC_CFI(rfi_virt2real)
+
+ .text
+ .align 128
+ENTRY_CFI(rfi_real2virt)
+#if !defined(BOOTLOADER)
+ rsm PSW_SM_I,%r0
+ load32 (rfi_r2v_1), %r1
+ nop
+ nop
+ nop
+ nop
+ nop
+
+ rsm PSW_SM_Q,%r0 /* disable Q bit to load iia queue */
+ mtctl %r0, %cr17 /* Clear IIASQ tail */
+ mtctl %r0, %cr17 /* Clear IIASQ head */
+ mtctl %r1, %cr18 /* IIAOQ head */
+ ldo 4(%r1), %r1
+ mtctl %r1, %cr18 /* IIAOQ tail */
+ load32 KERNEL_PSW, %r1
+ mtctl %r1, %cr22
+ rfi
+
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+ nop
+rfi_r2v_1:
+ tovirt_r1 %r2
+#endif /* defined(BOOTLOADER) */
+ bv 0(%r2)
+ nop
+ENDPROC_CFI(rfi_real2virt)
+
+#ifdef CONFIG_64BIT
+
+/************************ 64-bit real-mode calls ***********************/
+/* This is only usable in wide kernels right now and will probably stay so */
+ .text
+ /* unsigned long real64_call_asm(unsigned long *sp,
+ * unsigned long *arg0p,
+ * unsigned long fn)
+ * sp is value of stack pointer to adopt before calling PDC (virt)
+ * arg0p points to where saved arg values may be found
+ * iodc_fn is the IODC function to call
+ */
+ENTRY_CFI(real64_call_asm)
+ std %rp, -0x10(%sp) /* save RP */
+ std %sp, -8(%arg0) /* save SP on real-mode stack */
+ copy %arg0, %sp /* adopt the real-mode SP */
+
+ /* save fn */
+ copy %arg2, %r31
+
+ /* load up the arg registers from the saved arg area */
+ /* 32-bit calling convention passes first 4 args in registers */
+ ldd 0*REG_SZ(%arg1), %arg0 /* note overwriting arg0 */
+ ldd 2*REG_SZ(%arg1), %arg2
+ ldd 3*REG_SZ(%arg1), %arg3
+ ldd 4*REG_SZ(%arg1), %r22
+ ldd 5*REG_SZ(%arg1), %r21
+ ldd 6*REG_SZ(%arg1), %r20
+ ldd 7*REG_SZ(%arg1), %r19
+ ldd 1*REG_SZ(%arg1), %arg1 /* do this one last! */
+
+ /* set up real-mode stack and real-mode ap */
+ tophys_r1 %sp
+ ldo -16(%sp), %r29 /* Reference param save area */
+
+ b,l rfi_virt2real,%r2
+ nop
+
+ b,l save_control_regs,%r2 /* modifies r1, r2, r28 */
+ nop
+
+ load32 PA(r64_ret), %r2
+ bv 0(%r31)
+ nop
+r64_ret:
+ /* restore CRs before going virtual in case we page fault */
+ b,l restore_control_regs, %r2 /* modifies r1, r2, r26 */
+ nop
+
+ b,l rfi_real2virt,%r2
+ nop
+
+ tovirt_r1 %sp
+ ldd -8(%sp), %sp /* restore SP */
+ ldd -0x10(%sp), %rp /* restore RP */
+ bv 0(%rp)
+ nop
+ENDPROC_CFI(real64_call_asm)
+
+#endif
+
+ .text
+ /* http://lists.parisc-linux.org/hypermail/parisc-linux/10916.html
+ ** GCC 3.3 and later has a new function in libgcc.a for
+ ** comparing function pointers.
+ */
+ENTRY_CFI(__canonicalize_funcptr_for_compare)
+#ifdef CONFIG_64BIT
+ bve (%r2)
+#else
+ bv %r0(%r2)
+#endif
+ copy %r26,%r28
+ENDPROC_CFI(__canonicalize_funcptr_for_compare)
+