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-rw-r--r--arch/s390/boot/Makefile2
-rw-r--r--arch/s390/boot/compressed/vmlinux.lds.S21
-rw-r--r--arch/s390/boot/head.S32
-rw-r--r--arch/s390/boot/startup.c39
-rw-r--r--arch/s390/boot/text_dma.S167
5 files changed, 259 insertions, 2 deletions
diff --git a/arch/s390/boot/Makefile b/arch/s390/boot/Makefile
index 4df43e83363a..88932c25ad26 100644
--- a/arch/s390/boot/Makefile
+++ b/arch/s390/boot/Makefile
@@ -30,7 +30,7 @@ CFLAGS_sclp_early_core.o += -I$(srctree)/drivers/s390/char
obj-y := head.o als.o startup.o mem_detect.o ipl_parm.o ipl_report.o
obj-y += string.o ebcdic.o sclp_early_core.o mem.o ipl_vmparm.o cmdline.o
-obj-y += ctype.o
+obj-y += ctype.o text_dma.o
obj-$(CONFIG_PROTECTED_VIRTUALIZATION_GUEST) += uv.o
obj-$(CONFIG_RELOCATABLE) += machine_kexec_reloc.o
targets := bzImage startup.a section_cmp.boot.data section_cmp.boot.preserved.data $(obj-y)
diff --git a/arch/s390/boot/compressed/vmlinux.lds.S b/arch/s390/boot/compressed/vmlinux.lds.S
index 1c8ef393c656..112b8d9f1e4c 100644
--- a/arch/s390/boot/compressed/vmlinux.lds.S
+++ b/arch/s390/boot/compressed/vmlinux.lds.S
@@ -33,6 +33,27 @@ SECTIONS
*(.data.*)
_edata = . ;
}
+ /*
+ * .dma section for code, data, ex_table that need to stay below 2 GB,
+ * even when the kernel is relocate: above 2 GB.
+ */
+ _sdma = .;
+ .dma.text : {
+ . = ALIGN(PAGE_SIZE);
+ _stext_dma = .;
+ *(.dma.text)
+ . = ALIGN(PAGE_SIZE);
+ _etext_dma = .;
+ }
+ . = ALIGN(16);
+ .dma.ex_table : {
+ _start_dma_ex_table = .;
+ KEEP(*(.dma.ex_table))
+ _stop_dma_ex_table = .;
+ }
+ .dma.data : { *(.dma.data) }
+ _edma = .;
+
BOOT_DATA
BOOT_DATA_PRESERVED
diff --git a/arch/s390/boot/head.S b/arch/s390/boot/head.S
index c6b4b4c5dd58..028aab03a9e7 100644
--- a/arch/s390/boot/head.S
+++ b/arch/s390/boot/head.S
@@ -305,7 +305,7 @@ ENTRY(startup_kdump)
xc 0x300(256),0x300
xc 0xe00(256),0xe00
xc 0xf00(256),0xf00
- lctlg %c0,%c15,0x200(%r0) # initialize control registers
+ lctlg %c0,%c15,.Lctl-.LPG0(%r13) # load control registers
stcke __LC_BOOT_CLOCK
mvc __LC_LAST_UPDATE_CLOCK(8),__LC_BOOT_CLOCK+1
spt 6f-.LPG0(%r13)
@@ -319,6 +319,36 @@ ENTRY(startup_kdump)
.align 8
6: .long 0x7fffffff,0xffffffff
+.Lctl: .quad 0x04040000 # cr0: AFP registers & secondary space
+ .quad 0 # cr1: primary space segment table
+ .quad .Lduct # cr2: dispatchable unit control table
+ .quad 0 # cr3: instruction authorization
+ .quad 0xffff # cr4: instruction authorization
+ .quad .Lduct # cr5: primary-aste origin
+ .quad 0 # cr6: I/O interrupts
+ .quad 0 # cr7: secondary space segment table
+ .quad 0 # cr8: access registers translation
+ .quad 0 # cr9: tracing off
+ .quad 0 # cr10: tracing off
+ .quad 0 # cr11: tracing off
+ .quad 0 # cr12: tracing off
+ .quad 0 # cr13: home space segment table
+ .quad 0xc0000000 # cr14: machine check handling off
+ .quad .Llinkage_stack # cr15: linkage stack operations
+
+ .section .dma.data,"aw",@progbits
+.Lduct: .long 0,.Laste,.Laste,0,.Lduald,0,0,0
+ .long 0,0,0,0,0,0,0,0
+.Llinkage_stack:
+ .long 0,0,0x89000000,0,0,0,0x8a000000,0
+ .align 64
+.Laste: .quad 0,0xffffffffffffffff,0,0,0,0,0,0
+ .align 128
+.Lduald:.rept 8
+ .long 0x80000000,0,0,0 # invalid access-list entries
+ .endr
+ .previous
+
#include "head_kdump.S"
#
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c
index b7d6a76cb5e9..e3f339d248ce 100644
--- a/arch/s390/boot/startup.c
+++ b/arch/s390/boot/startup.c
@@ -1,9 +1,11 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/string.h>
#include <linux/elf.h>
+#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/kexec.h>
#include <asm/sclp.h>
+#include <asm/diag.h>
#include <asm/uv.h>
#include "compressed/decompressor.h"
#include "boot.h"
@@ -11,6 +13,43 @@
extern char __boot_data_start[], __boot_data_end[];
extern char __boot_data_preserved_start[], __boot_data_preserved_end[];
+/*
+ * Some code and data needs to stay below 2 GB, even when the kernel would be
+ * relocated above 2 GB, because it has to use 31 bit addresses.
+ * Such code and data is part of the .dma section, and its location is passed
+ * over to the decompressed / relocated kernel via the .boot.preserved.data
+ * section.
+ */
+extern char _sdma[], _edma[];
+extern char _stext_dma[], _etext_dma[];
+extern struct exception_table_entry _start_dma_ex_table[];
+extern struct exception_table_entry _stop_dma_ex_table[];
+unsigned long __bootdata_preserved(__sdma) = __pa(&_sdma);
+unsigned long __bootdata_preserved(__edma) = __pa(&_edma);
+unsigned long __bootdata_preserved(__stext_dma) = __pa(&_stext_dma);
+unsigned long __bootdata_preserved(__etext_dma) = __pa(&_etext_dma);
+struct exception_table_entry *
+ __bootdata_preserved(__start_dma_ex_table) = _start_dma_ex_table;
+struct exception_table_entry *
+ __bootdata_preserved(__stop_dma_ex_table) = _stop_dma_ex_table;
+
+int _diag210_dma(struct diag210 *addr);
+int _diag26c_dma(void *req, void *resp, enum diag26c_sc subcode);
+int _diag14_dma(unsigned long rx, unsigned long ry1, unsigned long subcode);
+void _diag0c_dma(struct hypfs_diag0c_entry *entry);
+void _diag308_reset_dma(void);
+struct diag_ops __bootdata_preserved(diag_dma_ops) = {
+ .diag210 = _diag210_dma,
+ .diag26c = _diag26c_dma,
+ .diag14 = _diag14_dma,
+ .diag0c = _diag0c_dma,
+ .diag308_reset = _diag308_reset_dma
+};
+static struct diag210 _diag210_tmp_dma __section(".dma.data");
+struct diag210 *__bootdata_preserved(__diag210_tmp_dma) = &_diag210_tmp_dma;
+void _swsusp_reset_dma(void);
+unsigned long __bootdata_preserved(__swsusp_reset_dma) = __pa(_swsusp_reset_dma);
+
void error(char *x)
{
sclp_early_printk("\n\n");
diff --git a/arch/s390/boot/text_dma.S b/arch/s390/boot/text_dma.S
new file mode 100644
index 000000000000..2414360ff22d
--- /dev/null
+++ b/arch/s390/boot/text_dma.S
@@ -0,0 +1,167 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Code that needs to run below 2 GB.
+ *
+ * Copyright IBM Corp. 2019
+ */
+
+#include <linux/linkage.h>
+#include <asm/errno.h>
+#include <asm/sigp.h>
+
+ .section .dma.text,"ax"
+/*
+ * Simplified version of expoline thunk. The normal thunks can not be used here,
+ * because they might be more than 2 GB away, and not reachable by the relative
+ * branch. No comdat, exrl, etc. optimizations used here, because it only
+ * affects a few functions that are not performance-relevant.
+ */
+ .macro BR_EX_DMA_r14
+ larl %r1,0f
+ ex 0,0(%r1)
+ j .
+0: br %r14
+ .endm
+
+/*
+ * int _diag14_dma(unsigned long rx, unsigned long ry1, unsigned long subcode)
+ */
+ENTRY(_diag14_dma)
+ lgr %r1,%r2
+ lgr %r2,%r3
+ lgr %r3,%r4
+ lhi %r5,-EIO
+ sam31
+ diag %r1,%r2,0x14
+.Ldiag14_ex:
+ ipm %r5
+ srl %r5,28
+.Ldiag14_fault:
+ sam64
+ lgfr %r2,%r5
+ BR_EX_DMA_r14
+ EX_TABLE_DMA(.Ldiag14_ex, .Ldiag14_fault)
+
+/*
+ * int _diag210_dma(struct diag210 *addr)
+ */
+ENTRY(_diag210_dma)
+ lgr %r1,%r2
+ lhi %r2,-1
+ sam31
+ diag %r1,%r0,0x210
+.Ldiag210_ex:
+ ipm %r2
+ srl %r2,28
+.Ldiag210_fault:
+ sam64
+ lgfr %r2,%r2
+ BR_EX_DMA_r14
+ EX_TABLE_DMA(.Ldiag210_ex, .Ldiag210_fault)
+
+/*
+ * int _diag26c_dma(void *req, void *resp, enum diag26c_sc subcode)
+ */
+ENTRY(_diag26c_dma)
+ lghi %r5,-EOPNOTSUPP
+ sam31
+ diag %r2,%r4,0x26c
+.Ldiag26c_ex:
+ sam64
+ lgfr %r2,%r5
+ BR_EX_DMA_r14
+ EX_TABLE_DMA(.Ldiag26c_ex, .Ldiag26c_ex)
+
+/*
+ * void _diag0c_dma(struct hypfs_diag0c_entry *entry)
+ */
+ENTRY(_diag0c_dma)
+ sam31
+ diag %r2,%r2,0x0c
+ sam64
+ BR_EX_DMA_r14
+
+/*
+ * void _swsusp_reset_dma(void)
+ */
+ENTRY(_swsusp_reset_dma)
+ larl %r1,restart_entry
+ larl %r2,.Lrestart_diag308_psw
+ og %r1,0(%r2)
+ stg %r1,0(%r0)
+ lghi %r0,0
+ diag %r0,%r0,0x308
+restart_entry:
+ lhi %r1,1
+ sigp %r1,%r0,SIGP_SET_ARCHITECTURE
+ sam64
+ BR_EX_DMA_r14
+
+/*
+ * void _diag308_reset_dma(void)
+ *
+ * Calls diag 308 subcode 1 and continues execution
+ */
+ENTRY(_diag308_reset_dma)
+ larl %r4,.Lctlregs # Save control registers
+ stctg %c0,%c15,0(%r4)
+ lg %r2,0(%r4) # Disable lowcore protection
+ nilh %r2,0xefff
+ larl %r4,.Lctlreg0
+ stg %r2,0(%r4)
+ lctlg %c0,%c0,0(%r4)
+ larl %r4,.Lfpctl # Floating point control register
+ stfpc 0(%r4)
+ larl %r4,.Lprefix # Save prefix register
+ stpx 0(%r4)
+ larl %r4,.Lprefix_zero # Set prefix register to 0
+ spx 0(%r4)
+ larl %r4,.Lcontinue_psw # Save PSW flags
+ epsw %r2,%r3
+ stm %r2,%r3,0(%r4)
+ larl %r4,restart_part2 # Setup restart PSW at absolute 0
+ larl %r3,.Lrestart_diag308_psw
+ og %r4,0(%r3) # Save PSW
+ lghi %r3,0
+ sturg %r4,%r3 # Use sturg, because of large pages
+ lghi %r1,1
+ lghi %r0,0
+ diag %r0,%r1,0x308
+restart_part2:
+ lhi %r0,0 # Load r0 with zero
+ lhi %r1,2 # Use mode 2 = ESAME (dump)
+ sigp %r1,%r0,SIGP_SET_ARCHITECTURE # Switch to ESAME mode
+ sam64 # Switch to 64 bit addressing mode
+ larl %r4,.Lctlregs # Restore control registers
+ lctlg %c0,%c15,0(%r4)
+ larl %r4,.Lfpctl # Restore floating point ctl register
+ lfpc 0(%r4)
+ larl %r4,.Lprefix # Restore prefix register
+ spx 0(%r4)
+ larl %r4,.Lcontinue_psw # Restore PSW flags
+ lpswe 0(%r4)
+.Lcontinue:
+ BR_EX_DMA_r14
+
+ .section .dma.data,"aw",@progbits
+.align 8
+.Lrestart_diag308_psw:
+ .long 0x00080000,0x80000000
+
+.align 8
+.Lcontinue_psw:
+ .quad 0,.Lcontinue
+
+.align 8
+.Lctlreg0:
+ .quad 0
+.Lctlregs:
+ .rept 16
+ .quad 0
+ .endr
+.Lfpctl:
+ .long 0
+.Lprefix:
+ .long 0
+.Lprefix_zero:
+ .long 0
generated by cgit v1.2.3 (git 2.39.0) at 2025-08-25 08:10:18 +0300