ARM fixes for 5.11:

- Fix latent bug with DC21285 (Footbridge PCI bridge) configuration
   accessors that affects GCC >= 4.9.2
 - Fix misplaced tegra_uart_config in decompressor
 - Ensure signal page contents are initialised
 - Fix kexec oops
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Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm

Pull ARM fixes from Russell King:

 - Fix latent bug with DC21285 (Footbridge PCI bridge) configuration
   accessors that affects GCC >= 4.9.2

 - Fix misplaced tegra_uart_config in decompressor

 - Ensure signal page contents are initialised

 - Fix kexec oops

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: kexec: fix oops after TLB are invalidated
  ARM: ensure the signal page contains defined contents
  ARM: 9043/1: tegra: Fix misplaced tegra_uart_config in decompressor
  ARM: footbridge: fix dc21285 PCI configuration accessors

arch/arm/include/asm/kexec-internal.h

@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ARM_KEXEC_INTERNAL_H
+#define _ARM_KEXEC_INTERNAL_H
+
+struct kexec_relocate_data {
+	unsigned long kexec_start_address;
+	unsigned long kexec_indirection_page;
+	unsigned long kexec_mach_type;
+	unsigned long kexec_r2;
+};
+
+#endif

arch/arm/include/debug/tegra.S

@@ -149,7 +149,34 @@
 
 		.align
 99:		.word	.
+#if defined(ZIMAGE)
+		.word	. + 4
+/*
+ * Storage for the state maintained by the macro.
+ *
+ * In the kernel proper, this data is located in arch/arm/mach-tegra/tegra.c.
+ * That's because this header is included from multiple files, and we only
+ * want a single copy of the data. In particular, the UART probing code above
+ * assumes it's running using physical addresses. This is true when this file
+ * is included from head.o, but not when included from debug.o. So we need
+ * to share the probe results between the two copies, rather than having
+ * to re-run the probing again later.
+ *
+ * In the decompressor, we put the storage right here, since common.c
+ * isn't included in the decompressor build. This storage data gets put in
+ * .text even though it's really data, since .data is discarded from the
+ * decompressor. Luckily, .text is writeable in the decompressor, unless
+ * CONFIG_ZBOOT_ROM. That dependency is handled in arch/arm/Kconfig.debug.
+ */
+		/* Debug UART initialization required */
+		.word	1
+		/* Debug UART physical address */
+		.word	0
+		/* Debug UART virtual address */
+		.word	0
+#else
 		.word	tegra_uart_config
+#endif
 		.ltorg
 
 		/* Load previously selected UART address */
@@ -189,30 +216,3 @@
 
 		.macro	waituarttxrdy,rd,rx
 		.endm
-
-/*
- * Storage for the state maintained by the macros above.
- *
- * In the kernel proper, this data is located in arch/arm/mach-tegra/tegra.c.
- * That's because this header is included from multiple files, and we only
- * want a single copy of the data. In particular, the UART probing code above
- * assumes it's running using physical addresses. This is true when this file
- * is included from head.o, but not when included from debug.o. So we need
- * to share the probe results between the two copies, rather than having
- * to re-run the probing again later.
- *
- * In the decompressor, we put the symbol/storage right here, since common.c
- * isn't included in the decompressor build. This symbol gets put in .text
- * even though it's really data, since .data is discarded from the
- * decompressor. Luckily, .text is writeable in the decompressor, unless
- * CONFIG_ZBOOT_ROM. That dependency is handled in arch/arm/Kconfig.debug.
- */
-#if defined(ZIMAGE)
-tegra_uart_config:
-	/* Debug UART initialization required */
-	.word 1
-	/* Debug UART physical address */
-	.word 0
-	/* Debug UART virtual address */
-	.word 0
-#endif

arch/arm/kernel/asm-offsets.c

@@ -12,6 +12,7 @@
 #include <linux/mm.h>
 #include <linux/dma-mapping.h>
 #include <asm/cacheflush.h>
+#include <asm/kexec-internal.h>
 #include <asm/glue-df.h>
 #include <asm/glue-pf.h>
 #include <asm/mach/arch.h>
@@ -170,5 +171,9 @@ int main(void)
   DEFINE(MPU_RGN_PRBAR,	offsetof(struct mpu_rgn, prbar));
   DEFINE(MPU_RGN_PRLAR,	offsetof(struct mpu_rgn, prlar));
 #endif
+  DEFINE(KEXEC_START_ADDR,	offsetof(struct kexec_relocate_data, kexec_start_address));
+  DEFINE(KEXEC_INDIR_PAGE,	offsetof(struct kexec_relocate_data, kexec_indirection_page));
+  DEFINE(KEXEC_MACH_TYPE,	offsetof(struct kexec_relocate_data, kexec_mach_type));
+  DEFINE(KEXEC_R2,		offsetof(struct kexec_relocate_data, kexec_r2));
   return 0; 
 }

arch/arm/kernel/machine_kexec.c

@@ -13,6 +13,7 @@
 #include <linux/of_fdt.h>
 #include <asm/mmu_context.h>
 #include <asm/cacheflush.h>
+#include <asm/kexec-internal.h>
 #include <asm/fncpy.h>
 #include <asm/mach-types.h>
 #include <asm/smp_plat.h>
@@ -22,11 +23,6 @@
 extern void relocate_new_kernel(void);
 extern const unsigned int relocate_new_kernel_size;
 
-extern unsigned long kexec_start_address;
-extern unsigned long kexec_indirection_page;
-extern unsigned long kexec_mach_type;
-extern unsigned long kexec_boot_atags;
-
 static atomic_t waiting_for_crash_ipi;
 
 /*
@@ -159,6 +155,7 @@ void (*kexec_reinit)(void);
 void machine_kexec(struct kimage *image)
 {
 	unsigned long page_list, reboot_entry_phys;
+	struct kexec_relocate_data *data;
 	void (*reboot_entry)(void);
 	void *reboot_code_buffer;
 
@@ -174,18 +171,17 @@ void machine_kexec(struct kimage *image)
 
 	reboot_code_buffer = page_address(image->control_code_page);
 
-	/* Prepare parameters for reboot_code_buffer*/
-	set_kernel_text_rw();
-	kexec_start_address = image->start;
-	kexec_indirection_page = page_list;
-	kexec_mach_type = machine_arch_type;
-	kexec_boot_atags = image->arch.kernel_r2;
-
 	/* copy our kernel relocation code to the control code page */
 	reboot_entry = fncpy(reboot_code_buffer,
 			     &relocate_new_kernel,
 			     relocate_new_kernel_size);
 
+	data = reboot_code_buffer + relocate_new_kernel_size;
+	data->kexec_start_address = image->start;
+	data->kexec_indirection_page = page_list;
+	data->kexec_mach_type = machine_arch_type;
+	data->kexec_r2 = image->arch.kernel_r2;
+
 	/* get the identity mapping physical address for the reboot code */
 	reboot_entry_phys = virt_to_idmap(reboot_entry);
 

arch/arm/kernel/relocate_kernel.S

@@ -5,14 +5,16 @@
 
 #include <linux/linkage.h>
 #include <asm/assembler.h>
+#include <asm/asm-offsets.h>
 #include <asm/kexec.h>
 
 	.align	3	/* not needed for this code, but keeps fncpy() happy */
 
 ENTRY(relocate_new_kernel)
 
-	ldr	r0,kexec_indirection_page
+	adr	r7, relocate_new_kernel_end
-	ldr	r1,kexec_start_address
+	ldr	r0, [r7, #KEXEC_INDIR_PAGE]
+	ldr	r1, [r7, #KEXEC_START_ADDR]
 
 	/*
 	 * If there is no indirection page (we are doing crashdumps)
@@ -57,34 +59,16 @@ ENTRY(relocate_new_kernel)
 
 2:
 	/* Jump to relocated kernel */
-	mov lr,r1
+	mov	lr, r1
-	mov r0,#0
+	mov	r0, #0
-	ldr r1,kexec_mach_type
+	ldr	r1, [r7, #KEXEC_MACH_TYPE]
-	ldr r2,kexec_boot_atags
+	ldr	r2, [r7, #KEXEC_R2]
  ARM(	ret	lr	)
  THUMB(	bx	lr	)
 
-	.align
-
-	.globl kexec_start_address
-kexec_start_address:
-	.long	0x0
-
-	.globl kexec_indirection_page
-kexec_indirection_page:
-	.long	0x0
-
-	.globl kexec_mach_type
-kexec_mach_type:
-	.long	0x0
-
-	/* phy addr of the atags for the new kernel */
-	.globl kexec_boot_atags
-kexec_boot_atags:
-	.long	0x0
-
 ENDPROC(relocate_new_kernel)
 
+	.align	3
 relocate_new_kernel_end:
 
 	.globl relocate_new_kernel_size

arch/arm/kernel/signal.c

@@ -693,18 +693,20 @@ struct page *get_signal_page(void)
 
 	addr = page_address(page);
 
+	/* Poison the entire page */
+	memset32(addr, __opcode_to_mem_arm(0xe7fddef1),
+		 PAGE_SIZE / sizeof(u32));
+
 	/* Give the signal return code some randomness */
 	offset = 0x200 + (get_random_int() & 0x7fc);
 	signal_return_offset = offset;
 
-	/*
+	/* Copy signal return handlers into the page */
-	 * Copy signal return handlers into the vector page, and
-	 * set sigreturn to be a pointer to these.
-	 */
 	memcpy(addr + offset, sigreturn_codes, sizeof(sigreturn_codes));
 
-	ptr = (unsigned long)addr + offset;
+	/* Flush out all instructions in this page */
-	flush_icache_range(ptr, ptr + sizeof(sigreturn_codes));
+	ptr = (unsigned long)addr;
+	flush_icache_range(ptr, ptr + PAGE_SIZE);
 
 	return page;
 }

arch/arm/mach-footbridge/dc21285.c

@@ -65,15 +65,15 @@ dc21285_read_config(struct pci_bus *bus, unsigned int devfn, int where,
 	if (addr)
 		switch (size) {
 		case 1:
-			asm("ldrb	%0, [%1, %2]"
+			asm volatile("ldrb	%0, [%1, %2]"
 				: "=r" (v) : "r" (addr), "r" (where) : "cc");
 			break;
 		case 2:
-			asm("ldrh	%0, [%1, %2]"
+			asm volatile("ldrh	%0, [%1, %2]"
 				: "=r" (v) : "r" (addr), "r" (where) : "cc");
 			break;
 		case 4:
-			asm("ldr	%0, [%1, %2]"
+			asm volatile("ldr	%0, [%1, %2]"
 				: "=r" (v) : "r" (addr), "r" (where) : "cc");
 			break;
 		}
@@ -99,17 +99,17 @@ dc21285_write_config(struct pci_bus *bus, unsigned int devfn, int where,
 	if (addr)
 		switch (size) {
 		case 1:
-			asm("strb	%0, [%1, %2]"
+			asm volatile("strb	%0, [%1, %2]"
 				: : "r" (value), "r" (addr), "r" (where)
 				: "cc");
 			break;
 		case 2:
-			asm("strh	%0, [%1, %2]"
+			asm volatile("strh	%0, [%1, %2]"
 				: : "r" (value), "r" (addr), "r" (where)
 				: "cc");
 			break;
 		case 4:
-			asm("str	%0, [%1, %2]"
+			asm volatile("str	%0, [%1, %2]"
 				: : "r" (value), "r" (addr), "r" (where)
 				: "cc");
 			break;