Semaphore CM11 + kexec hard boot

arch/arm/Kconfig

@@ -2191,6 +2191,32 @@ config ATAGS_PROC
 	  Should the atags used to boot the kernel be exported in an "atags"
 	  file in procfs. Useful with kexec.
 
+config KEXEC_HARDBOOT
+	bool "Support hard booting to a kexec kernel"
+	depends on KEXEC
+	help
+	  Allows hard booting (i.e., with a full hardware reboot) to a kernel
+	  previously loaded in memory by kexec.  This works around the problem of
+	  soft-booted kernel hangs due to improper device shutdown and/or
+	  reinitialization.  Support is comprised of two components:
+
+	  First, a "hardboot" flag is added to the kexec syscall to force a hard
+	  reboot in relocate_new_kernel() (which requires machine-specific assembly
+	  code).  This also requires the kexec userspace tool to load the kexec'd
+	  kernel in memory region left untouched by the bootloader (i.e., not
+	  explicitly cleared and not overwritten by the boot kernel).  Just prior
+	  to reboot, the kexec kernel arguments are stashed in a machine-specific
+	  memory page that must also be preserved.  Note that this hardboot page
+	  need not be reserved during regular kernel execution.
+
+	  Second, the zImage decompresor of the boot (bootloader-loaded) kernel is
+	  modified to check the hardboot page for fresh kexec arguments, and if
+	  present, attempts to jump to the kexec'd kernel preserved in memory.
+
+	  Note that hardboot support is only required in the boot kernel and any
+	  kernel capable of performing a hardboot kexec.  It is _not_ required by a
+	  kexec'd kernel.
+
 config CRASH_DUMP
 	bool "Build kdump crash kernel (EXPERIMENTAL)"
 	depends on EXPERIMENTAL

arch/arm/boot/compressed/head.S

@@ -314,6 +314,11 @@ restart:	adr	r0, LC0
 dtb_check_done:
 #endif
 
+#ifdef CONFIG_KEXEC_HARDBOOT
+  #include <asm/kexec.h>
+  #include <asm/memory.h>
+#endif
+
 /*
  * Check to see if we will overwrite ourselves.
  *   r4  = final kernel address

arch/arm/include/asm/kexec.h

@@ -17,6 +17,10 @@
 #define KEXEC_ARM_ATAGS_OFFSET  0x1000
 #define KEXEC_ARM_ZIMAGE_OFFSET 0x8000
 
+#ifdef CONFIG_KEXEC_HARDBOOT
+  #define KEXEC_HB_PAGE_MAGIC 0x4a5db007
+#endif
+
 #ifndef __ASSEMBLY__
 
 /**
@@ -53,6 +57,10 @@ static inline void crash_setup_regs(struct pt_regs *newregs,
 /* Function pointer to optional machine-specific reinitialization */
 extern void (*kexec_reinit)(void);
 
+#ifdef CONFIG_KEXEC_HARDBOOT
+extern void (*kexec_hardboot_hook)(void);
+#endif
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* CONFIG_KEXEC */

arch/arm/kernel/atags.c

@@ -4,29 +4,45 @@
 #include <asm/types.h>
 #include <asm/page.h>
 
+/*
+ * [PATCH] Backport arch/arm/kernel/atags.c from 3.10
+ *
+ * There is a bug in older kernels, causing kexec-tools binary to
+ * only read first 1024 bytes from /proc/atags. I guess the bug is
+ * somewhere in /fs/proc/, since I don't think the callback in atags.c
+ * does something wrong. It might affect all procfs files using that
+ * old read callback instead of fops. Doesn't matter though, since it
+ * was accidentally fixed when 3.10 removed it.
+ *
+ * This might have no particular effect on real devices, because the
+ * atags _might_ be organized "just right", but it might be very hard
+ * to track down on a device where it causes problems.
+ *
+ */
+
 struct buffer {
 	size_t size;
 	char data[];
 };
 
-static int
-read_buffer(char* page, char** start, off_t off, int count,
-	int* eof, void* data)
-{
-	struct buffer *buffer = (struct buffer *)data;
-
-	if (off >= buffer->size) {
-		*eof = 1;
-		return 0;
-	}
-
-	count = min((int) (buffer->size - off), count);
+static struct buffer* atags_buffer = NULL;
 
-	memcpy(page, &buffer->data[off], count);
-
-	return count;
+static ssize_t atags_read(struct file *file, char __user *buf,
+			  size_t count, loff_t *ppos)
+{
+	// These are introduced in kernel 3.10. I don't want to backport
+	// the whole chunk, and other things (ram_console) use static
+	// variable to keep data too, so I guess it's okay.
+	//struct buffer *b = PDE_DATA(file_inode(file));
+	struct buffer *b = atags_buffer;
+	return simple_read_from_buffer(buf, count, ppos, b->data, b->size);
 }
 
+static const struct file_operations atags_fops = {
+	.read = atags_read,
+	.llseek = default_llseek,
+};
+
 #define BOOT_PARAMS_SIZE 1536
 static char __initdata atags_copy[BOOT_PARAMS_SIZE];
 
@@ -66,12 +82,13 @@ static int __init init_atags_procfs(void)
 	b->size = size;
 	memcpy(b->data, atags_copy, size);
 
-	tags_entry = create_proc_read_entry("atags", 0400,
-			NULL, read_buffer, b);
+	tags_entry = proc_create_data("atags", 0400, NULL, &atags_fops, b);
 
 	if (!tags_entry)
 		goto nomem;
 
+	atags_buffer = b;
+
 	return 0;
 
 nomem:

arch/arm/kernel/machine_kexec.c

@@ -14,6 +14,7 @@
 #include <asm/cacheflush.h>
 #include <asm/mach-types.h>
 #include <asm/system_misc.h>
+#include <asm/mmu_writeable.h>
 
 extern const unsigned char relocate_new_kernel[];
 extern const unsigned int relocate_new_kernel_size;
@@ -22,6 +23,10 @@ extern unsigned long kexec_start_address;
 extern unsigned long kexec_indirection_page;
 extern unsigned long kexec_mach_type;
 extern unsigned long kexec_boot_atags;
+#ifdef CONFIG_KEXEC_HARDBOOT
+extern unsigned long kexec_hardboot;
+void (*kexec_hardboot_hook)(void);
+#endif
 
 static atomic_t waiting_for_crash_ipi;
 
@@ -120,10 +125,13 @@ void machine_kexec(struct kimage *image)
 	reboot_code_buffer = page_address(image->control_code_page);
 
 	/* Prepare parameters for reboot_code_buffer*/
-	kexec_start_address = image->start;
-	kexec_indirection_page = page_list;
-	kexec_mach_type = machine_arch_type;
-	kexec_boot_atags = image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET;
+	mem_text_write_kernel_word(&kexec_start_address, image->start);
+	mem_text_write_kernel_word(&kexec_indirection_page, page_list);
+	mem_text_write_kernel_word(&kexec_mach_type, machine_arch_type);
+	mem_text_write_kernel_word(&kexec_boot_atags, image->start - KEXEC_ARM_ZIMAGE_OFFSET + KEXEC_ARM_ATAGS_OFFSET);
+#ifdef CONFIG_KEXEC_HARDBOOT
+	mem_text_write_kernel_word(&kexec_hardboot, image->hardboot);
+#endif
 
 	/* copy our kernel relocation code to the control code page */
 	memcpy(reboot_code_buffer,
@@ -137,5 +145,11 @@ void machine_kexec(struct kimage *image)
 	if (kexec_reinit)
 		kexec_reinit();
 
+#ifdef CONFIG_KEXEC_HARDBOOT
+	/* Run any final machine-specific shutdown code. */
+	if (image->hardboot && kexec_hardboot_hook)
+		kexec_hardboot_hook();
+#endif
+
 	soft_restart(reboot_code_buffer_phys);
 }

arch/arm/kernel/relocate_kernel.S

@@ -4,6 +4,15 @@
 
 #include <asm/kexec.h>
 
+#ifdef CONFIG_KEXEC_HARDBOOT
+#include <asm/memory.h>
+#if defined(CONFIG_ARCH_TEGRA_2x_SOC) || defined(CONFIG_ARCH_TEGRA_3x_SOC)
+  #include <mach/iomap.h>
+#elif defined(CONFIG_ARCH_APQ8064)
+  #include <mach/msm_iomap.h>
+#endif
+#endif
+
 	.globl relocate_new_kernel
 relocate_new_kernel:
 
@@ -52,6 +61,12 @@ relocate_new_kernel:
 	b 0b
 
 2:
+#ifdef CONFIG_KEXEC_HARDBOOT
+	ldr	r0, kexec_hardboot
+	teq	r0, #0
+	bne	hardboot
+#endif
+
 	/* Jump to relocated kernel */
 	mov lr,r1
 	mov r0,#0
@@ -60,6 +75,40 @@ relocate_new_kernel:
  ARM(	mov pc, lr	)
  THUMB(	bx lr		)
 
+#ifdef CONFIG_KEXEC_HARDBOOT
+hardboot:
+	/* Stash boot arguments in hardboot page:
+	 *  0: KEXEC_HB_PAGE_MAGIC
+	 *  4: kexec_start_address
+	 *  8: kexec_mach_type
+	 * 12: kexec_boot_atags */
+	ldr	r0, =KEXEC_HB_PAGE_ADDR
+	str	r1, [r0, #4]
+	ldr	r1, kexec_mach_type
+	str	r1, [r0, #8]
+	ldr	r1, kexec_boot_atags
+	str	r1, [r0, #12]
+	ldr	r1, =KEXEC_HB_PAGE_MAGIC
+	str	r1, [r0]
+
+#if defined(CONFIG_ARCH_TEGRA_2x_SOC) || defined(CONFIG_ARCH_TEGRA_3x_SOC)
+	ldr     r0, =TEGRA_PMC_BASE
+	ldr	r1, [r0]
+	orr	r1, r1, #0x10
+	str	r1, [r0]
+loop:	b	loop
+#elif defined(CONFIG_ARCH_APQ8064)
+	/* Restart using the PMIC chip, see mach-msm/restart.c */
+	ldr	r0, =APQ8064_TLMM_PHYS
+	mov	r1, #0
+	str	r1, [r0, #0x820]  @ PSHOLD_CTL_SU
+loop:	b	loop
+#else
+#error "No reboot method defined for hardboot."
+#endif
+
+	.ltorg
+#endif
 	.align
 
 	.globl kexec_start_address
@@ -79,6 +128,12 @@ kexec_mach_type:
 kexec_boot_atags:
 	.long	0x0
 
+#ifdef CONFIG_KEXEC_HARDBOOT
+	.globl kexec_hardboot
+kexec_hardboot:
+	.long	0x0
+#endif
+
 relocate_new_kernel_end:
 
 	.globl relocate_new_kernel_size

arch/arm/mach-msm/Kconfig

@@ -2595,11 +2595,26 @@ config MSM_HSIC_SYSMON_TEST
 	  can be read and written to send character data to the sysmon port of
 	  the modem over USB.
 
+
 config MSM_CPU_PWRCTL
 	bool "Ensures that krait droop detectors are always off"
 	help
 	  Droop detector mechanism can adversely affect krait plls during
 	  stand alone power collapse operation. Selecting this option
 	  ensures that they are always off.
 
+config FORCE_FAST_CHARGE
+	bool "Force AC charge mode at will"
+	default y
+	help
+		A simple sysfs interface to force adapters that
+		are detected as USB to charge as AC.
+
+config FORCE_FAST_CHARGE
+	bool "Force AC charge mode at will"
+	default y
+	help
+	  A simple sysfs interface to force adapters that
+	  are detected as USB to charge as AC.
+
 endif

arch/arm/mach-msm/Makefile

@@ -386,8 +386,10 @@ obj-$(CONFIG_MSM_HSIC_SYSMON_TEST) += hsic_sysmon_test.o
 obj-$(CONFIG_MSM_RPM_SMD) += rpm-smd.o
 obj-$(CONFIG_MSM_CPR) += msm_cpr.o
 obj-$(CONFIG_MSM_VP_REGULATOR) += msm_vp.o
+obj-$(CONFIG_FORCE_FAST_CHARGE) += fastchg.o
 
 ifdef CONFIG_MSM_CPR
 obj-$(CONFIG_DEBUG_FS) += msm_cpr-debug.o
 endif
 obj-$(CONFIG_MSM_CPU_PWRCTL) +=  msm_cpu_pwrctl.o
+obj-$(CONFIG_FORCE_FAST_CHARGE) += fastchg.o