MIPS: Octeon: Add kexec and kdump support

[ralf@linux-mips.org: Original patch by Maxim Uvarov <muvarov@gmail.com>
with plenty of further shining, polishing, debugging and testing by me.]

Signed-off-by: Maxim Uvarov <muvarov@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: kexec@lists.infradead.org
Cc: horms@verge.net.au
Patchwork: https://patchwork.linux-mips.org/patch/1026/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

6 files changed, 335 insertions, 9 deletions

diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index 654b1ad39f05..033395ec82f1 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -192,6 +192,10 @@ endif
 #
 include $(srctree)/arch/mips/Kbuild.platforms
 
+ifdef CONFIG_PHYSICAL_START
+load-y                                  = $(CONFIG_PHYSICAL_START)
+endif
+
 cflags-y                        += -I$(srctree)/arch/mips/include/asm/mach-generic
 drivers-$(CONFIG_PCI)           += arch/mips/pci/
 
diff --git a/arch/mips/cavium-octeon/executive/cvmx-bootmem.c b/arch/mips/cavium-octeon/executive/cvmx-bootmem.c
index fdf5f19bfdb0..6d5ddbc112cc 100644
--- a/arch/mips/cavium-octeon/executive/cvmx-bootmem.c
+++ b/arch/mips/cavium-octeon/executive/cvmx-bootmem.c
@@ -688,3 +688,8 @@ int64_t cvmx_bootmem_phy_named_block_alloc(uint64_t size, uint64_t min_addr,
                 cvmx_spinlock_unlock((cvmx_spinlock_t *)&(cvmx_bootmem_desc->lock));
         return addr_allocated;
 }
+
+struct cvmx_bootmem_desc *cvmx_bootmem_get_desc(void)
+{
+        return cvmx_bootmem_desc;
+}
diff --git a/arch/mips/cavium-octeon/setup.c b/arch/mips/cavium-octeon/setup.c
index 67aa3b942f06..7c2b7aab77ba 100644
--- a/arch/mips/cavium-octeon/setup.c
+++ b/arch/mips/cavium-octeon/setup.c
@@ -25,6 +25,7 @@
 #include <linux/serial_8250.h>
 #include <linux/of_fdt.h>
 #include <linux/libfdt.h>
+#include <linux/kexec.h>
 
 #include <asm/processor.h>
 #include <asm/reboot.h>
@@ -58,11 +59,208 @@ struct octeon_boot_descriptor *octeon_boot_desc_ptr;
 struct cvmx_bootinfo *octeon_bootinfo;
 EXPORT_SYMBOL(octeon_bootinfo);
 
+static unsigned long long RESERVE_LOW_MEM = 0ull;
+#ifdef CONFIG_KEXEC
+#ifdef CONFIG_SMP
+/*
+ * Wait for relocation code is prepared and send
+ * secondary CPUs to spin until kernel is relocated.
+ */
+static void octeon_kexec_smp_down(void *ignored)
+{
+        int cpu = smp_processor_id();
+
+        local_irq_disable();
+        set_cpu_online(cpu, false);
+        while (!atomic_read(&kexec_ready_to_reboot))
+                cpu_relax();
+
+        asm volatile (
+        "       sync                                            \n"
+        "       synci   ($0)                                    \n");
+
+        relocated_kexec_smp_wait(NULL);
+}
+#endif
+
+#define OCTEON_DDR0_BASE    (0x0ULL)
+#define OCTEON_DDR0_SIZE    (0x010000000ULL)
+#define OCTEON_DDR1_BASE    (0x410000000ULL)
+#define OCTEON_DDR1_SIZE    (0x010000000ULL)
+#define OCTEON_DDR2_BASE    (0x020000000ULL)
+#define OCTEON_DDR2_SIZE    (0x3e0000000ULL)
+#define OCTEON_MAX_PHY_MEM_SIZE (16*1024*1024*1024ULL)
+
+static struct kimage *kimage_ptr;
+
+static void kexec_bootmem_init(uint64_t mem_size, uint32_t low_reserved_bytes)
+{
+        int64_t addr;
+        struct cvmx_bootmem_desc *bootmem_desc;
+
+        bootmem_desc = cvmx_bootmem_get_desc();
+
+        if (mem_size > OCTEON_MAX_PHY_MEM_SIZE) {
+                mem_size = OCTEON_MAX_PHY_MEM_SIZE;
+                pr_err("Error: requested memory too large,"
+                       "truncating to maximum size\n");
+        }
+
+        bootmem_desc->major_version = CVMX_BOOTMEM_DESC_MAJ_VER;
+        bootmem_desc->minor_version = CVMX_BOOTMEM_DESC_MIN_VER;
+
+        addr = (OCTEON_DDR0_BASE + RESERVE_LOW_MEM + low_reserved_bytes);
+        bootmem_desc->head_addr = 0;
+
+        if (mem_size <= OCTEON_DDR0_SIZE) {
+                __cvmx_bootmem_phy_free(addr,
+                                mem_size - RESERVE_LOW_MEM -
+                                low_reserved_bytes, 0);
+                return;
+        }
+
+        __cvmx_bootmem_phy_free(addr,
+                        OCTEON_DDR0_SIZE - RESERVE_LOW_MEM -
+                        low_reserved_bytes, 0);
+
+        mem_size -= OCTEON_DDR0_SIZE;
+
+        if (mem_size > OCTEON_DDR1_SIZE) {
+                __cvmx_bootmem_phy_free(OCTEON_DDR1_BASE, OCTEON_DDR1_SIZE, 0);
+                __cvmx_bootmem_phy_free(OCTEON_DDR2_BASE,
+                                mem_size - OCTEON_DDR1_SIZE, 0);
+        } else
+                __cvmx_bootmem_phy_free(OCTEON_DDR1_BASE, mem_size, 0);
+}
+
+static int octeon_kexec_prepare(struct kimage *image)
+{
+        int i;
+        char *bootloader = "kexec";
+
+        octeon_boot_desc_ptr->argc = 0;
+        for (i = 0; i < image->nr_segments; i++) {
+                if (!strncmp(bootloader, (char *)image->segment[i].buf,
+                                strlen(bootloader))) {
+                        /*
+                         * convert command line string to array
+                         * of parameters (as bootloader does).
+                         */
+                        int argc = 0, offt;
+                        char *str = (char *)image->segment[i].buf;
+                        char *ptr = strchr(str, ' ');
+                        while (ptr && (OCTEON_ARGV_MAX_ARGS > argc)) {
+                                *ptr = '\0';
+                                if (ptr[1] != ' ') {
+                                        offt = (int)(ptr - str + 1);
+                                        octeon_boot_desc_ptr->argv[argc] =
+                                                image->segment[i].mem + offt;
+                                        argc++;
+                                }
+                                ptr = strchr(ptr + 1, ' ');
+                        }
+                        octeon_boot_desc_ptr->argc = argc;
+                        break;
+                }
+        }
+
+        /*
+         * Information about segments will be needed during pre-boot memory
+         * initialization.
+         */
+        kimage_ptr = image;
+        return 0;
+}
+
+static void octeon_generic_shutdown(void)
+{
+        int cpu, i;
+        struct cvmx_bootmem_desc *bootmem_desc;
+        void *named_block_array_ptr;
+
+        bootmem_desc = cvmx_bootmem_get_desc();
+        named_block_array_ptr =
+                cvmx_phys_to_ptr(bootmem_desc->named_block_array_addr);
+
+#ifdef CONFIG_SMP
+        /* disable watchdogs */
+        for_each_online_cpu(cpu)
+                cvmx_write_csr(CVMX_CIU_WDOGX(cpu_logical_map(cpu)), 0);
+#else
+        cvmx_write_csr(CVMX_CIU_WDOGX(cvmx_get_core_num()), 0);
+#endif
+        if (kimage_ptr != kexec_crash_image) {
+                memset(named_block_array_ptr,
+                        0x0,
+                        CVMX_BOOTMEM_NUM_NAMED_BLOCKS *
+                        sizeof(struct cvmx_bootmem_named_block_desc));
+                /*
+                 * Mark all memory (except low 0x100000 bytes) as free.
+                 * It is the same thing that bootloader does.
+                 */
+                kexec_bootmem_init(octeon_bootinfo->dram_size*1024ULL*1024ULL,
+                                0x100000);
+                /*
+                 * Allocate all segments to avoid their corruption during boot.
+                 */
+                for (i = 0; i < kimage_ptr->nr_segments; i++)
+                        cvmx_bootmem_alloc_address(
+                                kimage_ptr->segment[i].memsz + 2*PAGE_SIZE,
+                                kimage_ptr->segment[i].mem - PAGE_SIZE,
+                                PAGE_SIZE);
+        } else {
+                /*
+                 * Do not mark all memory as free. Free only named sections
+                 * leaving the rest of memory unchanged.
+                 */
+                struct cvmx_bootmem_named_block_desc *ptr =
+                        (struct cvmx_bootmem_named_block_desc *)
+                        named_block_array_ptr;
+
+                for (i = 0; i < bootmem_desc->named_block_num_blocks; i++)
+                        if (ptr[i].size)
+                                cvmx_bootmem_free_named(ptr[i].name);
+        }
+        kexec_args[2] = 1UL; /* running on octeon_main_processor */
+        kexec_args[3] = (unsigned long)octeon_boot_desc_ptr;
+#ifdef CONFIG_SMP
+        secondary_kexec_args[2] = 0UL; /* running on secondary cpu */
+        secondary_kexec_args[3] = (unsigned long)octeon_boot_desc_ptr;
+#endif
+}
+
+static void octeon_shutdown(void)
+{
+        octeon_generic_shutdown();
+#ifdef CONFIG_SMP
+        smp_call_function(octeon_kexec_smp_down, NULL, 0);
+        smp_wmb();
+        while (num_online_cpus() > 1) {
+                cpu_relax();
+                mdelay(1);
+        }
+#endif
+}
+
+static void octeon_crash_shutdown(struct pt_regs *regs)
+{
+        octeon_generic_shutdown();
+        default_machine_crash_shutdown(regs);
+}
+
+#endif /* CONFIG_KEXEC */
+
 #ifdef CONFIG_CAVIUM_RESERVE32
 uint64_t octeon_reserve32_memory;
 EXPORT_SYMBOL(octeon_reserve32_memory);
 #endif
 
+#ifdef CONFIG_KEXEC
+/* crashkernel cmdline parameter is parsed _after_ memory setup
+ * we also parse it here (workaround for EHB5200) */
+static uint64_t crashk_size, crashk_base;
+#endif
+
 static int octeon_uart;
 
 extern asmlinkage void handle_int(void);
@@ -417,6 +615,8 @@ void octeon_user_io_init(void)
 void __init prom_init(void)
 {
         struct cvmx_sysinfo *sysinfo;
+        const char *arg;
+        char *p;
         int i;
         int argc;
 #ifdef CONFIG_CAVIUM_RESERVE32
@@ -568,6 +768,15 @@ void __init prom_init(void)
         if (octeon_is_simulation())
                 MAX_MEMORY = 64ull << 20;
 
+        arg = strstr(arcs_cmdline, "mem=");
+        if (arg) {
+                MAX_MEMORY = memparse(arg + 4, &p);
+                if (MAX_MEMORY == 0)
+                        MAX_MEMORY = 32ull << 30;
+                if (*p == '@')
+                        RESERVE_LOW_MEM = memparse(p + 1, &p);
+        }
+
         arcs_cmdline[0] = 0;
         argc = octeon_boot_desc_ptr->argc;
         for (i = 0; i < argc; i++) {
@@ -575,16 +784,30 @@ void __init prom_init(void)
                         cvmx_phys_to_ptr(octeon_boot_desc_ptr->argv[i]);
                 if ((strncmp(arg, "MEM=", 4) == 0) ||
                     (strncmp(arg, "mem=", 4) == 0)) {
-                        sscanf(arg + 4, "%llu", &MAX_MEMORY);
-                        MAX_MEMORY <<= 20;
+                        MAX_MEMORY = memparse(arg + 4, &p);
                         if (MAX_MEMORY == 0)
                                 MAX_MEMORY = 32ull << 30;
+                        if (*p == '@')
+                                RESERVE_LOW_MEM = memparse(p + 1, &p);
                 } else if (strcmp(arg, "ecc_verbose") == 0) {
 #ifdef CONFIG_CAVIUM_REPORT_SINGLE_BIT_ECC
                         __cvmx_interrupt_ecc_report_single_bit_errors = 1;
                         pr_notice("Reporting of single bit ECC errors is "
                                   "turned on\n");
 #endif
+#ifdef CONFIG_KEXEC
+                } else if (strncmp(arg, "crashkernel=", 12) == 0) {
+                        crashk_size = memparse(arg+12, &p);
+                        if (*p == '@')
+                                crashk_base = memparse(p+1, &p);
+                        strcat(arcs_cmdline, " ");
+                        strcat(arcs_cmdline, arg);
+                        /*
+                         * To do: switch parsing to new style, something like:
+                         * parse_crashkernel(arg, sysinfo->system_dram_size,
+                         *                &crashk_size, &crashk_base);
+                         */
+#endif
                 } else if (strlen(arcs_cmdline) + strlen(arg) + 1 <
                            sizeof(arcs_cmdline) - 1) {
                         strcat(arcs_cmdline, " ");
@@ -619,11 +842,18 @@ void __init prom_init(void)
         _machine_restart = octeon_restart;
         _machine_halt = octeon_halt;
 
+#ifdef CONFIG_KEXEC
+        _machine_kexec_shutdown = octeon_shutdown;
+        _machine_crash_shutdown = octeon_crash_shutdown;
+        _machine_kexec_prepare = octeon_kexec_prepare;
+#endif
+
         octeon_user_io_init();
         register_smp_ops(&octeon_smp_ops);
 }
 
 /* Exclude a single page from the regions obtained in plat_mem_setup. */
+#ifndef CONFIG_CRASH_DUMP
 static __init void memory_exclude_page(u64 addr, u64 *mem, u64 *size)
 {
         if (addr > *mem && addr < *mem + *size) {
@@ -638,14 +868,21 @@ static __init void memory_exclude_page(u64 addr, u64 *mem, u64 *size)
                 *size -= PAGE_SIZE;
         }
 }
+#endif /* CONFIG_CRASH_DUMP */
 
 void __init plat_mem_setup(void)
 {
         uint64_t mem_alloc_size;
         uint64_t total;
+        uint64_t crashk_end;
+#ifndef CONFIG_CRASH_DUMP
         int64_t memory;
+        uint64_t kernel_start;
+        uint64_t kernel_size;
+#endif
 
         total = 0;
+        crashk_end = 0;
 
         /*
          * The Mips memory init uses the first memory location for
@@ -658,6 +895,17 @@ void __init plat_mem_setup(void)
         if (mem_alloc_size > MAX_MEMORY)
                 mem_alloc_size = MAX_MEMORY;
 
+/* Crashkernel ignores bootmem list. It relies on mem=X@Y option */
+#ifdef CONFIG_CRASH_DUMP
+        add_memory_region(RESERVE_LOW_MEM, MAX_MEMORY, BOOT_MEM_RAM);
+        total += MAX_MEMORY;
+#else
+#ifdef CONFIG_KEXEC
+        if (crashk_size > 0) {
+                add_memory_region(crashk_base, crashk_size, BOOT_MEM_RAM);
+                crashk_end = crashk_base + crashk_size;
+        }
+#endif
         /*
          * When allocating memory, we want incrementing addresses from
          * bootmem_alloc so the code in add_memory_region can merge
@@ -672,6 +920,9 @@ void __init plat_mem_setup(void)
                                                 CVMX_BOOTMEM_FLAG_NO_LOCKING);
                 if (memory >= 0) {
                         u64 size = mem_alloc_size;
+#ifdef CONFIG_KEXEC
+                        uint64_t end;
+#endif
 
                         /*
                          * exclude a page at the beginning and end of
@@ -684,20 +935,67 @@ void __init plat_mem_setup(void)
                         memory_exclude_page(CVMX_PCIE_BAR1_PHYS_BASE +
                                             CVMX_PCIE_BAR1_PHYS_SIZE,
                                             &memory, &size);
+#ifdef CONFIG_KEXEC
+                        end = memory + mem_alloc_size;
 
                         /*
-                         * This function automatically merges address
-                         * regions next to each other if they are
-                         * received in incrementing order.
+                         * This function automatically merges address regions
+                         * next to each other if they are received in
+                         * incrementing order
                          */
-                        if (size)
-                                add_memory_region(memory, size, BOOT_MEM_RAM);
+                        if (memory < crashk_base && end >  crashk_end) {
+                                /* region is fully in */
+                                add_memory_region(memory,
+                                                  crashk_base - memory,
+                                                  BOOT_MEM_RAM);
+                                total += crashk_base - memory;
+                                add_memory_region(crashk_end,
+                                                  end - crashk_end,
+                                                  BOOT_MEM_RAM);
+                                total += end - crashk_end;
+                                continue;
+                        }
+
+                        if (memory >= crashk_base && end <= crashk_end)
+                                /*
+                                 * Entire memory region is within the new
+                                 *  kernel's memory, ignore it.
+                                 */
+                                continue;
+
+                        if (memory > crashk_base && memory < crashk_end &&
+                            end > crashk_end) {
+                                /*
+                                 * Overlap with the beginning of the region,
+                                 * reserve the beginning.
+                                  */
+                                mem_alloc_size -= crashk_end - memory;
+                                memory = crashk_end;
+                        } else if (memory < crashk_base && end > crashk_base &&
+                                   end < crashk_end)
+                                /*
+                                 * Overlap with the beginning of the region,
+                                 * chop of end.
+                                 */
+                                mem_alloc_size -= end - crashk_base;
+#endif
+                        add_memory_region(memory, mem_alloc_size, BOOT_MEM_RAM);
                         total += mem_alloc_size;
+                        /* Recovering mem_alloc_size */
+                        mem_alloc_size = 4 << 20;
                 } else {
                         break;
                 }
         }
         cvmx_bootmem_unlock();
+        /* Add the memory region for the kernel. */
+        kernel_start = (unsigned long) _text;
+        kernel_size = ALIGN(_end - _text, 0x100000);
+
+        /* Adjust for physical offset. */
+        kernel_start &= ~0xffffffff80000000ULL;
+        add_memory_region(kernel_start, kernel_size, BOOT_MEM_RAM);
+#endif /* CONFIG_CRASH_DUMP */
 
 #ifdef CONFIG_CAVIUM_RESERVE32
         /*
diff --git a/arch/mips/include/asm/octeon/cvmx-bootmem.h b/arch/mips/include/asm/octeon/cvmx-bootmem.h
index 877845b84b14..42db2be663f1 100644
--- a/arch/mips/include/asm/octeon/cvmx-bootmem.h
+++ b/arch/mips/include/asm/octeon/cvmx-bootmem.h
@@ -370,4 +370,6 @@ void cvmx_bootmem_lock(void);
  */
 void cvmx_bootmem_unlock(void);
 
+extern struct cvmx_bootmem_desc *cvmx_bootmem_get_desc(void);
+
 #endif /*   __CVMX_BOOTMEM_H__ */
diff --git a/arch/mips/kernel/crash_dump.c b/arch/mips/kernel/crash_dump.c
index d9ec3898f9fa..35bed0d2342c 100644
--- a/arch/mips/kernel/crash_dump.c
+++ b/arch/mips/kernel/crash_dump.c
@@ -3,8 +3,6 @@
 #include <linux/crash_dump.h>
 #include <asm/uaccess.h>
 
-unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
-
 static int __init parse_savemaxmem(char *p)
 {
         if (p)
diff --git a/arch/mips/kernel/relocate_kernel.S b/arch/mips/kernel/relocate_kernel.S
index 0b108587f065..e4142c5f7c2b 100644
--- a/arch/mips/kernel/relocate_kernel.S
+++ b/arch/mips/kernel/relocate_kernel.S
@@ -78,7 +78,19 @@ done:
         LONG_S          zero,(t0)
 #endif
 
+#ifdef CONFIG_CPU_CAVIUM_OCTEON
+        /* We need to flush I-cache before jumping to new kernel.
+         * Unfortunatelly, this code is cpu-specific.
+         */
+        .set push
+        .set noreorder
+        syncw
+        syncw
+        synci           0($0)
+        .set pop
+#else
         sync
+#endif
         /* jump to kexec_start_address */
         j               s1
         END(relocate_new_kernel)
@@ -110,7 +122,14 @@ LEAF(kexec_smp_wait)
 1:      LONG_L          s0, (t0)
         bne             s0, zero,1b
 
+#ifdef CONFIG_CPU_CAVIUM_OCTEON
+        .set push
+        .set noreorder
+        synci           0($0)
+        .set pop
+#else
         sync
+#endif
         j               s1
         END(kexec_smp_wait)
 #endif