Merge tag 'riscv-for-linus-5.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux

Pull RISC-V fixes from Palmer Dabbelt:
 "This contains a handful of mostly-independent patches:

   - make our port respect TIF_NEED_RESCHED, which fixes
     CONFIG_PREEMPT=y kernels

   - fix double-put of OF nodes

   - fix a misspelling of target in our Kconfig

   - generic PCIe is enabled in our defconfig

   - fix our SBI early console to properly handle line
     endings

   - fix max_low_pfn being counted in PFNs

   - a change to TASK_UNMAPPED_BASE to match what other
     arches do

  This has passed my standard 'boot Fedora' flow"

* tag 'riscv-for-linus-5.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/riscv-linux:
  riscv: Adjust mmap base address at a third of task size
  riscv: fixup max_low_pfn with PFN_DOWN.
  tty/serial: use uart_console_write in the RISC-V SBL early console
  RISC-V: defconfig: Add CRYPTO_DEV_VIRTIO=y
  RISC-V: defconfig: Enable Generic PCIE by default
  RISC-V: defconfig: Move CONFIG_PCI{,E_XILINX}
  RISC-V: Kconfig: fix spelling mistake "traget" -> "target"
  RISC-V: asm/page.h: fix spelling mistake "CONFIG_64BITS" -> "CONFIG_64BIT"
  RISC-V: fix bad use of of_node_put
  RISC-V: Add _TIF_NEED_RESCHED check for kernel thread when CONFIG_PREEMPT=y

arch/riscv/Kconfig

@@ -103,7 +103,7 @@ choice
 	prompt "Base ISA"
 	default ARCH_RV64I
 	help
-	  This selects the base ISA that this kernel will traget and must match
+	  This selects the base ISA that this kernel will target and must match
 	  the target platform.
 
 config ARCH_RV32I

arch/riscv/configs/defconfig

@@ -13,8 +13,6 @@ CONFIG_BLK_DEV_INITRD=y
 CONFIG_EXPERT=y
 CONFIG_BPF_SYSCALL=y
 CONFIG_SMP=y
-CONFIG_PCI=y
-CONFIG_PCIE_XILINX=y
 CONFIG_MODULES=y
 CONFIG_MODULE_UNLOAD=y
 CONFIG_NET=y
@@ -28,6 +26,10 @@ CONFIG_IP_PNP_DHCP=y
 CONFIG_IP_PNP_BOOTP=y
 CONFIG_IP_PNP_RARP=y
 CONFIG_NETLINK_DIAG=y
+CONFIG_PCI=y
+CONFIG_PCIEPORTBUS=y
+CONFIG_PCI_HOST_GENERIC=y
+CONFIG_PCIE_XILINX=y
 CONFIG_DEVTMPFS=y
 CONFIG_BLK_DEV_LOOP=y
 CONFIG_VIRTIO_BLK=y
@@ -63,7 +65,6 @@ CONFIG_USB_STORAGE=y
 CONFIG_USB_UAS=y
 CONFIG_VIRTIO_MMIO=y
 CONFIG_SIFIVE_PLIC=y
-CONFIG_RAS=y
 CONFIG_EXT4_FS=y
 CONFIG_EXT4_FS_POSIX_ACL=y
 CONFIG_AUTOFS4_FS=y
@@ -77,5 +78,6 @@ CONFIG_NFS_V4_1=y
 CONFIG_NFS_V4_2=y
 CONFIG_ROOT_NFS=y
 CONFIG_CRYPTO_USER_API_HASH=y
+CONFIG_CRYPTO_DEV_VIRTIO=y
 CONFIG_PRINTK_TIME=y
 # CONFIG_RCU_TRACE is not set

arch/riscv/include/asm/page.h

@@ -80,7 +80,7 @@ typedef struct page *pgtable_t;
 #define __pgd(x)	((pgd_t) { (x) })
 #define __pgprot(x)	((pgprot_t) { (x) })
 
-#ifdef CONFIG_64BITS
+#ifdef CONFIG_64BIT
 #define PTE_FMT "%016lx"
 #else
 #define PTE_FMT "%08lx"

arch/riscv/include/asm/processor.h

@@ -22,7 +22,7 @@
  * This decides where the kernel will search for a free chunk of vm
  * space during mmap's.
  */
-#define TASK_UNMAPPED_BASE	PAGE_ALIGN(TASK_SIZE >> 1)
+#define TASK_UNMAPPED_BASE	PAGE_ALIGN(TASK_SIZE / 3)
 
 #define STACK_TOP		TASK_SIZE
 #define STACK_TOP_MAX		STACK_TOP

arch/riscv/kernel/asm-offsets.c

@@ -39,6 +39,7 @@ void asm_offsets(void)
 	OFFSET(TASK_STACK, task_struct, stack);
 	OFFSET(TASK_TI, task_struct, thread_info);
 	OFFSET(TASK_TI_FLAGS, task_struct, thread_info.flags);
+	OFFSET(TASK_TI_PREEMPT_COUNT, task_struct, thread_info.preempt_count);
 	OFFSET(TASK_TI_KERNEL_SP, task_struct, thread_info.kernel_sp);
 	OFFSET(TASK_TI_USER_SP, task_struct, thread_info.user_sp);
 	OFFSET(TASK_TI_CPU, task_struct, thread_info.cpu);

arch/riscv/kernel/entry.S

@@ -144,6 +144,10 @@ _save_context:
 	REG_L x2,  PT_SP(sp)
 	.endm
 
+#if !IS_ENABLED(CONFIG_PREEMPT)
+.set resume_kernel, restore_all
+#endif
+
 ENTRY(handle_exception)
 	SAVE_ALL
 
@@ -228,7 +232,7 @@ ret_from_exception:
 	REG_L s0, PT_SSTATUS(sp)
 	csrc sstatus, SR_SIE
 	andi s0, s0, SR_SPP
-	bnez s0, restore_all
+	bnez s0, resume_kernel
 
 resume_userspace:
 	/* Interrupts must be disabled here so flags are checked atomically */
@@ -250,6 +254,18 @@ restore_all:
 	RESTORE_ALL
 	sret
 
+#if IS_ENABLED(CONFIG_PREEMPT)
+resume_kernel:
+	REG_L s0, TASK_TI_PREEMPT_COUNT(tp)
+	bnez s0, restore_all
+need_resched:
+	REG_L s0, TASK_TI_FLAGS(tp)
+	andi s0, s0, _TIF_NEED_RESCHED
+	beqz s0, restore_all
+	call preempt_schedule_irq
+	j need_resched
+#endif
+
 work_pending:
 	/* Enter slow path for supplementary processing */
 	la ra, ret_from_exception

arch/riscv/kernel/setup.c

@@ -181,7 +181,7 @@ static void __init setup_bootmem(void)
 	BUG_ON(mem_size == 0);
 
 	set_max_mapnr(PFN_DOWN(mem_size));
-	max_low_pfn = memblock_end_of_DRAM();
+	max_low_pfn = PFN_DOWN(memblock_end_of_DRAM());
 
 #ifdef CONFIG_BLK_DEV_INITRD
 	setup_initrd();

arch/riscv/kernel/smpboot.c

@@ -57,15 +57,12 @@ void __init setup_smp(void)
 
 	while ((dn = of_find_node_by_type(dn, "cpu"))) {
 		hart = riscv_of_processor_hartid(dn);
-		if (hart < 0) {
-			of_node_put(dn);
+		if (hart < 0)
 			continue;
-		}
 
 		if (hart == cpuid_to_hartid_map(0)) {
 			BUG_ON(found_boot_cpu);
 			found_boot_cpu = 1;
-			of_node_put(dn);
 			continue;
 		}
 
@@ -73,7 +70,6 @@ void __init setup_smp(void)
 		set_cpu_possible(cpuid, true);
 		set_cpu_present(cpuid, true);
 		cpuid++;
-		of_node_put(dn);
 	}
 
 	BUG_ON(!found_boot_cpu);

arch/riscv/mm/init.c

@@ -28,7 +28,8 @@ static void __init zone_sizes_init(void)
 	unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
 
 #ifdef CONFIG_ZONE_DMA32
-	max_zone_pfns[ZONE_DMA32] = PFN_DOWN(min(4UL * SZ_1G, max_low_pfn));
+	max_zone_pfns[ZONE_DMA32] = PFN_DOWN(min(4UL * SZ_1G,
+			(unsigned long) PFN_PHYS(max_low_pfn)));
 #endif
 	max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 

drivers/tty/serial/earlycon-riscv-sbi.c

@@ -10,13 +10,16 @@
 #include <linux/serial_core.h>
 #include <asm/sbi.h>
 
-static void sbi_console_write(struct console *con,
-			      const char *s, unsigned int n)
+static void sbi_putc(struct uart_port *port, int c)
 {
-	int i;
+	sbi_console_putchar(c);
+}
 
-	for (i = 0; i < n; ++i)
-		sbi_console_putchar(s[i]);
+static void sbi_console_write(struct console *con,
+			      const char *s, unsigned n)
+{
+	struct earlycon_device *dev = con->data;
+	uart_console_write(&dev->port, s, n, sbi_putc);
 }
 
 static int __init early_sbi_setup(struct earlycon_device *device,