powerpc fixes for 4.3

- Fix 32-bit TCE table init in kdump kernel from Nish
  - Fix kdump with non-power-of-2 crashkernel= from Nish
  - Abort cxl_pci_enable_device_hook() if PCI channel is offline from Andrew
  - Fix to release DRC when configure_connector() fails from Bharata
  - Wire up sys_userfaultfd()
  - Fix race condition in tearing down MSI interrupts from Paul
  - Fix unbalanced pci_dev_get() in cxl_probe() from Daniel
  - Fix cxl build failure due to -Wunused-variable gcc behaviour change from Ian
  - Tell the toolchain to use ABI v2 when building an LE boot wrapper from Benh
  - Fix THP to recompute hash value after a failed update from Aneesh
  - 32-bit memcpy/memset: only use dcbz once cache is enabled from Christophe
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Merge tag 'powerpc-4.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:

 - Fix 32-bit TCE table init in kdump kernel from Nish

 - Fix kdump with non-power-of-2 crashkernel= from Nish

 - Abort cxl_pci_enable_device_hook() if PCI channel is offline from
   Andrew

 - Fix to release DRC when configure_connector() fails from Bharata

 - Wire up sys_userfaultfd()

 - Fix race condition in tearing down MSI interrupts from Paul

 - Fix unbalanced pci_dev_get() in cxl_probe() from Daniel

 - Fix cxl build failure due to -Wunused-variable gcc behaviour change
   from Ian

 - Tell the toolchain to use ABI v2 when building an LE boot wrapper
   from Benh

 - Fix THP to recompute hash value after a failed update from Aneesh

 - 32-bit memcpy/memset: only use dcbz once cache is enabled from
   Christophe

* tag 'powerpc-4.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc32: memset: only use dcbz once cache is enabled
  powerpc32: memcpy: only use dcbz once cache is enabled
  powerpc/mm: Recompute hash value after a failed update
  powerpc/boot: Specify ABI v2 when building an LE boot wrapper
  cxl: Fix build failure due to -Wunused-variable behaviour change
  cxl: Fix unbalanced pci_dev_get in cxl_probe
  powerpc/MSI: Fix race condition in tearing down MSI interrupts
  powerpc: Wire up sys_userfaultfd()
  powerpc/pseries: Release DRC when configure_connector fails
  cxl: abort cxl_pci_enable_device_hook() if PCI channel is offline
  powerpc/powernv/pci-ioda: fix kdump with non-power-of-2 crashkernel=
  powerpc/powernv/pci-ioda: fix 32-bit TCE table init in kdump kernel

arch/powerpc/boot/Makefile

@@ -28,6 +28,9 @@ BOOTCFLAGS	+= -m64
 endif
 ifdef CONFIG_CPU_BIG_ENDIAN
 BOOTCFLAGS	+= -mbig-endian
+else
+BOOTCFLAGS	+= -mlittle-endian
+BOOTCFLAGS	+= $(call cc-option,-mabi=elfv2)
 endif
 
 BOOTAFLAGS	:= -D__ASSEMBLY__ $(BOOTCFLAGS) -traditional -nostdinc

arch/powerpc/include/asm/systbl.h

@@ -368,3 +368,4 @@ SYSCALL_SPU(memfd_create)
 SYSCALL_SPU(bpf)
 COMPAT_SYS(execveat)
 PPC64ONLY(switch_endian)
+SYSCALL_SPU(userfaultfd)

arch/powerpc/include/asm/unistd.h

@@ -12,7 +12,7 @@
 #include <uapi/asm/unistd.h>
 
 
-#define __NR_syscalls		364
+#define __NR_syscalls		365
 
 #define __NR__exit __NR_exit
 #define NR_syscalls	__NR_syscalls

arch/powerpc/include/uapi/asm/unistd.h

@@ -386,5 +386,6 @@
 #define __NR_bpf		361
 #define __NR_execveat		362
 #define __NR_switch_endian	363
+#define __NR_userfaultfd	364
 
 #endif /* _UAPI_ASM_POWERPC_UNISTD_H_ */

arch/powerpc/kernel/setup_32.c

@@ -38,6 +38,7 @@
 #include <asm/udbg.h>
 #include <asm/mmu_context.h>
 #include <asm/epapr_hcalls.h>
+#include <asm/code-patching.h>
 
 #define DBG(fmt...)
 
@@ -109,6 +110,8 @@ notrace unsigned long __init early_init(unsigned long dt_ptr)
  * This is called very early on the boot process, after a minimal
  * MMU environment has been set up but before MMU_init is called.
  */
+extern unsigned int memset_nocache_branch; /* Insn to be replaced by NOP */
+
 notrace void __init machine_init(u64 dt_ptr)
 {
 	lockdep_init();
@@ -116,6 +119,9 @@ notrace void __init machine_init(u64 dt_ptr)
 	/* Enable early debugging if any specified (see udbg.h) */
 	udbg_early_init();
 
+	patch_instruction((unsigned int *)&memcpy, PPC_INST_NOP);
+	patch_instruction(&memset_nocache_branch, PPC_INST_NOP);
+
 	/* Do some early initialization based on the flat device tree */
 	early_init_devtree(__va(dt_ptr));
 

arch/powerpc/lib/copy_32.S

@@ -73,6 +73,10 @@ CACHELINE_MASK = (L1_CACHE_BYTES-1)
  * Use dcbz on the complete cache lines in the destination
  * to set them to zero.  This requires that the destination
  * area is cacheable.  -- paulus
+ *
+ * During early init, cache might not be active yet, so dcbz cannot be used.
+ * We therefore skip the optimised bloc that uses dcbz. This jump is
+ * replaced by a nop once cache is active. This is done in machine_init()
  */
 _GLOBAL(memset)
 	rlwimi	r4,r4,8,16,23
@@ -88,6 +92,8 @@ _GLOBAL(memset)
 	subf	r6,r0,r6
 	cmplwi	0,r4,0
 	bne	2f	/* Use normal procedure if r4 is not zero */
+_GLOBAL(memset_nocache_branch)
+	b	2f	/* Skip optimised bloc until cache is enabled */
 
 	clrlwi	r7,r6,32-LG_CACHELINE_BYTES
 	add	r8,r7,r5
@@ -128,6 +134,10 @@ _GLOBAL(memset)
  * the destination area is cacheable.
  * We only use this version if the source and dest don't overlap.
  * -- paulus.
+ *
+ * During early init, cache might not be active yet, so dcbz cannot be used.
+ * We therefore jump to generic_memcpy which doesn't use dcbz. This jump is
+ * replaced by a nop once cache is active. This is done in machine_init()
  */
 _GLOBAL(memmove)
 	cmplw	0,r3,r4
@@ -135,6 +145,7 @@ _GLOBAL(memmove)
 	/* fall through */
 
 _GLOBAL(memcpy)
+	b	generic_memcpy
 	add	r7,r3,r5		/* test if the src & dst overlap */
 	add	r8,r4,r5
 	cmplw	0,r4,r7

arch/powerpc/mm/hugepage-hash64.c

@@ -85,7 +85,6 @@ int __hash_page_thp(unsigned long ea, unsigned long access, unsigned long vsid,
 	BUG_ON(index >= 4096);
 
 	vpn = hpt_vpn(ea, vsid, ssize);
-	hash = hpt_hash(vpn, shift, ssize);
 	hpte_slot_array = get_hpte_slot_array(pmdp);
 	if (psize == MMU_PAGE_4K) {
 		/*
@@ -101,6 +100,7 @@ int __hash_page_thp(unsigned long ea, unsigned long access, unsigned long vsid,
 	valid = hpte_valid(hpte_slot_array, index);
 	if (valid) {
 		/* update the hpte bits */
+		hash = hpt_hash(vpn, shift, ssize);
 		hidx =  hpte_hash_index(hpte_slot_array, index);
 		if (hidx & _PTEIDX_SECONDARY)
 			hash = ~hash;
@@ -126,6 +126,7 @@ int __hash_page_thp(unsigned long ea, unsigned long access, unsigned long vsid,
 	if (!valid) {
 		unsigned long hpte_group;
 
+		hash = hpt_hash(vpn, shift, ssize);
 		/* insert new entry */
 		pa = pmd_pfn(__pmd(old_pmd)) << PAGE_SHIFT;
 		new_pmd |= _PAGE_HASHPTE;

arch/powerpc/platforms/pasemi/msi.c

@@ -63,6 +63,7 @@ static struct irq_chip mpic_pasemi_msi_chip = {
 static void pasemi_msi_teardown_msi_irqs(struct pci_dev *pdev)
 {
 	struct msi_desc *entry;
+	irq_hw_number_t hwirq;
 
 	pr_debug("pasemi_msi_teardown_msi_irqs, pdev %p\n", pdev);
 
@@ -70,10 +71,10 @@ static void pasemi_msi_teardown_msi_irqs(struct pci_dev *pdev)
 		if (entry->irq == NO_IRQ)
 			continue;
 
+		hwirq = virq_to_hw(entry->irq);
 		irq_set_msi_desc(entry->irq, NULL);
-		msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap,
-				       virq_to_hw(entry->irq), ALLOC_CHUNK);
 		irq_dispose_mapping(entry->irq);
+		msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap, hwirq, ALLOC_CHUNK);
 	}
 
 	return;

arch/powerpc/platforms/powernv/pci-ioda.c

@@ -2049,9 +2049,23 @@ static long pnv_pci_ioda2_setup_default_config(struct pnv_ioda_pe *pe)
 	struct iommu_table *tbl = NULL;
 	long rc;
 
+	/*
+	 * crashkernel= specifies the kdump kernel's maximum memory at
+	 * some offset and there is no guaranteed the result is a power
+	 * of 2, which will cause errors later.
+	 */
+	const u64 max_memory = __rounddown_pow_of_two(memory_hotplug_max());
+
+	/*
+	 * In memory constrained environments, e.g. kdump kernel, the
+	 * DMA window can be larger than available memory, which will
+	 * cause errors later.
+	 */
+	const u64 window_size = min((u64)pe->table_group.tce32_size, max_memory);
+
 	rc = pnv_pci_ioda2_create_table(&pe->table_group, 0,
 			IOMMU_PAGE_SHIFT_4K,
-			pe->table_group.tce32_size,
+			window_size,
 			POWERNV_IOMMU_DEFAULT_LEVELS, &tbl);
 	if (rc) {
 		pe_err(pe, "Failed to create 32-bit TCE table, err %ld",

arch/powerpc/platforms/powernv/pci.c

@@ -99,6 +99,7 @@ void pnv_teardown_msi_irqs(struct pci_dev *pdev)
 	struct pci_controller *hose = pci_bus_to_host(pdev->bus);
 	struct pnv_phb *phb = hose->private_data;
 	struct msi_desc *entry;
+	irq_hw_number_t hwirq;
 
 	if (WARN_ON(!phb))
 		return;
@@ -106,10 +107,10 @@ void pnv_teardown_msi_irqs(struct pci_dev *pdev)
 	for_each_pci_msi_entry(entry, pdev) {
 		if (entry->irq == NO_IRQ)
 			continue;
+		hwirq = virq_to_hw(entry->irq);
 		irq_set_msi_desc(entry->irq, NULL);
-		msi_bitmap_free_hwirqs(&phb->msi_bmp,
-			virq_to_hw(entry->irq) - phb->msi_base, 1);
 		irq_dispose_mapping(entry->irq);
+		msi_bitmap_free_hwirqs(&phb->msi_bmp, hwirq - phb->msi_base, 1);
 	}
 }
 #endif /* CONFIG_PCI_MSI */

arch/powerpc/platforms/pseries/dlpar.c

@@ -422,8 +422,10 @@ static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
 
 	dn = dlpar_configure_connector(cpu_to_be32(drc_index), parent);
 	of_node_put(parent);
-	if (!dn)
+	if (!dn) {
+		dlpar_release_drc(drc_index);
 		return -EINVAL;
+	}
 
 	rc = dlpar_attach_node(dn);
 	if (rc) {

arch/powerpc/sysdev/fsl_msi.c

@@ -128,15 +128,16 @@ static void fsl_teardown_msi_irqs(struct pci_dev *pdev)
 {
 	struct msi_desc *entry;
 	struct fsl_msi *msi_data;
+	irq_hw_number_t hwirq;
 
 	for_each_pci_msi_entry(entry, pdev) {
 		if (entry->irq == NO_IRQ)
 			continue;
+		hwirq = virq_to_hw(entry->irq);
 		msi_data = irq_get_chip_data(entry->irq);
 		irq_set_msi_desc(entry->irq, NULL);
-		msi_bitmap_free_hwirqs(&msi_data->bitmap,
-				       virq_to_hw(entry->irq), 1);
 		irq_dispose_mapping(entry->irq);
+		msi_bitmap_free_hwirqs(&msi_data->bitmap, hwirq, 1);
 	}
 
 	return;

arch/powerpc/sysdev/mpic_u3msi.c

@@ -107,15 +107,16 @@ static u64 find_u4_magic_addr(struct pci_dev *pdev, unsigned int hwirq)
 static void u3msi_teardown_msi_irqs(struct pci_dev *pdev)
 {
 	struct msi_desc *entry;
+	irq_hw_number_t hwirq;
 
 	for_each_pci_msi_entry(entry, pdev) {
 		if (entry->irq == NO_IRQ)
 			continue;
 
+		hwirq = virq_to_hw(entry->irq);
 		irq_set_msi_desc(entry->irq, NULL);
-		msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap,
-				       virq_to_hw(entry->irq), 1);
 		irq_dispose_mapping(entry->irq);
+		msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap, hwirq, 1);
 	}
 
 	return;

arch/powerpc/sysdev/ppc4xx_msi.c

@@ -124,16 +124,17 @@ void ppc4xx_teardown_msi_irqs(struct pci_dev *dev)
 {
 	struct msi_desc *entry;
 	struct ppc4xx_msi *msi_data = &ppc4xx_msi;
+	irq_hw_number_t hwirq;
 
 	dev_dbg(&dev->dev, "PCIE-MSI: tearing down msi irqs\n");
 
 	for_each_pci_msi_entry(entry, dev) {
 		if (entry->irq == NO_IRQ)
 			continue;
+		hwirq = virq_to_hw(entry->irq);
 		irq_set_msi_desc(entry->irq, NULL);
-		msi_bitmap_free_hwirqs(&msi_data->bitmap,
-				virq_to_hw(entry->irq), 1);
 		irq_dispose_mapping(entry->irq);
+		msi_bitmap_free_hwirqs(&msi_data->bitmap, hwirq, 1);
 	}
 }
 

drivers/misc/cxl/Makefile

@@ -1,4 +1,4 @@
-ccflags-y := -Werror
+ccflags-y := -Werror -Wno-unused-const-variable
 
 cxl-y				+= main.o file.o irq.o fault.o native.o
 cxl-y				+= context.o sysfs.o debugfs.o pci.o trace.o

drivers/misc/cxl/pci.c

@@ -1249,8 +1249,6 @@ static int cxl_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	int slice;
 	int rc;
 
-	pci_dev_get(dev);
-
 	if (cxl_verbose)
 		dump_cxl_config_space(dev);
 

drivers/misc/cxl/vphb.c

@@ -48,6 +48,12 @@ static bool cxl_pci_enable_device_hook(struct pci_dev *dev)
 
 	phb = pci_bus_to_host(dev->bus);
 	afu = (struct cxl_afu *)phb->private_data;
+
+	if (!cxl_adapter_link_ok(afu->adapter)) {
+		dev_warn(&dev->dev, "%s: Device link is down, refusing to enable AFU\n", __func__);
+		return false;
+	}
+
 	set_dma_ops(&dev->dev, &dma_direct_ops);
 	set_dma_offset(&dev->dev, PAGE_OFFSET);