powerpc fixes for 4.20 #4

One notable fix for our change to split pt_regs between user/kernel, we forgot
 to update BPF to use the user-visible type which was an ABI break for BPF
 programs.
 
 A slightly ugly but minimal fix to do_syscall_trace_enter() so that we use
 tracehook_report_syscall_entry() properly. We'll rework the code in next to
 avoid the empty if body.
 
 Seven commits fixing bugs in the new papr_scm (Storage Class Memory) driver.
 The driver was finally able to be tested on the other hypervisor which exposed
 several bugs. The fixes are all fairly minimal at least.
 
 Fix a crash in our MSI code if an MSI-capable device is plugged into a non-MSI
 capable PHB, only seen on older hardware (MPC8378).
 
 Fix our legacy serial code to look for "stdout-path" since the device trees were
 updated to use that instead of "linux,stdout-path".
 
 A change to the COFF zImage code to fix booting old powermacs.
 
 A couple of minor build fixes.
 
 Thanks to:
   Benjamin Herrenschmidt, Daniel Axtens, Dmitry V. Levin, Elvira Khabirova,
   Oliver O'Halloran, Paul Mackerras, Radu Rendec, Rob Herring, Sandipan Das.
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Merge tag 'powerpc-4.20-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "One notable fix for our change to split pt_regs between user/kernel,
  we forgot to update BPF to use the user-visible type which was an ABI
  break for BPF programs.

  A slightly ugly but minimal fix to do_syscall_trace_enter() so that we
  use tracehook_report_syscall_entry() properly. We'll rework the code
  in next to avoid the empty if body.

  Seven commits fixing bugs in the new papr_scm (Storage Class Memory)
  driver. The driver was finally able to be tested on the other
  hypervisor which exposed several bugs. The fixes are all fairly
  minimal at least.

  Fix a crash in our MSI code if an MSI-capable device is plugged into a
  non-MSI capable PHB, only seen on older hardware (MPC8378).

  Fix our legacy serial code to look for "stdout-path" since the device
  trees were updated to use that instead of "linux,stdout-path".

  A change to the COFF zImage code to fix booting old powermacs.

  A couple of minor build fixes.

  Thanks to: Benjamin Herrenschmidt, Daniel Axtens, Dmitry V. Levin,
  Elvira Khabirova, Oliver O'Halloran, Paul Mackerras, Radu Rendec, Rob
  Herring, Sandipan Das"

* tag 'powerpc-4.20-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/ptrace: replace ptrace_report_syscall() with a tracehook call
  powerpc/mm: Fallback to RAM if the altmap is unusable
  powerpc/papr_scm: Use ibm,unit-guid as the iset cookie
  powerpc/papr_scm: Fix DIMM device registration race
  powerpc/papr_scm: Remove endian conversions
  powerpc/papr_scm: Update DT properties
  powerpc/papr_scm: Fix resource end address
  powerpc/papr_scm: Use depend instead of select
  powerpc/bpf: Fix broken uapi for BPF_PROG_TYPE_PERF_EVENT
  powerpc/boot: Fix build failures with -j 1
  powerpc: Look for "stdout-path" when setting up legacy consoles
  powerpc/msi: Fix NULL pointer access in teardown code
  powerpc/mm: Fix linux page tables build with some configs
  powerpc: Fix COFF zImage booting on old powermacs

arch/powerpc/boot/Makefile

@@ -197,7 +197,7 @@ $(obj)/empty.c:
 $(obj)/zImage.coff.lds $(obj)/zImage.ps3.lds : $(obj)/%: $(srctree)/$(src)/%.S
 	$(Q)cp $< $@
 
-$(obj)/serial.c: $(obj)/autoconf.h
+$(srctree)/$(src)/serial.c: $(obj)/autoconf.h
 
 $(obj)/autoconf.h: $(obj)/%: $(objtree)/include/generated/%
 	$(Q)cp $< $@

arch/powerpc/boot/crt0.S

@@ -15,7 +15,7 @@
 RELA = 7
 RELACOUNT = 0x6ffffff9
 
-	.text
+	.data
 	/* A procedure descriptor used when booting this as a COFF file.
 	 * When making COFF, this comes first in the link and we're
 	 * linked at 0x500000.
@@ -23,6 +23,8 @@ RELACOUNT = 0x6ffffff9
 	.globl	_zimage_start_opd
 _zimage_start_opd:
 	.long	0x500000, 0, 0, 0
+	.text
+	b	_zimage_start
 
 #ifdef __powerpc64__
 .balign 8

arch/powerpc/include/asm/perf_event.h

@@ -26,6 +26,8 @@
 #include <asm/ptrace.h>
 #include <asm/reg.h>
 
+#define perf_arch_bpf_user_pt_regs(regs) &regs->user_regs
+
 /*
  * Overload regs->result to specify whether we should use the MSR (result
  * is zero) or the SIAR (result is non zero).

arch/powerpc/include/uapi/asm/Kbuild

@@ -1,7 +1,6 @@
 # UAPI Header export list
 include include/uapi/asm-generic/Kbuild.asm
 
-generic-y += bpf_perf_event.h
 generic-y += param.h
 generic-y += poll.h
 generic-y += resource.h

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

@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _UAPI__ASM_BPF_PERF_EVENT_H__
+#define _UAPI__ASM_BPF_PERF_EVENT_H__
+
+#include <asm/ptrace.h>
+
+typedef struct user_pt_regs bpf_user_pt_regs_t;
+
+#endif /* _UAPI__ASM_BPF_PERF_EVENT_H__ */

arch/powerpc/kernel/legacy_serial.c

@@ -372,6 +372,8 @@ void __init find_legacy_serial_ports(void)
 
 	/* Now find out if one of these is out firmware console */
 	path = of_get_property(of_chosen, "linux,stdout-path", NULL);
+	if (path == NULL)
+		path = of_get_property(of_chosen, "stdout-path", NULL);
 	if (path != NULL) {
 		stdout = of_find_node_by_path(path);
 		if (stdout)
@@ -595,8 +597,10 @@ static int __init check_legacy_serial_console(void)
 	/* We are getting a weird phandle from OF ... */
 	/* ... So use the full path instead */
 	name = of_get_property(of_chosen, "linux,stdout-path", NULL);
+	if (name == NULL)
+		name = of_get_property(of_chosen, "stdout-path", NULL);
 	if (name == NULL) {
-		DBG(" no linux,stdout-path !\n");
+		DBG(" no stdout-path !\n");
 		return -ENODEV;
 	}
 	prom_stdout = of_find_node_by_path(name);

arch/powerpc/kernel/msi.c

@@ -34,5 +34,10 @@ void arch_teardown_msi_irqs(struct pci_dev *dev)
 {
 	struct pci_controller *phb = pci_bus_to_host(dev->bus);
 
-	phb->controller_ops.teardown_msi_irqs(dev);
+	/*
+	 * We can be called even when arch_setup_msi_irqs() returns -ENOSYS,
+	 * so check the pointer again.
+	 */
+	if (phb->controller_ops.teardown_msi_irqs)
+		phb->controller_ops.teardown_msi_irqs(dev);
 }

arch/powerpc/kernel/ptrace.c

@@ -3266,12 +3266,17 @@ long do_syscall_trace_enter(struct pt_regs *regs)
 	user_exit();
 
 	if (test_thread_flag(TIF_SYSCALL_EMU)) {
-		ptrace_report_syscall(regs);
 		/*
+		 * A nonzero return code from tracehook_report_syscall_entry()
+		 * tells us to prevent the syscall execution, but we are not
+		 * going to execute it anyway.
+		 *
 		 * Returning -1 will skip the syscall execution. We want to
 		 * avoid clobbering any register also, thus, not 'gotoing'
 		 * skip label.
 		 */
+		if (tracehook_report_syscall_entry(regs))
+			;
 		return -1;
 	}
 

arch/powerpc/mm/dump_linuxpagetables.c

@@ -19,6 +19,7 @@
 #include <linux/hugetlb.h>
 #include <linux/io.h>
 #include <linux/mm.h>
+#include <linux/highmem.h>
 #include <linux/sched.h>
 #include <linux/seq_file.h>
 #include <asm/fixmap.h>

arch/powerpc/mm/init_64.c

@@ -188,15 +188,20 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
 	pr_debug("vmemmap_populate %lx..%lx, node %d\n", start, end, node);
 
 	for (; start < end; start += page_size) {
-		void *p;
+		void *p = NULL;
 		int rc;
 
 		if (vmemmap_populated(start, page_size))
 			continue;
 
+		/*
+		 * Allocate from the altmap first if we have one. This may
+		 * fail due to alignment issues when using 16MB hugepages, so
+		 * fall back to system memory if the altmap allocation fail.
+		 */
 		if (altmap)
 			p = altmap_alloc_block_buf(page_size, altmap);
-		else
+		if (!p)
 			p = vmemmap_alloc_block_buf(page_size, node);
 		if (!p)
 			return -ENOMEM;
@@ -255,8 +260,15 @@ void __ref vmemmap_free(unsigned long start, unsigned long end,
 {
 	unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift;
 	unsigned long page_order = get_order(page_size);
+	unsigned long alt_start = ~0, alt_end = ~0;
+	unsigned long base_pfn;
 
 	start = _ALIGN_DOWN(start, page_size);
+	if (altmap) {
+		alt_start = altmap->base_pfn;
+		alt_end = altmap->base_pfn + altmap->reserve +
+			  altmap->free + altmap->alloc + altmap->align;
+	}
 
 	pr_debug("vmemmap_free %lx...%lx\n", start, end);
 
@@ -280,8 +292,9 @@ void __ref vmemmap_free(unsigned long start, unsigned long end,
 		page = pfn_to_page(addr >> PAGE_SHIFT);
 		section_base = pfn_to_page(vmemmap_section_start(start));
 		nr_pages = 1 << page_order;
+		base_pfn = PHYS_PFN(addr);
 
-		if (altmap) {
+		if (base_pfn >= alt_start && base_pfn < alt_end) {
 			vmem_altmap_free(altmap, nr_pages);
 		} else if (PageReserved(page)) {
 			/* allocated from bootmem */

arch/powerpc/platforms/pseries/Kconfig

@@ -140,8 +140,7 @@ config IBMEBUS
 	  Bus device driver for GX bus based adapters.
 
 config PAPR_SCM
-	depends on PPC_PSERIES && MEMORY_HOTPLUG
-	select LIBNVDIMM
+	depends on PPC_PSERIES && MEMORY_HOTPLUG && LIBNVDIMM
 	tristate "Support for the PAPR Storage Class Memory interface"
 	help
 	  Enable access to hypervisor provided storage class memory.

arch/powerpc/platforms/pseries/papr_scm.c

@@ -55,7 +55,7 @@ static int drc_pmem_bind(struct papr_scm_priv *p)
 	do {
 		rc = plpar_hcall(H_SCM_BIND_MEM, ret, p->drc_index, 0,
 				p->blocks, BIND_ANY_ADDR, token);
-		token = be64_to_cpu(ret[0]);
+		token = ret[0];
 		cond_resched();
 	} while (rc == H_BUSY);
 
@@ -64,7 +64,7 @@ static int drc_pmem_bind(struct papr_scm_priv *p)
 		return -ENXIO;
 	}
 
-	p->bound_addr = be64_to_cpu(ret[1]);
+	p->bound_addr = ret[1];
 
 	dev_dbg(&p->pdev->dev, "bound drc %x to %pR\n", p->drc_index, &p->res);
 
@@ -82,7 +82,7 @@ static int drc_pmem_unbind(struct papr_scm_priv *p)
 	do {
 		rc = plpar_hcall(H_SCM_UNBIND_MEM, ret, p->drc_index,
 				p->bound_addr, p->blocks, token);
-		token = be64_to_cpu(ret);
+		token = ret[0];
 		cond_resched();
 	} while (rc == H_BUSY);
 
@@ -223,6 +223,9 @@ static int papr_scm_nvdimm_init(struct papr_scm_priv *p)
 		goto err;
 	}
 
+	if (nvdimm_bus_check_dimm_count(p->bus, 1))
+		goto err;
+
 	/* now add the region */
 
 	memset(&mapping, 0, sizeof(mapping));
@@ -257,9 +260,12 @@ err:	nvdimm_bus_unregister(p->bus);
 
 static int papr_scm_probe(struct platform_device *pdev)
 {
-	uint32_t drc_index, metadata_size, unit_cap[2];
 	struct device_node *dn = pdev->dev.of_node;
+	u32 drc_index, metadata_size;
+	u64 blocks, block_size;
 	struct papr_scm_priv *p;
+	const char *uuid_str;
+	u64 uuid[2];
 	int rc;
 
 	/* check we have all the required DT properties */
@@ -268,8 +274,18 @@ static int papr_scm_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
-	if (of_property_read_u32_array(dn, "ibm,unit-capacity", unit_cap, 2)) {
-		dev_err(&pdev->dev, "%pOF: missing unit-capacity!\n", dn);
+	if (of_property_read_u64(dn, "ibm,block-size", &block_size)) {
+		dev_err(&pdev->dev, "%pOF: missing block-size!\n", dn);
+		return -ENODEV;
+	}
+
+	if (of_property_read_u64(dn, "ibm,number-of-blocks", &blocks)) {
+		dev_err(&pdev->dev, "%pOF: missing number-of-blocks!\n", dn);
+		return -ENODEV;
+	}
+
+	if (of_property_read_string(dn, "ibm,unit-guid", &uuid_str)) {
+		dev_err(&pdev->dev, "%pOF: missing unit-guid!\n", dn);
 		return -ENODEV;
 	}
 
@@ -282,8 +298,13 @@ static int papr_scm_probe(struct platform_device *pdev)
 
 	p->dn = dn;
 	p->drc_index = drc_index;
-	p->block_size = unit_cap[0];
-	p->blocks     = unit_cap[1];
+	p->block_size = block_size;
+	p->blocks = blocks;
+
+	/* We just need to ensure that set cookies are unique across */
+	uuid_parse(uuid_str, (uuid_t *) uuid);
+	p->nd_set.cookie1 = uuid[0];
+	p->nd_set.cookie2 = uuid[1];
 
 	/* might be zero */
 	p->metadata_size = metadata_size;
@@ -296,7 +317,7 @@ static int papr_scm_probe(struct platform_device *pdev)
 
 	/* setup the resource for the newly bound range */
 	p->res.start = p->bound_addr;
-	p->res.end   = p->bound_addr + p->blocks * p->block_size;
+	p->res.end   = p->bound_addr + p->blocks * p->block_size - 1;
 	p->res.name  = pdev->name;
 	p->res.flags = IORESOURCE_MEM;