[PATCH AUTOSEL 5.4 05/37] powerpc: dts: t104xrdb: fix phy type for FMAN 4/5

[PATCH AUTOSEL 5.4 05/37] powerpc: dts: t104xrdb: fix phy type for FMAN 4/5

[Sasha Levin]

From: Maxim Kiselev <bigunclemax@gmail.com>

[ Upstream commit 17846485dff91acce1ad47b508b633dffc32e838 ]

T1040RDB has two RTL8211E-VB phys which requires setting
of internal delays for correct work.

Changing the phy-connection-type property to `rgmii-id`
will fix this issue.

Signed-off-by: Maxim Kiselev <bigunclemax@gmail.com>
Reviewed-by: Maxim Kochetkov <fido_max@inbox.ru>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211230151123.1258321-1-bigunclemax@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/boot/dts/fsl/t104xrdb.dtsi | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/boot/dts/fsl/t104xrdb.dtsi b/arch/powerpc/boot/dts/fsl/t104xrdb.dtsi
index 099a598c74c0..bfe1ed5be337 100644
--- a/arch/powerpc/boot/dts/fsl/t104xrdb.dtsi
+++ b/arch/powerpc/boot/dts/fsl/t104xrdb.dtsi
@@ -139,12 +139,12 @@ pca9546@77 {
 		fman@400000 {
 			ethernet@e6000 {
 				phy-handle = <&phy_rgmii_0>;
-				phy-connection-type = "rgmii";
+				phy-connection-type = "rgmii-id";
 			};
 
 			ethernet@e8000 {
 				phy-handle = <&phy_rgmii_1>;
-				phy-connection-type = "rgmii";
+				phy-connection-type = "rgmii-id";
 			};
 
 			mdio0: mdio@fc000 {
-- 
2.34.1

[PATCH AUTOSEL 5.4 11/37] powerpc: Set crashkernel offset to mid of RMA region

[Sasha Levin]

From: Sourabh Jain <sourabhjain@linux.ibm.com>

[ Upstream commit 7c5ed82b800d8615cdda00729e7b62e5899f0b13 ]

On large config LPARs (having 192 and more cores), Linux fails to boot
due to insufficient memory in the first memblock. It is due to the
memory reservation for the crash kernel which starts at 128MB offset of
the first memblock. This memory reservation for the crash kernel doesn't
leave enough space in the first memblock to accommodate other essential
system resources.

The crash kernel start address was set to 128MB offset by default to
ensure that the crash kernel get some memory below the RMA region which
is used to be of size 256MB. But given that the RMA region size can be
512MB or more, setting the crash kernel offset to mid of RMA size will
leave enough space for the kernel to allocate memory for other system
resources.

Since the above crash kernel offset change is only applicable to the LPAR
platform, the LPAR feature detection is pushed before the crash kernel
reservation. The rest of LPAR specific initialization will still
be done during pseries_probe_fw_features as usual.

This patch is dependent on changes to paca allocation for boot CPU. It
expect boot CPU to discover 1T segment support which is introduced by
the patch posted here:
https://lists.ozlabs.org/pipermail/linuxppc-dev/2022-January/239175.html

Reported-by: Abdul haleem <abdhalee@linux.vnet.ibm.com>
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220204085601.107257-1-sourabhjain@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/kernel/machine_kexec.c | 15 +++++++++++----
 arch/powerpc/kernel/rtas.c          |  6 ++++++
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kernel/machine_kexec.c b/arch/powerpc/kernel/machine_kexec.c
index 7a1c11a7cba5..716f8bb17461 100644
--- a/arch/powerpc/kernel/machine_kexec.c
+++ b/arch/powerpc/kernel/machine_kexec.c
@@ -146,11 +146,18 @@ void __init reserve_crashkernel(void)
 	if (!crashk_res.start) {
 #ifdef CONFIG_PPC64
 		/*
-		 * On 64bit we split the RMO in half but cap it at half of
-		 * a small SLB (128MB) since the crash kernel needs to place
-		 * itself and some stacks to be in the first segment.
+		 * On the LPAR platform place the crash kernel to mid of
+		 * RMA size (512MB or more) to ensure the crash kernel
+		 * gets enough space to place itself and some stack to be
+		 * in the first segment. At the same time normal kernel
+		 * also get enough space to allocate memory for essential
+		 * system resource in the first segment. Keep the crash
+		 * kernel starts at 128MB offset on other platforms.
 		 */
-		crashk_res.start = min(0x8000000ULL, (ppc64_rma_size / 2));
+		if (firmware_has_feature(FW_FEATURE_LPAR))
+			crashk_res.start = ppc64_rma_size / 2;
+		else
+			crashk_res.start = min(0x8000000ULL, (ppc64_rma_size / 2));
 #else
 		crashk_res.start = KDUMP_KERNELBASE;
 #endif
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index c1e2e351ebff..9392661ac8a8 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -1244,6 +1244,12 @@ int __init early_init_dt_scan_rtas(unsigned long node,
 	entryp = of_get_flat_dt_prop(node, "linux,rtas-entry", NULL);
 	sizep  = of_get_flat_dt_prop(node, "rtas-size", NULL);
 
+#ifdef CONFIG_PPC64
+	/* need this feature to decide the crashkernel offset */
+	if (of_get_flat_dt_prop(node, "ibm,hypertas-functions", NULL))
+		powerpc_firmware_features |= FW_FEATURE_LPAR;
+#endif
+
 	if (basep && entryp && sizep) {
 		rtas.base = *basep;
 		rtas.entry = *entryp;
-- 
2.34.1

[PATCH AUTOSEL 5.4 30/37] powerpc/code-patching: Pre-map patch area

[Sasha Levin]

From: Michael Ellerman <mpe@ellerman.id.au>

[ Upstream commit 591b4b268435f00d2f0b81f786c2c7bd5ef66416 ]

Paul reported a warning with DEBUG_ATOMIC_SLEEP=y:

  BUG: sleeping function called from invalid context at include/linux/sched/mm.h:256
  in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 1, name: swapper/0
  preempt_count: 0, expected: 0
  ...
  Call Trace:
    dump_stack_lvl+0xa0/0xec (unreliable)
    __might_resched+0x2f4/0x310
    kmem_cache_alloc+0x220/0x4b0
    __pud_alloc+0x74/0x1d0
    hash__map_kernel_page+0x2cc/0x390
    do_patch_instruction+0x134/0x4a0
    arch_jump_label_transform+0x64/0x78
    __jump_label_update+0x148/0x180
    static_key_enable_cpuslocked+0xd0/0x120
    static_key_enable+0x30/0x50
    check_kvm_guest+0x60/0x88
    pSeries_smp_probe+0x54/0xb0
    smp_prepare_cpus+0x3e0/0x430
    kernel_init_freeable+0x20c/0x43c
    kernel_init+0x30/0x1a0
    ret_from_kernel_thread+0x5c/0x64

Peter pointed out that this is because do_patch_instruction() has
disabled interrupts, but then map_patch_area() calls map_kernel_page()
then hash__map_kernel_page() which does a sleeping memory allocation.

We only see the warning in KVM guests with SMT enabled, which is not
particularly common, or on other platforms if CONFIG_KPROBES is
disabled, also not common. The reason we don't see it in most
configurations is that another path that happens to have interrupts
enabled has allocated the required page tables for us, eg. there's a
path in kprobes init that does that. That's just pure luck though.

As Christophe suggested, the simplest solution is to do a dummy
map/unmap when we initialise the patching, so that any required page
table levels are pre-allocated before the first call to
do_patch_instruction(). This works because the unmap doesn't free any
page tables that were allocated by the map, it just clears the PTE,
leaving the page table levels there for the next map.

Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Debugged-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220223015821.473097-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/lib/code-patching.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index a05f289e613e..e417d4470397 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -41,9 +41,14 @@ int raw_patch_instruction(unsigned int *addr, unsigned int instr)
 #ifdef CONFIG_STRICT_KERNEL_RWX
 static DEFINE_PER_CPU(struct vm_struct *, text_poke_area);
 
+static int map_patch_area(void *addr, unsigned long text_poke_addr);
+static void unmap_patch_area(unsigned long addr);
+
 static int text_area_cpu_up(unsigned int cpu)
 {
 	struct vm_struct *area;
+	unsigned long addr;
+	int err;
 
 	area = get_vm_area(PAGE_SIZE, VM_ALLOC);
 	if (!area) {
@@ -51,6 +56,15 @@ static int text_area_cpu_up(unsigned int cpu)
 			cpu);
 		return -1;
 	}
+
+	// Map/unmap the area to ensure all page tables are pre-allocated
+	addr = (unsigned long)area->addr;
+	err = map_patch_area(empty_zero_page, addr);
+	if (err)
+		return err;
+
+	unmap_patch_area(addr);
+
 	this_cpu_write(text_poke_area, area);
 
 	return 0;
-- 
2.34.1