[PATCH AUTOSEL 4.19 4/6] PCI: dwc: Provide deinit callback for i.MX

[PATCH AUTOSEL 4.19 4/6] PCI: dwc: Provide deinit callback for i.MX

[Sasha Levin]

From: Mark Brown <broonie@kernel.org>

[ Upstream commit fc8b24c28bec19fc0621d108b9ee81ddfdedb25a ]

The i.MX integration for the DesignWare PCI controller has a _host_exit()
operation which undoes everything that the _host_init() operation does but
does not wire this up as the host_deinit callback for the core, or call it
in any path other than suspend. This means that if we ever unwind the
initial probe of the device, for example because it fails, the regulator
core complains that the regulators for the device were left enabled:

imx6q-pcie 33800000.pcie: iATU: unroll T, 4 ob, 4 ib, align 64K, limit 16G
imx6q-pcie 33800000.pcie: Phy link never came up
imx6q-pcie 33800000.pcie: Phy link never came up
imx6q-pcie: probe of 33800000.pcie failed with error -110
------------[ cut here ]------------
WARNING: CPU: 2 PID: 46 at drivers/regulator/core.c:2396 _regulator_put+0x110/0x128

Wire up the callback so that the core can clean up after itself.

Link: https://lore.kernel.org/r/20230731-pci-imx-regulator-cleanup-v2-1-fc8fa5c9893d@kernel.org
Tested-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Richard Zhu <hongxing.zhu@nxp.com>
Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/pci/controller/dwc/pci-imx6.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 3b2ceb5667289..c949d11f95507 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -642,6 +642,7 @@ static int imx6_pcie_host_init(struct pcie_port *pp)
 
 static const struct dw_pcie_host_ops imx6_pcie_host_ops = {
 	.host_init = imx6_pcie_host_init,
+	.host_deinit = imx6_pcie_host_exit,
 };
 
 static int imx6_add_pcie_port(struct imx6_pcie *imx6_pcie,
-- 
2.40.1


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[PATCH AUTOSEL 4.19 5/6] ARM: 9316/1: hw_breakpoint: fix single-stepping when using bpf_overflow_handler

[Sasha Levin]

From: Tomislav Novak <tnovak@fb.com>

[ Upstream commit e6b51532d5273eeefba84106daea3d392c602837 ]

Arm platforms use is_default_overflow_handler() to determine if the
hw_breakpoint code should single-step over the breakpoint trigger or
let the custom handler deal with it.

Since bpf_overflow_handler() currently isn't recognized as a default
handler, attaching a BPF program to a PERF_TYPE_BREAKPOINT event causes
it to keep firing (the instruction triggering the data abort exception
is never skipped). For example:

  # bpftrace -e 'watchpoint:0x10000:4:w { print("hit") }' -c ./test
  Attaching 1 probe...
  hit
  hit
  [...]
  ^C

(./test performs a single 4-byte store to 0x10000)

This patch replaces the check with uses_default_overflow_handler(),
which accounts for the bpf_overflow_handler() case by also testing
if one of the perf_event_output functions gets invoked indirectly,
via orig_default_handler.

Link: https://lore.kernel.org/linux-arm-kernel/20220923203644.2731604-1-tnovak@fb.com/

Signed-off-by: Tomislav Novak <tnovak@fb.com>
Tested-by: Samuel Gosselin <sgosselin@google.com> # arm64
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm/kernel/hw_breakpoint.c   |  8 ++++----
 arch/arm64/kernel/hw_breakpoint.c |  4 ++--
 include/linux/perf_event.h        | 22 +++++++++++++++++++---
 3 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
index 2ee5b7f5e7ad0..c71ecd06131ca 100644
--- a/arch/arm/kernel/hw_breakpoint.c
+++ b/arch/arm/kernel/hw_breakpoint.c
@@ -631,7 +631,7 @@ int hw_breakpoint_arch_parse(struct perf_event *bp,
 	hw->address &= ~alignment_mask;
 	hw->ctrl.len <<= offset;
 
-	if (is_default_overflow_handler(bp)) {
+	if (uses_default_overflow_handler(bp)) {
 		/*
 		 * Mismatch breakpoints are required for single-stepping
 		 * breakpoints.
@@ -803,7 +803,7 @@ static void watchpoint_handler(unsigned long addr, unsigned int fsr,
 		 * Otherwise, insert a temporary mismatch breakpoint so that
 		 * we can single-step over the watchpoint trigger.
 		 */
-		if (!is_default_overflow_handler(wp))
+		if (!uses_default_overflow_handler(wp))
 			continue;
 step:
 		enable_single_step(wp, instruction_pointer(regs));
@@ -816,7 +816,7 @@ static void watchpoint_handler(unsigned long addr, unsigned int fsr,
 		info->trigger = addr;
 		pr_debug("watchpoint fired: address = 0x%x\n", info->trigger);
 		perf_bp_event(wp, regs);
-		if (is_default_overflow_handler(wp))
+		if (uses_default_overflow_handler(wp))
 			enable_single_step(wp, instruction_pointer(regs));
 	}
 
@@ -891,7 +891,7 @@ static void breakpoint_handler(unsigned long unknown, struct pt_regs *regs)
 			info->trigger = addr;
 			pr_debug("breakpoint fired: address = 0x%x\n", addr);
 			perf_bp_event(bp, regs);
-			if (is_default_overflow_handler(bp))
+			if (uses_default_overflow_handler(bp))
 				enable_single_step(bp, addr);
 			goto unlock;
 		}
diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c
index 9f105fe58595d..5d120e39bf61a 100644
--- a/arch/arm64/kernel/hw_breakpoint.c
+++ b/arch/arm64/kernel/hw_breakpoint.c
@@ -661,7 +661,7 @@ static int breakpoint_handler(unsigned long unused, unsigned int esr,
 		perf_bp_event(bp, regs);
 
 		/* Do we need to handle the stepping? */
-		if (is_default_overflow_handler(bp))
+		if (uses_default_overflow_handler(bp))
 			step = 1;
 unlock:
 		rcu_read_unlock();
@@ -740,7 +740,7 @@ static u64 get_distance_from_watchpoint(unsigned long addr, u64 val,
 static int watchpoint_report(struct perf_event *wp, unsigned long addr,
 			     struct pt_regs *regs)
 {
-	int step = is_default_overflow_handler(wp);
+	int step = uses_default_overflow_handler(wp);
 	struct arch_hw_breakpoint *info = counter_arch_bp(wp);
 
 	info->trigger = addr;
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index efe30b9b11908..f17e08bd294c2 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -998,15 +998,31 @@ extern void perf_event_output(struct perf_event *event,
 			      struct pt_regs *regs);
 
 static inline bool
-is_default_overflow_handler(struct perf_event *event)
+__is_default_overflow_handler(perf_overflow_handler_t overflow_handler)
 {
-	if (likely(event->overflow_handler == perf_event_output_forward))
+	if (likely(overflow_handler == perf_event_output_forward))
 		return true;
-	if (unlikely(event->overflow_handler == perf_event_output_backward))
+	if (unlikely(overflow_handler == perf_event_output_backward))
 		return true;
 	return false;
 }
 
+#define is_default_overflow_handler(event) \
+	__is_default_overflow_handler((event)->overflow_handler)
+
+#ifdef CONFIG_BPF_SYSCALL
+static inline bool uses_default_overflow_handler(struct perf_event *event)
+{
+	if (likely(is_default_overflow_handler(event)))
+		return true;
+
+	return __is_default_overflow_handler(event->orig_overflow_handler);
+}
+#else
+#define uses_default_overflow_handler(event) \
+	is_default_overflow_handler(event)
+#endif
+
 extern void
 perf_event_header__init_id(struct perf_event_header *header,
 			   struct perf_sample_data *data,
-- 
2.40.1


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Re: [PATCH AUTOSEL 4.19 4/6] PCI: dwc: Provide deinit callback for i.MX

[Pavel Machek]

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Hi!

> From: Mark Brown <broonie@kernel.org>
> 
> [ Upstream commit fc8b24c28bec19fc0621d108b9ee81ddfdedb25a ]
> 
> The i.MX integration for the DesignWare PCI controller has a _host_exit()
> operation which undoes everything that the _host_init() operation does but
> does not wire this up as the host_deinit callback for the core, or call it
> in any path other than suspend. This means that if we ever unwind the
> initial probe of the device, for example because it fails, the regulator
> core complains that the regulators for the device were left enabled:

This is somehow not queued for 5.10. Mistake?

BR,
									Pavel
-- 
DENX Software Engineering GmbH,        Managing Director: Erika Unter
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany

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