Hi Mark,

On 19 November 2016 at 02:49, Mark Rutland mark.rutland@arm.com wrote:

On Wed, Nov 16, 2016 at 09:48:57PM +0800, fu.wei@linaro.org wrote:

...

From: Fu Wei fu.wei@linaro.org

Rename some enums and defines, to unify the format of enums and defines in arm_arch_timer.h, also update all the users of these enums and defines: drivers/clocksource/arm_arch_timer.c virt/kvm/arm/hyp/timer-sr.c

I'm happy with making definitions use a consistent ARCH_TIMER_ prefix, given they're exposed in headers...

...

And do some cleanups, according to the suggestion from checkpatch.pl: (1) using BIT(nr) instead of (1 << nr) (2) using 'unsigned int' instead of 'unsigned'

... but these changes are pointless churn. They make the patch larger, hardwer to review, and more painful to merge.

Please leave these as they are unless there is a functional problem. If there will be a functional problem unless these are changed, describe that in the commit message.

OK, Mark. I will take these out of patch, thanks :-)

Thanks, Mark.

...

No functional change.

Signed-off-by: Fu Wei fu.wei@linaro.org

drivers/clocksource/arm_arch_timer.c | 111 ++++++++++++++++++----------------- include/clocksource/arm_arch_timer.h | 40 ++++++------- virt/kvm/arm/hyp/timer-sr.c | 6 +- 3 files changed, 81 insertions(+), 76 deletions(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 15341cf..dd1040d 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -66,11 +66,11 @@ struct arch_timer { #define to_arch_timer(e) container_of(e, struct arch_timer, evt)

static u32 arch_timer_rate; -static int arch_timer_ppi[MAX_TIMER_PPI]; +static int arch_timer_ppi[ARCH_TIMER_MAX_TIMER_PPI];

static struct clock_event_device __percpu *arch_timer_evt;

-static enum arch_timer_ppi_nr arch_timer_uses_ppi = VIRT_PPI; +static enum arch_timer_ppi_nr arch_timer_uses_ppi = ARCH_TIMER_VIRT_PPI; static bool arch_timer_c3stop; static bool arch_timer_mem_use_virtual;

@@ -340,7 +340,7 @@ static void fsl_a008585_set_sne(struct clock_event_device *clk) if (!static_branch_unlikely(&arch_timer_read_ool_enabled)) return;

• if (arch_timer_uses_ppi == VIRT_PPI)
  

• if (arch_timer_uses_ppi == ARCH_TIMER_VIRT_PPI)
          clk->set_next_event = fsl_a008585_set_next_event_virt;
  else
          clk->set_next_event = fsl_a008585_set_next_event_phys;
  

@@ -352,7 +352,7 @@ static void __arch_timer_setup(unsigned type, { clk->features = CLOCK_EVT_FEAT_ONESHOT;

• if (type == ARCH_CP15_TIMER) {
  

• if (type == ARCH_TIMER_TYPE_CP15) {
          if (arch_timer_c3stop)
                  clk->features |= CLOCK_EVT_FEAT_C3STOP;
          clk->name = "arch_sys_timer";
  

@@ -360,14 +360,14 @@ static void __arch_timer_setup(unsigned type, clk->cpumask = cpumask_of(smp_processor_id()); clk->irq = arch_timer_ppi[arch_timer_uses_ppi]; switch (arch_timer_uses_ppi) {

•         case VIRT_PPI:
  

•         case ARCH_TIMER_VIRT_PPI:
                  clk->set_state_shutdown = arch_timer_shutdown_virt;
                  clk->set_state_oneshot_stopped = arch_timer_shutdown_virt;
                  clk->set_next_event = arch_timer_set_next_event_virt;
                  break;
  

•         case PHYS_SECURE_PPI:
  

•         case PHYS_NONSECURE_PPI:
  

•         case HYP_PPI:
  

•         case ARCH_TIMER_PHYS_SECURE_PPI:
  

•         case ARCH_TIMER_PHYS_NONSECURE_PPI:
  

•         case ARCH_TIMER_HYP_PPI:
                  clk->set_state_shutdown = arch_timer_shutdown_phys;
                  clk->set_state_oneshot_stopped = arch_timer_shutdown_phys;
                  clk->set_next_event = arch_timer_set_next_event_phys;
  

@@ -447,8 +447,8 @@ static void arch_counter_set_user_access(void)

static bool arch_timer_has_nonsecure_ppi(void) {

• return (arch_timer_uses_ppi == PHYS_SECURE_PPI &&
  

•         arch_timer_ppi[PHYS_NONSECURE_PPI]);
  

• return (arch_timer_uses_ppi == ARCH_TIMER_PHYS_SECURE_PPI &&
  

•         arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]);
  

}

static u32 check_ppi_trigger(int irq) @@ -469,14 +469,15 @@ static int arch_timer_starting_cpu(unsigned int cpu) struct clock_event_device *clk = this_cpu_ptr(arch_timer_evt); u32 flags;

• __arch_timer_setup(ARCH_CP15_TIMER, clk);
  

• __arch_timer_setup(ARCH_TIMER_TYPE_CP15, clk);
  
  flags = check_ppi_trigger(arch_timer_ppi[arch_timer_uses_ppi]);
  enable_percpu_irq(arch_timer_ppi[arch_timer_uses_ppi], flags);
  
  if (arch_timer_has_nonsecure_ppi()) {
  

•         flags = check_ppi_trigger(arch_timer_ppi[PHYS_NONSECURE_PPI]);
  

•         enable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI], flags);
  

•         flags = check_ppi_trigger(arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]);
  

•         enable_percpu_irq(arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI],
  

•                           flags);
  }
  
  arch_counter_set_user_access();
  

@@ -513,16 +514,17 @@ arch_timer_detect_rate(void __iomem *cntbase, struct device_node *np) static void arch_timer_banner(unsigned type) { pr_info("%s%s%s timer(s) running at %lu.%02luMHz (%s%s%s).\n",

•         type & ARCH_CP15_TIMER ? "cp15" : "",
  

•         type == (ARCH_CP15_TIMER | ARCH_MEM_TIMER) ?  " and " : "",
  

•         type & ARCH_MEM_TIMER ? "mmio" : "",
  

•         type & ARCH_TIMER_TYPE_CP15 ? "cp15" : "",
  

•         type == (ARCH_TIMER_TYPE_CP15 | ARCH_TIMER_TYPE_MEM) ?
  

•                 " and " : "",
  

•         type & ARCH_TIMER_TYPE_MEM ? "mmio" : "",
          (unsigned long)arch_timer_rate / 1000000,
          (unsigned long)(arch_timer_rate / 10000) % 100,
  

•         type & ARCH_CP15_TIMER ?
  

•                 (arch_timer_uses_ppi == VIRT_PPI) ? "virt" : "phys" :
  

•         type & ARCH_TIMER_TYPE_CP15 ?
  

•                 (arch_timer_uses_ppi == ARCH_TIMER_VIRT_PPI) ? "virt" : "phys" :
                  "",
  

•         type == (ARCH_CP15_TIMER | ARCH_MEM_TIMER) ?  "/" : "",
  

•         type & ARCH_MEM_TIMER ?
  

•         type == (ARCH_TIMER_TYPE_CP15 | ARCH_TIMER_TYPE_MEM) ? "/" : "",
  

•         type & ARCH_TIMER_TYPE_MEM ?
                  arch_timer_mem_use_virtual ? "virt" : "phys" :
                  "");
  

} @@ -588,8 +590,9 @@ static void __init arch_counter_register(unsigned type) u64 start_count;

  /* Register the CP15 based counter if we have one */

• if (type & ARCH_CP15_TIMER) {
  

•         if (IS_ENABLED(CONFIG_ARM64) || arch_timer_uses_ppi == VIRT_PPI)
  

• if (type & ARCH_TIMER_TYPE_CP15) {
  

•         if (IS_ENABLED(CONFIG_ARM64) ||
  

•             arch_timer_uses_ppi == ARCH_TIMER_VIRT_PPI)
                  arch_timer_read_counter = arch_counter_get_cntvct;
          else
                  arch_timer_read_counter = arch_counter_get_cntpct;
  

@@ -625,7 +628,7 @@ static void arch_timer_stop(struct clock_event_device *clk)

  disable_percpu_irq(arch_timer_ppi[arch_timer_uses_ppi]);
  if (arch_timer_has_nonsecure_ppi())

•         disable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI]);
  

•         disable_percpu_irq(arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]);
  
  clk->set_state_shutdown(clk);
  

} @@ -688,24 +691,24 @@ static int __init arch_timer_register(void)

  ppi = arch_timer_ppi[arch_timer_uses_ppi];
  switch (arch_timer_uses_ppi) {

• case VIRT_PPI:
  

• case ARCH_TIMER_VIRT_PPI:
          err = request_percpu_irq(ppi, arch_timer_handler_virt,
                                   "arch_timer", arch_timer_evt);
          break;
  

• case PHYS_SECURE_PPI:
  

• case PHYS_NONSECURE_PPI:
  

• case ARCH_TIMER_PHYS_SECURE_PPI:
  

• case ARCH_TIMER_PHYS_NONSECURE_PPI:
          err = request_percpu_irq(ppi, arch_timer_handler_phys,
                                   "arch_timer", arch_timer_evt);
  

•         if (!err && arch_timer_ppi[PHYS_NONSECURE_PPI]) {
  

•                 ppi = arch_timer_ppi[PHYS_NONSECURE_PPI];
  

•         if (!err && arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]) {
  

•                 ppi = arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI];
                  err = request_percpu_irq(ppi, arch_timer_handler_phys,
                                           "arch_timer", arch_timer_evt);
                  if (err)
  

•                         free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
  

•                         free_percpu_irq(arch_timer_ppi[ARCH_TIMER_PHYS_SECURE_PPI],
                                          arch_timer_evt);
          }
          break;
  

• case HYP_PPI:
  

• case ARCH_TIMER_HYP_PPI:
          err = request_percpu_irq(ppi, arch_timer_handler_phys,
                                   "arch_timer", arch_timer_evt);
          break;
  

@@ -737,7 +740,7 @@ static int __init arch_timer_register(void) out_unreg_notify: free_percpu_irq(arch_timer_ppi[arch_timer_uses_ppi], arch_timer_evt); if (arch_timer_has_nonsecure_ppi())

•         free_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI],
  

•         free_percpu_irq(arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI],
                          arch_timer_evt);
  
  

out_free: @@ -758,7 +761,7 @@ static int __init arch_timer_mem_register(void __iomem *base, unsigned int irq)

  t->base = base;
  t->evt.irq = irq;

• __arch_timer_setup(ARCH_MEM_TIMER, &t->evt);
  

• __arch_timer_setup(ARCH_TIMER_TYPE_MEM, &t->evt);
  
  if (arch_timer_mem_use_virtual)
          func = arch_timer_handler_virt_mem;
  

@@ -801,13 +804,15 @@ arch_timer_needs_probing(int type, const struct of_device_id *matches)

static int __init arch_timer_common_init(void) {

• unsigned mask = ARCH_CP15_TIMER | ARCH_MEM_TIMER;
  

• unsigned int mask = ARCH_TIMER_TYPE_CP15 | ARCH_TIMER_TYPE_MEM;
  
  /* Wait until both nodes are probed if we have two timers */
  if ((arch_timers_present & mask) != mask) {
  

•         if (arch_timer_needs_probing(ARCH_MEM_TIMER, arch_timer_mem_of_match))
  

•         if (arch_timer_needs_probing(ARCH_TIMER_TYPE_MEM,
  

•                                      arch_timer_mem_of_match))
                  return 0;
  

•         if (arch_timer_needs_probing(ARCH_CP15_TIMER, arch_timer_of_match))
  

•         if (arch_timer_needs_probing(ARCH_TIMER_TYPE_CP15,
  

•                                      arch_timer_of_match))
                  return 0;
  }
  
  

@@ -832,16 +837,16 @@ static int __init arch_timer_init(void) * their CNTHP_*_EL2 counterparts, and use a different PPI * number. */

• if (is_hyp_mode_available() || !arch_timer_ppi[VIRT_PPI]) {
  

• if (is_hyp_mode_available() || !arch_timer_ppi[ARCH_TIMER_VIRT_PPI]) {
          bool has_ppi;
  
          if (is_kernel_in_hyp_mode()) {
  

•                 arch_timer_uses_ppi = HYP_PPI;
  

•                 has_ppi = !!arch_timer_ppi[HYP_PPI];
  

•                 arch_timer_uses_ppi = ARCH_TIMER_HYP_PPI;
  

•                 has_ppi = !!arch_timer_ppi[ARCH_TIMER_HYP_PPI];
          } else {
  

•                 arch_timer_uses_ppi = PHYS_SECURE_PPI;
  

•                 has_ppi = (!!arch_timer_ppi[PHYS_SECURE_PPI] ||
  

•                            !!arch_timer_ppi[PHYS_NONSECURE_PPI]);
  

•                 arch_timer_uses_ppi = ARCH_TIMER_PHYS_SECURE_PPI;
  

•                 has_ppi = (!!arch_timer_ppi[ARCH_TIMER_PHYS_SECURE_PPI] ||
  

•                            !!arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]);
          }
  
          if (!has_ppi) {
  

@@ -858,7 +863,7 @@ static int __init arch_timer_init(void) if (ret) return ret;

• arch_timer_kvm_info.virtual_irq = arch_timer_ppi[VIRT_PPI];
  

• arch_timer_kvm_info.virtual_irq = arch_timer_ppi[ARCH_TIMER_VIRT_PPI];
  
  return 0;
  

} @@ -867,13 +872,13 @@ static int __init arch_timer_of_init(struct device_node *np) { int i;

• if (arch_timers_present & ARCH_CP15_TIMER) {
  

• if (arch_timers_present & ARCH_TIMER_TYPE_CP15) {
          pr_warn("multiple nodes in dt, skipping\n");
          return 0;
  }
  
  

• arch_timers_present |= ARCH_CP15_TIMER;
  

• for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++)
  

• arch_timers_present |= ARCH_TIMER_TYPE_CP15;
  

• for (i = ARCH_TIMER_PHYS_SECURE_PPI; i < ARCH_TIMER_MAX_TIMER_PPI; i++)
          arch_timer_ppi[i] = irq_of_parse_and_map(np, i);
  
  arch_timer_detect_rate(NULL, np);
  

@@ -895,7 +900,7 @@ static int __init arch_timer_of_init(struct device_node *np) */ if (IS_ENABLED(CONFIG_ARM) && of_property_read_bool(np, "arm,cpu-registers-not-fw-configured"))

•         arch_timer_uses_ppi = PHYS_SECURE_PPI;
  

•         arch_timer_uses_ppi = ARCH_TIMER_PHYS_SECURE_PPI;
  
  return arch_timer_init();
  

} @@ -909,7 +914,7 @@ static int __init arch_timer_mem_init(struct device_node *np) unsigned int irq, ret = -EINVAL; u32 cnttidr;

• arch_timers_present |= ARCH_MEM_TIMER;
  

• arch_timers_present |= ARCH_TIMER_TYPE_MEM;
  cntctlbase = of_iomap(np, 0);
  if (!cntctlbase) {
          pr_err("Can't find CNTCTLBase\n");
  

@@ -1008,28 +1013,28 @@ static int __init arch_timer_acpi_init(struct acpi_table_header *table) { struct acpi_table_gtdt *gtdt;

• if (arch_timers_present & ARCH_CP15_TIMER) {
  

• if (arch_timers_present & ARCH_TIMER_TYPE_CP15) {
          pr_warn("already initialized, skipping\n");
          return -EINVAL;
  }
  
  gtdt = container_of(table, struct acpi_table_gtdt, header);
  
  

• arch_timers_present |= ARCH_CP15_TIMER;
  

• arch_timers_present |= ARCH_TIMER_TYPE_CP15;
  
  

• arch_timer_ppi[PHYS_SECURE_PPI] =
  

• arch_timer_ppi[ARCH_TIMER_PHYS_SECURE_PPI] =
          map_generic_timer_interrupt(gtdt->secure_el1_interrupt,
          gtdt->secure_el1_flags);
  
  

• arch_timer_ppi[PHYS_NONSECURE_PPI] =
  

• arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI] =
          map_generic_timer_interrupt(gtdt->non_secure_el1_interrupt,
          gtdt->non_secure_el1_flags);
  
  

• arch_timer_ppi[VIRT_PPI] =
  

• arch_timer_ppi[ARCH_TIMER_VIRT_PPI] =
          map_generic_timer_interrupt(gtdt->virtual_timer_interrupt,
          gtdt->virtual_timer_flags);
  
  

• arch_timer_ppi[HYP_PPI] =
  

• arch_timer_ppi[ARCH_TIMER_HYP_PPI] =
          map_generic_timer_interrupt(gtdt->non_secure_el2_interrupt,
          gtdt->non_secure_el2_flags);
  
  

diff --git a/include/clocksource/arm_arch_timer.h b/include/clocksource/arm_arch_timer.h index d23c381..2625ff1 100644 --- a/include/clocksource/arm_arch_timer.h +++ b/include/clocksource/arm_arch_timer.h @@ -20,18 +20,18 @@ #include <linux/timecounter.h> #include <linux/types.h>

-#define ARCH_CP15_TIMER BIT(0) -#define ARCH_MEM_TIMER BIT(1) +#define ARCH_TIMER_TYPE_CP15 BIT(0) +#define ARCH_TIMER_TYPE_MEM BIT(1)

-#define ARCH_TIMER_CTRL_ENABLE (1 << 0) -#define ARCH_TIMER_CTRL_IT_MASK (1 << 1) -#define ARCH_TIMER_CTRL_IT_STAT (1 << 2) +#define ARCH_TIMER_CTRL_ENABLE BIT(0) +#define ARCH_TIMER_CTRL_IT_MASK BIT(1) +#define ARCH_TIMER_CTRL_IT_STAT BIT(2)

-#define CNTHCTL_EL1PCTEN (1 << 0) -#define CNTHCTL_EL1PCEN (1 << 1) -#define CNTHCTL_EVNTEN (1 << 2) -#define CNTHCTL_EVNTDIR (1 << 3) -#define CNTHCTL_EVNTI (0xF << 4) +#define ARCH_TIMER_CNTHCTL_EL1PCTEN BIT(0) +#define ARCH_TIMER_CNTHCTL_EL1PCEN BIT(1) +#define ARCH_TIMER_CNTHCTL_EVNTEN BIT(2) +#define ARCH_TIMER_CNTHCTL_EVNTDIR BIT(3) +#define ARCH_TIMER_CNTHCTL_EVNTI (0xF << 4)

enum arch_timer_reg { ARCH_TIMER_REG_CTRL, @@ -39,11 +39,11 @@ enum arch_timer_reg { };

enum arch_timer_ppi_nr {

• PHYS_SECURE_PPI,
  

• PHYS_NONSECURE_PPI,
  

• VIRT_PPI,
  

• HYP_PPI,
  

• MAX_TIMER_PPI
  

• ARCH_TIMER_PHYS_SECURE_PPI,
  

• ARCH_TIMER_PHYS_NONSECURE_PPI,
  

• ARCH_TIMER_VIRT_PPI,
  

• ARCH_TIMER_HYP_PPI,
  

• ARCH_TIMER_MAX_TIMER_PPI
  

};

enum arch_timer_spi_nr { @@ -57,13 +57,13 @@ enum arch_timer_spi_nr { #define ARCH_TIMER_MEM_PHYS_ACCESS 2 #define ARCH_TIMER_MEM_VIRT_ACCESS 3

-#define ARCH_TIMER_USR_PCT_ACCESS_EN (1 << 0) /* physical counter */ -#define ARCH_TIMER_USR_VCT_ACCESS_EN (1 << 1) /* virtual counter */ -#define ARCH_TIMER_VIRT_EVT_EN (1 << 2) +#define ARCH_TIMER_USR_PCT_ACCESS_EN BIT(0) /* physical counter */ +#define ARCH_TIMER_USR_VCT_ACCESS_EN BIT(1) /* virtual counter */ +#define ARCH_TIMER_VIRT_EVT_EN BIT(2) #define ARCH_TIMER_EVT_TRIGGER_SHIFT (4) #define ARCH_TIMER_EVT_TRIGGER_MASK (0xF << ARCH_TIMER_EVT_TRIGGER_SHIFT) -#define ARCH_TIMER_USR_VT_ACCESS_EN (1 << 8) /* virtual timer registers */ -#define ARCH_TIMER_USR_PT_ACCESS_EN (1 << 9) /* physical timer registers */ +#define ARCH_TIMER_USR_VT_ACCESS_EN BIT(8) /* virtual timer registers */ +#define ARCH_TIMER_USR_PT_ACCESS_EN BIT(9) /* physical timer registers */

#define ARCH_TIMER_EVT_STREAM_FREQ 10000 /* 100us */

diff --git a/virt/kvm/arm/hyp/timer-sr.c b/virt/kvm/arm/hyp/timer-sr.c index 798866a..695b9d9 100644 --- a/virt/kvm/arm/hyp/timer-sr.c +++ b/virt/kvm/arm/hyp/timer-sr.c @@ -37,7 +37,7 @@ void __hyp_text __timer_save_state(struct kvm_vcpu *vcpu)

  /* Allow physical timer/counter access for the host */
  val = read_sysreg(cnthctl_el2);

• val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN;
  

• val |= ARCH_TIMER_CNTHCTL_EL1PCTEN | ARCH_TIMER_CNTHCTL_EL1PCEN;
  write_sysreg(val, cnthctl_el2);
  
  /* Clear cntvoff for the host */
  

@@ -55,8 +55,8 @@ void __hyp_text __timer_restore_state(struct kvm_vcpu *vcpu) * Physical counter access is allowed */ val = read_sysreg(cnthctl_el2);

• val &= ~CNTHCTL_EL1PCEN;
  

• val |= CNTHCTL_EL1PCTEN;
  

• val &= ~ARCH_TIMER_CNTHCTL_EL1PCEN;
  

• val |= ARCH_TIMER_CNTHCTL_EL1PCTEN;
  write_sysreg(val, cnthctl_el2);
  
  if (timer->enabled) {
  

-- 2.7.4

On Wed, Nov 16, 2016 at 09:48:58PM +0800, fu.wei@linaro.org wrote:

From: Fu Wei fu.wei@linaro.org

The patch fix a potential bug about arch_timer_uses_ppi in arch_timer_register. On ARM64, we don't use ARCH_TIMER_PHYS_SECURE_PPI in Linux, so we will just igorne it in init code.

That's not currently the case. I assume you mean we will in later patches? If so, please make that clear in the commit message.

If arch_timer_uses_ppi is ARCH_TIMER_PHYS_NONSECURE_PPI, the orignal code of arch_timer_uses_ppi may go wrong.

How? What specifically happens?

We don't currently assign ARCH_TIMER_PHYS_NONSECURE_PPI to arch_timer_uses_ppi, so I assume a later patch changes this. This change should be folded into said patch; it doesn't make sense in isolation.

Thanks, Mark.

Signed-off-by: Fu Wei fu.wei@linaro.org

drivers/clocksource/arm_arch_timer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index dd1040d..6de164f 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -699,7 +699,7 @@ static int __init arch_timer_register(void) case ARCH_TIMER_PHYS_NONSECURE_PPI: err = request_percpu_irq(ppi, arch_timer_handler_phys, "arch_timer", arch_timer_evt);

• if (!err && arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI]) {
  

• if (!err && arch_timer_has_nonsecure_ppi()) {
  ppi = arch_timer_ppi[ARCH_TIMER_PHYS_NONSECURE_PPI];
  err = request_percpu_irq(ppi, arch_timer_handler_phys,
  			 "arch_timer", arch_timer_evt);
  

-- 2.7.4

Hi Mark,

On 19 November 2016 at 03:30, Mark Rutland mark.rutland@arm.com wrote:

On Wed, Nov 16, 2016 at 09:48:59PM +0800, fu.wei@linaro.org wrote:

...

From: Fu Wei fu.wei@linaro.org

The patch refactor original arch_timer_uses_ppi init code: (1) Extract a subfunction: arch_timer_uses_ppi_init (2) Use the new subfunction in arch_timer_of_init and arch_timer_acpi_init

This isn't a strict refactoring, since this now assigns ARCH_TIMER_PHYS_NONSECURE_PPI to arch_timer_uses_ppi, which we didn't do previously.

As a general note, please write your commit messages as prose rather than a list of bullet points. Please also explain the rationale for the change, rather than enumerating the changes. Call out things which are important and/or likely to surprise reviewers, for example:

• Can 32-bit ARM still use non-secure interrupts afer this change?

• Does the "arm,cpu-registers-not-fw-configured" proeprty still work?

That will make it vastly easier to have this code reviewed, and it will be far more helpful for anyone looking at this in future.

For example:

arm_arch_timer: rework PPI determination

Currently, the arch timer driver uses ARCH_TIMER_PHYS_SECURE_PPI to mean the driver will use the secure PPI *and* potentialy also use the non-secure PPI. This is somewhat confusing.

For arm64, where it never makes sense to use the secure PPI, this means we must always request the useless secure PPI, adding to the confusion. For ACPI, where we may not even have a valid secure PPI number, this is additionally problematic. We need the driver to be able to use *only* the non-secure PPI.

The logic to choose which PPI to use is intertwined with other logic in arch_timer_init(). This patch factors the PPI determination out into a new function, and then reworks it so that we can handle having only a non-secure PPI.

Great thanks for your example, will use this, :-)

maybe add : For ARM32, it still can use non-secure interrupts after this change, and the "arm,cpu-registers-not-fw-configured" property still works.

[...]

...

+/*

• • If HYP mode is available, we know that the physical timer
• • has been configured to be accessible from PL1. Use it, so
• • that a guest can use the virtual timer instead.
• • If no interrupt provided for virtual timer, we'll have to
• • stick to the physical timer. It'd better be accessible...
• • On ARM64, we we only use ARCH_TIMER_PHYS_NONSECURE_PPI in Linux.

It would be better to say that for arm64 we never use the secure interrupt.

For ARM64, we never use the secure interrupt, so it will be set to ARCH_TIMER_PHYS_NONSECURE_PPI instead.

...

• • On ARMv8.1 with VH extensions, the kernel runs in HYP. VHE
• • accesses to CNTP_*_EL1 registers are silently redirected to
• • their CNTHP_*_EL2 counterparts, and use a different PPI
• • number.
• */

+static int __init arch_timer_uses_ppi_init(void)

It would be better to call this something like arch_timer_select_ppi(). As it stands, the name is difficult to read.

Yes, good idea, will do

...

@@ -902,6 +904,10 @@ static int __init arch_timer_of_init(struct device_node *np) of_property_read_bool(np, "arm,cpu-registers-not-fw-configured")) arch_timer_uses_ppi = ARCH_TIMER_PHYS_SECURE_PPI;

• ret = arch_timer_uses_ppi_init();
  

• if (ret)
  

•         return ret;
  

This is clearly broken if you consider what the statement above is doing.

Maybe I misunderstand this, I tried to follow the original logic.

Are you saying: we should use arch_timer_select_ppi() first, then (maybe) change arch_timer_uses_ppi according to "arm,cpu-registers-not-fw-configured"?

Please correct me, if I misunderstand this.

Thanks, Mark.

On Wed, Nov 16, 2016 at 09:49:00PM +0800, fu.wei@linaro.org wrote:

From: Fu Wei fu.wei@linaro.org

The patch refactor original arch_timer_detect_rate function: (1) Separate out device-tree code, keep them in device-tree init function: arch_timer_of_init, arch_timer_mem_init;

Please write a real commit message.

(2) Improve original mechanism, if getting from memory-mapped timer
fail, try arch_timer_get_cntfrq() again.

This is *not* a refactoring. It's completely unrelated to the supposed refactoring from point (1), and if necessary, should be a separate patch.

*Why* are you maknig this change? Does some ACPI platform have an MMIO timer with an ill-configured CNTFRQ register? If so, report that to the vendor. Don't add yet another needless bodge.

I'd really like to split the MMIO and CP15 timers, and this is yet another hack that'll make it harder to do so.

Signed-off-by: Fu Wei fu.wei@linaro.org

drivers/clocksource/arm_arch_timer.c | 45 +++++++++++++++++++++++------------- 1 file changed, 29 insertions(+), 16 deletions(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index af22953..fe4e812 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -487,27 +487,31 @@ static int arch_timer_starting_cpu(unsigned int cpu) return 0; } -static void -arch_timer_detect_rate(void __iomem *cntbase, struct device_node *np) +static void arch_timer_detect_rate(void __iomem *cntbase) { /* Who has more than one independent system counter? */ if (arch_timer_rate) return;

• /*

• * Try to determine the frequency from the device tree or CNTFRQ,
  

• * if ACPI is enabled, get the frequency from CNTFRQ ONLY.
  

• * If we got memory-mapped timer(cntbase != NULL),
  

• * try to determine the frequency from CNTFRQ in memory-mapped timer.
  

  */

*WHY* ?

If we're sharing arch_timer_rate across MMIO and sysreg timers, the sysreg value is alreayd sufficient.

If we're not, they should be completely independent.

• if (!acpi_disabled ||

•    of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) {
  

• if (cntbase)
  

• 	arch_timer_rate = readl_relaxed(cntbase + CNTFRQ);
  

• else
  

• 	arch_timer_rate = arch_timer_get_cntfrq();
  

• }

• if (cntbase)

• arch_timer_rate = readl_relaxed(cntbase + CNTFRQ);
  

• /*

• * Because in a system that implements both Secure and
  

• * Non-secure states, CNTFRQ is only accessible in Secure state.
  

That's true for the CNTCTLBase frame, but that doesn't matter.

The CNTBase<n> frames should have a readable CNTFRQ.

• * So the operation above may fail, even if (cntbase != NULL),
  

• * especially on ARM64.
  

• * In this case, we can try cntfrq_el0(system coprocessor register).
  

• */
  

• if (!arch_timer_rate)

• arch_timer_rate = arch_timer_get_cntfrq();
  

• else

• return;
  

Urrgh.

Please have separate paths to determine the MMIO frequency and the sysreg frequency, and use the appropriate one for the counter you want to know the frequency of.

Thanks, Mark.

Hi Mark,

On 19 November 2016 at 03:56, Mark Rutland mark.rutland@arm.com wrote:

On Wed, Nov 16, 2016 at 09:49:01PM +0800, fu.wei@linaro.org wrote:

...

From: Fu Wei fu.wei@linaro.org

The patch refactor original arch_timer_needs_probing function: (1) Separate out arch_timer_needs_probing from arch_timer_common_init, and call it only if acpi disabled. (2) Rename arch_timer_needs_probing to arch_timer_needs_of_probing.

Please write a real commit message.

OK, how about this:

clocksource/drivers/arm_arch_timer: Refactor arch_timer_needs_probing, only use it in the DT init code

Currently, the arch_timer_common_init uses arch_timer_needs_probing call to wait for both timers been probed which is only for booting from DT.

For booting from ACPI, we don't need these in arch_timer_common_init, these code should be only in the DT init code.

This patch seperates arch_timer_needs_probing related code out into a new function named arch_timer_needs_of_probing, and then reworks arch_timer_of_init to use it, so that we can keep this only in the DT init code.

...

Signed-off-by: Fu Wei fu.wei@linaro.org

drivers/clocksource/arm_arch_timer.c | 34 +++++++++++++++++++--------------- 1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index fe4e812..9ddc091 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -792,15 +792,28 @@ static const struct of_device_id arch_timer_mem_of_match[] __initconst = { {}, };

-static bool __init -arch_timer_needs_probing(int type, const struct of_device_id *matches) +static bool __init arch_timer_needs_of_probing(void) { struct device_node *dn; bool needs_probing = false;

• unsigned int mask = ARCH_TIMER_TYPE_CP15 | ARCH_TIMER_TYPE_MEM;
  

• /* We have two timers, and both device-tree nodes are probed. */
  

• if ((arch_timers_present & mask) == mask)
  

•         return false;
  

• /*
  

•  * Only one type of timer is probed,
  

•  * check if we have another type of timer node in device-tree.
  

•  */
  

• if (arch_timers_present & ARCH_TIMER_TYPE_CP15)
  

•         dn = of_find_matching_node(NULL, arch_timer_mem_of_match);
  

• else
  

•         dn = of_find_matching_node(NULL, arch_timer_of_match);
  
  

• dn = of_find_matching_node(NULL, matches);
  

• if (dn && of_device_is_available(dn) && !(arch_timers_present & type))
  

• if (dn && of_device_is_available(dn))
          needs_probing = true;
  

• of_node_put(dn);
  
  return needs_probing;
  

@@ -808,17 +821,8 @@ arch_timer_needs_probing(int type, const struct of_device_id *matches)

static int __init arch_timer_common_init(void) {

• unsigned int mask = ARCH_TIMER_TYPE_CP15 | ARCH_TIMER_TYPE_MEM;
  

• /* Wait until both nodes are probed if we have two timers */
  

• if ((arch_timers_present & mask) != mask) {
  

•         if (arch_timer_needs_probing(ARCH_TIMER_TYPE_MEM,
  

•                                      arch_timer_mem_of_match))
  

•                 return 0;
  

•         if (arch_timer_needs_probing(ARCH_TIMER_TYPE_CP15,
  

•                                      arch_timer_of_match))
  

•                 return 0;
  

• }
  

Why can't we just move this into the DT-specific caller of arch_timer_common_init()?

yes, I have thought about this, but that means we have to split arch_timer_init, and use arch_timer_register and arch_timer_common_init directly in arch_timer_of_init.

In another word, I also need to modify arch_timer_of_init, not only arch_timer_common_init, but let me have a try in v17, see if you like it.

Thanks Mark.

...

• if (acpi_disabled && arch_timer_needs_of_probing())
  

•         return 0;
  
  arch_timer_banner(arch_timers_present);
  arch_counter_register(arch_timers_present);
  

-- 2.7.4

Hi Mark,

On 19 November 2016 at 04:03, Mark Rutland mark.rutland@arm.com wrote:

On Wed, Nov 16, 2016 at 09:49:03PM +0800, fu.wei@linaro.org wrote:

...

From: Fu Wei fu.wei@linaro.org

The patch refactor original memory-mapped timer init code: (1) Extract a subfunction for detecting a bast time frame: is_best_frame.

Please leave this logic in arch_timer_mem_init(). Pulling it out gains us nothing, but makes the patch harder to review.

OK, I have put it back to arch_timer_mem_init() in next version: v17

...

(2) Refactor "arch_timer_mem_init", make it become a common code for
    memory-mapped timer init.
(3) Add a new function "arch_timer_mem_of_init" for DT init.

These generally look fine.

Thanks, Mark.

...

Signed-off-by: Fu Wei fu.wei@linaro.org

drivers/clocksource/arm_arch_timer.c | 162 +++++++++++++++++++++++------------ 1 file changed, 107 insertions(+), 55 deletions(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 9ddc091..0836bb9 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -923,17 +923,35 @@ static int __init arch_timer_of_init(struct device_node *np) CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_of_init); CLOCKSOURCE_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_of_init);

-static int __init arch_timer_mem_init(struct device_node *np) +static bool __init is_best_frame(void __iomem *cntctlbase, u32 cnttidr, int n) +{

• u32 cntacr = CNTACR_RFRQ | CNTACR_RWPT | CNTACR_RPCT | CNTACR_RWVT |
  

•              CNTACR_RVOFF | CNTACR_RVCT;
  

• /* Try enabling everything, and see what sticks */
  

• writel_relaxed(cntacr, cntctlbase + CNTACR(n));
  

• cntacr = readl_relaxed(cntctlbase + CNTACR(n));
  

• if ((cnttidr & CNTTIDR_VIRT(n)) &&
  

•     !(~cntacr & (CNTACR_RWVT | CNTACR_RVCT)))
  

•         arch_timer_mem_use_virtual = true;
  

• else if (~cntacr & (CNTACR_RWPT | CNTACR_RPCT))
  

•         return false;
  

• return true;
  

+}

+static int __init arch_timer_mem_init(struct arch_timer_mem *timer_mem) {

• struct device_node *frame, *best_frame = NULL;
  void __iomem *cntctlbase, *base;
  

• unsigned int irq, ret = -EINVAL;
  

• struct arch_timer_mem_frame *best_frame = NULL;
  

• unsigned int irq;
  u32 cnttidr;
  

• int i, ret;
  
  

• arch_timers_present |= ARCH_TIMER_TYPE_MEM;
  

• cntctlbase = of_iomap(np, 0);
  

• cntctlbase = ioremap(timer_mem->cntctlbase, timer_mem->size);
  if (!cntctlbase) {
  

•         pr_err("Can't find CNTCTLBase\n");
  

•         pr_err("Can't map CNTCTLBase.\n");
          return -ENXIO;
  }
  
  

@@ -943,76 +961,110 @@ static int __init arch_timer_mem_init(struct device_node *np) * Try to find a virtual capable frame. Otherwise fall back to a * physical capable frame. */

• for_each_available_child_of_node(np, frame) {
  

•         int n;
  

•         u32 cntacr;
  

•         if (of_property_read_u32(frame, "frame-number", &n)) {
  

•                 pr_err("Missing frame-number\n");
  

•                 of_node_put(frame);
  

•                 goto out;
  

•         }
  

•         /* Try enabling everything, and see what sticks */
  

•         cntacr = CNTACR_RFRQ | CNTACR_RWPT | CNTACR_RPCT |
  

•                  CNTACR_RWVT | CNTACR_RVOFF | CNTACR_RVCT;
  

•         writel_relaxed(cntacr, cntctlbase + CNTACR(n));
  

•         cntacr = readl_relaxed(cntctlbase + CNTACR(n));
  

•         if ((cnttidr & CNTTIDR_VIRT(n)) &&
  

•             !(~cntacr & (CNTACR_RWVT | CNTACR_RVCT))) {
  

•                 of_node_put(best_frame);
  

•                 best_frame = frame;
  

•                 arch_timer_mem_use_virtual = true;
  

•                 break;
  

• for (i = 0; i < timer_mem->num_frames; i++) {
  

•         if (is_best_frame(cntctlbase, cnttidr,
  

•                           timer_mem->frame[i].frame_nr)) {
  

•                 best_frame = &timer_mem->frame[i];
  

•                 if (arch_timer_mem_use_virtual)
  

•                         break;
          }
  

•         if (~cntacr & (CNTACR_RWPT | CNTACR_RPCT))
  

•                 continue;
  

•         of_node_put(best_frame);
  

•         best_frame = of_node_get(frame);
  }
  

• iounmap(cntctlbase);
  
  

• ret= -ENXIO;
  

• base = arch_counter_base = of_iomap(best_frame, 0);
  

• if (!base) {
  

•         pr_err("Can't map frame's registers\n");
  

•         goto out;
  

• if (!best_frame) {
  

•         pr_err("Can't find frame for register\n");
  

•         return -EINVAL;
  }
  
  if (arch_timer_mem_use_virtual)
  

•         irq = irq_of_parse_and_map(best_frame, ARCH_TIMER_VIRT_SPI);
  

•         irq = best_frame->virt_irq;
  else
  

•         irq = irq_of_parse_and_map(best_frame, ARCH_TIMER_PHYS_SPI);
  

•         irq = best_frame->phys_irq;
  
  

• ret = -EINVAL;
  if (!irq) {
          pr_err("Frame missing %s irq",
                 arch_timer_mem_use_virtual ? "virt" : "phys");
  

•         goto out;
  

•         return -EINVAL;
  }
  
  

• /*
  

•  * Try to determine the frequency from the device tree,
  

•  * if fail, get the frequency from CNTFRQ.
  

•  */
  

• if (!arch_timer_rate &&
  

•     of_property_read_u32(np, "clock-frequency", &arch_timer_rate))
  

•         arch_timer_detect_rate(base);
  

• base = ioremap(best_frame->cntbase, best_frame->size);
  

• if (!base) {
  

•         pr_err("Can't map frame's registers\n");
  

•         return -ENXIO;
  

• }
  

• arch_timer_detect_rate(base);
  
  ret = arch_timer_mem_register(base, irq);
  

• if (ret)
  

• if (ret) {
  

•         iounmap(base);
  

•         return ret;
  

• }
  

• arch_counter_base = base;
  

• arch_timers_present |= ARCH_TIMER_TYPE_MEM;
  

• return 0;
  

+}

+static int __init arch_timer_mem_of_init(struct device_node *np) +{

• struct arch_timer_mem *timer_mem;
  

• struct device_node *frame_node;
  

• struct resource res;
  

• int i, ret = -EINVAL;
  

• timer_mem = kzalloc(sizeof(*timer_mem), GFP_KERNEL);
  

• if (!timer_mem)
  

•         return -ENOMEM;
  

• if (of_address_to_resource(np, 0, &res))
          goto out;
  

• timer_mem->cntctlbase = res.start;
  

• timer_mem->size = resource_size(&res);
  
  

• return arch_timer_common_init();
  

• i = 0;
  

• for_each_available_child_of_node(np, frame_node) {
  

•         int n;
  

•         struct arch_timer_mem_frame *frame = &timer_mem->frame[i];
  

•         if (of_property_read_u32(frame_node, "frame-number", &n)) {
  

•                 pr_err("Missing frame-number\n");
  

•                 of_node_put(frame_node);
  

•                 goto out;
  

•         }
  

•         frame->frame_nr = n;
  

•         if (of_address_to_resource(frame_node, 0, &res)) {
  

•                 of_node_put(frame_node);
  

•                 goto out;
  

•         }
  

•         frame->cntbase = res.start;
  

•         frame->size = resource_size(&res);
  

•         frame->virt_irq = irq_of_parse_and_map(frame_node,
  

•                                                ARCH_TIMER_VIRT_SPI);
  

•         frame->phys_irq = irq_of_parse_and_map(frame_node,
  

•                                                ARCH_TIMER_PHYS_SPI);
  

•         if (++i >= ARCH_TIMER_MEM_MAX_FRAMES)
  

•                 break;
  

• }
  

• timer_mem->num_frames = i;
  

• /* Try to determine the frequency from the device tree */
  

• if (!arch_timer_rate)
  

•         of_property_read_u32(np, "clock-frequency", &arch_timer_rate);
  

• ret = arch_timer_mem_init(timer_mem);
  

• if (!ret)
  

•         ret = arch_timer_common_init();
  

out:

• iounmap(cntctlbase);
  

• of_node_put(best_frame);
  

• kfree(timer_mem);
  return ret;
  

} CLOCKSOURCE_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem",

•                arch_timer_mem_init);
  

•                arch_timer_mem_of_init);
  
  

#ifdef CONFIG_ACPI static int __init map_generic_timer_interrupt(u32 interrupt, u32 flags) -- 2.7.4

On Wed, Nov 16, 2016 at 09:49:04PM +0800, fu.wei@linaro.org wrote:

+#define for_each_platform_timer(_g) for (; _g; _g = next_platform_timer(_g))

This doesn't fit the usual for_each_* pattern, since _g has to be manually initialised first. Either come up with a way of maknig this fit the usual pattern, or get rid of this, and use:

t = however_you_get_the_first_timer();

if (!t) bailt_out_somehow(); do { ... } while (t = next_platform_timer(t));

+/*

• • Release the memory we have allocated in acpi_gtdt_init.
• • This should be called, when the driver who called "acpi_gtdt_init" previously
• • doesn't need the GTDT info anymore.
• */

+void __init acpi_gtdt_release(void) +{

• kfree(timer_block);
• kfree(watchdog);
• timer_block = NULL;
• watchdog = NULL;

+}

Why is this not simply in the error path of acpi_gtdt_init()?

+/*

• • Get some basic info from GTDT table, and init the global variables above
• • for all timers initialization of Generic Timer.
• • This function does some validation on GTDT table.
• */

+int __init acpi_gtdt_init(struct acpi_table_header *table) +{

• timer_block = kcalloc(timer_count,

• 	      sizeof(struct acpi_gtdt_timer_block *),
  

• 	      GFP_KERNEL);
  

• if (!timer_block)

• return -ENOMEM;
  

• watchdog = kcalloc(timer_count, sizeof(struct acpi_gtdt_watchdog *),

• 	   GFP_KERNEL);
  

• if (!watchdog) {

• kfree(timer_block);
  

• timer_block = NULL;
  

• return -ENOMEM;
  

• }

Please have a common error path below, and branch to that when you need to free these.

+error:

• acpi_gtdt_release();
• return -EINVAL;

+}

[...]

diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 61a3d90..a1611d1 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -577,6 +577,13 @@ enum acpi_reconfig_event { int acpi_reconfig_notifier_register(struct notifier_block *nb); int acpi_reconfig_notifier_unregister(struct notifier_block *nb); +#ifdef CONFIG_ACPI_GTDT +int acpi_gtdt_init(struct acpi_table_header *table); +int acpi_gtdt_map_ppi(int type); +bool acpi_gtdt_c3stop(int type); +void acpi_gtdt_release(void);

Why do these need to be here?

What possible value is ther in exporting acpi_gtdt_release() !?

Thanks, Mark.

On Wed, Nov 16, 2016 at 09:49:06PM +0800, fu.wei@linaro.org wrote:

From: Fu Wei fu.wei@linaro.org

On platforms booting with ACPI, architected memory-mapped timers' configuration data is provided by firmware through the ACPI GTDT static table.

The clocksource architected timer kernel driver requires a firmware interface to collect timer configuration and configure its driver. this infrastructure is present for device tree systems, but it is missing on systems booting with ACPI.

Implement the kernel infrastructure required to parse the static ACPI GTDT table so that the architected timer clocksource driver can make use of it on systems booting with ACPI, therefore enabling the corresponding timers configuration.

Signed-off-by: Fu Wei fu.wei@linaro.org Signed-off-by: Hanjun Guo hanjun.guo@linaro.org

---

drivers/acpi/arm64/gtdt.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/acpi.h | 1 + 2 files changed, 96 insertions(+)

diff --git a/drivers/acpi/arm64/gtdt.c b/drivers/acpi/arm64/gtdt.c index 2de79aa..08d9506 100644 --- a/drivers/acpi/arm64/gtdt.c +++ b/drivers/acpi/arm64/gtdt.c @@ -51,6 +51,14 @@ static inline bool is_timer_block(void *platform_timer) return gh->type == ACPI_GTDT_TYPE_TIMER_BLOCK; } +static inline struct acpi_gtdt_timer_block *get_timer_block(unsigned int index) +{

• if (index >= acpi_gtdt_desc.timer_block_count || !timer_block)

• return NULL;
  

• return timer_block[index];

+}

static inline bool is_watchdog(void *platform_timer) { struct acpi_gtdt_header *gh = platform_timer; @@ -214,3 +222,90 @@ int __init acpi_gtdt_init(struct acpi_table_header *table) acpi_gtdt_release(); return -EINVAL; }

+/*

• • Get ONE GT block info for memory-mapped timer from GTDT table.
• • @data: the GT block data (parsing result)
• • @index: the index number of GT block
• • Note: we already verify @data in caller, it can't be NULL here.
• • Returns 0 if success, -EINVAL/-ENODEV if error.
• */

Documentation/kernel-doc-nano-HOWTO.txt

+int __init gtdt_arch_timer_mem_init(struct arch_timer_mem *data,

• 		    unsigned int index)
  

Nit: acpi_arch_timer_mem_init() to make it consistent with other ACPI calls ?

+{

• struct acpi_gtdt_timer_block *block;
• struct acpi_gtdt_timer_entry *frame;
• int i;
• block = get_timer_block(index);
• if (!block)

• return -ENODEV;
  

• if (!block->timer_count) {

• pr_err(FW_BUG "GT block present, but frame count is zero.");
  

• return -ENODEV;
  

• }
• if (block->timer_count > ARCH_TIMER_MEM_MAX_FRAMES) {

• pr_err(FW_BUG "GT block lists %d frames, ACPI spec only allows 8\n",
  

•        block->timer_count);
  

• return -EINVAL;
  

• }

Nit: these two checks can be carried out at GTDT init where the GTDT is parsed first. Actually you could have two functions one to init timers (say acpi_gtdt_timers_init()) and one watchdogs, that would eliminate the duplicated timer_block/watchdog arrays (both sized Platform Timer Count) and acpi_gtdt_timers_init() can return the number of entries found so that you can loop with a determined upper bound in the arm arch timer driver.

Just thinking aloud, these are just improvements I can carry them out later, the more important question here is the interface between the parsing code and the arch timer probing code which depends on other patches and that needs to be agreed, this patch is not really a problem.

• data->cntctlbase = (phys_addr_t)block->block_address;
• /*

• * We can NOT get the size info from GTDT table,
  

• * but according to "Table * CNTCTLBase memory map" of
  

• * <ARM Architecture Reference Manual> for ARMv8,
  

• * it should be 4KB(Offset 0x000 – 0xFFC).
  

That's the reason why it is not explicit in the GTDT table :)

• data->size = SZ_4K;
• data->num_frames = block->timer_count;
• frame = (void *)block + block->timer_offset;
• if (frame + block->timer_count != (void *)block + block->header.length)

• return -EINVAL;
  

• /*

• * Get the GT timer Frame data for every GT Block Timer
  

• */
  

• for (i = 0; i < block->timer_count; i++, frame++) {

• if (!frame->base_address || !frame->timer_interrupt)
  

• 	return -EINVAL;
  

• data->frame[i].phys_irq = map_gt_gsi(frame->timer_interrupt,
  

• 				     frame->timer_flags);
  

• if (data->frame[i].phys_irq <= 0) {
  

• 	pr_warn("failed to map physical timer irq in frame %d.\n",
  

• 		i);
  

• 	return -EINVAL;
  

• }
  

• if (frame->virtual_timer_interrupt) {
  

• 	data->frame[i].virt_irq =
  

• 		map_gt_gsi(frame->virtual_timer_interrupt,
  

• 			   frame->virtual_timer_flags);
  

• 	if (data->frame[i].virt_irq <= 0) {
  

• 		pr_warn("failed to map virtual timer irq in frame %d.\n",
  

• 			i);
  

• 		return -EINVAL;
  

You should unregister phys_irq here for correctness, right ?

• 	}
  

• }
  

• data->frame[i].frame_nr = frame->frame_number;
  

• data->frame[i].cntbase = frame->base_address;
  

• /*
  

•  * We can NOT get the size info from GTDT table,
  

•  * but according to "Table * CNTBaseN memory map" of
  

•  * <ARM Architecture Reference Manual> for ARMv8,
  

•  * it should be 4KB(Offset 0x000 – 0xFFC).
  

See above.

•  */
  

• data->frame[i].size = SZ_4K;
  

• }
• if (acpi_gtdt_desc.timer_block_count)

• pr_info("parsed No.%d of %d memory-mapped timer block(s).\n",
  

• 	index, acpi_gtdt_desc.timer_block_count);
  

I am not sure how helpful this message can be honestly.

• return 0;

+} diff --git a/include/linux/acpi.h b/include/linux/acpi.h index a1611d1..44b8c1b 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -582,6 +582,7 @@ int acpi_gtdt_init(struct acpi_table_header *table); int acpi_gtdt_map_ppi(int type); bool acpi_gtdt_c3stop(int type); void acpi_gtdt_release(void); +int gtdt_arch_timer_mem_init(struct arch_timer_mem *data, unsigned int index);

See above.

Overall it looks fine as long as the interface with clocksource is settled, which is what really needs to be agreed upon in this series.

Lorenzo

#endif

#else /* !CONFIG_ACPI */

2.7.4

Hi Lorenzo,

On 23 November 2016 at 19:53, Fu Wei fu.wei@linaro.org wrote:

Hi Lorenzo,

On 18 November 2016 at 22:22, Lorenzo Pieralisi lorenzo.pieralisi@arm.com wrote:

...

On Wed, Nov 16, 2016 at 09:49:06PM +0800, fu.wei@linaro.org wrote:

...

From: Fu Wei fu.wei@linaro.org

On platforms booting with ACPI, architected memory-mapped timers' configuration data is provided by firmware through the ACPI GTDT static table.

The clocksource architected timer kernel driver requires a firmware interface to collect timer configuration and configure its driver. this infrastructure is present for device tree systems, but it is missing on systems booting with ACPI.

Implement the kernel infrastructure required to parse the static ACPI GTDT table so that the architected timer clocksource driver can make use of it on systems booting with ACPI, therefore enabling the corresponding timers configuration.

Signed-off-by: Fu Wei fu.wei@linaro.org Signed-off-by: Hanjun Guo hanjun.guo@linaro.org

---

drivers/acpi/arm64/gtdt.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/acpi.h | 1 + 2 files changed, 96 insertions(+)

diff --git a/drivers/acpi/arm64/gtdt.c b/drivers/acpi/arm64/gtdt.c index 2de79aa..08d9506 100644 --- a/drivers/acpi/arm64/gtdt.c +++ b/drivers/acpi/arm64/gtdt.c @@ -51,6 +51,14 @@ static inline bool is_timer_block(void *platform_timer) return gh->type == ACPI_GTDT_TYPE_TIMER_BLOCK; }

+static inline struct acpi_gtdt_timer_block *get_timer_block(unsigned int index) +{

• if (index >= acpi_gtdt_desc.timer_block_count || !timer_block)
  

•         return NULL;
  

• return timer_block[index];
  

+}

static inline bool is_watchdog(void *platform_timer) { struct acpi_gtdt_header *gh = platform_timer; @@ -214,3 +222,90 @@ int __init acpi_gtdt_init(struct acpi_table_header *table) acpi_gtdt_release(); return -EINVAL; }

+/*

• • Get ONE GT block info for memory-mapped timer from GTDT table.
• • @data: the GT block data (parsing result)
• • @index: the index number of GT block
• • Note: we already verify @data in caller, it can't be NULL here.
• • Returns 0 if success, -EINVAL/-ENODEV if error.
• */

Documentation/kernel-doc-nano-HOWTO.txt

Great thanks , will fix all the comments :-)

...

...

+int __init gtdt_arch_timer_mem_init(struct arch_timer_mem *data,

•                             unsigned int index)
  

Nit: acpi_arch_timer_mem_init() to make it consistent with other ACPI calls ?

yes, it makes sense, will do this way for the function which is exported

...

...

+{

• struct acpi_gtdt_timer_block *block;
  

• struct acpi_gtdt_timer_entry *frame;
  

• int i;
  

• block = get_timer_block(index);
  

• if (!block)
  

•         return -ENODEV;
  

• if (!block->timer_count) {
  

•         pr_err(FW_BUG "GT block present, but frame count is zero.");
  

•         return -ENODEV;
  

• }
  

• if (block->timer_count > ARCH_TIMER_MEM_MAX_FRAMES) {
  

•         pr_err(FW_BUG "GT block lists %d frames, ACPI spec only allows 8\n",
  

•                block->timer_count);
  

•         return -EINVAL;
  

• }
  

Nit: these two checks can be carried out at GTDT init where the GTDT is parsed first. Actually you could have two functions one to init

this check is the verify the data in GT block, but the GTDT init won't get into the block, so I think that is better to keep this in GT block init function "acpi_arch_timer_mem_init()"

...

timers (say acpi_gtdt_timers_init()) and one watchdogs, that would eliminate the duplicated timer_block/watchdog arrays (both sized Platform Timer Count) and acpi_gtdt_timers_init() can return the number of entries found so that you can loop with a determined upper bound in the arm arch timer driver.

Yes, I did this way in previous patchset, but we still need to do scan loop in both functions for two types of platform timer. So I decide to keep the scan loop in the acpi_gtdt_init to get the number and the entries pointer of each type of platform timers in one go. then we don't need to scan GTDT in two functions.

I have thought about this again, I think I should keep the loop in each type of platform timers. The benefit we can get from this are: (1) reduce the global variables: static struct acpi_gtdt_timer_block **timer_block __initdata; static struct acpi_gtdt_watchdog **watchdog __initdata; make them in thire own init function. (2) avoid allocating and free memory in different functions.

we also can return all the GT block info in one go.

...

Just thinking aloud, these are just improvements I can carry them out later, the more important question here is the interface between the parsing code and the arch timer probing code which depends on other patches and that needs to be agreed, this patch is not really a problem.

yes, every time I modify the interface I have to change the driver :-(

...

...

• data->cntctlbase = (phys_addr_t)block->block_address;
  

• /*
  

•  * We can NOT get the size info from GTDT table,
  

•  * but according to "Table * CNTCTLBase memory map" of
  

•  * <ARM Architecture Reference Manual> for ARMv8,
  

•  * it should be 4KB(Offset 0x000 – 0xFFC).
  

That's the reason why it is not explicit in the GTDT table :)

...

• data->size = SZ_4K;
  

• data->num_frames = block->timer_count;
  

• frame = (void *)block + block->timer_offset;
  

• if (frame + block->timer_count != (void *)block + block->header.length)
  

•         return -EINVAL;
  

• /*
  

•  * Get the GT timer Frame data for every GT Block Timer
  

•  */
  

• for (i = 0; i < block->timer_count; i++, frame++) {
  

•         if (!frame->base_address || !frame->timer_interrupt)
  

•                 return -EINVAL;
  

•         data->frame[i].phys_irq = map_gt_gsi(frame->timer_interrupt,
  

•                                              frame->timer_flags);
  

•         if (data->frame[i].phys_irq <= 0) {
  

•                 pr_warn("failed to map physical timer irq in frame %d.\n",
  

•                         i);
  

•                 return -EINVAL;
  

•         }
  

•         if (frame->virtual_timer_interrupt) {
  

•                 data->frame[i].virt_irq =
  

•                         map_gt_gsi(frame->virtual_timer_interrupt,
  

•                                    frame->virtual_timer_flags);
  

•                 if (data->frame[i].virt_irq <= 0) {
  

•                         pr_warn("failed to map virtual timer irq in frame %d.\n",
  

•                                 i);
  

•                         return -EINVAL;
  

You should unregister phys_irq here for correctness, right ?

yup, thanks for pointing this bug out. :-)

...

...

•                 }
  

•         }
  

•         data->frame[i].frame_nr = frame->frame_number;
  

•         data->frame[i].cntbase = frame->base_address;
  

•         /*
  

•          * We can NOT get the size info from GTDT table,
  

•          * but according to "Table * CNTBaseN memory map" of
  

•          * <ARM Architecture Reference Manual> for ARMv8,
  

•          * it should be 4KB(Offset 0x000 – 0xFFC).
  

See above.

yes, you are right, I will fix both comments

...

...

•          */
  

•         data->frame[i].size = SZ_4K;
  

• }
  

• if (acpi_gtdt_desc.timer_block_count)
  

•         pr_info("parsed No.%d of %d memory-mapped timer block(s).\n",
  

•                 index, acpi_gtdt_desc.timer_block_count);
  

I am not sure how helpful this message can be honestly.

yup, I will simplify it :-)

...

...

• return 0;
  

+} diff --git a/include/linux/acpi.h b/include/linux/acpi.h index a1611d1..44b8c1b 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -582,6 +582,7 @@ int acpi_gtdt_init(struct acpi_table_header *table); int acpi_gtdt_map_ppi(int type); bool acpi_gtdt_c3stop(int type); void acpi_gtdt_release(void); +int gtdt_arch_timer_mem_init(struct arch_timer_mem *data, unsigned int index);

See above.

Overall it looks fine as long as the interface with clocksource is settled, which is what really needs to be agreed upon in this series.

Thanks for your help :-)

...

Lorenzo

...

#endif

#else /* !CONFIG_ACPI */

2.7.4

-- Best regards,

Fu Wei Software Engineer Red Hat

On Wed, Nov 16, 2016 at 09:49:07PM +0800, fu.wei@linaro.org wrote:

From: Fu Wei fu.wei@linaro.org

The patch add memory-mapped timer register support by using the information provided by the new GTDT driver of ACPI.

Signed-off-by: Fu Wei fu.wei@linaro.org

drivers/clocksource/arm_arch_timer.c | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index c494ca8..0aad60a 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -1067,7 +1067,28 @@ CLOCKSOURCE_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem", arch_timer_mem_of_init); #ifdef CONFIG_ACPI_GTDT -/* Initialize per-processor generic timer */ +static int __init arch_timer_mem_acpi_init(void) +{

• struct arch_timer_mem *timer_mem;
• int ret = 0;
• int i = 0;
• timer_mem = kzalloc(sizeof(*timer_mem), GFP_KERNEL);

Why do you need it zeroed? You don't clear it between iterations, so either you don't need this, or you have a bug in the loop.

• if (!timer_mem)

• return -ENOMEM;
  

• while (!gtdt_arch_timer_mem_init(timer_mem, i)) {

Huh?

Why doesn't GTDT expose a function to fill in the entire arch_timer_mem in one go?

There shouldn't be multiple instances, as far as I am aware. Am I mistaken?

• ret = arch_timer_mem_init(timer_mem);
  

• if (ret)
  

• 	break;
  

• i++;
  

• }
• kfree(timer_mem);
• return ret;

+}

Regardless, arch_timer_mem is small enough that you don't need dynamic allocaiton. Just put it on the stack, e.g.

static int __init arch_timer_mem_acpi_init(void) { int i = 0; struct arch_timer_mem timer_mem;

while (!gtdt_arch_timer_mem_init(timer_mem, i)) { int ret = arch_timer_mem_init(); if (ret) return ret; i++ }

return 0; }

Thanks, Mark.