program: add high leverage reduce only

programs/drift/src/controller/liquidation.rs

@@ -337,7 +337,7 @@ pub fn liquidate_perp(
     let margin_ratio = perp_market_map.get_ref(&market_index)?.get_margin_ratio(
         user_base_asset_amount.cast()?,
         MarginRequirementType::Maintenance,
-        user.is_high_leverage_mode(),
+        user.is_high_leverage_mode(false),
     )?;
 
     let margin_ratio_with_buffer = margin_ratio.safe_add(liquidation_margin_buffer_ratio)?;
@@ -351,7 +351,7 @@ pub fn liquidate_perp(
         .price;
 
     let liquidator_fee = get_liquidation_fee(
-        market.get_base_liquidator_fee(user.is_high_leverage_mode()),
+        market.get_base_liquidator_fee(user.is_high_leverage_mode(false)),
         market.get_max_liquidation_fee()?,
         user.last_active_slot,
         slot,
@@ -964,7 +964,7 @@ pub fn liquidate_perp_with_fill(
     let margin_ratio = perp_market_map.get_ref(&market_index)?.get_margin_ratio(
         user_base_asset_amount.cast()?,
         MarginRequirementType::Maintenance,
-        user.is_high_leverage_mode(),
+        user.is_high_leverage_mode(false),
     )?;
 
     let margin_ratio_with_buffer = margin_ratio.safe_add(liquidation_margin_buffer_ratio)?;

programs/drift/src/controller/orders.rs

@@ -126,7 +126,7 @@ pub fn place_perp_order(
         if let Some(config) = high_leverage_mode_config {
             let mut config = load_mut!(config)?;
             if !config.is_full() || params.is_max_leverage_order() {
-                config.update_user(user)?;
+                config.enable_high_leverage(user)?;
             } else {
                 msg!("high leverage mode config is full");
             }
@@ -2123,7 +2123,7 @@ pub fn fulfill_perp_order_with_amm(
                 user_stats,
                 fee_structure,
                 &MarketType::Perp,
-                user.is_high_leverage_mode(),
+                user.is_high_leverage_mode(false),
             )?;
             let (base_asset_amount, limit_price) = calculate_base_asset_amount_for_amm_to_fulfill(
                 &user.orders[order_index],
@@ -2232,7 +2232,7 @@ pub fn fulfill_perp_order_with_amm(
         quote_asset_amount_surplus,
         order_post_only,
         market.fee_adjustment,
-        user.is_high_leverage_mode(),
+        user.is_high_leverage_mode(false),
     )?;
 
     let user_position_delta =
@@ -2723,7 +2723,7 @@ pub fn fulfill_perp_order_with_match(
         referrer_stats,
         &MarketType::Perp,
         market.fee_adjustment,
-        taker.is_high_leverage_mode(),
+        taker.is_high_leverage_mode(false),
     )?;
 
     // Increment the markets house's total fee variables
@@ -3366,7 +3366,7 @@ pub fn burn_user_lp_shares_for_risk_reduction(
             quote_oracle_price,
             margin_calc.margin_shortage()?,
             user_custom_margin_ratio,
-            user.is_high_leverage_mode(),
+            user.is_high_leverage_mode(false),
         )?;
 
     let (position_delta, pnl) = burn_lp_shares(

programs/drift/src/instructions/keeper.rs

@@ -2734,7 +2734,13 @@ pub fn handle_disable_user_high_leverage_mode<'c: 'info, 'info>(
         "user must be in high leverage mode"
     )?;
 
-    user.margin_mode = MarginMode::Default;
+    let new_margin_mode = if user.margin_mode == MarginMode::HighLeverageReduceOnly {
+        MarginMode::Default
+    } else {
+        MarginMode::HighLeverage
+    };
+
+    user.margin_mode = new_margin_mode;
 
     let custom_margin_ratio_before = user.max_margin_ratio;
     user.max_margin_ratio = 0;

programs/drift/src/instructions/user.rs

@@ -3427,7 +3427,7 @@ pub fn handle_enable_user_high_leverage_mode<'c: 'info, 'info>(
 
     let mut config = load_mut!(ctx.accounts.high_leverage_mode_config)?;
 
-    config.update_user(&mut user)?;
+    config.enable_high_leverage(&mut user)?;
 
     Ok(())
 }

programs/drift/src/math/margin.rs

@@ -252,7 +252,7 @@ pub fn calculate_margin_requirement_and_total_collateral_and_liability_info(
     }
 
     let user_pool_id = user.pool_id;
-    let user_high_leverage_mode = user.is_high_leverage_mode();
+    let user_high_leverage_mode = user.is_high_leverage_mode(context.margin_type == MarginRequirementType::Maintenance);
 
     for spot_position in user.spot_positions.iter() {
         validation::position::validate_spot_position(spot_position)?;

programs/drift/src/math/orders.rs

@@ -860,7 +860,7 @@ pub fn calculate_max_perp_order_size(
     )?;
 
     let user_custom_margin_ratio = user.max_margin_ratio;
-    let user_high_leverage_mode = user.is_high_leverage_mode();
+    let user_high_leverage_mode = user.is_high_leverage_mode(false);
 
     let free_collateral_before = total_collateral.safe_sub(margin_requirement.cast()?)?;
 

programs/drift/src/state/high_leverage_mode_config.rs

@@ -15,7 +15,9 @@ pub struct HighLeverageModeConfig {
     pub max_users: u32,
     pub current_users: u32,
     pub reduce_only: u8,
-    pub padding: [u8; 31],
+    pub padding1: [u8; 3],
+    pub reduce_only_users: u32,
+    pub padding2: [u8; 24],
 }
 
 // implement SIZE const for ProtocolIfSharesTransferConfig
@@ -44,11 +46,15 @@ impl HighLeverageModeConfig {
         (self.current_users >= self.max_users) || self.is_reduce_only()
     }
 
-    pub fn update_user(&mut self, user: &mut User) -> DriftResult {
+    pub fn enable_high_leverage(&mut self, user: &mut User) -> DriftResult {
         if user.margin_mode == MarginMode::HighLeverage {
             return Ok(());
         }
 
+        if user.margin_mode == MarginMode::HighLeverageReduceOnly {
+            self.reduce_only_users = self.reduce_only_users.saturating_sub(1);
+        }
+
         user.margin_mode = MarginMode::HighLeverage;
 
         validate!(

programs/drift/src/state/user.rs

@@ -443,8 +443,8 @@ impl User {
         false
     }
 
-    pub fn is_high_leverage_mode(&self) -> bool {
-        self.margin_mode == MarginMode::HighLeverage
+    pub fn is_high_leverage_mode(&self, include_reduce_only: bool) -> bool {
+        self.margin_mode == MarginMode::HighLeverage || (include_reduce_only && self.margin_mode == MarginMode::HighLeverageReduceOnly)
     }
 
     pub fn get_fuel_bonus_numerator(&self, now: i64) -> DriftResult<i64> {
@@ -2103,6 +2103,7 @@ pub enum MarginMode {
     #[default]
     Default,
     HighLeverage,
+    HighLeverageReduceOnly,
 }
 
 #[derive(Clone, Copy, BorshSerialize, BorshDeserialize, PartialEq, Debug, Eq)]